Annual Progress Report:FROM QUARKS TO NUCLEI

submitted to theU.S. Department of Energy, Office of Science

S.L. Bültmann (P.I.), M. Amaryan, G.E. Dodge,

C.E. Hyde, S.E. Kuhn, and L.B. Weinstein,

Department of Physics, Old Dominion University Norfolk, VA

December 15, 2018

Period covered: Dec. 15, 2017 — Dec. 14, 2018

Recipient: Old Dominion University Research Foundation

P.O. Box 6369

Norfolk, VA 23508-0369

(ODURF project 100388-150)

DOE Grant: DE-FG02-96ER40960

Unexpended Funds: < $90, 000 Direct Costs expected for 3/14/2019

CONTENTS

I. Project Narrative: Progress in the Past Year 1A. Overview 1B. Nucleon Structure 2

1. Nucleon Spin Structure 22. BONuS 43. Deep Virtual Exclusive Scattering 7

C. Hadron Spectroscopy 101. Photoproduction and Decay of Light Mesons in CLAS 102. The GlueX Collaboration in Hall-D 11

D. Physics of the Nucleus 131. Bound Nucleon Modifications in Deuterium 142. Nucleon Knockout and Correlations Studies 153. Hadronization in DIS on Nuclei 194. Electrons for neutrinos 19

E. Physics Beyond the Standard Model 22F. An Electron Ion Collider 23

1. Physics Program Development 232. Detector Design and R&D. 24

II. Bibliography 26

References 26

III. Publications, Talks, and Theses 29A. Refereed Publications 29B. Talks, Colloquia and Seminars 30C. Conference Proceedings 33D. Theses 35

1. Bachelor’s Theses 35E. Proposals with ODU co-Spokespersons 35F. Conferences and Workshops Organized 35

IV. Personnel 36A. Faculty 36B. Postdoctoral Research Associates 37C. Graduate Students 38D. Undergraduate Students 38E. Technician 38F. Computer Support 39

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I. PROJECT NARRATIVE: PROGRESS IN THE PAST YEAR

A. Overview

Over the past 12 months covered by this progress report, we have continued ourleadership role at Jefferson Lab; making important discoveries using 6 GeV data; analyzingsome of the first 12 GeV data; participating in data collection in all four halls at JeffersonLab; getting two more experiments approved; advancing the e4ν (electrons for neutrinos)project; and working towards the realization of an Electron Ion Collider. Here are somehighlights:

• We are co-spokespersons of eleven approved experiments at 12 GeV and coordinatethree of the CLAS12 run groups.

• We published one paper in Nature and had a second accepted ”in principle” toNature (once minor editorial revisions are completed) as one of the leading authors.

• We took data for the tritium SRC experiment measuring 3He(e, e′p)and 3H(e, e′p)inHall A. We completed the analysis for the first paper to be submitted to PRL.

• We installed the Back Angle Neutron Detector (BAND) into Hall B. This includedbuilding the 58 short scintillator bars and assembling the 116 scintillators onto theBAND frame.

• We began construction of the dedicated RTPC detector for the Bonus12 experimentand developed its data analysis software.

• We collaborated in the construction of the CLAS12 polarized target cryostat andtarget holder.

• We installed the sweep magnet for the multi-energy DVCS experiment in Hall Cand are preparing the field mapping hardware and software.

• We received PAC approval for the Electrons for Neutrinos and Short Range Cor-relations experiments Run Group in CLAS12 with an A rating and a request thathalf the beam time be ”scheduled expeditiously”.

• We are preparing a White Paper and PAC proposal for the new Kaon beam line inJefferson Lab’s Hall D.

• L. Weinstein completed his term as Past Chair of the Jefferson Lab Users Organi-zation.

• M. Khachatryan received a JSA/IF Graduate Student Fellowship.• M. Khachatryan received first prize at the JLab User Group Annual Meeting poster

competition.

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B. Nucleon Structure

1. Nucleon Spin Structure

Our group has played a leading role in measurements of the nucleon spin structuresince the early 1990’s, both at SLAC and later at Jefferson Lab. In particular, we ledthe large program to map out the lower-Q2 spin structure of the proton and deuteronin Jefferson Lab’s Hall B, comprising the run groups EG1a, EG1b, EG4 and EG1-dvcsat energies up to 6 GeV with the CLAS detector. All results of these experiments havebeen published, with the exception of the proton results from EG4, which are still underanalysis. In the meantime, we began preparing for the next large experimental program inthe 12 GeV era, with a longitudinally polarized proton and deuteron (and later Lithium)target in CLAS12 known as Run Group C. In the following, we summarize our work overthe last year on both of these projects.

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EG4

The EG4 experiment took place in 2006 at JLab using the CLAS spectrometer inHall B. Its aim was to measure the inclusive spin structure functions g1p and g1d overa large x range and moderate to very low Q2 to test predictions for various sum rulesand calculations based on chiral perturbation theory (χPT). The deuteron results from

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this experiment have been analyzed by our former doctoral student K. Adhikari andhave been published as well as presented at several conferences. The proton analysishas been restarted with new collaborators (Dr. X. Zheng and our former doctoral stu-dent, Dr. J. Zhang, at Univ. of Virginia) and is progressing quickly. One of us (Dr.Kuhn) is working on detailed simulations, including radiative corrections, and extractingPhysics observables from the data. Preliminary results of the proton analysis have beenpresented at the international ECT* workshop on “Nucleon Spin Structure at low Q: AHyperfine View”, July 2-6 2018, Trento (Italy), where S. Kuhn gave the introductoryplenary talk. We expect to continue our involvement at about the same level for anotheryear, by which time we expect the data analysis to be complete and a paper to be written.

Duality and combined fits

Another remaining project from the 6 GeV era is to test the validity of quark-hadronduality in spin structure functions, using the results from the program in Hall B. This is alow-level effort by Dr. Kuhn and his Ph.D. advisee, V. Lagerquist. We expect to publisha paper on our results next year. We are also working on an updated phenomenological fitto world data which will be very helpful for the interpretation of upcoming spin structurefunction results.

Run Group C

Run group C consists of 6 experiments and will use CLAS12 with a 11 GeV beam tomeasure polarization observables in inclusive, semi-inclusive and exclusive (in particularDVCS) processes. Our group leads Experiment E12-06-109 (“EG12”) to measure inclusivespin structure functions of the nucleon over a wide range in momentum transfer Q2 andfinal state mass W (from elastic and quasi-elastic to deep inelastic scattering). Thisexperiment will complete our campaign to fully explore the spin structure of the nucleonin the valence region, over the range 0.06 < x < 0.8, see Fig. 1. It was approved byJefferson Lab PAC36 for the full requested 80 days with rating “A”. S. Kuhn is thecontact person for E12-06-109, and he and S. Bültmann are co-spokespersons. S. Kuhnis also the overall run group coordinator for run group C.

The main effort of our group over the past year has been the preparation for a suc-cessful first run of the CLAS12 Run Group C with a longitudinally polarized proton anddeuteron target. This effort involves Drs. Kuhn and Bültmann as well as Ph.D. studentV. Lagerquist. A second student, P. Pandey, has joined our group to work on this projectin the future. In this effort we are collaborating with groups from Jefferson Lab, Univer-sity of Virginia, Christopher Newport University, Fairfield University, IPNO Orsay, IdahoState University, and the Universidad Tecnica Federico Santa Maria in Valparaiso, Chile.

Over the last year, we have

• organized an extensive program of simulations, tests and prototyping to determine

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FIG. 2. 1 K refrigerator for the Run Group C longitudinally polarized target under constructionat Jefferson Lab.

the optimal configuration of the target and beam line,

• helped design and build various components of the polarized target, including therefrigerator (see Fig. 2),

• tested the dual target cell design, including NMR coils and correction coils for amore homogeneous magnetic field (V. Lagerquist),

• analyzed measurements of the CLAS12 solenoid field to arrive a precise model ofthis field, which is needed both for the polarized target design and to optimizereconstruction of charged particle tracks in CLAS12, and

• built a test stand for cryogenic tests at Jefferson Lab.

We expect that most remaining components of the target (including the 1 K refriger-ator) will be completed by early 2019, and the target will be assembled for tests duringthe next year. We have scheduled an Experimental Readiness Review for Run Group C inlate March 2019, and expect to submit a scheduling request for the experiment in summer2019. According to the present schedule for Hall B, we expect Run Group to run soonafter the anticipated long shutdown of the Jefferson Lab accelerator in 2020.

2. BONuS

The behavior of parton distribution functions at high Bjorken x is of great interest tothe community. To focus on just one example, the ratio of d and u quark distributions(d/u) as x → 1 depends sensitively on the mechanism by which spin-flavor symmetryis broken. In turn, precise knowledge of this ratio at high x results in lower systematicuncertainties in the interpretation of searches at high-energy colliders like the LHC. Inorder to investigate this ratio, one needs data on both proton and neutron targets. Toapproximate a free neutron target, the BONuS collaboration uses the spectator methodby detecting a low energy recoil proton in coincidence with the scattered electron, which

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allows us to correct for the initial (Fermi) momentum of the neutron in the deuteron. Afirst experimental run of BONuS in the 6 GeV era at Jefferson Lab demonstrated thismethod successfully.

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Projected 12 GeV d/u Extractions FIG. 3. Anticipated exper-imental uncertainties on theratio of d over u quarks vs.Bjorken-x from various Jeffer-son Lab experiments. Theexpected BONuS12 data areshown as dark green squares,with statistical error bars (in-visible except for the highestpoints in x), and systematicuncertainties indicated by theblack lines near the axis (lowerline: point to point systematicuncertainties; upper line: over-all uncertainty including nor-malization). Several predic-tions for the asymptotic valueof the ratio are indicated onthe right axis.

The BONuS experiment will run again at Jefferson Lab with a beam energy of 11 GeVin Hall B. This experiment (“BONuS12” or CLAS12 Run Group F) is approved with Arating and has been designated as one of the “high impact” experiments for early running.Drs. Bültmann (co-spokesperson and contact person) and Kuhn (co-spokesperson andRun Group F coordinator) are leading the preparation for BONuS12. The importanceof this experiment was emphasized in the most recent NSAC Long Range Plan, whichincludes Fig. 3 showing the expected experimental results. Presently, Run Group F isscheduled to be installed starting December 2019 to run in winter/spring 2020 as part ofthe CLAS12 experimental program.

Our group has been leading a multi-pronged effort to develop, design, prototype andbuild a new spectator proton recoil detector (“RTPC”), shown in Fig. 4, and ancillaryequipment in preparation for this new run. We are also spearheading the software de-velopment and simulation and reconstruction effort for BONuS12. Finally, with the helpof substantial supplemental funding for our DOE grant as well as support from a “4VA”grant, we have acquired many parts and equipment both for benchmark testing and thefinal detector.

Over the past year, three PIs (Drs. Bültmann, Dodge and Kuhn), one full-time post-doc (Dr. G. Charles followed by Dr. M. Hattawy), three graduate students (N.Dzbenski -advisor: G. Dodge, D. Payette - advisor: S. Kuhn, and J. Poudel - advisor: S. Bültmann)as well as several undergraduate students (D. Akers, M. Splitstone, E. Deir) have beenworking on this project. Two more graduate students have joined the project over thesummer and one of them, Madhusudan Pokhrel, will work on BONuS as his thesis project.

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FIG. 4. Engineering drawing of the new RTPC detector with its insertion holder and electronics.Beam direction is from left to right.. Proton racks are read out by ≈18000 pads 4 mm long and2.75 mm wide on a readout board at 7.9 cm radius. All pads are read out every 120 ns (yieldingabout 30-50 individual space points per track) by the DAQ system based on the DREAM chipdeveloped by Saclay (left). Each proton track is curved in the 5 T magnetic field of the centraldetector solenoid of CLAS12 and can be reconstructed in 3 dimensions, using the pad ID andtiming information.

We have made extensive progress towards the realization of the BONuS12 experiment andhave reached several important milestones:

• We completed the design and modeling of all parts of the detector and its integrationinto CLAS12 together with Hall B designer Cyril Wiggins. Several items (mandrels,GEM rings, etc.) have been fabricated in the Jefferson Lab shop. The HamptonUniversity group, with our help, has set up a clean room containing actuator-drivenassembly systems to build the first RTPC.

• We acquired, inspected and tested a full complement of GEM foils that will beshipped to Hampton University and assembled into a 3-layer amplification stageshortly.

• Together with the groups at Hampton University and Jefferson Lab, we have de-signed and procured prototypes for all necessary electronics boards, including thereadout pad board and the signal translation boards shown in green in Fig. 4. Theprototypes are presently being used to test the whole electrical assembly. The finalboards can be acquired in short order.

• We integrated BONuS12 into the standard CLAS12 simulation software, GEMC,and ran extensive simulations of proton tracks and coincident events including the

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signals they will generate.

• We also augmented the standard CLAS12 data analysis software with the necessaryroutines to analyze signals both from that simulation and from the real detector.We have completed the necessary specialized software for pattern recognition, trackreconstruction and track fitting (helix fitter), all within the CLAS12 COATJAVAframework.

• We continued testing detector components and the DREAM FEU-based data ac-quisition with our test stand at ODU, utilizing the EG6 RTPC detector and a setof DREAM electronics acquired with supplemental funding for this grant.

• Ancillary systems, including detector gas and HV, have been set up and tested andare being integrated into the Jefferson Lab EPICS slow control system.

Over the next year, our group, in collaboration with the College of William and Mary,Hampton University, James Madison University, Virginia Union University, University ofVirginia and Jefferson Lab, will build and operate two RTPC detectors (for redundancy)and all ancillary equipment to conduct the BONuS12 experiment. We also collaboratewith experts at Saclay on modifications of the data acquisition system (based on theDREAM chip developed by Saclay) and the changeover from standard CLAS12 operationto RTPC operation. We will use next summer for extensive tests of one RTPC at JeffersonLab, including the full DAQ system, with cosmic rays. All components of the experimentare expected to be completed and fully tested by Fall 2019, in time to begin installationin Hall B after the conclusion of Run Group B (presently scheduled for December 19,2019). Over the ensuing 7 weeks, we will install and align the RTPC, test it with cosmicrays and commission it with beam starting February 12, 2020. The present Jefferson Labschedule shows Run Group F running until May 1, 2020 for a total of 80 calendar days.Including 4 “Contingency” days at the end of this period, this corresponds to the full 42days of nominal 100% efficient “PAC days” approved for BONuS12.

3. Deep Virtual Exclusive Scattering

Deep Virtual Exclusive Scattering (DVES), encompassing deeply virtual Comptonscattering (DVCS) on the nucleon, eN → eNγ, and associated deep virtual meson pro-duction (DVMP) are centerpieces of the Jefferson Lab 12 GeV program. We have playeda leading role since the inception of the JLab DVCS program. DVCS and DVMP are alsocentral to the physics program of a future Electron Ion Collider. Our leadership role inthe EIC program is detailed in section 7.

C. Hyde is co-spokesperson of Hall A DVCS experiments E00-110, E07-007, E08-025,E12-06-114, and Hall C experiment E12-13-010. The goal of this program is to measureabsolute cross sections (unpolarized and electron helicity-dependent) as functions of Q2

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at fixed values of xB. The Q2-dependence of these cross sections is the essential test of

factorization, and will quantify the contribution to the scattering amplitude of higher-twistquark-gluon correlations. The larger goal of the global Deep Virtual Exclusive Scattering(DVES) effort is to provide sufficient constraints on the Generalized Parton Distributions(GPDs) to form spatial images of the quarks and gluons inside the proton (and otheratomic nuclei) and to constrain the contribution of parton orbital angular momentum tothe proton spin.

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FIG. 5. Kinematic coverage ofHall A DVCS experiment E12-06-114 from 2014–2016 run. Eachdisjoint group of events is one set-ting of the electron spectrometer(HRS). Each color corresponds toa Q2 scan at fixed xB. the inci-dent beam energies ranged from6.6 to 11 GeV.

In the past year, we continued the analysis of the Hall A DVCS 2014–2016 run ofE12-06-114. The kinematic coverage is illustrated in Fig. 5 In the past year, doctoralstudent Hashir Rashad (C.Hyde, supervisor) completed trigger efficiency studies and HRS(electron spectrometer) optics, tracking efficiency and acceptance studies. For 2019 hisgoal is to complete a DVCS analysis of these data, including a model of the H(e, e′γ)N∗ →Nπ channel at Nπ threshold [1], which is an important background to the exclusiveH(e, e′γ)p channel of interest. Inclusion of the threshold N∗ production will provide animportant validation of the systematic errors of our DVCS analyses. A preliminary crosssection result from the collaboration is presented in Fig. 6

Doctoral student Ms. Dilini Bulumulla (C. Hyde, supervisor) is analyzing CLAS12Run Group A (10.6 GeV beam incident on an unpolarized liquid H2 target) for deepvirtual σ- and ρ-meson production:

ep→ epππ (1)

The CLAS12 kinematic coverage for these reactions is illustrated in Fig. 7 The ρ-mesonis present only in the π+π− p-wave channel, but the σ = f0(500) and the f0(980) con-tribute to both the π+π− and π0π0 s-wave channels. We are following the deep virtualππ formalism of Lehmann-Dronke et al., [2, 3]. A particularly intriguing aspect of thisreaction is the predicted sensitivity to the pure gluon content of the σ-meson. In addition,we will perform a full analysis of s-channel helicity conservation (SCHC) in this reaction.

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Preliminary cross sections

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• Unpolarized: DVCS term dominant at ϕ = 180°, interference increases at ϕ = 0° and ϕ = 360°.

• Twist-2 dominant, Twist-3 very small.

• Unpolarized: good agreement of model KM15 with data.

• Polarized: fairly good agreement of both models with data.

• KM10a & KM15: global fits to DVCS data.

• KM10a: does not use Hall A data.

• KM15: use Hall A and CLAS data up to 2015.

K. Kumerički, S. Liuti, and H. Moutarde, 2016.

K. Kumerički and D. Müller, 2015.

http://calculon.phy.hr/gpd/

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FIG. 6. DVCS cross section (Left: unpolarized, Right: electron-helicity dependent) in onekinematic setting from Fig. 5, and one bin in t = (q − q′)2.

Ms. Bulumulla is also part of the forward Drift Chamber calibration and data qualitymonitoring groups within the CLAS12 collaboration.

FIG. 7. Event statistics in theQ2 vs xB plane from four hoursof CLAS12 Run Group A dataat 10.6 GeV. These are candi-date deep virtual exclusive events:H(e, e′p)X events with W > 2GeV and MX < 2 GeV.

We continue preparations for a multi-energy DVCS and deep π0 experiment in HallC (E12-13-010). This includes the construction of a sweep magnet (funded by an NSFMRI grant, (C.Hyde, M.Amaryan co-P.I.), which will allow us to move the calorimeter tosmaller angles compared to our previous Hall A DVCS experiments. Combined with the11 GeV beam and the HMS spectrometer, this will give us a broader reach in (Q2, xB)at multiple energies for Rosenbluth separations of Deep Virtual π0 production, and theenergy dependence of DVCS. The sweep magnet is now assembled at JLab, and ODU

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doctoral student M. Kerver (funded separately) is preparing the field mapping.

C. Hadron Spectroscopy

1. Photoproduction and Decay of Light Mesons in CLAS

Analyses of different meson photoproduction and decay channels based on CLAS g11and g12 run periods continued.

They follow CLAS Approved Analysis (CAA), with M. Amaryan as co-spokespersonwith members of 22 institutions as co-authors, including several non CLAS-member in-stitutions from Europe and India joining JLab for the first time. After an internal reviewand vote, this CAA was approved by the CLAS Collaboration. This is considered by thecharter of the Collaboration to be equivalent to PAC approval status.

Measurement of the photoproduction and decay of light mesons could shed light onmany aspects of non-perturbative Quantum Chromodynamics (QCD) , the spectrum ofbaryon resonances, the d and u quark mass difference, testing fundamental symmetries,as well as higher order gauge theory anomaly terms.

Experimental data have been collected using a tagged photon beam in Hall-B tostudy photoproduction of light mesons from a liquid hydrogen target. The wealth ofCLAS data allows us to study different decay modes of light mesons independent ofthe production vertex, making decaying mesons a laboratory in themselves. Dependingupon the channel, the CLAS dataset is comparable to or richer than the world’s higheststatistics measurement from such facilities as KLOE, CLEO, BES, MAMI and COSY.

In the following we describe the progress being made in different analyses during theperiod covered by this report.

The analysis of π0 photoproduction has been finalized. The paper entitled ”Exclusivephotoproduction off π0 up to large values of Mandelstam variables s, t and u with CLAS”with CLAS, with Moskov Amaryan and former ODU student Michael Kunkel currently atIKP Juelich, Germany, among the lead authors, has been published in Physicsal Review C[4]. Measurement of π0 in the Dalitz decay final state allows to provide experimental datain previously unmeasured terra incognita domain. The early theoretical models proposedto describe π0 photoproduction proposed decades ago finally have been tested [5], aswell as an quark counting rule [6] was examined at high values of all three Mandelstamvariables s, t and u and agree with an s−7 power law. Our data also clearly show thatGeneral Parton Distribution based models underestimate the experimental data by ordersof magnitude and favor Regge mechanism based models [5], [7], [8] and [9].

Ph.D. student, Torri Jeske is analysing η → π+π−γ decay and we expect her thesiswork to be completed in 2019 and subsequent paper be submitted.

M. Amaryan is also co-supervisor of a foreign graduate students, Cathrina Sowa fromBochum University, Germany is working to extend the photoproduction cross section

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measurement of η′ up to unmeasured 5.6 GeV of photon energy, Sudeep Ghosh formIndian Institute of Technology, Sudeep Ghosh has completed the Dalitz plot analysis ofη′ → π+π−η decay and submitted the analysis note for review by Hadron SpectroscopyWorking Group. The η′ decay matrix elements are extracted with the highest precisionobtained so far. His Ph.D. Thesis is submitted to the Indore Insitute Scientific Council.Another student Tyler Viducic is working on radiative decay of ρ meson, ρ→ π+π−γ tostudy possible manifestation of the elusive σ(f0(500) in the invariant mass of π

+π− fromthis decay.

The Light Meson Decay program, jointly chaired by Moskov Amaryan and SusanSchadmand (IKP Juelich) , also includes the Dalitz plot analysis of η → π+π−π0 de-cay analyzed by Daniel Lerch from IKP (currently at FSU) and is close to completion.We expect the analysis note to be finalized and subsequent paper to be submitted forpublication in 2018.

As almost all of these analysis are quite new in photoproduction experiments, hugeefforts have been devoted to establish common techniques and analysis tools to bring allthese results to the level of release and eventual publication. The light meson programwill continue with much improved CLAS12 setup.

2. The GlueX Collaboration in Hall-D

In June 2017 Moskov Amaryan, a new postdoctoral associate Marouen Baalouch (wholeft ODU in June 2018) and ODU graduate student Nilanga Wickrmaarachchi joinedGlueX Collaboration in Hall-D. We started analysis of new data obtained by GlueXCollaboration in 2016–2018.

The analysis led by graduate student Nilanga Wickramaarachchi resulted in a firstmeasurement of the Beam Asymmetry Σ for both t and u-channel production of thisreaction, presented in Fig.8.

This result could be the second Hall-D publication by the GlueX collaboration.

A new initiative to create a secondary beam of KL in Hall-D with the GLUEX setupfor hadron spectroscopy was developed and the Proposal was submitted to JLab PAC46with ODU co-authors Moskov Amaryan (spokesperson), Gail Dodge, Charles Hyde andformer ODU postdoc Ilya Larin [11]. In addition a KL2016 workshop [12] was organized inFebruary, 2016 with Moskov Amaryan as a chair and another workshop, YSTAR 2017 [13],was organized with Moskov Amaryan as a chair in February 2017 and a third workshopPKI2018 [14] was organized in February 2018 by Moskov Amaryan as chair.

The proposal to create a new facility with neutral KL beam at GlueX has a discoverypotential for dozens of excited hyperons as well as excited K∗’s to expand our understand-ing of hadron spectroscopy both in the hyperon as well as in the strange meson sectors.The current database is dominated by the decades old SLAC data. This new faciilty willhave a strong impact on estimation of thermodynamic properties of the early universe

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FIG. 8. Upper panel: Beam Asymmetry Σ in γp→ K+Σ0 as a function of t-Mandelstam. Lowerpanel: Beam Asymmetry Σ as a function of u-Mandelstam. Black points are for 00/900 degreespolarization of the beam, blue points for 450/1350 degrees and open circles are theoretical modelpredictions [10].

microseconds after the Big Bang, and on studies of the K−π system with orders of mag-nitude higher statistics. It will impact a broad range of topics including studies with Kππfinal states from open charm D-meson decays, charmonium decays of ηc and charmlessdecays of B-mesons . These data will also have an impact on the study of τ → Kπνdecays to get independent access to Vus, the most important ingredient to test unitarityrelation in the first row of CKM matrix elements. New high statistics data will also beused to establish or dismiss existence of elusive κ(800) meson. The proposal was deferredby PAC46 and we were encouraged to resubmit the proposal to PAC47 after the GlueXcollaboration prepares a White Paper per request of JLab management about the futurephysics program of Hall-D with the GlueX setup. Currently the proposal is signed by 200physicists from 61 universities worldwide, which is the largest collaboration at JLab ever.

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D. Physics of the Nucleus

Nucleon-Nucleon (NN) Short Range Correlations (SRC) are an extremely importantand interesting part of the structure of nuclei. They are a universal feature of nuclei[15–17]. The probability of a nucleon belonging to an NN SRC ranges from about 5% indeuterium to about 25% in heavy nuclei. NN SRC are responsible for the high momentumpart of the nuclear wave function and correspond to high density configurations wherenucleons overlap and the local density can be several times the average nuclear density.NN SRC are predominantly np pairs [18], even in heavy asymmetric nuclei such as lead[19]. Research by the ODU group has shown that the probability of SRC in a givennucleus is highly correlated with the strength of the EMC effect in that nucleus [20, 21].This important result is featured in the 2015 NSAC Long Range Plan.

In the past year we have learned a lot more about SRC and made a number ofconnections between SRC and other phenomena. We are continuing our data miningeffort on several fronts. Our measurement of the relative number of high momentumprotons and neutrons in nuclei from C through Pb using the (e,e’n) and (e,e’p) reactionswas published in Nature [22]. We used new measurements of the EMC effect and SRC crosssection ratios to derive a data-driven model of nucleon-modification in nuclei to show thatwe can describe the EMC effect using measured SRC abundances in nuclei and a singleSRC-pair structure modification for all nuclei (to appear in Nature). Our measurementof the center-of-mass momentum distributions of correlated pp pairs in these nuclei waspublished in PRL [23]. We explored how we can use correlation functions to describeaspects of NN SRC pairs [24]. And we continued our very successful e4ν initiative to useelectron scattering data from CLAS6 and CLAS12 to quantitatively understand neutrinoenergy reconstruction in neutrino-nucleus interactions, resulting in several invited talksand a prize-winning poster. The first e4ν analysis note is now under CLAS review.

We submitted two proposals to the Jefferson Lab PAC to study neutrino energy re-construction in Hall B (E12-17-006, L. Weinstein, co-spokesperson) and short range cor-relations in nuclei (E12-17-006A6, L. Weinstein, co-spokesperson). These were approvedtogether as a Run Group for 45 days of beam time with an A rating and a recommendationthat 20 of these days “be scheduled expeditiously”.

We measured the momentum distribution of protons in 3H and 3He(e, e′p) in JeffersonLab Hall A in Spring 2018. The data is mostly analyzed and a first paper is in preparation.

We are preparing the detectors to study the structure function of the bound nucleonas a function of its initial momentum by scattering an electron deep inelastically fromdeuterium and detecting the spectator backward nucleon. Experiment E12-11-003A willmeasure spectator neutrons using a dedicated back angle neutron detector (BAND) inconjunction with CLAS12. We built 58 of the BAND scintillators at ODU and led theassembly and installation of BAND in Hall B.

This work was done by Prof. L. Weinstein, Dr. F. Hauenstein, and M. Khachatryan, incollaboration with the Hen Group at MIT and the Piasetky group at Tel Aviv University.

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Thus SRC have become an even more fascinating topic, with new experiments ap-proved and conducted, new detectors, and new very-high-impact publications.

1. Bound Nucleon Modifications in Deuterium

In order to study possible modifications of the structure of a nucleon that is a partnerin a short-distance pair, we will measure deep inelastic electron scattering from deuterium,detecting the spectator recoil proton (or neutron), in order to determine the dependence ofthe neutron (or proton) structure function F2 on the momentum of the spectator nucleon.These experiments were motivated both by the earlier d(e, e′ps)X results [25] and also bynew papers showing the remarkable correlation between the strength of the EMC effectin a given nucleus and the probability that the nucleons in that nucleus belong to a ShortRange Correlation [20, 21, 26, 27].

These experiments will complement the BoNuS program described in Section I B 2.BoNuS will measure the bound neutron structure function at small recoil spectator protonmomentum (ps < 200 MeV/c) in order to measure scattering from neutrons that arealmost on shell. The experiments described here will extend these measurements to largerecoil spectator momentum (250 < ps < 550 MeV/c) in order to measure the momentumdependence of the bound nucleon structure function.

FIG. 9. The BAND detector installedon top of the SVT electronics racks inCLAS. Viewed from upstream. Thebeam pipe will pass through the holein the middle of the detector.

We put a major effort into preparing for Experiment E12-11-003A, “In Medium Proton

14

| [MeV/c]miss

p|0 100 200 300 400 500

|)m

issp(|

H(e,

e'p)

3σ/He

(e,e

'p)

3σ 1

2

3

Momentum Density (VMC)AV18+UX

LO E1 (1.0 fm)2N (1.0 fm)τLO E2N

Spectral FunctionCDA & KaptariBenhar & Pandharipande

FIG. 10. Extracted 3He to3H (e, e′p) cross-section ratio,σ3He(e,e′p)/σ3H(e,e′p)(pmiss) plot-ted vs. Pmiss compared with differentmodels of the corresponding mom-entum distribution ratio. The filledcircle and square markers correspondto the low and high Pmiss settingsrespectively. The open squares withdashed error bars show the highPmiss data shifted by 30% to reflectthe average difference between themeasured and PWIA calculated eventyield ratios.

Structure Functions, SRC, and the EMC Effect” (L.B. Weinstein, co-spokesperson), whichwill run in 2019 with the other CLAS12 deuterium measurements. This experimentwill use a Back Angle Neutron Detector (BAND) with 116 double-ended scintillatorsto detect spectator neutrons at angles from 160◦ to 170◦ relative to the beam line (seeFig. 9). In 2018 we passed the JLab Experimental Readiness review, built and tested 58scintillators at ODU, directed the assembly and installation of BAND in CLAS12, andstarted commissioning the detector.

We are preparing for an Experimental Readiness Review on Jefferson Lab ExperimentE12-11-107, “In Medium Nucleon Structure Functions, SRC, and the EMC effect”, ap-proved by PAC38 for 40 days of beam time in Hall C (L.B. Weinstein, co-spokesperson).We finished refurbishing the 5th and last plane of CLAS6 TOF scintillators for use inLAD (the Large Acceptance Detector). The scintillator stands and scattering chambermodifications have been designed by Jefferson Lab, and we are working out the cablingand electronics.

The scintillator refurbishing, LAD ERR preparation, and BAND work was done byL.B. Weinstein together with Katherine Price, an MS student, Caleb Fogler, a summergraduate student, our postdoc Florian Hauenstein, and our technician Tom Hartlove.

2. Nucleon Knockout and Correlations Studies

We ran the tritium (e, e′p) experiment in JLab Hall A as part of the tritium run group.This experiment measured the relative amounts of low-initial momentum and high-initialmomentum protons in 3H and 3He in order to test the hypothesis that, on average, theminority nucleons move faster in asymmetric nuclei. In other words, the naive expectationis that the ratio of protons in 3He to 3H is two at low-initial momentum due to nucleoncounting and is one at high-initial momentum due to pn pair counting.

Thanks to the increase in the JLab operating budget that came in the winter of2018, the (e, e′p) run was advanced from fall 2018 to April. Thanks to the efforts of our

15

postdoc, Florian Hauenstein, we were ready to run the experiment in under a month.Working with collaborators including the Hen group at MIT, we took the data, analyzedit, and have prepared a paper draft for collaboration review prior to journal submission.Fig. 10 shows the measured 3He(e, e′p) to 3H(e, e′p) cross section ratio, corrected for themissing energy acceptance, bin migration, and radiation, compared to ratios of calculatedmomentum distributions. The measured cross section ratio agrees very well with thecalculated momentum distribution ratios up to pmiss ≈ 250 MeV/c, where it exceeds thecalculations. The data overall supports the transition from single-nucleon dominance atlow pmiss, towards an np-SRC pair dominant region at high pmiss. However, full reactioncalculations are needed to assess the implications of the observed 30% deviation of thedata from the PWIA calculation in the expected np-SRC pair dominance region.

We will extend the tritum-type measurements to heavier nuclei by comparing the rel-ative amounts of low- and high-initial momentum protons in 40Ca and 48Ca to see how theaddition of eight neutrons changes the proton momentum distribution by increasing thenumber of high-relative momentum pn pairs. This experiment, E12-17-005, “The CaFeExperiment: Isospin Dependence of Short-Range Nucleon Pairing in Nuclei”, spokesper-sons: L.B. Weinstein, O. Hen, E. Cohen, D.W. Higinbotham, was approved for 4 days inHall C by Jefferson Lab PAC 45. In 2018 we prepared and passed a JLab ExperimentalReadiness Review (ERR) and Hall C bought the necessary calcium targets.

We continue to mine CLAS6 data for nuclear physics. Three analyses have beenpublished or accepted in prominent journals.

We have directly measured the relative number of high momentum protons and neu-trons in nuclei from C through Pb for the first time using the (e,e’n) and (e,e’p) reactions.We detected neutrons in the CLAS6 electromagnetic calorimeter and protons using thestandard tracking. We then chose two sets of kinematics, one with low missing momen-tum (pmiss < 250 MeV/c where ~pmiss = ~q− ~pN , and pN is the momentum of the detectednucleon) and one with high missing momentum pmiss > 300 MeV/c). In the absenceof final state interactions, high and low missing momentum correspond to high and lowinitial momentum of the struck nucleon. We plotted the ratio of neutrons to protons forhigh pmiss and for low pmiss. This ratio scaled as N/Z for low-initial-momentum nucleons,as expected form simple counting, but was equal to unity for high-initial-momentum nu-cleons (see Fig. 11). This directly shows that, counterintuitively, increasing the fractionof neutrons in a nucleus increases the fraction of high-momentum protons in that nucleus.This is the first direct experimental evidence that protons move faster than neutrons inneutron-rich nuclei. This analysis was approved by the CLAS Collaboration and the pa-per has been published in Nature [22]. L. Weinstein helped supervise this analysis, whichwas performed by Meytal Duer from Tel Aviv University.

We are also studying the center-of-mass momentum distributions of correlated pppairs in these nuclei. Since the correlated pairs are due to the short distance interaction,the relative momentum distribution of the pairs should be the same for all nuclei. How-ever, by measuring the distribution of the center-of-mass momentum of the pairs, we candetermine which pairs in the nucleus form the short-range correlated pairs. This analysis

16

FIG. 11. [A(e, e′n)/σn]/[A(e, e′p)/σp]reduced cross-section ratio for low-momentum (green circles) and high-momentum (purple triangles) events.The initial nucleon momenta corre-sponding to each type of event areillustrated in the insert. The linesshow the simple N/Z expectation forlow-momentum nucleons and the np-dominance expectation (i.e., ratio = 1)for high-momentum nucleons. The in-ner error bars are statistical while theouter ones include both statistical andsystematic uncertainties.

was approved by the CLAS Colaboration and the paper been published in PRL [23]. L.Weinstein helped supervise this analysis, which was performed by Erez Cohen from TelAviv University.

Further analysis of this data, to extract the ratio of (e, e′pp) to (e, e′p) events as afunction of missing momentum out to pmiss = 1000 MeV/c, is continuing, primarily bythe Hen Group, with help from L. Weinstein.

0.7

0.8

0.9

1

1.1

1.2

0.2 0.4 0.6 0.8

[FA 2/A

]/[F

d 2/2

]

xB

SLACJLab Hall CThis work

-0.05

0

0.05

0.2 0.4 0.6 0.8

Median norm. uncertainty

nd S

RC

�F

p 2+

�F

n 2

Fd 2

xB3

4

9

12

27

56

197

208

A

FIG. 12. | Universality of SRC pair quark distributions. The EMC effect for differentnuclei, as observed in (left) ratios of (FA2 /A)/(F

d2 /2) as a function of xB and (right) the modi-

fication of SRC pairs, as described by the right-hand side of Eq. 3. Different colors correspondto different mass-number nuclei, as indicated by the color scale on the right. The open circlesare the SLAC data of [28] and the open squares are the Jefferson Lab data of [29]. The nucleus-independent (universal) behavior of the SRC modification, as predicted by the SRC-driven EMCmodel, is clearly observed. The error bars on the symbols show the statistical uncertainty andthe gray bands show the median normalization uncertainty.

We also performed new, high precision, measurements of inclusive per-nucleon (e, e′)cross section ratios of nucleus A to deuterium in the DIS and quasielastic (QE) regionsto extract the EMC effect and SRC ratios. We used these new high-precision ratios,

17

together with existing world data, to extract a data-driven nucleon modification functionfor nucleons in SRC pairs. We found that combining the EMC and SRC data leads to asingle universal data-driven nucleon modification function for nucleons in all nuclei from3He to Pb. If we describe the nuclear structure function as:

FA2 = ZFp2 +NF

n2 + n

ASRC(∆F

p2 + ∆F

n2 ) (2)

then when we take the ratio to the deuteron, we can write the universal modificationfunction in terms of measured quantities as

ndSRC(∆Fp2 + ∆F

n2 )

F d2=FA2 /F

d2 − (Z −N)(F

p2 /F

d2 )−N

(A/2)a2 −N(3)

where FA2 , Fd2 , F

n2 and F

p2 are the structure functions for nucleus A, the deuteron, the

neutron and the proton, respectively, nASRC is the number of SRC pairs in nucleus A,∆F p2 and ∆F

n2 are the difference between the bound and free nucleon structure functions,

∆F2 = Fbound2 − F

free2 , and a2 is the measured per-nucleon QE cross-section ratio of

nucleus A to deuterium for 1.5lexle1.9. We calculate the left side of Eq. 2 for all nucleiusing the measured quantities on the right side of the equation.

Fig. 12 shows the non-isoscalar corrected-EMC data,, where the EMC slopes range asmall positive slope for 3He to a large negative slope for Pb. It also shows the results ofthe nucleon modification from Eq. 2 for all measured nuclei. This nucleon modificationfunction has the same slope for all measured nuclei and the differences in magnitudeare within the normalization uncertainties of the different measurements. Thus this is auniversal modification function.

The association of the EMC effect with SRC pairs implies that it is a dynamicaleffect. Most of the time, nucleons bound in nuclei have the same internal structureas that of free nucleons. However, for short time intervals when two nucleons form atemporary high local-density SRC pair, their internal structure is briefly modified. Whenthe two nucleons disassociate, their internal structure again becomes similar to that offree nucleons. This dynamical picture differs significantly from the traditional staticmodification in the nuclear mean- field, previously proposed as an explanation for theEMC effect.

These results will appear in Nature. L. Weinstein helped supervise this analysis,which was performed by Barak Schmookler from MIT and Meytal Duer from Tel AvivUniversity.

Because of the remarkable number, range and impact of our data-mining analysesof the 6-GeV CLAS data (2 Nature and 1 Science papers, plus many others), the PACapproved 45 days of beam time with a scientific rating of A for experiment E12-17-006a,“Exclusive Studies of Short Range Correlations in Nuclei using CLAS12”, in conjunctionwith the E12-17-006, “Electrons for Neutrinos”. We plan to take about 10 times morenuclear data than CLAS6 using beam energies from 1.1 to 6.6 GeV on a range of targetsincluding d, 4He, C, O, 40Ar, 40Ca, 48Ca, 120Sn, and Pb, in order to answer a range of

18

pressing questions including the existence and properties of Three-Nucleon SRCs, con-straining the NN interaction and ab-initio calculations of the nuclear wave function atshort distances, understanding factorized effective theories and effective SRC formationmechanisms, studies of three-nucleon correlations, and exploring the detailed connectionof SRCs and the EMC effect. L. Weinstein is co-spokesperson of these proposals.

3. Hadronization in DIS on Nuclei

Members of the ODU group are working to help prepare for CLAS12 running. How-ever, no work was done specifically for the hadronization proposals, since they are notexpected to run before 2021.

4. Electrons for neutrinos

Lastly, we started an initiative to use electron scattering data from CLAS6 andCLAS12 to quantitatively understand neutrino energy reconstruction in charged current(CC) neutrino-nucleus interactions.

The extraction of neutrino mixing parameters from neutrino oscillation experimentsrelies on the reconstruction of the incident neutrino energy and knowledge of the neutrino-nucleus interaction cross-section for various nuclei and incident neutrino energies. The en-ergy reconstruction is done using the yield and kinematics of particles produced from neu-trino interactions in nuclei. Different detectors use different techniques. Water Cherenkov-detector based experiments, which cannot measure protons, create charged-current quasi-elastic (QE) enhanced event samples by rejecting pions and then estimate the neutrinoenergy based on only the measured lepton kinematic information. Calorimetric-detectorexperiments use a combination of leptonic and hadronic information. However, none ofthese energy reconstruction techniques have been tested experimentally using beams ofknown energy.

Because neutrinos and electrons are both leptons, they interact with nuclei in similarways. We are using CLAS6 data to study electron scattering from a variety of targets at arange of beam energies in order to test neutrino event selection and energy reconstructiontechniques and to benchmark neutrino event generators. Event generators are criticalinputs for analysis of neutrino oscillation and cross section experiments; providing data totest and improve those generators can significantly decrease the systematic uncertaintiesin neutrino experiments.

We have analyzed e2a data from CLAS6 with 2.2 and 4.4 GeV electrons incident on3He, 4He, C, and Fe targets, selecting (e, e′) and (e, e′p) events with no detected pions.We then used (e, e′π) events and the known CLAS geometrical acceptance to estimateand subtract the number of (e, e′) events with undetected pions to achieve a true zero-pion (e, e′) event sample. We did the same thing with (e, e′pπ) events to achieve a true

19

FIG. 13. PRELIMINARY: The number of 0π (e, e′p) events versus the reconstructed energy for2.2 GeV electrons incident on 4He, C and Fe in three bins of p⊥, p⊥ < 0.2 (blue), 0.2 ≤ p⊥ < 0.4(red), and p⊥ ≥ 0.4 GeV/c (green). The left side shows the kinematic energy reconstructionusing just the electron kinematics and the right side shows the calorimetric energy reconstructionEcalrec = El + Tp. Each event is weighted by 1/σMott to make the electron sample more similar toa neutrino event sample.

zero-pion (e, e′p) event sample. We reconstructed the beam energy in one of two ways,(1) using only the scattered lepton information:

Ekinrec =2M�+ 2MEl −m2l

2(M − El + pl cos θl)

where El, pl,ml and θl are the scattered lepton energy, momentum, mass, and scatteringangle, M is the nucleon mass and � is the average nucleon separation energy; and (2)using the total energy of the final state particles for (e, e′p) events:

Ecalrec = El + Tp

where Tp is the kinetic energy of the detected proton. The first formula is used by someneutrino experiments, where they assume that most neutrino-nucleus interactions arequasielastic. Note that ml is non-negligible for outgoing muons.

One significant difference between neutrino and electron scattering comes from thedifferent propagators for the exchanged bosons. The propagator has the form (Q2+M2B)

−1

where Q2 is the four-momentum transfer squared and MB is the mass of the exchangedboson. Because Charged Current Quasielastic (CC QE) neutrino scattering occurs viaW exchange and the W mass is very large, the weak propagator has the form M−2W .Because the electromagnetic interaction occurs via massless photon exchange, the boson

20

propagator leads to the Mott cross section. Therefore, we weighted each event by 1/σMottto account for this difference.

Fig. 13 shows the reconstructed beam energies for 2.2 GeV electrons scattering from4He, C and Fe for both reconstruction techniques, for different bins in the perpendicularmissing momentum, ~p⊥ = ~p

e⊥ + ~p

p⊥, where ~p

e⊥ and ~p

p⊥ are the momenta of the detected

electron and proton, perpendicular to the beam line. The calorimetric method has muchgreater energy resolution, although the low energy tail (Erec < 1.8 GeV) is very similar.Only 35 to 54% of (e, e′p) events reconstruct to within 10% of the correct beam energyusing the calorimetric method and only 30 to 40% of events reconstruct to the correctbeam energy using the lepton-only kinematic method. The highest percentage is for 4Heand the lowest is for Fe. These percentages are reduced by another 1/3 for 4.4 GeVelectrons. The energy reconstruction is far worse for events with large p⊥.

FIG. 14. PRELIMINARY: The number of 0π 2.2 GeV C(e, e′p) events versus the kinematicreconstructed energy in three bins of p⊥, p⊥ < 0.2 (blue), 0.2 ≤ p⊥ < 0.4 (red), and p⊥ ≥ 0.4GeV/c (green). The left side shows the results for events generated with GENIE and the rightside shows the data.

In 2018 we refined our data analysis, accounting for multiple pion and proton eventsand refining other cuts and corrections. We submitted an analysis note to CLAS forapproval of our analysis methods.

We also compared our data to the output of neutrino event generators in order tocompare the quality of the actual and simulated beam energy reconstruction, using GE-NIE, one of the standard neutrino event generators (see Fig. 14). A far greater fraction ofGENIE events reconstructs to the beam energy than the data, indicating that the non-QEreaction channels in GENIE are not strong enough.

Based on this analysis, we resubmitted our conditionally approved proposal to extendthese measurements to a much wider range of beam energies and targets to much betterconstrain and understand beam energy reconstruction methods in nuclear targets. Jeffer-son Lab experiment E12-17-006, “Electrons for Neutrinos: Addressing Critical Neutrino-Nucleus Issues”, spokespersons: L.B. Weinstein, O. Hen, E. Piasetzky, K. Mahn, and S.Stepanyan, was approved for 45 days with an A rating by PAC46.

This work has generated tremendous excitement in the neutrino community. Membersof the ODU and MIT groups have given many talks in the last year at conferences,

21

workshops and neutrino collaboration meetings, including four invited talks and a prize-winning poster by the ODU group.

The data analysis is being performed by Mariana Khachatryan under the supervisionof F. Hauenstein and L.B. Weinstein. The work on GENIE is being performed by AdiAshkenazi and Afroditi Papadopolou of MIT, under the supervision of L. Weinstein andO. Hen.

E. Physics Beyond the Standard Model

Only 20% of the matter in the universe is understood, the remaining 80% consistsof “Dark Matter”, whose constituents and interactions (other than gravity) are entirelyunknown. The 2014 HEPAP P5 report [30] stresses the importance of identifying thephysics of dark matter. Given the absence of evidence for WIMPS (Weakly InteractingMassive Particles), it is important to look for other forms of dark matter, especially thepossibility that dark matter interacts through a new force that couples only indirectly tonormal matter [31].

Such dark matter would interact with regular matter and with itself through yet-to-be-discovered hidden-sector forces. Scientists believe that heavy photons – also calleddark photons – might be mediators of such a dark force, just as regular photons arecarriers of the electromagnetic force between normal charged particles.

FIG. 15. The 95% C.L. power-constrained upper limits on �2 versusA′ mass obtained in this analysis. Alimit at the level of 6 × 106 is set.Existing limits from beam dump, col-lider and fixed target experiments arealso shown. The region labeled aeis an exclusion based on the electrong2. The green band labeled aµ ± 2σrepresents the region that an A′ canbe used to explain the discrepancybetween the measured and calculatedmuon anomalous magnetic moment.See Ref. [32] for details.

The Heavy Photon Search (HPS) experiment at Jefferson Lab [33, 34] is searchingfor new heavy vector boson(s), aka ‘heavy photons’ or ‘dark photons’ or ‘hidden sectorphotons’, in the mass range of 20 MeV/c2 to 1000 MeV/c2. If they exist, heavy photons

22

mix with ordinary photons through kinetic mixing, which induces their weak coupling toelectrons, �e, where e is the electron charge and � ≤ 10−2. Since they couple to electrons,heavy photons are radiated in electron scattering and can subsequently decay into e+e−.If � is large enough, �2 ≈ 10−6, this would appear as a narrow mass peak which canbe observed above the copious QED trident background. For suitably small couplings,10−10 < �2 < 10−8, heavy photons travel detectable distances before decaying, providinga second signature.

The HPS experiment exploits both these signatures to search for heavy photons overa wide range of couplings, �2 > 10−10, and masses, 10−2 < MA′ < 0.3 GeV, using a newcompact, large acceptance forward spectrometer containing a silicon microstrip vertextracker (SVT) and a PbWO4 electromagnetic calorimeter.

The first results of the 2015 Engineering Run were published in Ref. [32]. L. Weinsteinchaired the HPS Presentations and Publications Committee until this year. Fig. 15 showsthe results of this first measurement.

This work was performed by Drs. Weinstein, Bueltmann and Charles, along with for-mer graduate student (and now JLab postdoc) Holly Szumila-Vance. We do not anticipatefurther significant involvement with the HPS experiment.

F. An Electron Ion Collider

Undergraduate students, graduate students, post-docs, and faculty in our group areinvolved in a number of research projects associated with the proposed Electron IonCollider. These activities are described below, with indication of funding sources, whichinclude this grant, JLab LDRD funds, and BNL Generic Detector R&D for an EIC funds.Dr. Hyde’s leadership role in EIC science is exemplified by his election by the EIC UsersGroup to a two year term as Vice Chair of the EICUG Steering Committee.

1. Physics Program Development

• Deep Inelastic Scattering on Nuclei:Jefferson Lab LDRD project 2017-4a Nuclear Gluons with Charm at an EIC pro-vided one month summer salary to Dr. C. Hyde and two month’s salary to Dr.Florian Hauenstein. With the broad range or π/K/p particle ID (PID) proposed inthe JLEIC detector design, Dr. Hauenstein studied the sensitivity of flavor taggedNuclear-SIDIS: AZ(e, e′h)X to determine the quark-flavor and anti-quark flavor de-pendence of nuclear parton distributions in the shadowing, anti-shadowing, andEMC domains. Combining vertex tagging with π/K PID, we have found charm-tagging efficiency in excess of 10%. This will allow precision studies of nuclear gluondistributions, via the photon gluon fusion reaction γ∗+ g → cc in Nuclei. Dr. Hydeis also applying jet reconstruction algorithms in EIC kinematics.

23

• Deep inelastic scattering on light nuclei, with forward spectator tagging.This project was previously financed by JLab LDRD funds. Diffractive DIS on thedeuteron refers to the d(e, e′pn)X reaction, with the pn pair in the forward directionat low mass. In this reaction, the final state partonic jet X is initially in a smallcolor neutral configuration, and hence there is no final state interaction of the jetwith the np pair. In our upcoming work, we will incorporate calculations of thelow energy NN interaction. This will reveal how well we can use diffractive DIS toprobe the quark-gluon structure of the NN interaction.

• Geometry Tagging: The forward multiplicity of evaporation neutrons and knock-out protons has been proposed as a probe of the centrality of the virtual photonin low-xB DIS on nuclei [35]. A detailed study of geometry tagging via evapora-tion neutrons, protons, and light ions, as well as detection of evaporation residuesis the subject of BNL Generic Detector R&D for an EIC project eRD17. In thisproject, C. Hyde is also studying the coherent deep virtual vector meson productionon nuclei, e.g. AZ(e, e′φ)AZ. Nuclear break-up in the final state will be vetoed byforward detectors. However, the diffractive pattern that maps the spatial distribu-tion of gluons in the nucleus can be washed out by excitation of bound states of thetarget nucelus in the final state. The only feasible approach to veto these events inheavy nuclei is to detect one or more decay photons from the excited state. ProjecteRD17 provided part time support to graduate student Caleb Fogler last year. Weconsidered 208Pb as a case study, because virtually every photon decay cascade asa γ-ray of at least 2.6 MeV. In the collider, these photons are boosted forward bya γ-factor ≥ 40. Thus at least 50% of all bound states decay by emitting at leastone photon of laboratory energy ≥ 100 MeV into a cone in the detector of size ±25mrad. We have added a high precision PbWO4 calorimeter in the forward ion regionof the JLEIC design. This calorimeter could be assembled from crystals plannedfor JLab12 experiments. Caleb Fogler also studied background in this calorimeterdirect from the interaction region, and found it to be small. In the next year, wewill evaluate background from hadronic showering in adjacent detectors.

2. Detector Design and R&D.

• A Detector of Internally Reflected Cherenkov Light (DIRC) for Particle I.D. BNLGeneric Detector R&D for an EIC project, eRD14.State of VA funds purchased a 40 ps blue laser for timing studies of micro-channelplate detectors in high magnetic fields. These studies were initiated this past year,and will continue in 2019.

• EIC Background studies from Beam-Gas InteractionsThis is a new FY2018 BNL Generic Detector R&D for an EIC project, eRD21(L. Elourdhiri–JLab spokesperson). Christine Ploen was funded in 2018 from the

24

eRD21 project. She developed a GEANT4 model of Beam-Gas interactions, andbenchmarked it with HERA-II background studies. She entered the ODU physicsgraduate program in Fall 2018, and will be funded by eRD21 in 2019 to continuethese background studies with detailed JLEIC parameters (C. Hyde, supervisor).

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arXiv:1804.06528 [hep-ph].

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[19] O. Hen, M. Sargsian, L. Weinstein, et al., Science 346, 614 (2014).

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Phys. Rev. Lett. 106, 052301 (2011).

[21] O. Hen, G. A. Miller, E. Piasetzky, and L. B. Weinstein, Rev. Mod. Phys. 89, 045002

(2017).

[22] M. Duer et al. (CLAS Collaboration), Nature 560, 617 (2018).

[23] E. O. Cohen et al. (CLAS Collaboration), Phys. Rev. Lett. 121, 092501 (2018).

[24] R. Cruz-Torres, A. Schmidt, G. Miller, L. Weinstein, N. Barnea, R. Weiss, E. Piasetzky,

and O. Hen, Physics Letters B 785, 304 (2018).

[25] A. V. Klimenko et al. (CLAS), Phys. Rev. C73, 035212 (2006), nucl-ex/0510032.

[26] O. Hen, E. Piasetzky, and L. B. Weinstein, Phys. Rev. C 85, 047301 (2012).

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Burkert, D. Calvo, M. Carpinelli, A. Celentano, G. Charles, L. Colaneri, W. Cooper,

C. Cuevas, A. D’Angelo, N. Dashyan, M. De Napoli, R. De Vita, A. Deur, R. Dupre,

H. Egiyan, L. Elouadrhiri, R. Essig, V. Fadeyev, C. Field, A. Filippi, A. Freyberger,

M. Garçon, N. Gevorgyan, F. X. Girod, N. Graf, M. Graham, K. A. Griffioen, A. Grillo,

M. Guidal, R. Herbst, M. Holtrop, J. Jaros, G. Kalicy, M. Khandaker, V. Kubarovsky,

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http://arxiv.org/abs/1804.06528http://dx.doi.org/10.1126/science.1256785http://dx.doi.org/10.1103/RevModPhys.89.045002http://dx.doi.org/10.1103/RevModPhys.89.045002http://dx.doi.org/10.1103/PhysRevLett.121.092501http://dx.doi.org/ https://doi.org/10.1016/j.physletb.2018.07.069http://arxiv.org/abs/nucl-ex/0510032http://dx.doi.org/10.1103/PhysRevC.92.015211http://arxiv.org/abs/1506.00871http://science.energy.gov/~/media/hep/hepap/pdf/May-2014/FINAL_P5_Report_Interactive_060214.pdfhttp://science.energy.gov/~/media/hep/hepap/pdf/May-2014/FINAL_P5_Report_Interactive_060214.pdfhttp://arxiv.org/abs/1608.08632

E. Leonora, K. Livingston, T. Maruyama, K. McCarty, J. McCormick, B. McKinnon,

K. Moffeit, O. Moreno, C. Munoz Camacho, T. Nelson, S. Niccolai, A. Odian, M. Ori-

unno, M. Osipenko, R. Paremuzyan, S. Paul, N. Randazzo, B. Raydo, B. Reese, A. Rizzo,

P. Schuster, Y. G. Sharabian, G. Simi, A. Simonyan, V. Sipala, D. Sokhan, M. Solt, S. Stepa-

nyan, H. Szumila-Vance, N. Toro, S. Uemura, M. Ungaro, H. Voskanyan, L. B. Weinstein,

B. Wojtsekhowski, and B. Yale (Heavy Photon Search Collaboration), Phys. Rev. D 98,

091101 (2018).

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arXiv:1411.0887 [hep-ph].

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http://dx.doi.org/10.1103/PhysRevD.98.091101http://dx.doi.org/10.1103/PhysRevD.98.091101https://confluence.slac.stanford.edu/display/hpsg/Heavy+Photon+Search+Expe% rimenthttps://confluence.slac.stanford.edu/display/hpsg/Heavy+Photon+Search+Expe% rimenthttps://misportal.jlab.org/mis/physics/experiments/viewProposal.cfm?paperId=738https://misportal.jlab.org/mis/physics/experiments/viewProposal.cfm?paperId=738http://dx.doi.org/10.1103/PhysRevLett.114.082301http://arxiv.org/abs/1411.0887

III. PUBLICATIONS, TALKS, AND THESES

A. Refereed Publications

Publications with an ODU leading author:

1. M. Duer et al. [CLAS Collaboration], Nature 560, no. 7720, 617 (2018)doi:10.1038/s41586-018-0400-z.

2. R. Cruz-Torres et al., “Short Range Correlations and the isospin dependence ofnuclear correlation functions”, Phys. Lett. B 785, 304 (2018).

3. E. O. Cohen et al. [CLAS Collaboration], Phys. Rev. Lett. 121, no. 9, 092501(2018) doi:10.1103/PhysRevLett.121.092501 [arXiv:1805.01981 [nucl-ex]].

4. M. C. Kunkel et al. [CLAS Collaboration], Phys. Rev. C 98, no. 1, 015207 (2018)doi:10.1103/PhysRevC.98.015207 [arXiv:1712.10314 [hep-ex]].

5. K. P. Adhikari et al. [CLAS Collaboration], Phys. Rev. Lett. 120, no. 6, 062501(2018) doi:10.1103/PhysRevLett.120.062501 [arXiv:1711.01974 [nucl-ex]].

6. A. Del Dotto et al., “Design and R&D; of RICH detectors for EIC experiments,”Nucl. Instrum. Meth. A 876, 237 (2017). https://doi.org/10.1016/j.nima.2017.03.032

Other Publications

7. N. Hirlinger Saylor et al. [CLAS Collaboration], Phys. Rev. C 98, no. 4, 045203(2018) doi:10.1103/PhysRevC.98.045203 [arXiv:1810.02110 [hep-ex]].

8. J. T. Goetz et al. [CLAS Collaboration], arXiv:1809.00074 [nucl-ex].

9. S. Lombardo et al. [CLAS Collaboration], Phys. Rev. D 98, no. 5, 052009 (2018)doi:10.1103/PhysRevD.98.052009 [arXiv:1808.01918 [hep-ex]].

10. E. Golovatch et al. [CLAS Collaboration], arXiv:1806.01767 [nucl-ex].

11. D. H. Ho et al. [CLAS Collaboration], Phys. Rev. C 98, no. 4, 045205 (2018)doi:10.1103/PhysRevC.98.045205 [arXiv:1805.04561 [nucl-ex]].

12. G. V. Fedotov et al. [CLAS Collaboration], Phys. Rev. C 98, no. 2, 025203 (2018)doi:10.1103/PhysRevC.98.025203 [arXiv:1804.05136 [nucl-ex]].

13. J. Bono et al. [CLAS Collaboration], Phys. Lett. B 783, 280 (2018)doi:10.1016/j.physletb.2018.07.004 [arXiv:1804.04564 [nucl-ex]].

14. T. Chetry et al. [CLAS Collaboration], Phys. Lett. B 782, 646 (2018)doi:10.1016/j.physletb.2018.06.003 [arXiv:1802.06746 [nucl-ex]].

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https://doi.org/10.1016/j.nima.2017.03.032https://doi.org/10.1016/j.nima.2017.03.032

15. S. Chandavar et al. [CLAS Collaboration], Phys. Rev. C 97, no. 2, 025203 (2018)doi:10.1103/PhysRevC.97.025203 [arXiv:1712.02184 [nucl-ex]].

16. K. Park et al. [CLAS Collaboration], Phys. Lett. B 780, 340 (2018)doi:10.1016/j.physletb.2018.03.026 [arXiv:1711.08486 [nucl-ex]].

17. P. Roy et al. [CLAS Collaboration], Phys. Rev. C 97, no. 5, 055202 (2018)doi:10.1103/PhysRevC.97.055202 [arXiv:1711.05176 [nucl-ex]].

18. S. Jawalkar et al. [CLAS Collaboration], Phys. Lett. B 782, 662 (2018)doi:10.1016/j.physletb.2018.06.014 [arXiv:1709.10054 [nucl-ex]].

19. Z. Akbar et al. [CLAS Collaboration], Phys. Rev. C 96, no. 6, 065209 (2017)doi:10.1103/PhysRevC.96.065209 [arXiv:1708.02608 [nucl-ex]].

B. Talks, Colloquia and Seminars

1. M. Amaryan, “Secondary K0L Beam Facility at JLab for Straange Hadron Spec-troscopy”, Invited talk at the workshop on Pion-Kaon Interactions, Feb. 14-15,Newport News, VA

2. M. Amaryan, “Strange Hadron Spectroscopy with Secondary KL Beam at GlueX,invited talk at the workshop on Correlations in Partonic and Hadronic Interactions,Sep. 24-28, 2018, Yerevan, Armenia.

3. D. Bulumulla, “Exclusive two-pion production in σ channel”, Contributed Talk,Center for Frontiers in Nuclear Science, Workshop on Next Generation GPD Studieswith Exclusive Meson Production at EIC, 6–8 June 2018, Stony Brook NY

4. F. Hauenstein “Scattering on Tritium: From EMC to SRC”, Invited talk at theJefferson Lab User Group Meeting, Newport News, VA, USA, 20.06.18.

5. F. Hauenstein “Electrons for Neutrinos: How electron scattering data can improveneutrino oscillation experiments”, Invited talk at the APS South East Section meet-ing 2018, Knoxville, TN, USA, 09.11.18

6. F. Hauenstein “From Quarks to Nucleons in A=3 Mirror Nuclei”, Invited talk atthe Mid-Atlantic APS Section meeting, College Park, MD, USA, 10.11.18

7. F. Hauenstein “Polarization Observables and pΛ Scattering Length Measured in the~pp→ pK+Λ Reaction”, contributed talk at HYP2018: International Conference onHypernuclear and Strange Particle Physics, Portsmouth, VA, USA, 28.07.18

8. F. Hauenstein “BAND Status and Schedule”, Data Mining Workshop, MIT, Boston,MA, USA, 01.08.18

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9. C.Hyde “Ion Polarimetry R& D Required for the Electron Ion Colldier”, contributedtalk at the EIC Users Group Polarimetry Working Group Meeting, 30 November2018, https://indico.bnl.gov/event/5376/

10. C. Hyde “Exploring the QCD Structure of the NN Interaction via Tagged DIS andDVES on Light Nuclei”, Invited talk at the Institute for Nuclear Theory program onProbing Nucleons and Nuclei in High Energy Collisions, October 1 — 16 November2018, Seattle WA

11. C. Hyde “Three Dimensional Imaging of the Proton and Atomic Nuclei”, InvitedSeminar, Kansas University Department of Physics, 24 September 2018, LawrenceKansas

12. C. Hyde “Outlook and Next Steps”, Invited talk at the Electron Ion ColliderUsers Group annual meeting, 30 July — 2 August 2018, The Catholic University ofAmerica, Washington D.C.

13. C. Hyde “From JLab12 GeV to the Electron Ion Collider: Generalized PartonDistributions” Jefferson Laboratory Users Organization annual meeting, 18–20 June2018, Newport News, VA.

14. C. Hyde “Deeply Virtual Exclusive Scattering and Spectator Tagging at an Elec-tron Ion Collider”, Workshop on the Nature of Hadron Mass and Quark-GluonConfinement”, 1–4 July 2018, Asia Pacific Center for Theoretical Physics, PohangKorea.

15. C. Hyde Four invited lectures: Three Dimensional Imaging of Protons, Neutrons,and Nuclei; Electron Ion Collider Interaction Region Design and Detector Concepts;Physics of Nuclei with an Electron ion Collider Imaging Protons, Neutrons, andNuclei with an Electron ion Collider at the Nuclear Physics School, 25–29 June2018, Asia Pacific Center for Theoretical Physics, Pohang Korea.

16. C. Hyde Generalized Parton Distributions with Jefferson Lab 12 GeV, contributedtalk to the XXVIth International Workshop on Deep Inelastic Scattering and Re-lated Subjects, 16–20 April 2018, Kobe Japan.

17. C. Hyde Next Generation Neutron Structure Measurements with Spectator Taggingat EIC, contributed talk to the XXVIth International Workshop on Deep InelasticScattering and Related Subjects, 16–20 April 2018, Kobe Japan.

18. S. Bueltmann “Future of 3D Imaging at Jefferson Lab”, invited talk at the XXVIthInternational Workshop on Deep Inelastic Scattering and Related Subjects, 16–20April 2018, Kobe, Japan.

19. C. Hyde Spectator Tagging with the Electron Ion Collider, invited talk at theinternational workshop on Polarized Light Ion Physics with EIC, 5–9 Feb 2018,Ghent, Belgium

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https://indico.bnl.gov/event/5376/

20. M. Khachatryan, “Study of neutrino energy reconstruction using electron scatter-ing” contributed talk at the APS DNP meeting, October 22-27, 2018, Waikoloa,Hawaii.

21. M. Khachatryan, “Validation of neutrino energy estimation using electron scatter-ing”. Invited talk at the Gordon Research Conference on Photonuclear Reactions:August 5–10, 2018, Holderness, NH.

22. M. Khachatryan, “Validation of neutrino energy estimation using electron scatter-ing data”, poster presented at the Jefferson Lab Users Group Summer meeting,June 19, 2018, Jefferson Lab, Newport News, VA. Awarded 1st Prize in the postercompetition.

23. H. Rashad, “Update on HRS Efficiencies”, Hall A DVCS Collaboration Meeting, 26January 2018, Jefferson Lab, Newport News VA

24. L. Weinstein, “Overview of Future New Observables”, invited talk presented at theParton Distributions as a Bridge from Low to High Energies Workshop, JeffersonLab, Newport News, VA, 9 Nov, 2018.

25. L. Weinstein, “Tag, you’re it! Spectator tagging and bound nucleon structure”,invited talk presented at the workshop on Short-range nuclear correlations at anElectron-Ion Collider, Center for Frontiers in Nuclear Science, Brookhaven NationalLab, 6 Sept 2018.

26. L. Weinstein, “Electrons for Neutrinos”, invited talk presented at the NuFact 2018,the 20th workshop on Neutrinos From Accelerators, Blacksburg, VA, 16 August,2018.

27. L. Weinstein, “The Nucleons Go Two By Two: Correlations in Nuclei”, NuclearPhysics Seminar, Michigan State University, East Lansing, MI, 22 March, 2018.

28. L. Weinstein, “Guesstimation: Solving the world’s problems on the back of a cock-tail napkin”, Physics Colloquium, Michigan State University, East Lansing, MI, 22March, 2018.

29. L. Weinstein, “Guesstimation: Solving the world’s problems on the back of a cocktailnapkin”, Physics Colloquium, University of Illinois-Chicago, Chicago, IL, 21 March,2018.

30. L. Weinstein, “Electrons for Neutinos”, invited talk presented at the Neutrino CrossSection Strategy Workshop, Fermi National Accelerator Lab, Batavia, IL, 14 March,2018.

31. N. Baltzell, “Software and Computing Perspectives for Hall B: from Raw Data toPhysics Results”, Seminar at Jefferson Lab: October 3, 2018, Newport News VA.

32. M. Hattawy, “3D Partonic Struture of Nucleons and Nuclei”, invited talk at LightCone 2018, Jefferson Lab, May 14-18,2018.

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33. M. Hattawy, “Update on Run Group F: BONUS12”, CLAS collaboration meeting,Jefferson Lab, July 10-13, 2018.

34. M. Hattawy, “The ALERT target system”, ALERT collaboration meeting, JLab,Nov 12, 2018.

35. M. Hattawy, “Deeply virtual Compton scattering measurement off bound protonsin He-4”, CLAS collaboration meeting, Nov 13-16, 2018.

36. S.E. Kuhn, “Overview of new measurements of electromagnetic form factors, po-larizabilities and spin structure function functions”, keynote address at the inter-national ECT* workshop on Nucleon Spin Structure at low Q: A Hyperfine View,July 2-6 2018, Trento (Italy).

37. S.E. Kuhn, “Tagged Structure Functions’, invited talk at the workshop on Corre-lations in Partonic and Hadronic Interactions, Sep 24-28, 2018, Yerevan, Armenia.

38. V. Lagerquist, “Duality in the spin-dependent structure function g1p”. Invited talkat the James Madison University Quark Hadron Duality Workshop: September23-25, 2018, Harrisonburg, VA.

39. J. Poudel, “The BONuS12 Experiment Measuring the Neutron Structure Functionat large Bjorken-x”, contributed talk at the APS DNP meeting, October 22–27,2018, Waikoloa, Hawaii.

40. J. Poudel, “DREAM Based DAQ for the BONuS12 Experiment at Jefferson Lab” ,contributed talk at the 21st IEEE Real Time Conference, June 9–15, 2018, Williams-burg, VA.

41. J. Poudel, “Readiness and Plans: RG-F (The BONuS12 Experiment)” , contributedtalk at the CLAS collaboration meeting, November 13–16, 2018, Jefferson Lab,Newport News, VA.

C. Conference Proceedings

1. S.E. Kuhn, “The BONuS measurements of the free neutron structure function”,Proceedings of the International Workshop on (e, e′p) Processes (EEP17), Bled,Slovenia, July 2-6, 2017. Published by O. Hen, D. Higinbotham, S. Sirca, E. Voutier(editors), Blejske Delavnice Iz Fizike Vol 18 No 3, Society of Mathematicians andPhysicists of Slovenia, Ljubljana (January 2018).

2. M. Amaryan, U. G. Meissner, C. Meyer, J. Ritman and I. Strakovsky, “Workshop onPion-Kaon Interactions (PKI2018): Mini-Proceedings,” arXiv:1804.06528 [hep-ph].

3. I. V. Anikin et al., “Nucleon and nuclear structure through dilepton pro-duction,” Acta Phys. Polon. B 49, 741 (2018) doi:10.5506/APhysPolB.49.741[arXiv:1712.04198 [nucl-ex]].

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doi:10.5506/APhysPolB.49.741

4. “High-performance DIRC detector for the future Electron Ion Colliderexperiment,” G. Kalicy et al. [PID Consortium], JINST 13, no. 04, C04018(2018). doi:10.1088/1748-0221/13/04/C04018

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doi:10.1088/1748-0221/13/04/C04018

D. Theses

1. Bachelor’s Theses

• Phillip Stuckey, B.S. thesis, May 2018 “Simulation of a Cosmic-Ray Muon Set-Upfor Testing a Cherenkov Imaging Detector”, C. Hyde, Advisor

• Jason Morgan, B.S. thesis, May 2018 “Measurement and Characterization of a 5TSolenoid Field”, S. Kuhn, Advisor

• Matthew Splitstone, B.S. thesis, May 2018 “Optical and high voltage testing ofGEM foils for use in BONuS12 RTPC”, S. Kuhn, Advisor

• Eric Deir, B.S. thesis, December 2018 “Testing the CAEN QDC Data AcquisitionSystem in Conjunction with a FTPC Prototype”, S. Bueltmann, Advisor.

E. Proposals with ODU co-Spokespersons

1. E12-17-006, “Electrons for Neutrinos: Addressing Critical Neutrino- Nucleus Is-sues”, spokesperson: L.B. Weinstein, O. Hen, E. Piasetzky, K. Mahn, and S. Stepa-nyan, Jefferson Lab PAC46, approved (together with E12-17-006a) for 45 days ofbeam time with a scientific rating of A.

2. E12-17-006a, “Exclusive Studies of Short Range Correlations in Nuclei usingCLAS12”, spokespersons, L.B. Weinstein, O. Hen, A. Schmidt, E. Piasetzky, S.Stepanyan, and H. Szumila-Vance, Jefferson Lab PAC46, approved (together withE12-17-006) for 45 days of beam time with a scientific rating of A.

F. Conferences and Workshops Organized

1. M. Amaryan “Workshop on Pion-Kaon Interactions (PKI2018)”, February 14-15,2018, Thomas Jefferson National Accelerator Facility, Newport News, VA, USA.

2. M. Amaryan “Workshop on Correlations in Partonic and Hadronic Interactions”,September 24-28, Yerevan, Armenia.

3. C. Hyde, Convener, Weeks 5& 6, Institute for Nuclear Theory Program 18-03 “Prob-ing Nucleons and Nuclei at High Energy”, 1 October — 16 November 2018, SeattleWA.

4. C. Hyde, International Organizing Committee member of the “Electron Ion ColliderUsers Group Annual Meeting”, 30 July — 2 August 2018, Catholic University,Washington D.C.

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IV. PERSONNEL

A. Faculty

• Moskov Amaryan is leading a topical collaboration analyzing the high statisticsCLAS data on photoproduction of light mesons. This is a CLAS Approved Analysis(CAA) which has attracted new foreign collaborators to JLab. The η → π+π−γdecay channel is the doctoral thesis subject of Torri Jeske. The ρ → π+π−γ decaychannel is th e doctoral thesis subject of Tyler Viducic. Another student supervisedby Dr. Amaryan, Nilanga Wickramaarachhci is working on GlueX experiment andhis doctoral thesis topoic is a measurement of a beam asymmetry in photoproductionof K+Σ0 final state. Dr. Amaryan is also working on a proposal to Jefferson LabPAC 47 for a tertiary neutral kaon beam (produced by bremsstrahlung photons) inJLab Hall D.

• Stephen Bültmann is primarily working on the preparations for the Bonus12 ex-periment, scheduled to take data in early 2020. Graduate students Jiwan Poudeland Madhusudhan Pokhrel are working with Dr. Bültmann on the Bonus12 ex-periment, focusing on the development of the deuterium gas target and the RTPCdata acquisition system. Jiwan Poudel is also actively involved in the data analysisof the ongoing run group A experiment taking data with CLAS12. He is focusingon time-like Compton scattering. For the eg12 experiment, a new solid polarizedtarget for CLAS12, which was the subject of a previous NSF-MRI grant, needs to bedeveloped. Graduate student Isurumali Neththikumara helped during the summer2018 with the target development for Bonus12.

• Gail Dodge is working on the BoNuS12 experiment, particularly on the optimizationof the recoil detector and is supervising graduate student Nathan Dzbenski. She isalso dean of the College of Sciences since May 2017.

• Charles Hyde is focused on Deep Virtual Exclusive Reactions, and and simulationsand R&D for a future electron-ion collider. His student Hashir Rashad is workingon Hall A 12 GeV DVCS analysis. Graduate student Dilini Bulumulla is analyzingCLAS12 Run Group A data from Spring and Fall 2018. Her thesis research is focusedon deep virtual σ- and ρ-meson production. Mitchel Kerver passed his writtenqualifier exam in August 2018, and has received a one year EIC Center fellowshipfrom Jefferson Lab. He is working on simulations of the e + d → e + p + n + Vreaction, with a particular emphasis on high mass np final states in exclusive vectormeson production. This study will be for both the EIC, and the CLAS12 RunGroup B run in Spring 2019. Dr. Hyde collaborates on eRD14 EIC Detector R&D consortium for particle ID, and the eRD21 studies of machine background in the

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EIC interaction regions. Dr. Hyde is Vice-Chair of the EIC Users Group SteeringCommittee. He is also the chair of the physics department since May 2017.

• Sebastian Kuhn continues to lead the CLAS12 run group C which will use longi-tudinally polarized targets to measure inclusive and semi-inclusive spin structurefunctions of the proton and the neutron. He is supervising Victoria Lagerquist andPushpa Pandey on the design, prototyping and testing for the polarized target.Dr. Kuhn is also leading the “BoNuS” collaboration and is preparing the BoNuS12experiment. He is supervising David Payette on the BONuS12 project.

• Lawrence Weinstein studies short range correlations in nuclei, with attention tothe relationships between correlations and the EMC effect, atomic systems, andneutron stars. He is supervising Marianna Khachatryan in analysis of CLAS6 datafor neutrino energy reconstruction and is working with Florian Hauenstein on thetritium and BAND experiments. He is co-spokesperson of the Jefferson Lab NuclearData Mining Collaboration and co-leader of the newly approved Run Group M inCLAS.

• Stepan Stepanyan is a Jefferson Lab senior staff scientist in Hall B and JLab profes-sor at ODU. He is supervising graduate student Joseph Newton on his J/Ψ analysisof the run group A data currently being taken with CLAS12.

B. Postdoctoral Research Associates

• Dr. Gabriel Charles joined our group in June 2016 and left in January 2018. Heaccepted a permanent research position at Saclay, France. He was working on thedetector design for the Bonus12 experiment, as well as simulation and data analysiscode. He was supported 100% by this grant.

• Dr. Florian Hauenstein joined our group in October 2016. During the term of thisreport, he was 66% funded by this grant and 17% from JLab Hall A for researchwith Dr. Weinstein on the tritium experiment which took data in Spring 2018, and16% from the JLab LDRD project Nuclear Gluons with JLEIC. He has also beenworking on the BAND detector for Run Group B in Hall B.

• Dr. Marouen Baalouch joined our group in January 2017 and left at the end ofMay 2018. He accepted a research position in France. He was responsible for ourcomputational cluster, for which he was supported 50% by ODU as a matchingcontribution to this grant. He was working with Dr. Amaryan on the CLAS mesondecay initiative, with 25% FTE support from the current grant and 25% fundingfrom JLab Hall D.

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• Dr. Mohammad Hattawy joined our group in May 2018. He is working on thedetector design for the Bonus12 experiment, as well as simulation and data analysiscode. He is supported 50% by this grant.

• Dr. Nathan Baltzell was member of the group from August 2018 to Dec 2, 2018. Heaccepted a staff position at Jefferson Lab’s Hall B. He was mainly involved in therun group A experiment in Hall B currently taking data. He was 100% supportedby Jefferson Lab.

C. Graduate Students

We supported seven full time graduate students during the past year from the grant,and provided partial support to five additional students. One student was supportedby Jefferson Lab and two students were supported in part by the department at researchassistants. If funding permits, we will provide full su