Electron-Ion Colliders

Sam Aronson IUPAP WG 9 Meeting

Cambridge, MA July 24, 2011

  Focus on initiatives in the US Nuclear Physics community   Topics

•  EIC Science •  BNL and JLab plans •  Process for developing EIC plans into a DOE-based initiative

EIC High √s (~100GeV), high L (~1034/cm2sec) machine, staged approach; driven by US “QCD” community

Beyond form factors and quark distributions – Generalized Parton and Transverse Momentum Distributions

Proton form factors, transverse charge & current densities

Structure functions, quark longitudinal momentum & helicity distributions

X. Ji, D. Mueller, A. Radyushkin (1994-1997)

Correlated quark momentum and helicity distributions in transverse space - GPDs

Extend longitudinal quark momentum & helicity distributions to transverse momentum distributions - TMDs 2000’s

CompellingColdQCDMa0erDiscoveriesatRHIC

  Stronghintsofgluondensitysatura2onfromsuppres‐sionofforward‐forwarddi‐hadronsincentrald+Au

  Indica2onsofsmallposi2vecontribu2ontoprotonspinfrom0.05<xg<0.2gluons,viahelicitycorrela2ons

B h+v pickups Y h+v kickers

B h+v kickers Y h+v pickups

5-9 GHz, cooling times ~1 h

Horiz. Kicker (open)

RHICLuminosityUpgradesUnderWay RHIC breakthrough in bunched-

beam stochastic cooling overcomes intrabeam scattering limits, facilitates ~x10 improvement in heavy-ion collision rates, 4 years earlier and at ~1/7 the cost envis-ioned in 2007 NP Long Range Plan.

 Much of the new system commissioned during 2010, rest anticipated for 2012-2014 runs (aided by ARRA funds).

 Electron lenses (with ARRA + AIP support) to be installed for 2013 run will use few keV e+p collisions to compensate partially for p+p beam-beam betatron tune shift/spread

 Hope to improve polarized p+p luminosities by factor ~2

What Will EIC Have That HERA Didn’t?

1)   Heavy-ion beams to take advantage of coherent contributions of many nucleons to gluon density, provide more cost-effective reach into gluon saturation regime when QCD coupling is still weak

3)   Polarized proton and 3He (for neutron), as well as electron, beams to pursue search for gluon contributions to nucleon spin down to very soft gluons, and map spin-momentum correlations of quarks and gluons inside nucleons

INT Workshop – examples of output

  Articulating the compelling EIC measurements; matrices are shorthand summaries of INT work •  Spin with polarized e, p •  Gluon saturation with e, A

Vis-à-vis earlier MeRHIC design, this allows for:

  more IP’s

  reduced cost

  reusing infrastructure + det. components for STAR, PHENIX

  easier upgrade path from 5 GeV eRHIC-I

  minimal environmental impact concerns

  IR design to reach 1034 luminosity

RHIC: >275 GeV p or >110 GeV/u Au with

DX magnets removed

BNL’sEICConcept:eRHIC⇒High‐Resolu@on,Ultra‐FastImagingofGluon‐DominatedMaGer

JLab Concept: MEIC Layout

Prebooster Ion source

Three Figure-8 rings stacked

vertically

Ion transfer beam line

Medium energy IP with horizontal crab crossing

Electron ring

Injector

12 GeV CEBAF

SRF linac

Warm large booster (up to 20 GeV/c)

Cold 97 GeV/c proton collider

ring

medium energy IP

low energy IP

Three compact rings: •  3 to 11 GeV electron •  Up to 20 GeV/c proton (warm) •  Up to 100 GeV/c proton (cold)

https://eic.jlab.org/wiki/index.php/Machine_designs

ColliderPerformanceParametersforRHICvs.JLabDesignsHaveConvergedinPastYear

e+pfacilities

e+Afacilities

Activity/Project (Blue=Accel. + Det. R&D; Red=EIC Science Case) Total Cost FY10 FY11 FY12 est. FY13 est.

EIC Polarized Electron “Gatling” Gun $810K $128K $382K $300K

Laser System for Polarized Electron Source Photocathode

$430K $225K $205K

FEL-Based Coherent Electron Cooling $414K $95K $319K

Study of FEL Options for eRHIC $384K $205K $179K

Upgrade of IP2 Cryosystem for Coherent Electron Cooling Test

$2152K (Prog. Dev.)

$648K $817K $687K

CMOS Pixel Vertex Detector for EIC $607K $199K $202K $206K

Getting to Know Your Constituents: Studies of Partonic Matter at EIC

$413K $167K

Realization of e+A Physics Event Generator for the EIC

$384K $158K $137K $89K

Signatures of Saturation and Universality in e+A Collisions at eRHIC

$423K $79K $191K $153K

Electroweak Physics with an Electron-Ion Collider

$369K $203K $166K

Exploring the Role of Glue in Hadron Structure by an EIC

$597K $191K $202K $204K

Total approved to date = $6983K $1055K $2643K $1942K $1097K

New Proposal: Quantum Electrodynamics for QCD Precision Studies at the EIC

$282K $146K $136K

StrongBNLLDRD+PDSupportforeRHICPrograms

April 10, 2011: 3rd EIC International Advisory Committee meeting

May 9-10, 2011: Detector Advisory Committee review of first round of submitted EIC detector R&D proposals

Aug. 1-3, 2011: eRHIC technical design review

Fall 2011: EIC science White Paper (Steering Committee appointed and charged, with BNL-JLab-EICC agreement)

eRHIC cost review

Fall 2012 (??): Town Meetings for next Nuclear Physics LRP?

UpcomingandRecentPlanningExercisesandMilestones

•  2010INTWorkshop“yellowbook”–anGcipated~500pages,availableSpring2011–shouldserveasstarGngpoint,but…

•  WhitePapershouldbe~100pages,aimedatnon‐experts,usefulfor“champions”withinDOE,suitableforrestofNPcommunity

•  Needs~5‐pagegeneralintro(“elevatorspeech”amplified)tolayoutgoals,importanceanduniqueness,answerbasicquesGonsraisedatlastLongRangePlaninclear,concise,compellingfashion

•  ~10‐pagesciencesecGonstofleshout“goldenexperimentmatrices”forseveralareas,withsimulated“moneyplots,”lightontechnicaldetail

•  ~10‐15pagesonbasicmachineparameters,designopGons,challenges+~10pagesondetectordesignfeaturesandchallenges

•  SteeringCommi0eecomprisingexperimentalist/theoristpairs,broadlyrepresentaGveofinterestedinsGtuGons

AimforEICScienceWhitePaperbyEndofCY2011

EIC Realization Imagined Activity Name 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025

12 Gev Upgrade

FRIB

EIC Physics Case NSAC LRP

CD0

Machine Design/R&D

CD1/D’nselect

CD2/CD3

Construction

Poten@alElectron‐IonColliderTimelineShownbyHughMontgomeryatINTWorkshop,Sept.2010

N.B. It is unlikely ONP could support operations at 3 major facilities (RHIC, CEBAF, FRIB) and simultaneous construction of a 4th (EIC) after ~2018.

Discussion/Ques@ons