The SuperB Detector
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DESCRIPTIONThe SuperB Detector. Fabrizio Bianchi University of Torino and INFN-Torino III Mexican Workshop on Flavour Physics Mexico City , 7-9 December 2011. Outline. The Physics Case. The Machine. The Detector. Milestones. The Physics Case. - PowerPoint PPT Presentation
The SuperB DetectorFabrizio BianchiUniversity of Torino and INFN-Torino
III Mexican Workshop on Flavour PhysicsMexico City , 7-9 December 2011
1OutlineThe Physics Case.
F. Bianchi2The Physics CaseCurrent flavor physics landscape is defined by BaBar, Belle, CDF, D0, Cleo-c, BES results.Triumph of the CKM paradigm.Indirect constraints on New Physics.Handed over to LHCb in the summer.
First collision in SuperB will be in 2016 and the first full run is expected in 2017.LHCb will have re-defined some areas of Flavor Physics.LHC may (or may not) have found New Physics.In both scenarios SuperB results can be used to constraint Flavor Dynamics at high energy
F. Bianchi3The Energy Scale of NP: LNP (1)SuperB does not operate at High Energy.Whats the point of having it ?
Two paths in the quest for NP:The relativistic path:Increase the energy and look for direct production of new particles.The quantum path:Increase the luminosity and look for effects of physics beyond the standard model in loop diagrams.
Model dependent indirect searches for NP at SuperB reach higher scales then can be attained at LHC.B mixing and top: everyone knew the top was light until ARGUS found B mixing to be large.
F. Bianchi4The Energy Scale of NP: LNP (2)F. Bianchi5
Example: MSSM. Simple, constrained by LHC data, but general enough to illustrate the issue: In many NP scenarios the energy frontier experiments will probe diagonal elements of mixing matrices.
Flavor experiments are required to probe off-diagonal ones.
The Timeline of Flavor PhysicsF. Bianchi6
Expected data sample for SuperBfF. Bianchi7(4S) region:75ab1 at the (4S)Also run above / below the (4S)~75 x109 B, D and t pairs(5 years run)
(3770) region:1 ab1 at thresholdAlso run at nearby resonances~4 x 109 D pairs(< 1 year run)
RSuper B Physics Program in a NutshellTest of CKM Paradigm at 1% level.
B rare decays
Lepton Flavor Violation.
Many more topics: Electro-Weak measurements, new hadrons,
See A. Perez presentation at this conference.
F. Bianchi8The CKM ParadigmF. Bianchi9
b = f1; a = f2; g = f3
Summer 2011: Triumph of CKMF. Bianchi10
Good agreement: no evident discrepancy or tension, even with different statistical analysis.
Test of CKM ParadigmF. Bianchi11Unitarity Triangle Angles() = 12() = 0.1() = 12
Cabibbo-Kobayashi-Maskawa Matrix Elements|Vub| : Incl. = 2%; Excl. = 3%|Vcb|: = 1%|Vus|: Can be measured precisely using decays|Vcd| and |Vcs|: can be measured at/near charm threshold.
SuperB Measures the sides and angles of the Unitarity TriangleThe "dream" scenario with 75ab-1F. Bianchi12
CKM measurements: SuperB vs. LHCbLHC: no Susy so farF. Bianchi13
Susy mass scale is likely to be above 1 TeV.B Rare DecaysF. Bianchi14
Lepton Flavor ViolationF. Bianchi15
15Charm at SuperBAt the U(4S) with 75 ab-1:Large improvement in D0 mixing and CPV: factor 12 improvement in statistical error wrt BaBar (0.5 ab-1).Time-dependent measurements will benefit also of an improved (2x) D0 proper-time resolution.
At the Y(3770) with 500 fb-1: coherent production with 100x BESIII data and CM boost up to =0.56.Almost zero background environment.Possibility of time-dependent measurements exploiting quantum coherence.Study CPV with Flavor and CP tagging.
Charm Mixing and CPVF. Bianchi17
Decays of Y (3770) D0D0 produce coherent (C=-1) pairs of D0s. Quantum correlations in their subsequent decays allow measurements of strong phases.Required for improved measurement of CKM angle g.Also required for D0 mixing studies
Bs PhysicsCan cleanly measure AsSL using U(5S) data
SuperB can also study rare decays with many neutral particles, such as , which can be enhanced by SUSY.
Golden Measurements: SuperB vs. LHCbF. Bianchi19
The MachineF. Bianchi20Machine: Parameter Requirements from PhysicsF. Bianchi21ParameterRequirementCommentLuminosity (top-up mode)1036 cm-2s-1 @ U(4S)Baseline/Flexibility with headroom at 4. 1036 cm-2s-1 Integrated luminosity75 ab-1Based on a New Snowmass Year of 1.5 x 107 seconds(PEP-II & KEKB experience-based)CM energy range threshold to U (5S)For Charm special runs (still asymmetric)Minimum boostbg 0.237~(4.18x6.7GeV)1 cm beam pipe radius. First measured point at 1.5 cme- Polarization
Boost up to 0.56 in runs at low energy under evaluation for charm physics 80%Enables t CP and T violation studies, measurement of t g-2 and improves sensitivity to lepton flavor-violating decays. Detailed simulation, needed to ascertain a more precise requirement, are in progress.e+e- CollidersF. Bianchi22
How to get 100 times more luminosity ?F. Bianchi23
xy Vertical beam-beam parameter Ib Bunch current (A)n Number of bunches by* IP vertical beta (cm)E Beam energy (GeV) Present day B-factories
PEP-II KEKBE(GeV) 9x3.1 8x3.5Ib 1x1.6 0.75x1n 1700 1600I (A) 1.7x2.7 1.2x1.6y* (cm) 1.1 0.6 y 0.08 0.11L (x1034) 1 2 Answer:Increase IbDecrease y*Increase yIncrease nA New IdeaPantaleo Raimondi came up with a new scheme to attain high luminosity in a storage ring:
Change the collision so that only a small fraction of one bunch collides with the other bunchLarge crossing angleLong bunch length
Due to the large crossing angle the effective bunch length (the colliding part) is now very short so we can lower y* by a factor of 50
The beams must have very low emittance like present day light sourcesThe x size at the IP now sets the effective bunch length
In addition, by crabbing the magnetic waist of the colliding beams we greatly reduce the tune plane resonances enabling greater tune shifts and better tune plane flexibilityThis increases the luminosity performance by another factor of 2-3F. Bianchi24
The Accelerator StrategySuperB is a 2 rings, asymmetric energies (e- @ 4.18, e+ @ 6.7 GeV) collider with:large Piwinski angle and crab waist (LPA & CW) collision schemeultra low emittance lattices ideas taken from ILC designlongitudinally polarized electron beamtarget luminosity of 1036 cm-2 s-1 at the U(4S)possibility to run at t/charm threshold still with polarized electron beam with L = 1035 cm-2 s-1
Design criteria :Minimize building costsMinimize running costs (wall-plug power and water consumption)Reuse of some PEP-II B-Factory hardware (magnets, RF)
SuperB can also be a good light source: work is in progress to design Synchrotron Radiation beamlines (collaboration with Italian Institute of Technology)
F. Bianchi25Baseline Collider parameters
Baseline peak luminosity at Y(4S) is 10 36 cm-2 s -1 .It ca be increased by adding RF power up to a factor of 4 .The runs near charm threshold Y(3770) pay a factor O(10) in luminosity. At charm threshold the boost( bg ) can be increased up to 0.5 for time dependent measurements, still with a reasonable polarization.
3.5 min beam lifetime . CONTINUOUS INJECTION as in PEPIIInjected 90% polarized electrons26Synchrotron light options @ SuperBComparison of brightness and flux for different energies dedicated SL sources & SuperB HER and LER from bending magnets .
Synchrotron light options @ SuperBComparison of brightness and flux for different energies dedicated SL sources & SuperB HER and LER with undulators.Light properties from undulators better than most SL
With UndulatorsSuperB vs SuperKEKBF. Bianchi29
SuperB Luminosity Model75 ab-1The Detector11/18/201131Detector Evolution: from toBabar and Belle designs have proven to be very effective for B-Factory physics.Follow the same ideas for SuperB detector.Try to reuse same components as much as possible.
Main issues:Machine backgrounds somewhat larger than in Babar/Belle.Beam energy asymmetry a bit smaller.Strong interaction with machine design.
A SuperB detector is possible with todays technology.Baseline is reusing large (expensive) parts of Babar.Quartz bars of the DIRC.Barrel EMC CsI(Tl) crystal and mechanical structure.Superconducting coil and flux return yoke.
Some areas require moderate R&D and engineering developments to improve performance:Small beam pipe technology.Thin silicon pixel detector for first layer.Drift chamber CF mechanical structure, gas and cell size.Photon detection for DIRC quartz bars .Forward PID system (TOF or focusing RICH).Forward calorimeter crystals.Minos-style scintillator for Instrumented flux return.Electronics and trigger.Computing: has to handle a massive amount of data.F. Bianchi32
Detector Layout F. Bianchi33
Silicon Vertex Tracker The Babar SVT technology is adequate for R > 3cm:use design similar to Babar SVT
Layer-0 is subject to large background and needs to be extremely thin: More than 5MHz/cm2, 1MRad/yr, < 0.5%X0
Striplets baseline option: mature technology, not so robust against background.Marginal with background rate higher than ~ 5 MHz/cm2Moderate R&D needed on module interconnection/mechanics/FE chip (FSSR2)
Upgrade to pixel (Hybrid or CMOS MAPS), more robust against background, foreseen for a second generation of Layer-0
The Drift ChamberProvides precision momentum measurements. Provides particle ID via dE/dx for all low momentum tracks, even those that miss the PID system.
Build on BABAR