Heavy Flavor Physics in STAR

The STAR Upgrade ProgramFlemming VidebkBrookhaven National LaboratoryFor the STAR collaboration

Winter Workshop on Nuclear Dynamics,Feb 2013

1OverviewIntroductionNear Term UpgradesMuon Telescope Detector (MTD)Realization & Planned Physics from MTDHeavy Flavor Tracker (HFT)Realization & Planned Physics from HFTFuture Plans (STAR decadal Plan)iTPC Forward upgrades for pA and eRHICStatus and Summary

2/8/20132----- Meeting Notes (11/10/12 17:33) -----overview of talks2Hot QCD matter: high luminosity RHIC II (fb-1 equivalent)Heavy Flavor Tracker: precision charm and beautyMuon Telescope Detector: e+ and + at mid-rapidityTrigger and DAQ upgrades to make full use of luminosityTools: jets combined with precision particle identificationPhase structure of QCD matter: Beam Energy Scan Phase IIFixed Target to access lowest energy at high luminosityLow energy electron cooling to boost luminosity for sNN 55 micron for 750 MeV/c K)DCA resolution performancer- and z 182/8/20130.4% X0192/8/2013Physics Run-14,15 projections

RCP=a*N10%/N(60-80)%Assuming D0 v2 distribution from quark coalescence. 500M Au+Au m.b. events at 200 GeV.

- Charm v2 Medium thermalization degreeDrag coefficients!Assuming D0 Rcp distribution as charged hadron.500M Au+Au m.b. events at 200 GeV.

Charm RAA Energy loss mechanism!Color charge effect!Interaction with QCD matter! 202/8/2013B tagged J/

PromptJ/ from BCurrent measurement via J/-hadron correlation have large uncertainties.

Combine HFT+MTD in di-muon channel Separate secondary J/ from promptJ/ Constrain the bottom production at RHIC

STAR arXiv: 1208.2736.HFT project statusHFT upgrade was approved CD-2/3 October 2011 and is well into fabrication phaseAll detector components have passed the prototype phase successfullyA PXL prototype with 3+ sectors instrumented is planned for an engineering run and data taking in STAR in mid to end MarchThe full assembly including PXL, IST and SSD should be available for RHIC Run-14, which is planned to be a long Au-Au run2/8/201321Future PlansBeam Energy Scan II ( Huis talk Monday)Exploit pA physicsPrepare STAR for eRHIC on 2020-2025 timescale (eSTAR)2/8/201322

Better tracking and dE/dx PID capabilityh 1.0-1.7 region -- broad physics impact ontransverse spin physics program hyperon and exotic particle searcheshigh pT identified particlesBES Phase II+Long range rapidity gap correlations.2/8/201323Inner TPC UpgradeCurrent pad plane layout. 13 rows and gaps.Fill all inner sector with active pads.Configuration still under discussionSome planned p+A measurementsNuclear modifications of the gluon PDFCorrelated charm productionGluon saturationForward-forward correlations (extension of existing 0-0)h-h0-0-h-0Drell-YanAble to reconstruct x1, x2, Q2 event-by-eventCan be compared directly to nuclear DISTrue 2 1 provides model-independent access to x2 < 0.001polarized protons off nuclei can be studied at RHIC.

Forward-forward correlations and Drell-Yan are also very powerful tools to unravel the dynamics of forward transverse spin asymmetries Collins vs Sivers effects, TMDs or Twist-3, 2/8/201324Easier to measureEasier to interpret242/8/201325Forward instrumentation optimized for p+A and transverse spin physicsCharged-particle trackinge/h and /0 discriminationPossibly baryon/meson separation

FHC (E864)~ 6 GEM disksTracking: 2.5 < < 4RICH/Threshold Baryon/meson separationprotonnucleus2017+W-Powder EMCalFHC (E864)Pb-Sc HCalForward Calorimeter System (FCS)Forward Instrumentation Upgrade2/8/201326Calorimeter:EM: Pb-glass (FMS) augmented by Tungsten SPACALSmaller Moliere radius for better 2- separationKeep high E resolutionHadron calorimetry for e/h discrim., jet reconstruction Very Forward GEM Tracker (VFGT)Likely GEM-basedDetails of the design depend on experience with FGTParticle IdentificationRICH problematic with accessible pT resolutionThreshold Cerenkov detector under consideration Detector will not be included in initial upgradeSchedule: proposal this year, construction start 2015+Ready for data 2017 at the earliestPlans for Forward UpgradeSummarySTAR has an ongoing upgrade program that will enable significant physics measurements in 2013-1017Further high precision Heavy Flavor measurements will be carried out to explore the sQGPHFT upgrades will provide direct topological reconstruction for charmMTD will provide precision Heavy Flavor measurements in muon channelsFuture upgrades for 2017+ Enhanced TPC capabilities for BES II (and eSTAR)Forward Upgrades to exploit a p+A programFull calorimetry (EM+Hadronic) Modern tracking technology to make most of existing magnetic field Strong set of measurements to be made. Both complementary to, and supporting, those at a future eRHIC2/8/201327Work on this272/8/201328Backup2/8/201329

TPC

TOF

EMC

HFTNeutral particles e, K p d

TPC TOF TPCLog10(p)Multiple-fold correlations among the identified particles!Nearly perfect coverage at mid-rapidityHyperons & Hyper-nucleiJetsHeavy-flavor hadrons

MTD

High pT muonsJets & CorrelationsCharged hadronsParticle Identification in STAR30What are the properties of cold nuclear matter?Is there evidence for saturation of the gluon density?

PHENIX, Phys. Rev. Lett. 107, 172301 (2011)

RHIC may provide unique access to the onset of saturationComplementarity: LHC likely probes deeply saturated regime Future questions for p+AWhat is the gluon density in the (x,Q2) range relevant at RHIC?What role does saturation of gluon densities play at RHIC?What is Qs at RHIC, and how does it scale with A and x?What is the impact parameter dependence of the gluon density?Upgrades to both STAR and PHENIX to extend observables (focus on EM)Timescale: medium-term (~2017+) STARpreliminary2/8/2013Measure charm correlation with MTD upgrade: ccbare+An unknown contribution to di-electron mass spectrum is from ccbar, which can be disentangled by measurements of e correlation. Simulation with Muon Telescope Detector (MTD) at STAR from ccbar: S/B=2 (Meu>3 GeV/c2 and pT(e)2 parton scattering, many sources of smearing

LHC mid-y ~ RHIC y=4

MSCPixel Insertion TubePixel Support TubeIDSEast Support CylinderOuter Support CylinderWest Support CylinderPITPSTESCOSCWSCShroudsMiddle Support CylinderInner Detector SupportInner Detector Support (IDS)Carbon Fiber Structures provide support for 3 inner detector systems and FGT.All systems are highly integrated into IDS.Installed for run-12342/8/201334Insertion check setup

Two sector only shown in D-Tube (sector holding part). Next slides shows how this will be moved into position around the beam pipe (test setup).2/8/2013352/8/201336Tracking: proof of principle

Pt Resolution in STAR Forward TPCJ. Putschke, Thesis

Charged hadron Rcp at ||~3.1||~3.1nucl-ex/0703016STAR magnetic field allows for moderate pT resolution in forward directione.g. FTPC, position resolution ~100 m Some added momentum resolution can be garnered from radial magnetic field at poletip

Likely insufficient for RICH particle identification, but sufficient for charge sign discrimination in Drell-Yan: detailed simulations underwaySTAR inner detector Support2/8/2013

37382/8/2013Charmed baryons (Lambdac) Run-16

cpK Lowest mass charm baryons c = 60 m

c/D enhancement? 0.11 (pp PYTHIA) 0.4-0.9 (Di-quark correlation in QGP) S.H. Lee etc. PRL 100, 222301 (2008) Total charm yield in heavy ion collisions

38392/8/2013Access bottom production via electrons

particlec (m)Massqc,b x (F.R.)x e (B.R.)D01231.8650.540.0671D3121.8690.210.172B04595.2790.400.104B4915.2790.400.109Two approaches: Statistical fit with model assumptions Large systematic uncertainties With known charm hadron spectrum to constrain or be used in subtraction

39402/8/2013Statistic projection of eD, eB RCP & v2

Curves: H. van Hees et al. Eur. Phys. J. C61, 799(2009). (Be) spectra obtained via the subtraction of charm decay electrons from inclusive NPEs: - no model dependence, reduced systematic errors.

Unique opportunity for bottom e-loss and flow. - Charm may not be heavy enough at RHIC, but how is bottom?

40