1 / 20

STAR @ Laboratory of Particle Physics, JINR Present, Past and Future activities Zulkarneev R.Ya.

STAR @ Laboratory of Particle Physics, JINR Present, Past and Future activities Zulkarneev R.Ya. Outline. STAR Detector Overview Past BEMC Creation Study of BEMC performances BEMC : Potentialities inherent Present current scientific programme &

iria
Download Presentation

STAR @ Laboratory of Particle Physics, JINR Present, Past and Future activities Zulkarneev R.Ya.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. STAR @ Laboratory of Particle Physics, JINRPresent, Past and FutureactivitiesZulkarneev R.Ya.

  2. Outline • STAR Detector Overview • Past • BEMC Creation • Study ofBEMC performances BEMC : Potentialities inherent • Present current scientific programme & STAR White Paper • Heavy Flavour Physics • Femtoscopy(HBT) group results • Soft Photon Physics Spin Physics • Software • Future

  3. STAR Detector overview 120 separate modules or 4800 towers: ∆φ,∆η = 0.05,0.05

  4. LPP: BEMC Creation (1999-2004) Barrel Electromagnetic Calorimeter (BEMC) hardware : assembling of the modules  design and construction of the PMT-boxes  design and manufacture of the optical system Total contributionof LPP STAR groupin the BEMC creation was estimated in terms of money as much as US 931 K $ On January 2005 the Technical Advisory Committee of STAR collaboration has reviewed the BEMC Project and concludes that BEMC has met cost, scope, and schedule, and is ready to operate.

  5. BEMC : potentialities inherent Proton Spin problem Access to investigate the unique processes with production of the direct photons, Drell-Yan’s pairs, W- and Z-bosons Hot & dense matter at RHIC Possibilities for search of new kindQGP signals through observation: Gammas &  Electrons J/ψ , Upsilon and  other states  EMC adds a new triggering capabilities:high Pt, Jets , J/ψ,…

  6. LPP:Study of BEMC performances (2001-2003) QM2004 : “Performance of the STAR Barrel Electromagnetic Calorimeter” Eγ,e = (1.0 - 50) GeV ∆E/E ~ 0.16/√E GeV η = [1;-1] φ = [0;2π] Typical MIP spectrum Figure 21. On this plot you can see relative SMD electron registration efficiency. This was done by demanding at least 2 SMD hits in both SMD planes directly under the projected track. Also deposition of at least 200 Mev was requred. SMD efficiency was studied on a part of electron sample selected using a narrow cut on dEdx in a “safe” region (TPC) + BEMC cut applied.

  7. The STAR Collaboration’s Critical Assessment of theEvidence from the RHIC Collisions (STARWhite Paper, 14 January 2005) …central AuAu-interactions at RHIC producedence, rapidly thermalizing mattercharacterized by: 1) initial energy densities above the critical values predicted by lattice GCD for establishment of a QGP;2) nearly ideal fluid flow established most probably at a stage preceding hadron formation; and 3)opacity to jets. …We pose a setof important open questions, and suggest additional measurements…which should be addressed before there can be a compelling basisto conclude that we havedefinitively formed thermalized, deconfinement matter at RHIC. What are the critical needs from future experiments? ...measure the nuclear modification factors for charmed meson production, to look for the prediction to reduce energy loss for heavy quarks… …look for the extra suppression of charmonium compared to open charm… …develop thermometers for early stage of collisions …well before chemical freezeout

  8. LPP: Current Physics Programme • Investigation of inclusive high PT non- photonic electron spectra in PP-, dAu- and AuAu- collisions at RHIC energies. Why high PT electron spectra? • Heavy Flavour States (HFS) are accessible through • theirb, c  e + Xleptonic channel decays.That • is direct way to Heavy Flavour Physicsstudy • Search of direct soft photons produced in dAu- and AuAu- collisions at 200GeV (Soft Photnos Physics) • The40-160 MeV photonsare accessible at STAR TPC • Do its serve as a kind of Thermometer for early • stages of the matter producted at RHIC ? • Study of two particle correlation functions in AuAu- collisions at RHIC energies (HBT-femtometry technics). • Study of transverse spin structure of the proton. (Spin physics)

  9. LPP: Heavy Flavour Physics • 1.Investigation of high Pt non-photonic electron spectra in pp-, dA- and • AuAu- collisions at 200 GeV • ∆Pt :(1.0 – 10.0)GeV ;BEMC , TPC and STAR triggering systems • ∆ η :[1.0 , -1.0] • Goals: • cross-sections of (cˉc)-, (b‾b)-states production; • info for HFS-triggering; • to look at thesuppressionof theheavy flavour states • producted in hot & dense matter ; • J/ψ- productionin long time prospect • Physics Working Group : Heavy flavour • Status:data analysis & publication of the first results

  10. p + p d + Au LPP:Heavy Flavor Physics Heavy (c-,b-) quarks suppression: • is theoretically more well controlled • measurement of it provides a critical check of partonic energyloss nature • Transition from hadronic to QGP is strong sensitive to number of active quark flavours and their mass • provides reference data for studies of color screening via quarconium suppression in future 200 GeV pp  e + X σ(c¯ , c) µb = 1290  210  400σ(b¯ , b) µb = 5.45±0.97±2.0

  11. LPP: Heavy Flavor Physics(continuation) • Non-photonic electrons: • semileptonic charm & beauty decays • Drell-Yan processes • Photonic electrons: • photon conversion, γ → e+e- • π0 and η Dalitz decays, π0 →γe+e- a) inclusive electron ((e-+e+)/2) spectra for pp, dAu and AuAu collisions at √sNN=200 GeV. b)inclusive to background ratio for pp and 0-5% most central AuAu collisions c) invariant e+e- mass spectrum Non-photonic electron spectra for pp, dAu and AuAu collisions at √sNN=200 GeV

  12. LPP: Heavy Flavor Physics(continuation) The modification factor, RAA for dAu, and AuAu collisions at √sNN=200 GeV • Strong suppression of non-photonic electrons has been observed in Au+Au, increasing with centrality • RAA ~ 0.2-0.3 for pT > 3 GeV/c • suggests large energy loss of heavy quarks ! to be published Phys.Rev.Lett. two person of LPP group are the principal authors of the publication!

  13. LPP:Femtometry-HBT group results II. Study of the correlation functions of “exsotic pair particles“ The LPP-France-Slovac-Czech Rep.group has been done the study of proton-lambda correlation in AuAu-collisions at RHIC  Being based on the known proton-lambda scattering lengths, the averagesizeof the proton and lambda sources was found to be ~3 fm,close tothesize of the proton sourcedetermined from proton-proton correlation function. For proton-antilambda and antiproton-lambda systems, the correlation functions have been measured for the first time and the corresponding spin averaged scattering length was estimated. A new perspective is open:  the correlation study of particle scattering in the systems which can hardly be accessible by other nuclear means.

  14. LPP: Soft Photon Physics • Search of the direct soft photons in dAu-,AuAu-collisions at 200GeV • ∆Pγ : (40 – 160) MeV ; TPC and STAR triggering systems. • ∆ηγ: [0.7 ,-0.7] • Ultimate goal: tests for theoretical model predictions; • receiving the datato estimatethe temperature of • thermalized stage(s) of the collision fireball; • Physics Working Group : Spectra • Status of the initial • stage of work: studies of background- inclusive soft gamma spectra • produced in AuAu-, dAu- collisions at 200 GeV- • in progress

  15. What does mean “DIRECT “PHOTONS QGP HadronGas EM & Weak Decay after freeze-out Pre-equilibrium Parton Cascade backgroundPHOTONS PROMT DIRECT PHOTONS THERMALDIRECT PHOTONS mainly hard gammas Eγ > 1 GeV more soft gammas Eγ < 1GeV direct photons = AuAu-inclusive photons – T ( dAu-inclusivephotons)

  16. Soft photons:theoretic predictions there are a lot of model predictions for photon spectra in soft energy region thermal radiation sensitive :  to initial state temperature;  degrees of freedom and EOS;  little interaction with surrounding matter But experimentally very challenging:  large background of photons from hadron decays(neutral mesons)

  17. LPP: Spin Physics IV.The study of reactions:PP↑→ ( π+ ,π-)+ X and PP → ( π+ , π- )+X at 200 GeV A complete quark spin density matrix is given by three quark distributions :  f1 (x) -related with the longitudinal momentum quarks in nucleon; g1 (x) -related with helicity distribution in polarized nucleon and h1 (x) - related with transverse spin distribution (correlation between left- and right quarks ) in the transverse polarized nucleon. SPIN crisis can’t be resolve on compelling base withoutthe h1(x)measurement Goal:observation of dependence of high Pt hadrons pair production plane on the incident proton beam polarisation in order to get transverse spin distribution in the proton (transversity) Status:proposal preparation in progress!

  18. LPP: STAR Software Development • NEOSTAR cluster • STAR framework • Offline DB mirror • STAR Database Browsers • STAR DB Browser • BEMC Browser • EEMC Browser • STAR Content Management System • Drupal • STAR GRID applications • Job Tracker (WS) • Job submission GUI • Log4c++, WS appender STAR collaborationhas been using this software since 2003 STAR Content Management System BEMC, BSMD, EEMC database browser visualization Offline database browser

  19. Future • More Physics! • J/Psi and oniums... • Direct Photons : more statistics and understanding of the background puzzle  Participation in the STAR upgrade in order to enhance soft gamma photon efficiency registration, to extend energy interval up to 1 GeV  PROPOSAL in PROGRESS • Spin Physics • More Software! • Grid Computing: Job Tracker Web Service • HEP Visualization

More Related