Report of PAC for Particle Physics

1. Report of PAC for Particle Physics T. Hallman JINR Scientific Council Meeting June 2-4, 2005 Dubna, Russia

2. Recommendations on New Projects • The PAC recommends approval of the project “Astrophysical Studies in the NUCLEON space experiment” for execution until the end of 2008. • The PAC recommends approval of the opening of the new theme “Study of e+e- interactions, linear collider physics and detector” for execution until 2008. • The PAC looks forward to receiving additional information on the main research directions for the FAIR project (e.g. PAX) at a future meeting

3. Recommendations on Current Experiments • The PAC appreciates the ongoing and planned studies at the LHC, RHIC, and the Tevatron, and looks forward to their realization with active participation from JINR physicists. • The PAC looks forward to a report at its next meeting to a report concerning the software and computing activities being actively carried out to allow JINR scientists to produce first scientific results at the time of LHC start-up • The PAC recommends BLTP theoreticians to be more actively involved in the preparations of the research programmes planned at the LHC.

4. Recommendations on Current Experiments • The PAC recommends continuation of the following activities: • NA49 • PHENIX • PICASO • BECQUEREL • ALICE • ATLAS • CMS • STAR • CDF • D0 • COMPASS • HADES • Thermalization

5. Recommendations on Closing Experiments • The PAC recommends closure of the following activities: • DEKPHI • HARP/PS214 • HYPERON-M • HERA-B • GAMMA-2 • CERES/NA45 • EXCHARM-II • DISK • WASA • BES • KAPPA • SINGLET • Energy Plus Transmutation • Theoretical and Experimental investigation of electronuclear method of energy production and radioactive waste transmutation

6. Draft JINR Particle Physics road map The role of the Road Map is to: • ensure scientific excellence of JINR • maximise the scientific output within the resources • support and develop existing facilities and infrastructure

7. Worldwide Priorities in particle physics • the origin of mass; • the properties of neutrinos; • the properties of the strong interaction including properties of nuclear matter; • the origin of the matter-antimatter asymmetry in the universe; • the unification of particles and forces including gravity;

9. JINR bears JINR bears JINR bears JINR bears JINR JINR JINR JINR Full Responsibility Full Responsibility Full Responsibility Full Responsibility Participate Participates Participate Participate ME1/1 ME1/1 ME1/1 SE SE SE HE HE HE Search for the HIGGS; Origin of Mass; Super Symmetry JINR in the CMS Physics Program

10. JINR in CMS Physics The field of special interest of Dubna group is study of Drell-Yan processes in the large invariant mass region The idea is to test Standard Model calculations for muon pairs Production up to the highest reachable invariant masses • Many theoretical predictions suggest possible violation of the SM • Unique opportunity to test the SM up to 3-5 TeV mass region (Tevatron region is limited only of 0.8 TeV) • Studt facilitated by excellent performance of CMS Muon system • Possibility of strong theoretical support of this research program st JINR

11. JINR plans for physics with CMS At the stage of data taking and physics analysis JINR CMS project will be organized as a joint effort of several groups from LPP, LHE, LPP and LIT distributed following task forces: • Data taking and technical support group (LPP and LHC) • Input data control and processing (production) (P.Moissenz + 4,LPP) • Data processing (V.Korenkov + 5, LIT) • Physics analysis (S.Shmatov + 5, LPP) • Theoretical support (O.Teryaev, D.Bardin, BLTP) These groups already exist, most physicists are below 35 Permanent weekly seminar in LPP, Wednesday, 15:00 (in plan monthly meeting with other RDMS physicists)

12. The ATLAS Detector at the CERN LHC Search for the HIGGS; Origin of Mass; Super Symmetry

13. Preparing to do science with ATLAS • Physical process simulations and new research proposals of the ATLAS-JINR • group were discussed at the both Workshops on the ATLAS physical program • (Dubna (April and November, 2004). The main topics are the following: • Search for the SM Higgs boson with the ATLAS detector via the process H → 4μ • (G.Chelkov, I.Boiko, K.Nikolaev, R.Sadikov) • Other Dubna proposals are to utilize the ATLAS large-mass Higgs • discovery potential by means of reactionsH→2W→2l, orH→2W→l jj • (Yu.Kulchitsky) and H→2Z→2l , or H→2Z→lljj(V.Vinogradov)on • the basis of the already simulated ATLAS DC1 and DC2 data. The proposals • rely on the Higgs boson production via the Vector Boson Fusion mechanism • (the two accompanied forward jets allows very good background reduction) • and on the maximal Higgs boson decay rates into WW- or ZZ-pair at • MHIGGS = 400 -- 1000 GeV.

14. JINR preparations for physics with ATLAS : H  μμμμ Study of Higgs Boson Decays H  μμμμ (Boyko I., Chelkov G., Nikolaev K.) • Using the full simulation of ATLAS detector • Study effects of pile-up (first time in ATLAS!) • Background study. Preprint JINR (Р1-2004-44)

15. TRD Electron ID MUON m+m- pairs PHOS g,p0 JINR Preparations for science with ALICE

16. Planned JINR Scientific Analyses on ALICE 1.Study of hot and dense nuclear matter in nuclear – nuclear (AA) collisions in the frame of QCD predictions: • Light resonance ( , , ) production; Chiral symmetry restoration; • Particle correlations; Space-time evolution and interferometry measurements. • Heavy-quark and quarkonium ( J/,  families) production. Quarkonium suppression (Dimuons decay mode; Di-electrons decay mode). • Direct photon production. ‘Prompt’ photon characteristics and two-photons correlation.

17. Physics Simulation in ALICE -- Particle Identification: 480 HIJINGevents Particle identification with Inner Tracking System and Time Projection Chamber Simulation ofΦ  K+K- including the tracking and detector (ITS,TPC) efficiencies Development of New Cluster Finding Algorithm The Study of the HBT Correlations 480 HIJINGevents

18. Physics With ALICE Effective mass distribution of (K+K-) paires. Particle identification switched on! The resonance peak after (K+K+) background subtraction. Mass and width BW fit parameters are respectrively: 1019.60± 0.04 MeV and 4.30 ± 0.12 MeV. For the BW fit the gaussian effective mass resolution (1.23 MeV) has been taken into account by a convolution of BW and gaussian functions.. The S/B increases from 0.5% at the lowest pT(K+K-) < 0.6 GeV/c to 6.2% at the highest pt > 2.2 GeV/c with the significance equal to 120.

19. Detection of Upsilons in p-Pb and Pb-p collisions in ALICE muon spectrometer( ptm > 3GeV/c) bb̃BGR & Signal p-Pb

20. CMS Computing at JINR Unprecedented LHC Research program can not be carried out with conventional even most advanced computing facilities 1 CMS event = 1 MB 100-200 events will recorded in 1 sec ~ 21015 B/year (2 PetaB/year) To support LHC Research programme the generation of computing network organization based on GRID concept is under development (LCG project) In JINR this activity has been started on the basis of LIT since almost the very beginning of the CMS project JINR is on of the founder of RDMS LHC Regional Computer Center At present JINR computer facilities is very well integrated in the LCG project

21. MYRINET cluster COMMON PC-farm LHC INTERACTIVE PC-farm LCG JINR Central Complex for Information andComputing 6 – Interactive 18 – Common PC-farm 30 – LHC 14 – MYRINET (Parallel) 20 – LCG 20 – File servers 8 – LCG-user interface

22. Conclusions • Preparations are underway to realize the benefit of JINR’s contributions to the LHC and play a central role in the scientific programs of CMS, ALICE, and ATLAS • The exercise commissioned by the Directorate at the suggestion of the Scientific Council to review the scientific priorities of the projects within the context of a realistic budget is continuing