HADES at FAIR P. Salabura Jagiellonian University Kraków

HADES at SIS100 + Side View ECAL for SIS100 (E)=6%/E FW START FW ECAL for SIS100 arxXiv:1109.55 (E)=6%/E + Spectrometer with M/M - 2% at / Particle identification e//p/K– combined RICH, dE/dx (MDC) and TOF : tof ~80 ps(RPC) electrons : RICH (hadron blind), TOF, RPC/Pre-Shower -> to be replaced by lead glass (OPAL) ECAL new ! : photons (18-450) ECAL Operates since 2002: Upgrade(2010): new DAQ (20 KHz Au+Au collisions)

Study of hadron properties in dense baryonic matter The case of Large B and moderate T : interesting region in phase diagram not probed experimentally by means of rare penetrating probes. HADES @ SIS100 : Continuation of Physics Programme at SIS18 L. McLerran, R.D. Pisarski 2007 Probes: dielectrons : sensitive probe of extended baryon structure -medium modifications ? meson in medium properties Multistrange baryons: -(1321),  ,  mesons Strategy: Systematic measurements in p +p, p+A and A+A at 2- 8 AGeV RHIC, BES Na61 experiment: chemical freeze-out VDM CBM Fair Begun et. al. arXiv:1208.410 HADES

Radiation from baryonic matter Dense matter 2-40 ; baryon resonances + nucleons + (20-30%) pions Vacumm RNe+e- q pion cloud e+ e- e- e+ e+ e- q q q - qq q e- e+ q qq - q q q How does the radiation from such matter look like?

33 (J=3/2)  N (J=1/2) M1 Transition Time like region : M. Pena, G. Ramahlo PRD85 (2012) 113014 ? space like region: „pion cloud” I. G. Aznauryan and V. D. Burkert, Prog. Part. Nucl. Phys. 67, 1 (2012) arXiv:1109.1720 „quark core” „dipole fit” cloud/core ~ 0.44/0.56 large contributions (30% at Q2=0) of pion cloud Dalitz decay: sensitivity to |GM |2 (q2) in time like region: „QED” Mee [GeV/c2]

 -meson in hot and dense matter Data : Na60 acceptance corrected : EPJC 59 (2009) 607 calculations: Hess/Rapp: NPA806(2008)339. „Baryonic loops ” pion loop direct  - N* / Resonance decays !  - /N* couplings play big role in „rho” melting observed in UrHIC -> connection to Baryon Resonance Dalitz decays

e+e- from Baryon Resonances in vacuum eTFF-em. Transition Form Factors pp->ppe+e- @1.25 GeV pp->ppe+e- @3.5 GeV contribution fixed from 1 pion production BR (Ne+e-)  4*10-5 agrees with model predictions. G(q2 ) dependence not very essential at this low energy.. Resonances with Mass up to 2 GeV included calculations with point-like RN* does not describe data FF(q2 ) dependence very important -> Vector Meson contribution !

e+e- from nuclear matter *  HADES: PRC84 (2011) 014902 e- 0 B=1 „excess” : B= 1 : B= 1 VM: M>0.6 B = 0 0 excess VM meson cocktail („freeze-out” component)

e+e- excess SIS100? Reference measurements for Au + Au collisions at FAIR pp vs pA @ 3.5 GeV HADES PLB715 (2012) 304

Multistrange baryon production data: HADES PRL 103 (2009) 132310 Ar+KCl @ 1.756 AGeV at SIS18 (1321) production significantly larger than transport model (UrQMD) and statistical model predictions Excitation function of  ,  (also ) not known below sNN <7 GeV… 640 MeV below NN threshold !

Particle rates in Ar+KCl @ 1.75 AGeV data: HADES: EPJA 47 (2011) 21 SHM: S. Wheaton, J. Cleymans, Comp. Phys. Comm. 180 (2009) 84 calculation with Thermus (SHM): strangeness: canonical ensamble with suppression induced via strangeness conservation colume (RC ) enhanced  (2),  (hidden strangeness) enhanced  (~25) overal 2/n.d.f ~2.3 !

HADES at SIS100: phase space coverage for e+e- yCM yCM yCM Ebeam = 1 GeV/u overall acceptance for di- electron pairs Acc ≈ 35% with nice mid-rapidity coverage Ebeam = 8 GeV/u Acc ≈ 20% shift towards backward rapidity Ebeam = 11 GeV/u  Acc ≈ 20%

 mass dependence on beam energy Simple model: pure BW  d/dm (~1/Mee 3)  exp(-M/T) Higher beam energy enhance  pole region

Tracking detector occupancies Au+Au @ 1.23 GeV/u equivalent to NiNi @ 8 AGeV and factor 2 lower than Au+Au 4 AGeV Cell size is factor of 2 larger tracking efficiency

PID capabilities at SIS100 RPC Au+Au @ 4 AGeV ToF K/ ~1.2 GeV/c p/~1.8 GeV/c K/ ~0.8 GeV/c p/~1.8 GeV/c

HADES : expected performance at SIS100 data !: Au+Au @ 1.2 AGeV : track density equivalent to Ni+Ni @ 8 AGeV K- hadron ID K0s First measurement at such low beam energy ! Lepton ID f

Count rate estimates, dilepton cocktails.. Au+ Au @ 4.0 GeV per 1 hour K+ 6*106 K- 4*105 K0s 2*104   K+ K- 4.2 *104   p- 6.0 104   - 200  e+e- 12 CB rejection not yet optimimized (no Ecal matching, close pair identification,..)

Summary SIS100 opens new opportunities : larger beam energy, larger density compressed baryonic matter not studied before by means of penetrating Results from SIS18 strongly motivate continuation of HADES physics programme at SIS100 HADES detector is in big part ready for new campaigns

Reaction plane reconstruction in FW Ag+Ag @ 1.65 AGeV Cut on the Q magnitude: Q > 6 Q > 3 No cut  4 < b < 8 Au+Au @ 1.25 AGeV Q > 6 Q > 3 No cut  5 < b < 10

Ecal for HADES electron ID:   reconstruction Ni+Ni @ 8 AGeV C+C @ 8 AGeV = 6% S/B = 2% Ni+Ni @ 8 AGeV = 6% S/B = 0.4%

HADES @ SIS100 : Phase space covarege K-  K0 UrQMD: 4 mln events Au+Au @ 4 AGeV

Kaonic Nuclear clusters Stat. model predictions for cluster formation in Au-Au collisions promising candidate ?: K- pp system predictions from theory : 20-70 MeV binding energy , hadronic decay into p experimental evidences : FINUDA K- absorption on nucleus M (p) = 2255±7 MeV/c2 , = 67 ± 14 MeV/c2 M. Agnello et al., PRL 94, 212303 (2005). DISTO p + p -> K+ + X X-> p MX = 2265 ± 2 (stat) ± 5 (syst) MeV/c2 X = 118 ± 8 (stat) ± 10 (syst) MeV/c2 RMS radius of (p) < 1.7 fm ! Y. Yamazaki et al..arXiv:1002.3526    R. Kotte : (p) source in ArKcl but  no sensitivity to p potential and ..no signal in p inv. mass visible