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φ and ω resonance decay modes Alexey Stavinskiy, Georgy Sharkov ITEP

φ and ω resonance decay modes Alexey Stavinskiy, Georgy Sharkov ITEP. X GDRE meeting. Phase diagram of nuclear matter. NICA. , ω resonances. If resonance decays before kinetic freeze-out  Possible rescattering of hadronic daughters 

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φ and ω resonance decay modes Alexey Stavinskiy, Georgy Sharkov ITEP

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  1. φand ω resonance decay modes Alexey Stavinskiy, Georgy Sharkov ITEP X GDRE meeting

  2. Phase diagram of nuclear matter NICA G. Sharkov ITEP GDRE

  3. ,ω resonances Ifresonance decays before kinetic freeze-out  Possible rescattering of hadronic daughters  Reconstruction probability decrease for hadronic mode A.V. Stavinsky, Acta Phys. Polon B40; 1179-1184, 2009 ω(782) π+ π-π0B.R. 0.89 (c = 23 fm) ω(782) π+ π-B.R. 0.017 ω(782) π0B.R. 0.089 ω(782) e+e-B.R. 0.000072 φ(1020) K+ K-B.R. 0.49 (c = 44 fm) φ(1020)  ηB.R. 0.013 φ(1020) e+e-B.R. 0.000297 G. Sharkov ITEP GDRE

  4. t hadrons with &without QGP quarks&gluons G. Sharkov ITEP GDRE

  5. Simple estimation • Put resonance in center of collision with p=0 • Look for decay probability after some reasonable time G. Sharkov ITEP GDRE

  6. Model l0~cτβ/√(1-β2) ~ ~(β=1/3 for this estimate)~ ~15fm(for φ) & 8fm(for ω) li l0 η η φ  li~2fm for any hadron & 1fm for any pair of hadrons l hadronization Kinetic freeze-out G. Sharkov ITEP GDRE

  7. Model • Upper line – lepton mode Splitting – two hadron and hadron-photon modes l -decay products trajectory length within matter φ β= 1/3 ω l,fm G. Sharkov ITEP GDRE

  8. Is it really possible measurement? • Existing data from PHENIX&STAR • B • B • B • B φ/w  e+e- φ K+K- w p+p-p0, p0g φηg ? G. Sharkov ITEP GDRE

  9. Φ(1020) K+ K-B.R. 0.49 c = 44 fm Φ(1020) e+e-B.R. 0.000296 c = 44 fm d+Au PHENIX Φ K+K- STAR Preliminary √sNN = 200 GeV Au+Au PHENIX Φ e+e- √sNN = 200 GeV G. Sharkov ITEP GDRE

  10. ω(782) π+ π-π0B.R. 0.89 c = 23 fm ω(782) π0 B.R. 0.089 c = 23 fm η(547) π+ π-π0B.R. 0.23 c = 167225 fm PHENIX η,ω π+π-π0 p+p Au+Au p+p ω π0 PHENIX √sNN = 200 GeV ω π0 PHENIX G. Sharkov ITEP GDRE

  11. Φ Production  K+K- and e+e- e+e- K+K- • The leptonic channel yield is a little higher than hadronic channel • More accurate measurement is required to confirm whether there is branch ratio modification Y. Nakamiya, for the PHENIX collaboration QM 2008, India G. Sharkov ITEP GDRE

  12. Yield comparison between fe+e- and f K+K- Comparison of integrated yield is not enough, because effect depend on the velocity of resonance, thus pc.m. region. Low pc.m. mesons tend to decay inside the hot/dense matter f f Low pc.m. High pc.m. • Thus, pc.m. -dependent information is essential for comparison. G. Sharkov ITEP GDRE

  13. 10K AuAu@25AGeV EPOS events dN/dIM, 1/0.1MeV G. Sharkov ITEP GDRE

  14. e+e-, π+π- Invariant mass ω→π+π- dN/dIM, 1/0.1MeV ω→e+e- G. Sharkov ITEP GDRE

  15. CBM simulationInput info • PLUTO generator (generates one particle from 25AGeV AuAu artificial fireball) • 104 events for each resonance decay mode • Setup: Target, Magnet, MVD, STS, RICH, TOF, TRD, ECAL(FullMC) • CBMROOT (DEC08), standard cuts G. Sharkov ITEP GDRE

  16. dielectrons Mean 0.7791 Sigma 0.0101 Mean 1.01701 Sigma 0.0101 IM e+e- ,GeV/c2 ,GeV/c2 • 28% of ωreconstructed • 27% of φreconstructed G. Sharkov ITEP GDRE

  17. Mean 1.0198 Sigma 0.0039 • 14% of φreconstructed • Need to play with ID (K+hno ID, hno ID+hno ID) G. Sharkov ITEP FRRC

  18. Conclusions • Comparison of vector mesons decay modes is proposed to study. Pc.m. dependence. • AuAu collisions simulated using EPOS • Hadronic and leptonic modes • mixed modes (ω→πoγ; φ→ηγ): combinatorics • PLUTO e+e-(ω , φ), K+K-(ω, φ) simulated and reconstructed in CBMROOT G. Sharkov ITEP GDRE

  19. TO DO • HKM calculations. (Yu. Sinyukov, Yu. Karpenko) • Magnitude of the effect • Energy dependence? P1(p1) & P2(p2) − escape probability for i-th decay product after decay • EPOS2 realistic event-by-event calculations • Comparison with RHIC data • RHIC energy scan, FAIR, NICA G. Sharkov ITEP GDRE

  20. EPOS2 & HKM G. Sharkov ITEP GDRE

  21. 14% of φreconstructed • Need to play with ID (K+hno ID, hno ID+hno ID) G. Sharkov ITEP GDRE

  22. Direct photons analysis Re: [URQMD] ftn15 (fwd) a1(1260) η' ω K* "hm, yes photons are mesons in urqmd. however, photons should not be calculated within the urqmd, but explicitely outside with a different code. everybody should ignore all processes with photons involved. we will move them out of the model in the next version. cheers, Marcus Bleicher" f1(1285) • Only from decay • 2 γγelastic scatterings(?!) UrQMD code G. Sharkov ITEP GDRE

  23. Formulas G. Sharkov ITEP GDRE Stavinskiy,ITEP,10.06.08

  24. e+ e- f,w Momentum Electron ID gEnergy g p0 g p0 g g K+ p+ w f K- p- g Hadron ID Momentum Momentum Hadron ID Electron, hadron and photon in PHENIX f/w  e+e- • PHENIX acceptance • -0.35 < η < 0.35 • 2 x 90°in azimuthal angle for two arms • Event selection • BBC • Electron ID • RICH • EMCal • photon ID • EMCal • Hadron ID • TOF • EMCal-TOF w p+p-p0, p0g f  K+K- G. Sharkov ITEP GDRE

  25. Extended f  K+K- analysis Consistency between f  K+K- and f e+e- f Double ID analysis K+ K- f candidates d+Au no ID analysis 0-20% h+ h- f candidates No ID Single ID Double ID No ID Single ID Double ID e+e- Single ID analysis M.B. p+p K+ or K- h+ or h- f candidates f d+Au 0-20% M.B. p+p • fK+K- measurements have been extended to both higher and lower pT using new methods, i.e. no kaon ID and single kaon ID methods. • The three independent kaon analyses are consistent with each other. In p+p, spectra of e+e- and K+K- show reasonable agreement! G. Sharkov ITEP GDRE

  26. Spectra comparison between fe+e- and f K+K- f e+e- AuAu MB f e+e-20-40% x 10-3 fe+e- 40-92% x 10-1 f K+K- AuAu MB (no PID) f K+K- AuAu MB (double PID) fK+K- AuAu MB (PRC72 014903) f K+K- 20-40% x 10-3 (double PID) f K+K- 40-92% x 10-1 (double PID) fK+K-40-92% x 10-1 (PRC72 014903) Au+Au M.B. 40-92% 20-40% Errors are too large to make any clear statement about the comparison of spectra for f  e+e- and f  K+K-. G. Sharkov ITEP GDRE

  27. Yield comparison between fe+e- and f K+K- Question 1’: Have we observed changes of yield between e+e- and K+K- ? • Comparison of integrated yield is not enough, because • mass modification effects depend on the pT region. • Low pT mesons tend to decay inside the hot/dense matter f f Low pT High pT • In addition, • To determine the integrated yield, an extrapolation to lower pT is needed. • There is a large uncertainty in the calculation. • Thus, pT-dependent information is essential for comparison. Now, we should ask Have we observed changes of spectra between e+e- and K+K- ? G. Sharkov ITEP GDRE

  28. What is the difference? • Modes absorbtion vs Mass modification • Standard mesons vs modified mesons • φ→KK & φ→η • Modes absorbtion vs K/K* ratio • Lepton modes vs thermal model • Hadron stage vs equilibrium stage • Modes absorbtion vs both other approaches • Internal cross-check - 3 modes G. Sharkov ITEP GDRE Stavinskiy,ITEP,10.06.08

  29. Real σMN in matter can differ from that in free space • ω photoproducton on nuclear targets (ELSA) M.Kotulla et al., ArXiv: nucl-ex/08020980 σωN ≈ 70 mb (in nuclear medium, 0.5 < P <1.6 GeV/c) σωN ≈ 25 mb (in free space - the model calculations) •  photoproducton on nuclear targets T.Ishikawa et al., Phys.Lett.B608,215,(2005) σφN= 35 ± 14 mb (in nuclear medium) σφN ≈ 10 mb (in free space) “φ-puzzle” photoproducton on nuclear targets G. Sharkov ITEP GDRE

  30. wp0g dAu MB (PRC75 151902) wp0p+p- dAu MB(PRC75 151902) w e+e- pp MB (PHENIX preliminary) wp0g pp MB (PRC75 151902) wp0p+p- pp MB(PRC75 151902) wp0g pp ERT (PHENIX preliminary) wp0p+p- pp ERT (PHENIX preliminary) Measurements of win wide pT range pT spectra of w are measured for several decay modes in d+Au and p+p. w d+Au p+p G. Sharkov ITEP GDRE Spectra show good agreement among several decay channels.

  31. Branching ratiosas an instrument for density integral measurements • mesons ( mesons) • new source of information • Interplay between different ALICE subdetectors(?) G. Sharkov ITEP GDRE Stavinskiy,ITEP,9.04.08

  32. G. Sharkov ITEP GDRE

  33. Why  ?(common part) Themeson was proposed in the middle of 80’(Koch,Muller,Rafelski PR142,ShorPRL54) as one of the most promising QGP messengers because of the following reasons: • an enhancement of –meson, as well as other strange hadrons in QGP phase • interaction cross section is small and will keep information about the early hot and dense phase • meson spectrum is not distorted by feeddown from resonance decays • strangeness local conservation for  Stavinskiy,ITEP,9.04.08 G. Sharkov ITEP GDRE

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