φ and ω decay modes ratios Stavinskiy,ITEP, Why , ω ? If resonance decays before kinetic freeze-out  Possible rescattering of hadronic daughters  Reconstruction probability decrease for hadronic mode ω(782)  π + π - π 0 B.R (c  = 23 fm) ω(782)  π + π - B.R ω(782)  π 0  B.R ω(782)  e + e - B.R φ(1020)  K + K - B.R (c  = 44 fm) φ(1020)  η  B.R φ(1020)  e + e - B.R

hadrons quarks&gluons with &without QGP t

Model l l0l0 lili φ η η  hadronization Kinetic freeze-out l 0 ~cτβ/√(1-β 2 ) ~ ~(β=1/3 for this estimate)~ ~15fm(for φ)&8fm(for ω) l i ~2fm for any hadron & 1fm for any pair of hadrons Stavinskiy,ITEP,

Formulas Stavinskiy,ITEP,

Upper line – lepton mode φ ω Splitting – two hadron and hadron-photon modes l,fm l -decay products trajectory length within matter β= 1/3 Stavinskiy,ITEP, Results

Is it really possible measurements? Existing data from PHENIX& STAR –B φ  e + e - φ  K + K -   +  -  ,    φ  η  Stavinskiy,ITEP,

Electron, hadron and photon in PHENIX PHENIX acceptance < η < x 90°in azimuthal angle for two arms Event selection BBC Electron ID RICH EMCal MomentumElectron ID  e+e+ e-e-  MomentumHadron ID K+K+ K-K- photon ID EMCal Hadron ID TOF EMCal-TOF  e + e -  K + K -   +  -  ,         Energy Momentum Hadron ID      

Φ(1020)  K + K - B.R c  = 44 fm Φ(1020)  e + e - B.R c  = 44 fm STAR Preliminary d+Au Au+Au √s NN = 200 GeV PHENIX Φ K+ K-Φ K+ K- Φ e+e-Φ e+e-

ω(782)  π + π - π 0 B.R c  = 23 fm ω(782)  π 0  B.R c  = 23 fm η(547)  π + π - π 0 B.R c  = fm Au+Au p+p √s NN = 200 GeV PHENIX ω π0ω π0 ω π0ω π0 η,ω π+ π- π0η,ω π+ π- π0

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

 e + e - AuAu MB  e + e % x  e + e % x  K + K - AuAu MB (no PID)  K + K - AuAu MB (double PID)  K + K - AuAu MB (PRC )  K + K % x (double PID)  K + K % x (double PID)  K + K % x (PRC ) Errors are too large to make any clear statement about the comparison of spectra for  e + e - and      40-92% 20-40% Au+Au Spectra comparison between  e + e - and  K + K - M.B.

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

If resonance decays before kinetic freeze-out  not reconstructed due to rescattering of daughters K *0 (c  = 4 fm) survival probability  time between chemical and kinetic freeze-out, source size and p T of K *0 Chemical freeze-out  elastic interactions πK  K *0  πK regenerate K *0 (892) until kinetic freeze-out K *0 /K may reveal time between chemical and kinetic freeze-out Chemical freeze-out Kinetic freeze-out K * measured π K K*K* π π K*K* K K K * lost π K K*K* K*K* π K Φ  information early stages of the collision Φ  different production for hadronic and leptonic channels K*  time between chemical and kinetic freeze-out S. Pal et al., Nucl.Phys. A707 (2002) P. Fachini BNL,SQM2007

Chemical freeze-out Kinetic freeze-out Chemical = Kinetic freeze-out K*/K -  p+p ratio reproduced by thermal model at chemical freeze-out  Au+Au reproduced by thermal model at kinetic freeze-out STAR K*  Ratios

Branching ratio between e + e - and K + K - may be sensitive to mass modification, since M phi is approximately 2  M K.  Compare yields of  e + e - and  K + K - Y. Nakamiya Hiroshima University, Japan for the PHENIX collaboration QM 2008, India

Φ Production  K + K - and e + e - The leptonic channel yield is a little higher than hadronic channel More accurate measurement is required to confirm whether there is branch ratio modification e+e-e+e- K+K-K+K-

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 Stavinskiy,ITEP,

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

To Do To make calculations for the effect of interest within realistic model To create algorithm for photonic modes identification in AA interactions To check this algorithm for ALICE&CBM conditions with realistic simulations Stavinskiy,ITEP,

Extra slides

Teams (open draft ) –V.Fedotov(ITEP) analysis procedure for ideal detector for η  energy ) –G.Sharkov(ITEP) realistic simulations for photonic modes –A.S. Stavinskiy,ITEP,

 Measurements of  in wide p T range Spectra show good agreement among several decay channels. p T spectra of  are measured for several decay modes in d+Au and p+p. p+p d+Au   0  dAu MB (PRC )  0  +  - dAu MB(PRC )  e + e - pp MB (PHENIX preliminary)  0  pp MB (PRC )  0  +  - pp MB(PRC )  0  pp ERT (PHENIX preliminary)  0  +  - pp ERT (PHENIX preliminary)

 Branching ratios as an instrument for density integral measurements   mesons  mesons )  new source of information  Interplay between different ALICE subdetectors(?) Stavinskiy,ITEP,

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,