Fragmentation and Recombination for Exotics in Heavy Ion Collisions Chiho NONAKA Nagoya University What I will show here was done several years ago. I am May 21, 2010 @ExHIC10, Kyoto

Hadronization Mechanism Relativistic Heavy Ion Collision Low PT Thermal-statistical model:hadron ratios, chemical freezeout, P.Braun-Munsinger, PLB465,99 Hydrodynamic expansion:PT spectra kinetic freezeout, Shnedermann,PRC48,93 High PT Perturbative QCD is applicable. Fragmentation mechanism t hydrodynamic expansion freeze-out hadronization thermalization collision ? A lot of particles jump into the detector. Some experimental data which we could not understand using these hadronization mechanism confronted us. Chiho NONAKA

Baryon Puzzle at RHIC qq g p/p ratio ~ 1 (PT>2 GeV) Large p/ ratio at high PT Fragmentation g qq : fragmentation functions (PHENIX:nucl-ex/0307022) p/p ratio ~ 1 (PT>2 GeV) in central collisions p/p ratio << 1 Chiho NONAKA

Baryon Puzzle at RHIC 2. Difference in baryon and meson jet-suppression Fragmentation Parton energy loss at high PT hard scattering in medium jet quenching Suppression in RCPbaryon occurs at higher PT than RCPmeson RCPbaryon is the same as RCPmeson. Chiho NONAKA

Baryon Puzzle at RHIC 3.Difference in baryon and meson elliptic flow Fragmentation parton energy loss　　L Saturation in v2baryon occurs at higher PT than v2meson. v2baryon should be the same as v2meson. Chiho NONAKA

Quark Number Scaling Elliptic flow Chiho NONAKA

ReCo Models (RHIC) ALCOR: Biro, Levai, Zimanyi, PLB347,6(1995), HIP17, 205(2003) Dynamical model for hadronization Duke:Fries, Nonaka, Bass, Asakawa, Mueller, PRL90,202303 (2003) ReCo(thermal) + Fragmentation with energy loss No soft -hard ReCo Texas:Greco, Ko, Levai, PRL90,202302(2003), PRC68,034904(2003) Monte Carlo implementation Soft (thermal/AMPT), hard (minijet) partons Soft-hard ReCo Resonance decay effect on v2, charm flow, v4, v6 Ohio: Molnar, Lin, Voloshin, PRL90, 092301(2003),PRC68, 044901(2003) Elliptic flow: quark number scaling, flavor ordering, charm hadrons Oregon: Hwa,Yang, PRC67, 034902(2003),PRC67, 064902(2003) Meson: Thermal-thermal, thermal-shower, shower-shower ReCo Chiho NONAKA

ReCo+Fragmentation Model Duke Recombination at moderate PT Recombination occurs in an instant. The parton spectrum is shifted to higher pT in the hadron spectrum. Entropy and energy conservation No gluon dynamics Fragmentation at high PT The parton spectrum has a power law tail (quarks and gluons) from pQCD. The parton spectrum is shifted to lower pT in the hadron spectrum. recombining partons: p1+p2=ph fragmenting parton: ph = z p, z<1 ReCo Frag. PT>2GeV Chiho NONAKA

Hadron Spectra 2 4 6 8 10 PT(GeV) Meson: ReCo up to ~3 GeV Baryon: 12 PT(GeV)

Hadron Ratios vs. PT ReCo R + F Statistical model 2 < PT < 4~5 GeV ReCo baryon/meson~1 4 < PT < 6 GeV steep drop: transition from ReCo to fragmentation supports transition from ReCo to fragmentation at intermediate PT. Chiho NONAKA

Nuclear Modification Factors 2 < PT < 4 GeV RCP (baryon) > RCP (meson) ReCo 4 < PT < 6 GeV steep drop transition from ReCo to 　　　　fragmentation 　High PT suppression fragmentation R F R f ? Chiho NONAKA

Nuclear modification factor Velkovska(PHENIX)@QM2004 f Recombination mechanism works!

Quark Number Scaling Elliptic flow Chiho NONAKA

Quark Number Scaling elliptic flow of quarks elliptic flow of hadrons Chiho NONAKA

Elliptic Flow Mesons  meson v2 ~ v2K Baryons Hydrodynamical model mass effect ? # of constituent quarks ?  meson v2 ~ v2K v2 baryon saturates at higher PT at high PT: fragmentation v2 baryon ~ v2 meson PLB587,73(2004) Chiho NONAKA

v2 of  PHENIXPRL99(2007)052301 QM2005 Chiho NONAKA

Elliptic Flow from fragmentation ReCo Frag. parton energy loss　　L at high PT: fragmentation v2 baryon ~ v2 meson universal v2 at high PT For resonances and exotics: Chiho NONAKA

v2 for Resonance Particles QGP resonances: hadronizing QGP, no rescattering HG resonances: hadron final stage, h-h rescattering quarks n=2 scaling n=4 scaling Final Interactions freeze-out process Key: v2 is additive for composite particles Total is determined by experiments and related to width of particles and cross section in the hadronic medium. Chiho NONAKA

K*0 Elliptic Flow (STAR) nucl-ex/0412019 # of valence quarks Chiho NONAKA

v2 for Exotics Recombination: the same scaling for direct and molecule Differences come from fragmentation mechanism Chiho NONAKA

v2 for Exotics 5 q state molecule ReCo Frag. (ReCo + Frag.) Chiho NONAKA

v2 for Exotics Recombination: the same scaling for direct and molecule Differences come from fragmentation mechanism H dibaryon heavy flavor, Lc, X, Y, Z, Tcc …? thermalization, ReCo ? universal v2 at high PT ? v2 is measureable? →　yields, ratios Chiho NONAKA

Summary elliptic flow analysis with ReCo + fragmentation model: useful tool of understanding of ・production process of resonance particles 　　　　・hadron structure ex. exotic particles Chiho NONAKA