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Strange vector mesons in Dense and Hot M atter

Strange vector mesons in Dense and Hot M atter. Pornrad Srisawad Department of Physics,Naresuan  University,  Phitsanulok , Thailand . Work in Collaborate with. E Bratkovskaya and Yu-Ming Zheng. STSP-2014. Contents. Why we love strange vector meson?

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Strange vector mesons in Dense and Hot M atter

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  1. Strange vector mesons in Dense and Hot Matter Pornrad Srisawad Department of Physics,Naresuan University, Phitsanulok, Thailand  Work in Collaborate with E Bratkovskaya and Yu-Ming Zheng STSP-2014

  2. Contents • Why we lovestrange vector meson? • What is the properties of strange vector meson in dense matter and hot matter ? • Star and FAIR looking for strange vector meson

  3. Whystrange vector meson in dense matter ? • as a probe of the hot medium and (QGP) formation • Kaonicatoms (nuclear opt. potential) • Production (AND propagation) in HIC’s • Understanddata • Learnabouthadronnature and mediumeffects RHIC low-energy and future of FAIRS and NICA

  4. Characteristic of K  and K*Meson Charged (892)meson : Mass : 891.66 +/- 0.26 MeV Width : 50.80 +/- 0.90 MeV Decay Modes for present study Life time : ~ 4 fm Quark Structure: NeutralK  meson: Mass : 493.67 +/- 0.01 MeV Quark Structure :

  5. Elastic scattering between and a nucleon. loop selfenergy diagram.

  6. KN and KN scattering in hot nuclear medium • smooth at lowenergies→ mildrepulsion • (30 MeV) • :stronglydominatedbysub-thres.(1405) → attractiondueto in-medshift of (1405) + broadening • moderatelyattractivepotential: • phenomenol. models MeV

  7. Kaons change their properties in dense matter in-medium energy” In-medium energy

  8. STAR Experiment STAR DATA (Run IV & V) Au+Au 62.4 GeV ~ 7e+6 events Au+Au 200 GeV ~ 13e+6 events Cu+Cu 62.4 GeV ~ 10e+6 events Cu+Cu 200 GeV ~ 8e+6 events STAR Time Projection Chamber was used to select kaons and pions. Modification inK0* Mass , Width andpTspectrain-medium dynamical effects

  9. Neutral K*0meson : Mass : 896.10 +/- 0.27 MeV Width : 50.70 +/- 0.60MeV Decay Modes : K ~ 100 % Decay Modes for present study K+  K-  BR ~ 66% ……….. Life time : ~ 4 fm Quark Structure :

  10. K* thermally produced at the chemical freeze-out stage  K* Daughter particles’ Rescattering Effect destroys part of K* signal K K*   K Regeneration Effect compensates against lost K* yield K*   K* K K K time Regeneration and Rescattering Effects K*reconstructed K*lost K*reconstructed Chemical freeze-out Thermal freeze-out K*/K ratio in p+p and A+A collisions to understand rescattering effect.

  11. Signal : Simple Breit-Wigner K0* Invariant Mass Spectrum MinBias MinBias M0 and Gamma Background : Linear function The signal was obtained by subtracting the combinatorial background distribution (generated using mixed event technique) from the kaon-pion invariant mass distribution. Phys. Rev. C 71 (2005) 064902

  12. Particle Ratio (K*/K-) Rescattering crosssection, > 5 times the regeneration cross-section, Phys. Rev.D 9, 1872(1974) (K*/K-)A+A/(K*/K-)p+p ratio with centrality => rescattering effect over regeneration .

  13. The spectral function of K* base on chirally motivated models of the meson selfenegies (1) C1 is normalization constant as is in medium meson mass is K* energy

  14. In-medium decay width of K* (2) M is K energy two sources of medium effects

  15. a repulsive shift corresponding to the mass modification in negligible changes in shape. neglected the effect of pion modifications in the K∗ width A.Ilnera,D. Cabreraa,P. Srisawad,E. Bratkovskaya arXiv:1312.5215 [hep-ph]

  16. Medium effects in hot hadronic matter In framework of Chiral Perturbation Theory Kaon collision width Mass shift Mean-field potential Self energy of kaons at rest Attractive mass shift up to T = 100-120 MeV Fuchs, et al Nucl.Phys.56 (2006)1

  17. The spectral function of Kaonbase on chirally motivated models of the meson selfenegies dependent on temperature . that is mildly shifted to lower energies while becoming broadedonly at very high temperatures arXiv:1312.5215 [hep-ph]

  18. In-medium decay width of K* in hot matter Form factor of dipole form

  19. Off –shell in-medium width of the K* arXiv:1312.5215 [hep-ph] width is slightly enhanced in the lower mass region with increasing temperatures due to the attraction

  20. The spectral function of K* within a Breit –Wigner quasi-particle dependent on temperature . K∗ peak experiences a very small shift to higher in low energy region arXiv:1312.5215 [hep-ph]

  21. Summary Medium effects in dense matter 1. K* experiences a mild repulsive mass shift from nucleons. of about 5 % of normal nuclear matter density. 2. Decay width ofK* is barely modified by the properties of K in medium 3. The spectral function of K* maintains a single–peak structure, which facilitates it treatment in microscopic transport model.

  22. Medium effects in hot matter The changes in the k* width are accompanied by a small repulsive mass shift. 2. K* resonances are only sensitive to the hadronic mediumin absence of baryons for the typical temperature range expected in the hadronic phase of HIC. 谢谢你的关注

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