Related papers: eta' multiplicity and Witten-Veneziano relation at…
We discuss and propose the minimal generalization of the Witten-Veneziano relation to finite temperatures, prompted by STAR and PHENIX experimental results on the multiplicity of eta' mesons. After explaining why these results show that the…
To accomodate recent RHIC data on eta prime multiplicity, we propose a minimal modification of the Witten-Veneziano relation at high temperature. This renders a significant drop of eta prime mass at high temperature signaling a restoration…
The Witten-Veneziano relation, or, alternatively, its generalization proposed by Shore, facilitates understanding and describing the complex of eta and eta' mesons. We present an analytic, closed-form solution to Shore's equations which…
PHENIX has measured high transverse momentum (pT) identified hadrons in different collision species and energies in the last five RHIC runs. The systematic study of the high pT hadron production provides an idea on interaction of hard…
We discuss some subtleties in connection with the new attempts to provide a firm basis for ths Witten-Veneziano formula.
The pi0 meson has been a crucial proble for observing jet quenching in ultrarelativistic heavy-ion collisions at RHIC. Measurements of the eta meson in the same collisions have also shed light on a possible dependence of the observed…
We revisit the question of whether the U_A(1) symmetry is effectively restored in hot and dense medium. In particular, by generalizing the Witten-Veneziano formula to finite temperature, we investigate whether the mass of eta'-meson will…
We calculate the thermally averaged rates for the $\eta$-$\pi$ conversion and $\eta$ scattering using the Di Vecchia-Veneziano model and t' Hooft model, which incorporate explicitly the $U(1)_A$ anomaly. Assuming an exponential suppression…
PHENIX and STAR data on the intercept parameter of the two-pion Bose-Einstein correlation functions in sqrt(s_{NN}) = 200 GeV Au+Au collisions are analyzed in terms of different models of hadronic multiplicities. To describe this combined…
We investigate the centrality dependence of the pT-correlations in the event-by-event analysis of relativistic heavy-ion collisions at RHIC made recently by the PHENIX and STAR Collaborations. We notice that sigma^2 dynamical scales to a…
A reduction of the mass of the eta'(958) meson may signal restoration of the U_A(1) symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a combined…
We explore the dependence of the pT correlations in the event-by-event analysis of relativistic heavy-ion collisions at RHIC made recently by the PHENIX and STAR Collaborations. We point out that the observed scaling of strength of…
Production of resonances is considered in the framework of the single-freeze-out model of ultra-relativistic heavy ion collisions. The formalism involves the virial expansion, where the probability to form a resonance in a two-body channel…
A reduction of the mass of the \eta'(958) meson may indicate the restoration of the UA(1) symmetry in a hot and dense hadronic matter, corresponding to the return of the 9th, "prodigal" Goldstone boson. We report on an analysis of a…
With RHIC running in its second phase at higher luminosities the new data sets collected so far by PHENIX and STAR are allowing improvements in the study of vector meson photo-production in Ultra peripheral Collision events in Au+Au at the…
Measurement of Bose-Einstein or HBT correlations of identified charged particles provide insight into the space-time structure of particle emitting sources in heavy-ion collisions. In this paper we present the latest results from the RHIC…
The hidden local symmetry effective theory, Wilsonian matched to QCD at a matching scale near the chiral scale $\sim 4\pi f_\pi$ as formulated by Harada and Yamawaki, presents a scenario drastically different from the standard scenario of…
This article is based on my Proceedings for the 47th Course of the International School of Subnuclear Physics on the Most Unexpected at LHC and the Status of High Energy Frontier, Erice, Sicily, Italy, 2009. Results from the PHENIX…
In high energy heavy ion collisions a hot and dense medium is formed, where the U_A(1) or chiral symmetry may temporarily be restored. As a consequence, the mass of the eta'(958) mesons may be reduced to its quark model value, and the…
We introduce a novel approach to estimate the thermodynamic pressure from heavy-ion collisions based on recently measured higher-order moments of particle multiplicities by the STAR experiment. We start with fitting the experimental results…