Related papers: Universal pion freeze-out phase-space density
We discuss various aspects of pion physics in the nuclear medium. We first study s-wave pion-nucleus interaction in connection with chiral symmetry restoration and quark condensate in the nuclear medium. We then adress the question of…
Transverse momentum spectra of negative and positive pions produced at mid-(pseudo)rapidity in inelastic or non-single-diffractive proton-proton collisions and in central nucleus-nucleus collisions over an energy range from a few GeV to…
We present measurements of the pion transverse momentum (p_t) spectra in central Si-nucleus collisions in the rapidity range 2.0<y<5.0 for p_t down to and including p_t=0. The data exhibit an enhanced pion yield at low p_t compared to what…
Pion condensation in ultra-relativistic collisions presents a compelling theoretical phenomenon with significant implications for the dynamics of hadronic matter. Various theoretical frameworks offer insight into the nature of…
Exclusive measurements of the quasi-free $pp \to pp\pi^+\pi^-$ reaction have been carried out at WASA@COSY by means of $pd$ collisions at $T_p$ = 1.2 GeV. Total and differential cross sections have been extracted covering the energy region…
Transverse momentum spectra of $\pi^{\pm}$, $\rm K^{\pm}$ and p($\bar{\rm p}$) up to $p_{\rm T}$ = 20 GeV/$c$ at mid-rapidity in pp and Pb-Pb collisions at $\sqrt{s_{\rm NN}}=$ 2.76 TeV have been measured using the ALICE detector at the…
Relative hadron abundances from high-energy heavy-ion collisions reveal substantial inhomogeneities of temperature and baryon-chemical potential within the decoupling volume. The freeze-out volume is not perfectly "stirred", i.e. the…
The particle production and their ratios for $\pi$, $K$, $p$, and $\Lambda$ are studied in Pb + Pb collisions at $\sqrt{s_{NN}}$ = 2.76 TeV based on a blast-wave model with thermal equilibrium mechanism. The transverse momentum spectra of…
The total cross section for the pp to pp $\pi^0$ reaction at energies close to threshold is calculated in a covariant one-boson-exchange model. The amplitudes for the elementary BN to N$\pi^0$ processes are taken to be the sum of s, u and t…
We determine the decoupling surfaces for the hydrodynamic description of heavy ion collisions at RHIC and LHC by comparing the local hydrodynamic expansion rate with the microscopic pion-pion scattering rate. The pion $p_T$ spectra for…
The BRAHMS measurement of proton-to-pion ratios in Au+Au and p+p collisions at 62.4 and 200 GeV is presented as a function of transverse momentum and collision centrality within the pseudorapidity range 0 < eta < 3.2. The p/pi ratio…
Deeply bound 1s states of $\pi^-$ in $^{115,119,123}$Sn were preferentially observed using the Sn($d$,$^3$He) pion-transfer reaction under the recoil-free condition. The 1s binding energies and widths were precisely determined, and were…
We recapitulate a thermodynamically consistent excluded volume hadron gas model and examine its differences with other ``thermal models'' used in the literature. Preliminary experimental data for particle number ratios in the collisions of…
With a view towards implementation in microscopic transport simulations of heavy-ion collisions, the properties of spin-isospin modes are studied in nuclear matter consisting of nucleons and Delta isobars that interact by the exchange of pi…
The latest results on the search for collective phenomena in pp interactions at the U-70 accelerator at IHEP (Protvino) are presented. This the long-term experiment has been carried out at the SVD-2 setup. We received the evidence of the…
Mid-rapidity production of $\pi^{\pm}$, $\rm{K}^{\pm}$ and ($\bar{\rm{p}}$)p measured by the ALICE experiment at the LHC, in Pb-Pb and inelastic pp collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV, is presented. The invariant yields are…
The mass distributions of baryon resonances populated in near-central collisions of Au on Au and Ni on Ni are deduced by defolding the $p_t$ spectra of charged pions by a method which does not depend on a specific resonance shape. In…
A thermal-model analysis of particle production of p-p collisions at sqrt(s) = 17 GeV using the latest available data is presented. The sensitivity of model parameters on data selections and model assumptions is studied. The system-size…
Neutral pion and $\eta$ meson invariant differential yields were measured in non-single diffractive p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV with the ALICE experiment at the CERN LHC. The analysis combines results from three…
A summary of current interferometry data in relativistic heavy ions is presented. At sqrt{s}=17GeV a sudden increase in the pion source volume is observed for central PbPb collisions. This seems to imply that the pion phase density has…