We present an analysis of the process ee → γ orZ → ππγ, in the kinematical region where √ s, the c.m. energy of the ee pair, is large but much below the Z-pole. The subprocess γ orZ → ππγ can be described by the convolution of the hard scattering coefficient γ orZ → qq̄γ and the general distribution amplitude of two pions qq̄ → ππ. In the case of neutral pion, the production through γ is the domi...

To explain the production of light nuclei in heavy-ion collisions at extreme energies, we focus on deuteron case. A Gibbs ensemble chemical freeze-out is a prerequisite to investigate non-equilibrium evolution expanding fireball. Quantum statistical approaches allow describe correlations including bound state formation strongly interacting and hot system. We consider virial approach evaluate pr...

Recently, neutron stars with very strong surface magnetic fields have been suggested as the site for the origin of observed soft gamma repeaters (SGRs). We investigate the influence of a strong magnetic field on the properties and internal structure of such strongly magnetized neutron stars (magnetars). The presence of a sufficiently strong magnetic field changes the ratio of protons to neutron...

Development has begun of a new experiment to measure the charged pion polarizability απ − βπ . The charged pion polarizability ranks among the most important tests of low-energy QCD presently unresolved by experiment. Analogous to precision measurements of π◦→ γγ that test the intrinsic odd-parity (anomalous) sector of QCD, the pion polarizability tests the intrinsic evenparity sector of QCD. T...

We discuss a dynamical mechanism of pion production from disoriented chiral condensates (DCC). It leads to an explosive production of pions via the parametric amplification mechanism, which is similar to the reheating mechanism in inflationary cosmology. Classically, it is related with the instability in the solutions of the Mathieu equation and we explore the quantum aspects of the mechanism. ...

The scaling of pion multiplicities with system size in proton-nucleus and nucleus-nucleus reactions at 200 A GeV is investigated. A nuclear geometry calculation of incoherent multiple scattering including effects of deceleration of the participating particles is presented. Pion multiplicities at high transverse momenta agree relatively well with an overall scaling with the number of binary coll...

Based on the Sakata model, we propose a model for the single pion production process in n-N collision which is essentially an extension of the Lindenbaum-Sternheimer model. It is pointed out that the analyses of sub-Bev single pion production phenomena will give us useful information about the level scheme of the Sakata Model. As a first step of the investigation of this model an analysis of th...