Freeze out of the expanding system

The freeze out (FO) of the expanding systems, created in relativistic heavy ion collisions, is discussed. We start with kinetic FO model, which realizes complete physical FO in a layer of given thickness, and then combine our gradual FO equations with Bjorken type system expansion into a unified model. We shall see that the basic FO features, pointed out in the earlier works, are not smeared out by the expansion.Comment: 3 pages, 2 figure

Modified Boltzmann Transport Equation and Freeze Out

We study Freeze Out process in high energy heavy ion reaction. The description of the process is based on the Boltzmann Transport Equation (BTE). We point out the basic limitations of the BTE approach and introduce Modified BTE. The Freeze Out dynamics is presented in the 4-dimensional space-time in a layer of finite thickness, and we employ Modified BTE for the realistic Freeze Out description.Comment: 9 pages, 2 figure

Dual Properties of the Structure Functions

By using the concept of duality between direct channel resonances and Regge exchanges we relate the small- and large-$x$ behavior of the structure functions. We show that even a single resonance exhibits Bjorken scaling at large $Q^2$.Comment: 4 pages talk given at XXXI International Symposium on Multiparticle Dynamics, Sep. 1-7, 2001, Datong China URL http://ismd31.ccnu.edu.cn

On the nature of the Lambda(1405) as a superposition of two states

We use recent data on the $K^- p \to \pi^0 \pi^0 \Sigma^0$ reaction with the $\pi^0 \Sigma^0$ mass distribution of forming the $\Lambda(1405)$ with a peak at 1420 MeV and a relatively narrow width of $\Gamma = 38$ MeV, together with those of the $\pi^- p \to K^0 \pi \Sigma$ reaction to show that there are two $\Lambda(1405)$ states instead of one as so far assumed.Comment: Contribution to the PANIC05 Conference, Santa Fe, October 200

Kinetic description of particle emission from expanding source

The freeze out of the expanding systems, created in relativistic heavy ion collisions, is discussed. We combine kinetic freeze out equations with Bjorken type system expansion into a unified model. The important feature of the proposed scenario is that physical freeze out is completely finished in a finite time, which can be varied from 0 (freeze out hypersurface) to infinity. The dependence of the post freeze out distribution function on the freeze out time will be studied. As an example, model is completely solved and analyzed for the gas of pions. We shall see that the basic freeze out features, pointed out in the earlier works, are not smeared out by the expansion of the system. The entropy evolution in such a scenario is also studied.Comment: 8 pages, 4 figures. Accepted to Physics Letters

Resonance-reggeon and parton-hadron duality in strong interactions

By using the concept of duality between direct channel resonances and Regge exchanges we relate the small- and large-$x$ behavior of the structure functions. We show that even a single resonance exhibits Bjorken scaling at large $Q^2$.Comment: 18 pages, 7 figures, 2 style files. To be published in Eur. Phys. J. A. Several typos are corrected, references are updated, LaTeX slyle is change

The KˉN→KΞ\bar{K} N \rightarrow K \Xi reaction in coupled channel chiral models up to next-to-leading order

We study the meson-baryon interaction in S-wave in the strangeness S=-1 sector using a chiral unitary approach based on a next-to-leading order chiral SU(3) Lagrangian. We fit our model to the large set of experimental data in different two-body channels. We pay particular attention to the $\bar{K} N \rightarrow K \Xi$ reaction, where the effect of the next-to-leading order terms in the Lagrangian are sufficiently large to be observed, since at tree level the cross section of this reaction is zero. For these channels we improve our approach by phenomenologically taking into account effects of the high spin hyperonic resonances.Comment: 8 pages, 4 figures, presented at the II Russian-Spanish Congress "Particle and Nuclear Physics at all Scales and Cosmology", Saint-Petersburg, October 1-4, 2013. arXiv admin note: text overlap with arXiv:1311.5025; and with arXiv:hep-ph/0505239 by other author