Minoru Biyajima

Analyses of k(t) distributions at RHIC by means of some selected statistical and stochastic models

The new data on k_t distributions obtained at RHIC are analysed by means of selected models of statistical and stochastic origin in order to estimate their importance in providing new information on hadronization process, in particular on the value of the temperature at freeze-out to hadronic phase.

Stochastic background of a KNO scaling function given by the Peřina-McGill formula and the gamma distribution utilized by Carruthers and Shih —their interrelation and phenomenological applications

Abstract It is found that a KNO scaling function given by the Peřina-McGill formula (i.e., the generalized Glauber-Lachs formula) satisfies the Fokker-Planck equation and moreover, the gamma distribution utilized in Carruthers and Shihs recent study is a stationary solution. Numerically these two KNO scaling functions are almost the same despite their different approaches. Comparisons of two KNO scaling functions with data at the CERN ISR and SPS collider show that charged pions with a pseudorapidity cutoff (| η | ⩽ 1.5) are dominantly incoherent. This fact is also confirmed through analyses of a negative pion interferometry as well as charge-charge correlation at the ISR region.

A potential including the Heaviside function in the 1 + 1 dimensional hydrodynamics by Landau : Its basic properties and application to data at RHIC energies

In the 1 + 1 dimensional hydrodynamics originally proposed by Landau, we derive a new potential and distribution function including the Heaviside function and investigate their mathematical and physical properties. Using the original distribution derived by Landau, a distribution function found by Srivastava et al., our distribution function, and the Gaussian distribution proposed by Carruthers et al., we analyze the data of the rapidity distribution on charged pions and K mesons at RHIC energies (

Scaling Behavior of (Nch)−1dNch/dη at by the PHOBOS Collaboration and Its Implication: A Possible Explanation Employing the Ornstein-Uhlenbeck Process

\sqrt{{s_{NN}}}

Comparative analysis of multiplicity distributions in inelastic processes for different colliding particles and nuclei

= 62.4 GeV and 200GeV). Three distributions derived from the hydrodynamics show almost the same chi-squared values provided the CERN MINUIT is used. We know that our calculations of hadron’s distribution do not strongly depend on the range of integration of fluid rapidity, contrary to that of Srivastava et al. Finally, the roles of the Heaviside function in concrete analyses of data are investigated.

Improved Coulomb correction formulae for Bose-Einstein correlations

Recently, interesting data concerning

Time evolution of relativistic d + Au and Au + Au collisions

dN_{ch}/d\eta

Stochastic background of negative binomial distribution

in Au-Au collisions [

A possible modification of the Lopylov-Podgoretsky-Cocconi formulation☆

\eta=-\ln \tan (\theta/2)

Totally chaotic poissonian-like sources in multiparticle production processes?

] with centrality cuts have been reported from the PHOBOS Collaboration. In most treatment these data are divided by the number of participants (nucleons) in collisions. Instead of this method, we use the total multiplicity