arXiv subjects
Publications and source records attributed to A. Bialas.
A model-independent lower bound on the entropy S of the multiparticle system produced in high energy collisions, provided by the Renyi entropy H_2, is shown to be very effective. Estimates show that the ratio H_2/S remains close to one half for all realistic values of the parameters.
We study the asymptotic solutions of a version of the Balitsky-Kovchegov evolution with discrete steps in rapidity. We derive a closed iterative equation in momentum space. We show that it possesses traveling-wave solutions and extract their properties. We find no evidence for chaotic behaviour due to discretization.
It is pointed out that the average semi-inclusive particle phase-space density at freeze-out can be determined from the coincidence probability of the events observed in multiparticle production. The method of measurement is described and its accuracy examined.
Recent improvements in the method of estimating Renyi entropies from measurements of coincidences between the events observed in high energy collisions are reviewed. A new, more precise, formulation of the method is presented and its accuracy analysed.
Relation between Renyi entropies and moments of the Wigner function, representing the quantum mechanical description of the M-particle semi-inclusive distribution at freeze-out, is investigated. It is shown that in the limit of infinite volume of the system, the classical and quantum descriptions are equivalent. Finite volume corrections are derived and shown to be small for systems encountered in relativistic heavy ion collisions.
Coincidence probabilities, which yield Renyi entropies, are investigated in a generalized Gaussian model, which includes interparticle correlations
It is pointed out that the moments of phase-space particle density at freeze-out can be determined from the coincidence probabilities of the events observed in multiparticle production. A method to measure the coincidence probabilities is described and its validity examined.
The charge and baryon balance functions are studied in the coalescence hadronization mechanism of quark-gluon plasma. Assuming that in the plasma phase the $q\bar{q}$ pairs form uncorrelated clusters whose decay is also uncorrelated, one can understand the observed small width of the charge balance function in the Gaussian approximation. The coalescence model predicts even smaller width of the baryon-antibaryon balance function: $σ_{B\bar{B}}/σ_{+-}= \sqrt{2/3}$.
We consider a version of QCD dipole cascading corresponding to a finite number n of discrete steps Delta Y of branching in rapidity. The discretization scheme preserving the holomorphic factorizability and scale-invariance in position space of the dipole splitting function, we derive an exact recurrence formula from step to step which plays the role of a ``discrete-time'' Balitsky-Kovchegov equation. The BK solutions are recovered in the limit n=infinity and Delta Y=0.
A group of transformations changing the phases of the single particle density matrix, but leaving unchanged the predictions for identical particles concerning the momentum distributions, momentum correlations etc., is identified. Its implications for the determinations of the interaction region from studies of Bose-Einstein correlations are discussed.
It is shown that the wounded nucleon model describes very well the recent PHOBOS data on particle production in D-Au collisions at 200 GeV. Contribution to particle production from a single wounded nucleon is determined. A two-component model is formulated and shown to account for most of the important features of the data.
It is shown that, in the presence of correlations in particle emission, the measured HBT radii are related to the correlation range rather than to the size of the interaction volume. Only in the case of weak correlations the standard interpretation may be applicable, The earlier discussion [1] of short-range correlations in configuration space is generalized to include also the correlations of particle momenta.
It is proposed that soft particle production in hadronic collisions is dominated by multiple gluon exchanges between partons from the colliding hadrons, followed by radiation of hadronic clusters from the coloured partons distributed uniformly in rapidity. This explains naturally two dominant features of the data: (a) The linear increase of rapidity spectra in the regions of limiting fragmentation and, (b) the proportionality between the increasing width of the limiting fragmentation region and the height of the central plateau.
It is shown that the method of eliminating the statistical fluctuations from event-by-event analysis proposed recently by Fu and Liu can be rewritten in a compact form involving the generalized factorial moments.
It is shown that the quark-antiquark coalescence mechanism for pion production allows to explain the small width of the balance function observed for central collisions of heavy ions, provided effects of the finite acceptance region and of the transverse flow are taken into account. In contrast, the standard hadronic cluster model is not compatible with this data.
Central production cross-sections of hard dijets with 2,1 or 0 rapidity gap at Tevatron are analyzed in terms of diffractive (``a la Good-Walker'') and non diffractive fluctuations of the incident particles. The observed large factorization breaking and the unexpected high value of the 2 to 1 gap cross-section ratio are explained in terms of scattering with and between the incident particles.
It is argued that the breakdown of factorization observed recently in the diffractive dijet production in deep inelastic lepton induced and hadron induced processes is naturally explained in the Good-Walker picture of diffraction dissociation. The explicit formula for the hadronic cross-section is given and successfully compared with the existing data.
It is pointed out that the recent data on charge fluctuations observed in heavy ion collisions are compatible with production of a system of weakly correlated constituent quarks and antiquarks.