arXiv subjects
Publications and source records attributed to A. Bialas.
It is shown that the transverse momentum distributions of particles emerging from the decay of statistical clusters, distributed according to a power law in their transverse energy, closely resembles that following from the Tsallis non-extensive statistical model. The experimental data are well reproduced with the cluster temperature $T\approx 160$ MeV.
It is observed that the finite size of hadrons produced in high energy collisions implies that their positions are correlated, since the probability of finding two hadrons on top of each other is highly reduced. It is then shown that this effect can naturally explain the values of the correlation function below one, observed at LEP and LHC for pairs of identical pions.
It is pointed out that the size of the interaction region, as determined from HBT analyses, is increased due to the transition time necessary the convert the quarks and gluons into hadrons. A rough estimate yields an increase of R_HBT by about 15%.
Interpretation of long-range rapidity correlations in terms of the fluctuating rapidity density distribution of the system created in high-energy collisions is proposed. When applied to recent data of the STAR coll., it shows a substantial asymmetric component in the shape of this system in central Au-Au collisions, implying that boost invariance is violated on the event-by-event basis even at central rapidity. This effect may seriously influence the hydrodynamic expansion of the system.
The concept of the "wounded" hadronic constituents is formulated. Preliminary estimates indicate that it may help to understand the transverse mass dependence of particle production in hadron-nucleus and nucleus-nucleus collisions.
It is shown that the recently proposed method of studying the long-range correlations in multiparticle production can be effectively used to verify the hydrodynamic nature of the longitudinal expansion of the partonic system created in the collision. The case of ALICE detector is explicitly considered.
The idea of glue clusters, i.e. short-range correlations in the quark-gluon plasma close to freeze-out, is used to estimate the width of balance functions in momentum space. A good agreement is found with the recent measurements of STAR collaboration for central $Au-Au$ collisions.
A new method to study the long-range correlations in multiparticle production is developped. It is proposed to study the joint factorial moments or cumulants of multiplicity distributions in several (more than two) bins. It is shown that this step dramatically increases the discriminative power of data.
A model-independent method of studying the forward-backward correlations in symmetric high energy processes is developed. The method allows a systematic study of properties of various particle sources and to uncover asymmetric structures hidden in symmetric hadron-hadron and nucleus-nucleus inelastic reactions.
Exploiting the idea that the fast partons of an energetic projectile can be treated as sources of color radiation interpreted as wee partons, it is shown that the recently observed property of extended limiting fragmentation implies a scaling law for the rapidity distribution of fast partons. This leads to a picture of a self-similar process where, for fixed total rapidity Y, the sources merge with probability varying as 1/y.
We argue that the idea that the parton system created in relativistic heavy-ion collisions is formed in a state with transverse momenta close to thermodynamic equilibrium and its subsequent dynamics at early times is dominated by pure transverse hydrodynamics of the perfect fluid is compatible with the data collected at RHIC. This scenario of early parton dynamics may help to solve the problem of early equilibration.
The idea that the parton system created in relativistic heavy-ion collisions (i) emerges in a state with transverse momenta close to thermodynamic equilibrium and (ii) its evolution at early times is dominated by the 2-dimensional (transverse) hydrodynamics of the ideal fluid is investigated. It is argued that this mechanism may help to solve the problem of early equilibration.
Particle production in Au-Au, Cu-Cu, d-Au and p-p collisions at 200 GeV c.m. energy are analyzed in the wounded quark-diquark model. Existing data are well reproduced. Emission functions of wounded and unwounded constituents are determined. Implications for the collective evolution of the system are discussed.
Renyi entropies of a black hole are evaluated by counting the states of the Hawking radiation which fills a thin shell surrounding the horizon. The width of the shell is determined from its energy content and the corresponding mass defect. The Bekenstein-Hawking formula for the entropy of the black hole is correctly reproduced.
We propose a generalization of the Bjorken in-out Ansatz for fluid trajectories which, when applied to the (1+1) hydrodynamic equations, generates a one-parameter family of analytic solutions interpolating between the boost-invariant Bjorken picture and the non boost-invariant one by Landau. This parameter characterises the proper-time scale when the fluid velocities approach the in-out Ansatz. We discuss the resulting rapidity distribution of entropy for various freeze-out conditions and compare it with the original Bjorken and Landau results.
A systematic study of the relations between fluctuations of the extensive multiparticle variables and integrals of the inclusive multipaticle densities is analysed. The generalized factorial moments are introduced and their physical meaning discussed. The effects of the additive conservation laws are analysed.
Small momentum transfer elastic proton-proton cross-section at high energies is calculated assuming the nucleon composed of two constituents - a quark and a diquark. A comparison to data (described very well up to -t = 2 GeV^2/c) allows to determine some properties of the constituents. While quark turns out fairly small, the diquark appears to be rather large, comparable to the size of the proton.
Recently suggested method of measuring Renyi entropies of multiparticle systems produced in high-energy collisions is presented in the form of a "do-list", explaining explicitely how to perform the measurement and suggesting improvements in the treatment of the data.