K. Zalewski

Hydrodynamics and long range correlations

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.

Thermodynamics of Van der Waals Fluids with quantum statistics

We consider thermodynamics of the van der Waals fluid of quantum systems. We derive general relations of thermodynamic functions and parameters of any ideal gas and the corresponding van der Waals fluid. This provides unambiguous generalization of the classical van der Waals theory to quantum statistical systems. As an example, we apply the van der Waals fluid with fermi statistics to characterize the liquid-gas critical point in nuclear matter. We also introduce the Bose-Einstein condensation in the relativistic van der Waals boson gas, and argue, that it exhibits two-phase structure separated in space.

Violation of a quark model sum rule in photoproduction

Abstract A sum rule following from the quark model of photoproduction is shown to be strongly violated by the experimental data at 3 GeV/ c .

Systematics of the relations following from the quark model (IV). Photoproduction

Abstract The quark model is applied to photoproduction processes. Relations for differential cross sections, relations for spin density matrices, and relations between strong and electromagnetic processes are derived and discussed.

Moments of the Wigner function and Renyi entropies at freeze-out

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.

Hidden asymmetry and long range rapidity correlations

Abstract 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 Collaboration, 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.

Thermodynamics of the low density excluded volume hadron gas

We consider thermodynamics of the excluded volume particles at finite temperature and chemical potential, in the low density approximation. We assume Boltzmann statistics and study the influence of the excluded volume on an ideal gas thermodynamics at the same temperature, pressure and numbers of particles. We show, that considering the change of the free enthalpy due to the excluded volume, and using the Maxwell identities, one can derive relevant thermodynamic functions and parameters of multi-component gases. The derivation is quite general as particles may have different sizes and shapes which can also depend on their momenta. Besides its simplicity and generality, our approach has the advantage of eliminating the transcendental equations occurring in earlier studies. A representative example of the excluded volume thermodynamics is the single-component gas of hard spheres. For this case, using the viral expansion, the validity limits of the low-density approximation are also discussed.

Blast-wave model description of the Hanbury-Brown?Twiss radii in pp collisions at LHC energies

The blast wave model is applied to the recent data on HBT radii in pp collisions, measured by the ALICE collaboration. A reasonable description of data is obtained for a rather low temperature of the kinetic freeze-out, T ~ 100 MeV, and the transverse profile corresponding to the emission from a shell of a fairly small width 2 d ~ 1.5 fm. The size and the life-time of the produced system are determined for various multiplicities of the produced particles.

Bose-Einstein correlations and thermal cluster formation in high-energy collisions

The blast wave model is generalized to include the production of thermal clusters, as suggested by the apparent success of the statistical model of particle production at high energies. The formulae for the HBT correlation functions and the corresponding HBT radii are derived.

Multibin long-range correlations

A new method to study the long-range correlations in multiparticle production is developed. It is proposed to measure the joint factorial moments or cumulants of multiplicity distribution in several (more than two) bins. It is shown that this step dramatically increases the discriminative power of data.