arXiv subjects

Andrzej Bialas

Publications and source records attributed to Andrzej Bialas.

11 recordsLinked to original sources

arXiv2019

Femtoscopy of stopped protons

The longitudinal proton-proton femtoscopy (HBT) correlation function, based on the idea that in a heavy ion collision at $\sqrt{s} \lesssim 20$ GeV stopped protons are likely to be separated in configuration space, is evaluated. It shows a characteristic oscillation which appears sufficiently pronounced to be accessible in experiment. The proposed measurement is essential for estimating the baryon density in the central rapidity region, and can be also viewed as an (almost) direct verification of the Lorentz contraction of the fast-moving nucleus.

hep-ph↗

arXiv2017

Wounded quarks and diquarks in heavy ion collisions

A model in which the soft collisions of the nucleon are described in terms of interactions of its two constituents (a quark and a diquark) is proposed. When adjusted to describe precisely the elastic proton-proton scattering data and supplemented with the idea of wounded constituents, the model accounts rather well for the centrality dependence of particle production in the central rapidity region at RHIC energies.

nucl-th↗

arXiv2016

Stopped nucleons in configuration space

In this note, using the colour string model, we study the configuration space distribution of stopped nucleons in heavy-ion collisions. We find that the stopped nucleons from the target and the projectile end up separated from each other by the distance increasing with the collision energy. In consequence, for the center of mass energies larger than 6 or 10 GeV (depending on the details of the model) it appears that the system created is not in thermal and chemical equilibrium, and the net baryon density reached is likely not much higher than that already present in the colliding nuclei.

hep-ph↗

arXiv2016

Multi-particle correlations in transverse momenta from statistical clusters

We evaluate $n$-particle ($n=2,3,4,5$) transverse momentum correlations for pions and kaons following from the decay of statistical clusters. These correlation functions could provide strong constraints on a possible existence of thermal clusters in the process of particle production.

hep-ph↗

arXiv2016

Short-range two-particle correlations from statistical clusters

The two-particle short-range correlation functions in rapidity, azimuthal angle and transverse momentum, following from the decay of statistical clusters are evaluated and discussed.

hep-ph↗

arXiv2015

Finite size of hadrons and Bose-Einstein correlations in $pp$ collisions at 7 TeV

Space-time correlations between produced particles, induced by the composite nature of hadrons, imply specific changes in the properties of the correlation functions for identical particles. The expected magnitude of these effects is evaluated using the recently published blast-wave model analysis of the data for $pp$ collisions at $\sqrt{s}$ = 7 TeV.

hep-ph↗

arXiv2015

Finite size of hadrons and Bose-Einstein Correlations

In this presentation I report on the results of the paper we published recently together with Kacper Zalewski. It exploits the consequences of the observation that the hadrons, being the composite objects, cannot be produced too close to each other and thus must be correlated in space-time. One of these consequences, which we discuss here, is that the correlation function need not be larger than 1 (as is necessary if the space-time correlations are absent). Since the data from LEP and from LHC do show that the correlation function falls below 1, the particles must be correlated and we show that our observation does explain this unexpected effect.

hep-ph↗

arXiv2015

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.

hep-ph↗

arXiv2014

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.

hep-ph↗

arXiv2010

Asymmetric 1+1-dimensional hydrodynamics in collision

The possibility that particle production in high-energy collisions is a result of two asymmetric hydrodynamic flows is investigated, using the Khalatnikov form of the 1+1-dimensional approximation of hydrodynamic equations. The general solution is discussed and applied to the physically appealing "generalized in-out cascade" where the space-time and energy-momentum rapidities are equal at initial temperature but boost-invariance is not imposed. It is demonstrated that the two-bump structure of the entropy density, characteristic of the asymmetric input, changes easily into a single broad maximum compatible with data on particle production in symmetric processes. A possible microscopic QCD interpretation of asymmetric hydrodynamics is proposed.

hep-ph↗

arXiv1997

Deep inelastic scattering of leptons from nuclear targets and the BFKL pomeron

We calculate shadowing in the process of deep inelastic interactions of leptons with nuclei in the perturbative regime of QCD. We find appreciable shadowing for heavy nuclei (e.g. Pb) in the region of small Bjorken scaling variable $10^{-5}\leq x \leq 10^{-3}$. This shadowing depends weakly on $Q^2$, but it may be strongly influenced, especially at $x \geq 10^{-3}$, by the existence of real parts of the forward scattering amplitudes.

hep-ph↗