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K. Tywoniuk

Publications and source records attributed to K. Tywoniuk.

26 records · Page 2Linked to original sources
arXiv2007

Gluon shadowing in the Glauber-Gribov model at HERA

We calculate shadowing using new data on the gluon density of the Pomeron recently measured with high precision at HERA. The calculations are made in a Glauber-Gribov framework and Pomeron tree-diagrams are summed up within a unitarity-conserving procedure. The total cross section of $\vphot A$ interaction is then found in a parameter-free description, employing gluon diffractive and inclusive distribution functions as input. A strong shadowing effect is obtained, in good agreement with several other models. Impact parameter dependence of gluon shadowing is also presented.

hep-ph↗
arXiv2007

Heavy-quark production from Glauber-Gribov theory at LHC

We present predictions for heavy-quark production for proton-lead collisions at LHC energy 5.5 TeV from Glauber-Gribov theory of nuclear shadowing. We have also made predictions for baseline cold-matter (in other words inital-state) nuclear effects in lead-lead collisions at the same energy that has to be taken into account to understand properly final-state effects.

hep-ph↗
arXiv2007

pi0 Fixed pT suppression and elliptic flow at LHC

Using a final state interaction model which describes the data on these two observables, at RHIC, we make predictions at the LHC -- using the same cross-section and pT-shift. The increase in the medium density between these two energies (by a factor close to three) produces an increase of the fixed pT pi0 suppression by a factor 2 at large pT and of v2 by a factor 1.5.

hep-ph↗
arXiv2006

Gluon shadowing in the Glauber-Gribov model

New data from HERA experiment on (diffractive) deep inelastic scattering has been used to parameterize nucleon and Pomeron structure functions. Within the Gribov theory, the parameterizations were employed to calculate gluon shadowing for various heavy ions and compared our results with predictions from other models. Calculations for d+Au collisions at forward rapidities at ultra-relativistic energies have been made and are compared to RHIC data on the nuclear modification factor. Results for gluon shadowing are also confronted with recent data on the nuclear modification factor at $\sqrt{s} = 17.3$ GeV at various values of the Feynman variable $x_F$, and the energy dependence of the effect is discussed.

hep-ph↗
arXiv2006

Gluon shadowing and unitarity effects

New data from HERA experiment on deep inelastic scattering have been used to parametrize nucleon and Pomeron structure functions. Within the Gribov theory, the parameterizations were employed to calculate gluon shadowing for various heavy ions. The latter was compared with predictions from other models. Calculations of multiplicity reduction due to gluon shadowing for d+Au collisions at forward rapidities at $\sqrt{s}$=200 GeV are in good agreement with BRAHMS data on the nuclear modification factor.

hep-ph↗
arXiv2005

Freeze-out of strange hadrons at RHIC

The production and freeze-out conditions of strange particles, produced in Au+Au collisions at RHIC energies, are studied within microscopic transport model. The system of final particles can be represented as a core, containing the particles which are still interacting with each other, and a halo, in which the particles have already decoupled from the system. In microscopic calculations hadrons are continuously emitted from the whole reaction volume. At RHIC, however, significant fractions of both mesons and baryons are emitted from the surface region within the first two fm/c. Different species decouple at different times. Strange mesons (kaons and $ϕ$) are frozen at earlier times and, therefore, can probe earlier stages of the reaction.

hep-ph↗
arXiv2004

Elliptic flow at RHIC: where and when does it formed?

Evolution of the elliptic flow of hadrons in heavy-ion collisions at RHIC energies is studied within the microscopic quark-gluon string model. The elliptic flow is shown to have a multi-component structure caused by (i) rescattering and (ii) absorption processes in spatially asymmetric medium. Together with different freeze-out dynamics of mesons and baryons, these processes lead to the following trend in the flow formation: the later the mesons are frozen, the weaker their elliptic flow, whereas baryon fraction develops stronger elliptic flow during the late stages of the fireball evolution. Comparison with the PHOBOS data demonstrates the model ability to reproduce the v2(eta) signal in different centrality bins.

hep-ph↗