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Jana Bielcikova

Publications and source records attributed to Jana Bielcikova.

8 recordsLinked to original sources

Heavy-ion physics at the LHC: Review of Run I results

In this work we review what we consider are, some of the most relevant results of heavy-ion physics at the LHC. This paper is not intended to cover all the many important results of the experiments, instead we present a brief overview of the current status on the characterization of the hot and dense QCD medium produced in the heavy-ion collisions. Recent exciting results which are still under debate are discussed too, leading to intriguing questions like whether we have a real or fake QGP formation in small systems.

hep-ex↗

Jet reconstruction and underlying event studies in p+p and d+Au collisions from STAR

Description of parton interaction with the hot and dense nuclear matter created in heavy-ion collisions at high energies is a complex task, which requires a detailed knowledge of jet production in p+p and d+Au collisions. Measurements in these collision systems are therefore essential to disentangle initial state nuclear effects from cold nuclear matter effects, medium-induced $k_T$ broadening and jet quenching. To obtain complete description of the p+p (d+Au) collision it is also important to study particle production in the underlying event. The measured properties of underlying event can be used to tune the QCD based Monte-Carlo models. In this paper some of the recent results on jet and underlying event properties in p+p and d+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV measured by the STAR experiment are presented. In particular, the preliminary results on charged and strange particle fragmentation functions in p+p collisions are discussed and confronted with PYTHIA simulations. Next, the measurement of inclusive jet spectrum and di-jet correlations in d+Au collisions is presented and compared with the measurements in p+p collisions to estimate the size of cold nuclear matter effects. Finally, the study of underlying event properties in p+p collisions is shown and compared to PYTHIA simulation.

nucl-ex↗

Medium properties and jet-medium interaction from STAR

We report recent STAR results on medium modification of 2- and 3-particle correlations in heavy-ion collisions at RHIC. In particular properties of an additional extended correlation in pseudo-rapidity (``the ridge''), not present in p+p or d+Au collisions, are discussed. Next, the shape modification of the away-side correlation peak at low- and intermediate-$p_T$ is investigated to look for signals of Mach cone shock waves or Čerenkov gluon emission.

nucl-ex↗

Two-particle correlations with strange baryons and mesons at RHIC

We present results on two-particle correlations using singly-strange particles ($Λ$, $\barΛ$, $K^0_S$) and charged hadrons at intermediate p_T in d+Au and Au+Au collisions at RHIC. We discuss properties of the near-side correlation peak in both azimuthal and pseudo-rapidity space and separate jet-like contributions from the long-range pseudo-rapidity correlations (the ridge). In particular, we study the centrality and p_T dependence of the jet and ridge yields for various trigger and associated particle species and compare the results to model predictions.

nucl-ex↗

Azimuthal and pseudo-rapidity correlations with strange particles at intermediate-p$_T$ at RHIC

We present results on two-particle azimuthal correlations with strange trigger particles ($K^0_S$, $Λ$, $Ξ$, $Ω$) associated with unidentified charged particles %at intermediate $p_T$ in d+Au and Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. We investigate, in detail, the near-side associated yield as a function of centrality, $p_T$ and strangeness content in the trigger particle to look for possible flavor and baryon/meson differences. We compare our results to a fragmentation and recombination model, where the study of $Ω$-triggered correlations is used as a critical test of the validity of the recombination picture.

nucl-ex↗

High-pT strange particle spectra and correlations in STAR

We present results on strange particle production in p+p, d+Au and Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. We discuss the nuclear modification factors ($R_{CP}$) and ratios of particle yields in order to investigate the range of anomalous baryon production.The medium modification of the fragmentation process is further explored by studying azimuthal correlations at intermediate-$p_T$ for $K^0_S$, $Λ$ and $\barΛ$ trigger particles. The results are compared to fragmentation and recombination models.

nucl-ex↗

High-p_T azimuthal correlations of neutral strange baryons and mesons in STAR at RHIC

We present results on two-particle azimuthal correlations of high-$p_T$ neutral strange baryons ($Λ$,$\barΛ$) and mesons ($K^0_S$) associated with non-identified charged particles in d+Au and Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. In particular, we discuss properties of the near-side yield of associated charged particles as a function of centrality, transverse momentum and $z_T$, as well as possible baryon/meson and particle/antiparticle differences. The results are compared to the proton and pion triggered correlations and to fragmentation and recombination models.

nucl-ex↗

Semihard scattering unraveled from collective dynamics at $\sqrt{s}$=17 GeV

We present a study of elliptic flow ($v_2$) and two-particle azimuthal correlations of charged hadrons and high transverse momentum ($p_T$) pions measured by the CERES experiment in Pb+Au collisions at $\sqrt{s}$~=~17 GeV. Azimuthal anisotropy $v_2$ increases linearly with $p_T$ to a value of 10% at $p_T$~=~1.5 GeV/$c$. Beyond this $p_T$ the slope decreases indicating a possible saturation at high $p_T$. Two-pion azimuthal anisotropies ($p_T>$~1.2 GeV/$c$) exceed $v_2$ by about 60% in semicentral collisions and reveal non-harmonic contributions at close ($Δϕ\approx0$) and back-to-back ($Δϕ\approxπ$) angles that can be attributed to semihard processes. While the close-angle peak remains unchanged, the back-to-back peak is broadened and disappears in central collisions.

nucl-ex↗