arXiv subjects

Jan Rak

Publications and source records attributed to Jan Rak.

5 recordsLinked to original sources

arXiv2015

Fragmentation in the phi^3 Theory and the LPHD Hypothesis

We present analytic solution of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) equation at leading order (LO) in the phi^3 theory in 6 space-time dimensions. If the phi^3 model was the theory of strong interactions, the obtained solution would describe the distribution of partons in a jet. We point out that the local parton-hadron duality (LPHD) conjecture does not work in this hypothetical situation. That is, treatment of hadronisation of shower partons is essential for the description of hadron distributions in jets stemming from proton-proton (pp) collisions at \sqrt{s} = 7 TeV and from electron-positron (e+e-) annihilations at various collision energies. We use a statistical model for the description of hadronisation.

hep-ph↗

arXiv2010

Jet properties from direct $γ$ - hadron correlation in PHENIX at RHIC

Two-particle correlations of direct photon triggers with associated hadrons are obtained by isolation method in p+p collisions at \sqrt{s} = 200 GeV in PHENIX at RHIC. The initial momentum of the away-side parton is tightly constrained, because the parton-photon pair is balanced in momentum at the leading order in perturbative quantum chromodynamics (pQCD). Therefore making such correlations can be used as a tool to measure the away-side parton fragmentation function. The direct photon associated yields in p+p collisions are compared with PYTHIA and the effect of the $k_{T}$ smearing in the spectra is discussed.

hep-ex↗

arXiv2007

From RHIC to LHC

Measurements of the nuclear modification factor of inclusive yields of $π^0$, $p\bar{p}$, non-phtonic electrons and prompt photon measured at RHIC are reviewed. Some of the difficulties arising from interpretation of these measurements such as similarity of the suppression pattern of light and heavy quarks, quarks and gluons, light quarks and prompt photon are discussed. The potential of two-particle and promt photon correlation technique to unravel some of these open questions is presented. An emphasis is given to the influence of partonic transverse momentum on the prompt-photon correlations. The smearing between the trigger photon and back-to-back jet at LHC energy is discussed.

hep-ex↗

arXiv2007

Jet properties from di-hadron correlations in p+p collisions at s**(1/2) = 200-GeV

An analysis of high pT hadron spectra associated with high pT $π^0$ particles in p+p collisions at s**(1/2) = 200-GeV is presented. The shape of the azimuthal angular correlation is used to determine the value of partonic intrinsic momentum $\sqrt{\left } = 2.68 \pm 0.07(\rm stat) \pm 0.34(\rm sys)$ GeV/c. The effect of kT-smearing of inclusive $π^0$ cross section is discussed.

hep-ex↗

arXiv2004

PHENIX measurement of jet properties and their modification in heavy-ion collisions

The properties of jets produced in p+p, d+Au and Au+Au collisions at sqrt{s_NN}=200 GeV are studied using the method of two particle correlations. The trigger particle is assumed to be a leading particle from a high p_T jet while the associated particle is assumed to come from either the same jet or the away jet. From the angular width and yield of the same and away side correlation peaks, the parameters characterizing the jet properties are extracted.

hep-ex↗