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Nur Hussain

Publications and source records attributed to Nur Hussain.

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Baryon number transportation over full rapidity space in pp collisions at LHC energies

The estimation of anti-baryon to baryon ratio is considered to be a useful tool for studying baryon number transport in pp, pA and AA collisions. For this study, the Pythia event generator with various tunes is used to measure the ${\Anti-Lamda}$/$\Lamda$ ratio as a function of rapidity (y), transverse momentum (pT ), and multiplicity within both ALICE and LHCb acceptances. The results obtained using various MC data for pp collisions at \sqrt{s} = 7 TeV are compared with the experimentally measured values of ${\Anti-Lamda}$/$\Lamda$ ratio of ALICE and LHCb experiments. Out of the various studied tunes of Pythia 8.3, the string junction model is found to be the most successful in describing the experimentally observed results. Evidence of a considerable amount of baryon number transportation from the beam fragmentation to the ALICE and LHCb acceptances could be recognised.

hep-ph

Spectator partons contribution in the rapidity width of lamda in p+p collisions at various SPS and LHC energies

Pseudorapidity distributions of all primary charged particles produced in p+p collisions at various Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies using UrQMD-3.4 and PYTHIA8.2-generated events are estimated and compared with the existing results of UA5 and ALICE collaborations. With both the sets of generated data, the variation of rapidity widths with the rest masses of different mesons and baryons of p+p collisions at various Super Proton Synchrotron (SPS) and LHC energies are presented. An increase in the width of the rapidity distribution of lambda, similar to heavy-ion data, could be seen in p+p collisions as well from SPS to the LHC energies (up to {sqrt_s} =13 TeV) when the entire rapidity space is considered, indicating its universal feature both in p+p and A+A collisions. The genesis of the increased width of rapidity distribution of Lambda in p+p collision is found to be in the production of light flavored quarks and diquarks from the spectator partons of the colliding hadrons resulting {lambda}/{anti_lambda}>1 at the extreme rapidities of the studied p+p collisions. At the LHC energies for central p+p collision, when there is no spectator partons, the rapidity width of {lambda} is found to take the same Gaussian shape as that of lambda and the widths of both the distributions become the same confirming no non-trivial contribution to the rapidity width of {lambda} as seen in heavy-ion and non-central p+p collisions.

nucl-th

Role of net baryon density on rapidity width of identified particles from the lowest energies available at the CERN Super Proton Synchrotron to those at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider

Widths of the rapidity distributions of various identified hadrons generated with the UrQMD-3.4 event generator at all the Super Proton Synchrotron (SPS) energies have been presented and compared with the existing experimental results. An increase in the width of the rapidity distribution of $Λ$ could be seen with both Monte Carlo (MC) and experimental data for the studied energies. Using MC data, the study has been extended to Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. A similar jump, as observed in the plot of rapidity width versus rest mass at Alternating Gradient Synchrotron (AGS) and all SPS energies, persists even at RHIC and LHC energies, confirming its universal nature from AGS to the highest LHC energies. Such observation indicates that pair production may not be the only mechanism of particle production at the highest LHC energies. However, with MC data, the separate mass scaling for mesons and baryons is found to exist even at the top LHC energy.

nucl-th