arXiv subjects

Buddhadeb Bhattacharjee

Publications and source records attributed to Buddhadeb Bhattacharjee.

6 recordsLinked to original sources

arXiv2025

Heavy flavor particle production in p+p collisions at the CERN Large Hadron Collider energies

The study of heavy-flavored baryon and meson production in proton-proton (pp) collisions provides crucial insight into the hadronization mechanisms of Quantum Chromodynamics (QCD). In this work an attempt has been made to describe the existing ALICE and LHCb results on the $p_\mathrm{T}$-differential production cross-section of $\Lambda_c^+$, $D^0$, $\Lambda_b^0$ and $B^0$ ($\bar{B}^0$), and $p_\mathrm{T}$-dependent $\Lambda_c^+/D^0$ and $\Lambda_b^0/B^0(\bar{B}^0)$ ratios, in light of the color-string junction inspired PYTHIA-8.314 model. A comparison of the results obtained with various datasets generated with different tuning parameters and the existing experimental results of ALICE and LHCb at $\sqrt{s} = 7$ and $13$ TeV underlines the relevance of string-junction dynamics in heavy-flavored particle production. The results of the present investigation reveal that while stopping the junction-antijunction reconfiguration in the non-perturbative PYTHIA-8.314 model successfully describes the considered ALICE experimental observables of the charm sector, on the other hand, allowing junction-antijunction reconfiguration, keeping other fragmentation parameters the same, better describes the LHCb experimental observables of both charm and bottom sectors.

hep-ph↗

arXiv2024

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↗

arXiv2024

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↗

arXiv2021

Effect of color reconnection on multiplicity dependent charged particle production in Pythia-generated $pp$ collisions at the LHC energies

The transverse momentum ($p_{\rm T}$) spectra of inclusive charged particles and its dependence on charged-particle multiplicity are studied in pp collisions at $\sqrt{s}$ = 7 and 13 TeV using the Monte Carlo event generator PYTHIA Monash. The results of the minimum bias pp collisions are compared with the ALICE published results at the same energies. The variations of the effective temperature (T$_{\rm {Eff}}$) and average transverse momentum ($\langle p_{\mathrm{T}} \rangle$) with charged-particle multiplicity are also studied. The $p_{\rm T}$ spectra of the charged particles are observed to get harder with increasing charged-particle multiplicity. Moreover, a sharp increase in the T$_{\rm {Eff}}$ and $\langle p_{\mathrm{T}} \rangle$ with increasing multiplicity followed by a gradual decrease with the further increase in multiplicity could also be observed. Further, it could be observed that the color reconnection (CR) mechanism has a considerable effect on flattening the T$_{\rm {Eff}}$ and $\langle p_{\mathrm{T}} \rangle$ with increasing multiplicity, which indicates that phase-transition may not necessarily be the only mechanism that could give rise to such an effect.

hep-ph↗

arXiv2019

Color reconnection as a possible mechanism of intermittency in the emission spectra of charged particles in PYTHIA-generated high-multiplicity $\textit{pp}$ collisions at energies available at the CERN Large Hadron Collider

Nonstatistical fluctuation in pseudorapidity ($η$), azimuthal ($ϕ$), and pseudorapidity-azimuthal ($η-ϕ$) distribution spectra of primary particles of PYTHIA Monash (default) generated $pp$ events at $\sqrt{s}=$ 2.76, 7, and 13 TeV have been studied using the scaled factorial moments technique. A weak intermittent type of emission could be realized for minimum-bias (MB) $pp$ events in $χ(η-ϕ)$ space and a much stronger intermittency could be observed in high-multiplicity (HM) $pp$ events in all $χ(η)$, $χ(ϕ)$, and $χ(η-ϕ)$ spaces at all the studied energies. For HM $pp$ events, at a particular energy, the intermittency index $α_{q}$ is found to be largest in two-dimensional $χ(η-ϕ)$ space and least in $χ(η)$ space, and no center of mass energy dependence of $α_{q}$ could be observed. The anomalous dimensions $d_{q}$ are observed to be increased with the order of the moment $q$, suggesting a multifractal nature of the emission spectra of various studied events. While, the coefficient $λ_q$ is found to decrease monotonically with the order of the moment $q$ for two-dimensional analysis of MB $pp$ events as well as for one-dimensional analysis of HM $pp$ events, a clear minimum in $λ_q$ values could be observed from the two-dimensional HM $pp$ data analysis. For PYTHIA Monash generated sets of data, the strength of the intermittency is found to vary significantly with the variation of the strength of the color reconnection (CR) parameter, i.e., reconnection range RR, for RR = 0.0, 1.8 and 3.0, thereby, establishing a strong connection between the CR mechanism and the observed intermittent type of emission of primary charged particles of the studied high-multiplicity $pp$ events.

hep-ph↗

arXiv2017

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.

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