arXiv subjects

Tumpa Biswas

Publications and source records attributed to Tumpa Biswas.

3 recordsLinked to original sources

arXiv2026

Exploring the Effects of Color Reconnection on Net-Charge Fluctuations in $pp$ Collisions at $\sqrt{s}=2.76 \text{ TeV}$ using PYTHIA Monash

This work explores the effects of various color reconnection (CR) configurations on the net charge fluctuations of charged particles generated in $pp$ collisions at a center-of-mass energy of $\sqrt{s}$ = 2.76 TeV, simulated with the PYTHIA Monash using the variable $\nu_{(+,-,\text{dyn})}$. The results are compared with experimental data from ALICE, revealing that the current PYTHIA simulation settings overestimate the net charge fluctuations relative to the experimental observations. Furthermore, $\nu_{(+,-,\text{dyn})}$ exhibits a clear dependence on the MPICR range parameter, where increasing the range leads to more negative $\nu_{(+,-,\text{dyn})}$ values, suggesting the geometric extent of CR directly modulates the strength of local charge correlation. To ensure these effects are not a trivial consequence of particle density, a comparison with a retuned NoCR baseline at fixed multiplicity was performed. This analysis confirms that CR induces a genuine dynamical shift in fluctuations that persists independently of the average charged-particle density. The study also shows that the net charge and net pion channels display the strongest suppression in $\langle N_{\text{ch}} \rangle \nu_{(+-,\text{dyn})}$ compared to the net kaon and net proton channels. Overall, the study offers a useful benchmark against experimental results and sheds light on the underlying dynamics of the PYTHIA Monash.

nucl-ex↗

arXiv2024

The study of strongly intensive observables for $π^{\pm,0}$ in $pp$ collisions at LHC energy in the framework of PYTHIA model

The fractal and phase transitional properties of each type of pions (i.e. $π^{\pm,0}$) through one-dimensional $η-$space, at an energy of $\sqrt{s}=13~$TeV, have been studied with the help of the Scaled Factorial Moment (SFM) framework. To generate simulated data sets for $pp$ collisions under the minimum bias (MB) condition at $\sqrt{s}=13~$TeV, we have employed the Monte Carlo-based event simulator PYTHIA. Various parameters such as the Levy index $(μ)$, degree of multifractality $(r)$, anomalous fractal dimension $(d_q)$, multifractal specific heat $(c)$ and critical exponent $(ν)$ have been calculated. To study the Bose Einstein(BE) effect due to identical particles (here pions) we have also derived these parameters for mixed pion pairs (i.e. $\{π^{+},π^{-}\}$, $\{π^{+},π^{0}\}$ and $\{π^{-},π^{0}\}$) and we find that the effects of identical particles weakened for the mixture with respect to the individual distributions. The quest for the quark-hadron phase transition has also been conducted within the framework of the Ginzburg-Landau (GL) theory of second-order phase transition. Analysis revealed that for PYTHIA-generated MB events, there is a clear indication of the quark-hadron phase transition according to the GL theory. Furthermore, the values of the multifractal specific heat ($c$) for each $π^{+}, π^{-}, π^{0}$ and the mixture pair data sets of pions generated by PYTHIA model at MB condition, indicate a transition from multifractality to monofractality in $pp$ collisions at $\sqrt{s}=13~$TeV.

hep-ph↗

arXiv2023

Net-charge particle ratio fluctuations in $pp$ collisions at several LHC energies

Event-by-event particle ratio fluctuations for simulated data sets of three different models named UrQMD, AMPT, and Pythia are studied using the fluctuation variable $ν_{dyn}$. The simulated data sets produced in $pp$ collisions at four different LHC energies $\sqrt{s} = 2.76, 5.02, 7$ and $13$ TeV are generated and considered for this analysis. The variation of fluctuation parameter $ν_{dyn}$ for accepted pair of meson and baryon combination $i.e.$ $[π, K]$, $[π, p]$ and $[p, K]$ with the increasing value of the mean multiplicity of charged particles ($\langle N_{ch} \rangle$) are investigated. It has been observed that the correlation between the particle pair $[π, K]$ is more than that of the two other particle pairs $[π, p]$ and $[p, K]$. However, the energy-wise inspection of the fluctuation variable $ν_{dyn}$ for $0-10\%$ centrality data shows the increase in the correlation between the particles in each pair for all three models considered.

hep-ph↗