# Limiting fragmentation in high-energy nuclear collisions at the CERN Large Hadron Collider

Sahoo, Pragati (Discipline of Physics, School of Basic Sciences, Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore, 453552, India) ; Pareek, Pooja (Discipline of Physics, School of Basic Sciences, Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore, 453552, India) ; Tiwari, Swatantra Kumar (Discipline of Physics, School of Basic Sciences, Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore, 453552, India) ; Sahoo, Raghunath (Discipline of Physics, School of Basic Sciences, Indian Institute of Technology Indore, Simrol, Khandwa Road, Indore, 453552, India)

09 April 2019

Abstract: The hypothesis of limiting fragmentation (LF), or, as it has been otherwise recently called, longitudinal scaling, is an interesting phenomena in the high-energy multiparticle production process. This paper discusses different regions of phase space and their importance in hadron production, giving special emphasis on the fragmentation region. Although it was conjectured as a universal phenomenon in high-energy physics, with the advent of higher center-of-mass energies, it has become prudent to analyze and understand the validity of such a hypothesis in view of the increasing inelastic nucleon-nucleon cross section (${\sigma }_{\mathrm{in}}$). In this work, we revisit the phenomenon of limiting fragmentation for nucleus-nucleus ($A$+$A$) collisions in the pseudorapidity distribution of charged particles at various energies. We use energy-dependent ${\sigma }_{\mathrm{in}}$ to transform the charged-particle pseudorapidity distributions ($d{N}_{\mathrm{ch}}^{AA}/d\eta$) into differential cross section per unit pseudorapidity ($d{\sigma }^{AA}/d\eta$) of charged particles and study the phenomenon of LF. We find that in $d{\sigma }^{AA}/d\eta$ LF seems to be violated at Large Hadron Collider (LHC) energies while considering the energy-dependent ${\sigma }_{\mathrm{in}}$. We also perform a similar study using the A Multi-Phase Transport model with a string melting scenario and also find that LF is violated at LHC energies.

Published in: Physical Review C 99 (2019)