Temperature and Multiplicity Fluctuations as a New Tool of Characterization for Heavy Ion Collisions at LHC Energy

Abstract

A method has been proposed to study event-by-event fluctuations in Temperature (T), both globally and locally. The global temperature fluctuations, obtained from the event-by-event distribution of mean transverse mass ($\langle m_\mathrm{T} \rangle$) over a large phase space, provide the heat capacity (C) and specific heat ($c_v$) of the system, which is an important thermodynamic quantity. The fluctuations in multiplicity also provide the key features of a Grand Canonical Ensembles (GCE) and related to isothermal compressibility ($k_{T}$). Large number of particles produced in each collision at the LHC makes it possible to divide the available phase space to several bins in rapidity (y) and azimuthal angle ($\phi$). Bin to bin fluctuations in $\langle m_\mathrm{T} \rangle$  and T provide a means to access the remnant of the fluctuations from the early stage of the collision. This new method of studying global and local temperature fluctuations, and their application to experimental data at the LHC will be presented. We present the result of global and local temperature fluctuations at the $\sqrt{s_\mathrm{NN}}$  = 2.76 TeV by the use of AMPT event generator in this manuscript.