Estimation of the isothermal compressibility from event-by-event multiplicity fluctuation studies

The first estimation of the isothermal compressibility ($_{k_T}$) of matter is presented for a wide range of collision energies from $\sqrt{s_{NN}}$ = 7.7 GeV to 2.76 TeV. $_{k_T}$ is estimated with the help of event-byevent charged particle multiplicity fluctuations from experiment. Dynamical fluctuations are extracted by removing the statistical fluctuations obtained from the participant model. $_{k_T}$ is also estimated from event generators AMPT, UrQMD, EPOS and a hadron resonance gas model. The values of isothermal compressibility are estimated for the Large Hadron Collider (LHC) energies with the help of the event generators.