Temperature and fluid velocity on the freeze-out surface from <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>π</mml:mi></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>K</mml:mi></mml:math>, and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>p</mml:mi></mml:math> spectra in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:mi>p</mml:mi><mml:mi>p</mml:mi></mml:mrow></mml:math>, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>p</mml:mi></mml:math>-Pb, and Pb-Pb collisions
Aleksas Mazeliauskas, Vytautas Vislavicius
Abstract
We present a new approach to take into account resonance decays in the blast-wave model fits of identified hadron spectra. Thanks to precalculated decayed particle spectra, we are able to extract, in a matter of seconds, the multiplicity dependence of the single freeze-out temperature ${T}_{\mathrm{fo}}$, average fluid velocity $\ensuremath{\langle}{\ensuremath{\beta}}_{\mathrm{T}}\ensuremath{\rangle}$, velocity exponent $n$, and the volume $dV/dy$ of an expanding fireball. In contrast to blast-wave fits without resonance feed-down, our approach results in a freeze-out temperature of ${T}_{\text{fo}}\ensuremath{\approx}150\phantom{\rule{0.28em}{0ex}}\text{MeV}$, which has only weak dependence on multiplicity and collision system. Finally, we discuss separate chemical and kinetic freeze-outs separated by partial chemical equilibrium.