Evidence of rescattering effect in Pb-Pb collisions at the LHC through production of $\rm{K}^{*}(892)^{0}$ and $\phi(1020)$ mesons

Measurements of K$^{*}$(892)$^{0}$ and φ(1020)resonance production in Pb–Pb and pp collisions at √sNN =5.02 TeV with the ALICE detector at the Large Hadron Collider are reported. The resonances are measured at midrapidity (|y|<0.5) via their hadronic decay channels and the transverse momentum($p$$_{T}$) distributions are obtained for various collision centrality classes up to $p$$_{T}$ = 20 GeV/$c$. The $p$$_{T}$-integrated yield ratio K$^{*}$(892)$^{0}$/K in Pb–Pb collisions shows significant suppression relative to pp collisions and decreases towards more central collisions. In contrast, the φ(1020)/K ratio does not show any suppression. Furthermore, the measured K$^{∗}$(892)$^{0}$/K ratio in central Pb–Pb collisions is significantly suppressed with respect to the expectations based on a thermal model calculation, while the φ(1020)/K ratio agrees with the model prediction. These measurements are an experimental demonstration of rescattering of K$^{∗}$(892)$^{0}$ decay products in the hadronic phase of the collisions. The K$^{∗}$(892)$^{0}$/K yield ratios in Pb–Pb and pp collisions are used to estimate the time duration between chemical and kinetic freeze-out, which is found to be ∼4–7 fm/$c$ for central collisions. The $p$$_{T}$-differential ratios of K$^{∗}$(892)$^{0}$/K, φ(1020)/K, K$^{∗}$(892)$^{0}$/π,φ(1020)/π, $p$/K$^{∗}$(892)$^{0}$ and $p$/φ(1020)are also presented for Pb–Pb and pp collisions at √sNN = 5.02 TeV. These ratios show that the rescattering effect is predominantly a low-$p$$_{T}$ phenomenon.