Observation of abnormal suppression of ${\mathrm{f}}_0$(980) production in p$-$Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}$ = 5.02 TeV

The dependence of ${\mathrm{f}}_0$(980) production on the final-state charged-particle multiplicity in p$-$Pb collisions at $\sqrt{s_{\mathrm{N}\mathrm{N}}}=5.02$ TeV is reported. The production of ${\mathrm{f}}_0$(980) is measured with the ALICE detector via the ${\mathrm{f}}_0(980)\to {\pi }^{+}{\pi }^{-}$ decay channel in a midrapidity region of $-0.5<y<0$. Particle yield ratios of ${\mathrm{f}}_0$(980) to $\pi$ and ${\mathrm{K}}^{\ast }$(892)${}^0$ are found to be decreasing with increasing charged-particle multiplicity. The magnitude of the suppression of the ${\mathrm{f}}_0$(980)/$\pi$ and ${\mathrm{f}}_0$(980)/${\mathrm{K}}^{\ast }$(892)${}^0$ yield ratios is found to be dependent on the transverse momentum $p_{\mathrm{T}}$, suggesting different mechanisms responsible for the measured effects. Furthermore, the nuclear modification factor $Q_{\mathrm{p}\mathrm{P}\mathrm{b}}$ of ${\mathrm{f}}_0$(980) is measured in various multiplicity ranges. The $Q_{\mathrm{p}\mathrm{P}\mathrm{b}}$ shows a strong suppression of the ${\mathrm{f}}_0$(980) production in the $p_{\mathrm{T}}$ region up to about 4 GeV/$c$. The results on the particle yield ratios and $Q_{\mathrm{p}\mathrm{P}\mathrm{b}}$ for ${\mathrm{f}}_0$(980) may help to understand the late hadronic phase in p$-$Pb collisions and the nature of the internal structure of ${\mathrm{f}}_0$(980) particle.