Multiplicity Dependence of the D+ s /D+ Yield Ratio, and Searches for D∗+ s and Ds1(2460)+ in LHCb PbPb Collisions

Abstract

The multiplicity dependence of both the D+s /D+ yield ratio and the prompt tonon-prompt production fractions of the D+ and D+s mesons are studied in PbPb collision data at a center-of-mass energy of √ s = 5.02 TeV. The data sample corresponds to an integrated luminosity of 230 μb−1 collected with the LHCb detector. An enhanced D+ s to D+ production is observed with increasing multiplicity, compatible with the strangeness enhancement signature. Additionally, as multiplicity increases, the prompt to non-prompt D+s production fraction manifests an increasing tendency, while the prompt to non-prompt D+ production fraction exhibits a non-monotonic behavior. Furthermore, searches for the D∗+s and Ds1(2460)+ states are performed, both in the D+s γ decay channel, but no evidence for the latter is found.