Bottom quark energy loss and hadronization with B$^{+}$ and $ {\textrm{B}}_{\textrm{s}}^0 $ nuclear modification factors using pp and PbPb collisions at $ \sqrt{s_{\textrm{NN}}} $ = 5.02 TeV
The production cross sections of $ {\textrm{B}}_{\textrm{s}}^0 $ and B$^{+}$ mesons are reported in proton-proton (pp) collisions marc:recorded by the CMS experiment at the CERN LHC with a center-of-mass energy of 5.02 TeV. The data sample corresponds to an integrated luminosity of 302 pb$^{−1}$. The cross sections are based on measurements of the $ {\textrm{B}}_{\textrm{s}}^0 $→ J/ψ(μ$^{+}$μ$^{−}$)ϕ(1020)(K$^{+}$K$^{−}$) and B$^{+}$→ J/ψ(μ$^{+}$μ$^{−}$)K$^{+}$ decay channels. Results are presented in the transverse momentum (p$_{T}$) range 7–50 GeV/c and the rapidity interval |y| < 2.4 for the B mesons. The measured p$_{T}$-differential cross sections of B$^{+}$ and $ {\textrm{B}}_{\textrm{s}}^0 $ in pp collisions are well described by fixed-order plus next-to-leading logarithm perturbative quantum chromodynamics calculations. Using previous PbPb collision measurements at the same nucleon-nucleon center-of-mass energy, the nuclear modification factors, R$_{AA}$, of the B mesons are determined. For p$_{T}$> 10 GeV/c, both mesons are found to be suppressed in PbPb collisions (with R$_{AA}$ values significantly below unity), with less suppression observed for the $ {\textrm{B}}_{\textrm{s}}^0 $ mesons. In this p$_{T}$ range, the R$_{AA}$ values for the B$^{+}$ mesons are consistent with those for inclusive charged hadrons and D$^{0}$ mesons. Below 10 GeV/c, both B$^{+}$ and $ {\textrm{B}}_{\textrm{s}}^0 $ are found to be less suppressed than either inclusive charged hadrons or D$^{0}$ mesons, with the $ {\textrm{B}}_{\textrm{s}}^0 $R$_{AA}$ value consistent with unity. The R$_{AA}$ values found for the B$^{+}$ and $ {\textrm{B}}_{\textrm{s}}^0 $ are compared to theoretical calculations, providing constraints on the mechanism of bottom quark energy loss and hadronization in the quark-gluon plasma, the hot and dense matter created in ultrarelativistic heavy ion collisions.[graphic not available: see fulltext]
Benecke, A., Bethani, A., Bruno, G., Caputo, C., de Favereau de Jeneret, J., Delaere, C., Donertas, I. S., Giammanco, A., Guzel, A. O., Jain, S., Jain, S., Lemaitre, V., Lidrych, J., Mastrapasqua, P., Tran, T. T., Wertz, S., CMS, & et al. (2025). Bottom quark energy loss and hadronization with B$^{+}$ and $ {\textrm{B}}_{\textrm{s}}^0 $ nuclear modification factors using pp and PbPb collisions at $ \sqrt{s_{\textrm{NN}}} $ = 5.02 TeV. Journal of High Energy Physics, 02. https://doi.org/10.1007/JHEP02(2025)195 (Original work published 2025)