The production yields of the orbitally excited charm-strange mesons $\mathrm{D_{s1}(1^{+})(2536)^+}$ and $\mathrm{D_{s2}^{*}(2^{+})(2573)^+}$were measured for the first time in proton-proton (pp) collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV with the ALICE experiment at the LHC. The $\mathrm{D_{s1}^+}$ and $\mathrm{D_{s2}^{*+}}$ mesons were measured at midrapidity ($|y|<~0.5$) in minimum-bias and high-multiplicity pp collisions in the transverse-momentum interval $2<~p_{\rm T}<~24$ GeV/$c$. Their production yields relative to the $\mathrm{D_{s}^{+}}$ ground-state yield were found to be compatible between minimum-bias and high-multiplicity collisions, as well as with previous measurements in ${\rm e}^{\pm}$p and ${\rm e^+ e^-}$ collisions. The measured $\mathrm{D_{s1}^+/D_{s}^{+}}$ and $\mathrm{D_{s2}^{*+}/D_{s}^{+}}$ yield ratios are described by statistical hadronization models and can be used to tune the parameters governing the production of excited charm-strange hadrons in Monte Carlo generators, such as PYTHIA 8.
Phys. Rev. D 111, 112005 (2025)
HEP Data
e-Print: arXiv:2409.11938 | PDF | inSPIRE
CERN-EP-2024-233
Figure group
Figure 1
Invariant-mass distributions $M(\mathrm{K}\uppi\uppi \kzero) - M(\mathrm{K}\uppi\uppi)$ of $\Dsone$ (top panels) and $\Dstwo$ (bottom panels) candidates and charge conjugates in the $2\pt24 \GeVc$ interval, for the \INEL and HMV0 (\nolinebreak{0--0.1\% V0M}) samples. The blue solid lines show the total fit functions described in the text, and the red dashed lines represent the combinatorial background. The raw-yield ($S$) values are reported together with their statistical uncertainties, as well as the estimated significance of the signal (Signif.). The bottom sub-panels of each panel display the differences between the data and the fit, normalized by the experimental uncertainties, to show the agreement between the data and the fit. |     |
Figure 2
$\Dsone/\Ds$ (left) and $\Dstwo/\Ds$ (right) ratio times BR as a function of the average charged-particle multiplicity \avdndeta in pp collisions at $\s= 13 \TeV$ at midrapidity ($|y| 0.5$). The experimental results are compared with the theoretical predictions based on the SHM , the SHMc , PYTHIA 8 , and EPOS4HQ . The statistical and systematic uncertainties on the measured ratios are depicted as vertical lines and boxes, respectively. The theoretical uncertainty on the predicted ratios is depicted as a shaded band for the \Dsone. |   |
Figure 3
$\pt$-integrated yields of prompt \Dsone (left) and \Dstwo (right) mesons divided by the $\pt$-integrated yields of prompt $\Ds$ mesons. The measurements are compared to the ones performed at LEP . For the ALICE measurements, the results consider the BR of the decay of interest computed as described in the text considering the RQM predictions and PDG information . The experimental results are compared with the theoretical predictions based on the SHM and the SHMc models. |  |