Investigation of $T_{cs0}^{*}(2870)^{0}$ in $pp$ collisions at $\sqrt{s}$ = 7 TeV with the PACIAE model

TL;DR

The paper investigates whether $T_{cs0}^{*}(2870)^{0}$ can be interpreted as a hadronic molecular state produced in $pp$ collisions at $\sqrt{s}=7$ TeV. It combines the PACIAE parton/hadron cascade with the DCPC phase-space coalescence to assemble four candidate molecular states from meson pairs $D^{0}K^{0}_{S}$, $D^{+}K^{-}$, $D^{*+}K^{*-}$, and $D^{*0}\bar{K}^{*0}$, using $m_0=2866$ MeV/$c^2$ and $\Delta m=28.5$ MeV/$c^2$. The results show a hierarchical pattern in yields and provide predicted rapidity, transverse-momentum, and angular distributions that can be tested by LHC data, supporting a hadronic-molecule interpretation and guiding future studies at higher energies and in other collision systems.

Abstract

We have used the parton and hadron cascade model PACIAE together with the Dynamically Constrained Phase-space Coalescence model (DCPC) to study the $T_{cs0}^{*}(2870)^{0}$ production in $pp$ collision at $\sqrt{s}$ = 7 TeV, following the LHCb observation of $T_{cs0}^{*}(2870)^{0}$ in the $B^{-}\to D^{-}D^{0}K^{0}_{S}$ decays in $pp$ collisions at $\sqrt{s}$ = 7, 8, and 13 TeV [PRL 134(2025)101901]. The final hadronic states of the $pp$ collisions at $\sqrt{s}$ = 7 TeV are first simulated by the PACIAE model. Four sets of $T_{cs0}^{*}(2870)^{0}$ candidates are then recombined by the DCPC model using the constituent meson pair of $D^{0}K^{0}_{S}$, $D^{+}K^{-}$, $D^{*+}K^{*-}$, and $D^{*0} \bar{K}^{*0}$ based on the above simulated final hadronic states, respectively. We calculate their rapidity distributions, transverse momentum spectra, and angular distribution between the two component mesons, as well as angular distribution between $D$ component meson and $T_{cs0}^{*}(2870)^{0}$. Our results show that the yields of four $T_{cs0}^{*}(2870)^{0}$ candidates follow the magnitude order of $D^{0}K^{0}_{S}$ $>$ $D^{+}K^{-}$ $>$ $D^{*+}K^{*-}$ $\sim$ $D^{*0} \bar{K}^{*0}$. Similar ordering behavior is also observed in the aforementioned distributions.

Figures (4)

• Figure 1: The yield of $T_{cs0}^{*}(2870)^{0}$ recombined from $D^0 K^0_S$ (triangles-down), $D^+ K^-$ (triangles-up), $D^{*+} K^{*-}$ (circles), and $D^{*0} \bar{K}^{*0}$ (squares) varying with the parameter $\Delta m$ under the $R_0$ range of 1.0 fm $<R_0<$ 5.0 fm in $pp$ collisions at $\sqrt{s}$ = 7 TeV.
• Figure 2: The simulated $p_T$ spectra and the corresponding experimental data of $\pi^{+}+\pi^{-}$, $K^{+}+K^{-}$, $K^{0}_{S}$, $(D^{0}+\bar{D}^0)/2$ and $(D^{+}+D^{-})/2$. The empty markers refer to the results simulated by the PACIAE model, and the solid markers refer to the ALICE data ALICE:2015ialALICE:2017olhALICE:2020jsh.
• Figure 3: The simulated $y$ (left panel) and $p_T$ (right panel) distributions of four $T_{cs0}^{*}(2870)^{0}$ candidates recombined from the $D^{0}K^{0}_{S}$ (triangles-down), the $D^{+}K^{-}$ (triangles-up), the $D^{*+}K^{*-}$ (circles), and the $D^{*0} \bar{K}^{*0}$ (squares) in $pp$ collisions at $\sqrt{s}$ = 7 TeV are shown, respectively. The black, blue, and red markers refer to results calculated in $R_0$ range of 1.0 fm $<R_0<$ 5.0 fm, 1.0 fm $<R_0<$ 3.0 fm, and 1.0 fm $<R_0<$ 2.0 fm, respectively.
• Figure 4: The angular distribution between two component mesons (left panel, where triangles-down for ($D^0$, $K^0_s$) and triangles-up for ($D^+$, $K^-$)), as well as the one between $D$ component meson and $T_{cs0}^{*}(2870)^{0}$ (right panel, where triangles-down for ($D^0$, $T_{cs0}^{*}(2870)^{0}$) and triangles-up for ($D^+$, $T_{cs0}^{*}(2870)^{0}$)) in $pp$ collisions at $\sqrt{s}$=7 TeV. The black, blue, and red markers refer to the results calculated in the $R_0$ range of 1.0 fm $<R_0<$ 5.0 fm, 1.0 fm $<R_0<$ 3.0 fm, and 1.0 fm $<R_0<$ 2.0 fm, respectively.