Forming Molecular States with Hadronic Rescattering

TL;DR

This paper introduces a method to model the production of exotic molecular states in high-energy collisions using hadronic rescattering within the Pythia event generator, providing cross section estimates for specific states at the LHC.

Contribution

It presents a novel approach to simulate and estimate the production cross sections of exotic hadronic molecules via hadronic rescattering at the LHC.

Findings

The $ ext{χ}_{c1}(3872)$ cross section contributes about 1% to the measured value.

Expected yields of $P_c^+$ states during LHCb Run 3 are estimated.

Prompt background exceeds the $P_c^+$ signal from rescattering.

Abstract

A method for modelling the prompt production of molecular states using the hadronic rescattering framework of the general-purpose Pythia event generator is introduced. Production cross sections of possible exotic hadronic molecules via hadronic rescattering at the LHC are calculated for the $\chi_{c1}(3872)$ resonance, a possible tetraquark state, as well as three possible pentaquark states, $P_c^+(4312)$, $P_c^+(4440)$, and $P_c^+(4457)$. For the $P_c^+$ states, the expected cross section from $\Lambda_b$ decays is compared to the hadronic-rescattering production. The $\chi_{c1}(3872)$ cross section is compared to the fiducial $\chi_{c1}(3872)$ cross-section measurement by LHCb and found to contribute at a level of O(1%). Finally, the expected yields of $P_c^+$ production from hadronic rescattering during Run 3 of LHCb are estimated. The prompt background is found to be significantly larger than the prompt $P_c^+$ signal from hadronic rescattering.