Investigation of $P_{cs}(4459)^0$ pentaquark via its strong decay to $\Lambda J/\Psi$

TL;DR

This paper investigates the decay of the newly observed $P_{cs}(4459)^0$ pentaquark to determine its quantum numbers, using QCD sum rules to calculate decay width and support its $J^P=1/2^-$ assignment.

Contribution

It provides the first theoretical calculation of the decay width of $P_{cs}(4459)^0$ and confirms its quantum numbers and pentaquark structure based on QCD sum rule analysis.

Findings

Decay width consistent with experimental data

Quantum numbers $J^P=1/2^-$ confirmed

Supports diquark-diquark-antiquark substructure

Abstract

Recently the observation of a new pentaquark state, the hidden-charmed strange $P_{cs}(4459)^0$, was reported by the LHCb Collaboration. The spin-parity quantum numbers of this state were not determined as a result of insufficient statistics. To shed light on its quantum numbers, we investigate its decay, $P_{cs}(4459)^0 \rightarrow J/\psi \Lambda $, the mode that this state has been observed, within the QCD sum rule framework. We obtain the width of this decay assigning the spin-parity quantum numbers of $P_{cs}(4459)^0$ state as $J^P=\frac{1}{2}^-$ and its substructure as diquark-diquark-antiquark. To this end, we first calculate the strong coupling constants defining the considered decay and then use them in the width calculations. The obtained width is consistent with the experimental observation, confirming the quantum numbers $J^P=\frac{1}{2}^-$ and compact pentaquark nature for $P_{cs}(4459)^0$ state.