Spin 3/2 Pentaquark Resonance Signature in Lattice QCD

TL;DR

This study explores the existence of spin-3/2 pentaquark states in lattice QCD, finding potential signals in the isoscalar 3/2+ channel but not in the 3/2- channel, thus guiding future research directions.

Contribution

First lattice QCD investigation of spin-3/2 pentaquarks using a specific interpolating field, identifying potential resonance signals in certain channels.

Findings

No evidence of attraction in the 3/2- channel near physical quark masses.

Possible binding signals detected in the isoscalar 3/2+ channel.

Suggests the 3/2+ channel as a promising candidate for further pentaquark studies.

Abstract

The possible discovery of the Theta+ pentaquark has motivated a number of studies of its nature using lattice QCD. While all the analyses thus far have focussed on spin-1/2 states, here we report the results of the first exploratory study in quenched lattice QCD of pentaquarks with spin 3/2. For the spin-3/2 interpolating field we use a product of the standard N and K* operators. We do not find any evidence for the standard lattice resonance signature of attraction (i.e., binding at quark masses near the physical regime) in the J^P = 3/2- channel. Some evidence of binding is inferred in the isoscalar 3/2+ channel at several quark masses, in accord with the standard lattice resonance signature. This suggests that this is a good candidate for the further study of pentaquarks on the lattice.