Photo-production of lowest $\Sigma^*_{1/2^-}$ state within the Regge-effective Lagrangian approach

TL;DR

This paper predicts the production cross sections of the elusive $ ext{Sigma}^*_{1/2^-}$ state in photon-induced reactions using a Regge-effective Lagrangian model, aiding future experimental searches.

Contribution

It introduces a theoretical framework for $ ext{Sigma}^*_{1/2^-}$ photo-production, considering multiple exchange diagrams, to guide experimental detection of this poorly understood state.

Findings

Predicted differential cross sections for $ ext{gamma} n o K^+ ext{Sigma}^{*-}_{1/2^-}$.

Provided total cross section estimates to assist experimental searches.

Highlighted the importance of $t$-channel $K$ exchange in the production process.

Abstract

Since the lowest $\Sigma^{*}$ state, with quantum numbers spin-parity $J^{P} =1/2^{-}$, is far from established experimentally and theoretically, we have performed a theoretical study on the $\Sigma^*_{1/2^-}$ photo-production within the Regge-effective Lagrangian approach. Taking into account that the $\Sigma^*_{1/2^-}$ couples to the $\bar{K}N$ channel, we have considered the contributions from the $t$-channel $K$ exchange diagram. Moreover, these contributions from $t$-channel $K^*$ exchange, $s$-channel nucleon pole, $u$-channel $\Sigma$ exchange, and the contact term, are considered. The differential and total cross sections of the process $\gamma n \to K^{+}\Sigma^{*-}_{1/2^-}$ are predicted with our model parameters. The results should be helpful to search for the $\Sigma^*_{1/2^-}$ state experimentally in future.