Kaon-induced \(\phi \Sigma \) production off the proton

Abstract

We investigate the reaction mechanism of \(K^-p \rightarrow \phi \Sigma ^0\) within a hybrid Regge approach based on effective Lagrangians. The nonresonant background includes Reggeized t-channel K and \(K^*\) exchanges, together with ground-state \(\Sigma \) and nucleon exchanges in the s and u channels, respectively. To describe the structures observed at \(3.0 \leqslant P_{\textrm{Lab}} \leqslant 4.5\) GeV, we include the high-mass \(\Sigma (2620)\) and \(\Sigma (3000)\) resonances and examine the spin-parity assignments \(J^P = 1/2^\pm ,\) \(3/2^\pm ,\) and \(5/2^\pm .\) The \(K^*\)-Reggeon exchange dominates the forward-angle cross sections, whereas the smaller K-Reggeon contribution is important for the total cross section at low energies and for the spin-density matrix elements. The nonresonant background alone is not sufficient to reproduce the local structures in the total cross section or the differential cross sections at large \(-t'.\) Including the two resonances, particularly the \(\Sigma (3000),\) substantially improves the agreement with the available data. The \(J^P=5/2^-\) assignment for the \(\Sigma (3000)\) provides a reasonable overall description, although the present data do not permit a definitive determination.