Kaon-induced $\varphi \Sigma$ production off the proton

Abstract

We investigate the reaction mechanism of $K^{-}p\to \varphi {\Sigma }^0$ within a hybrid Regge approach based on effective Lagrangians. The nonresonant background includes Reggeized $t$-channel $K$ and $K^{\ast }$ exchanges, together with ground-state $\Sigma$ and nucleon exchanges in the $s$ and $u$ channels, respectively. To describe the structures observed at $3.0⩽P_{\mathrm{Lab}}⩽4.5$ 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 $K^{\ast }$-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 $-t^{\prime }$. 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.

Comments: 11 pages, 8 figures