Multichannel analysis of the reaction $\text{K}{}^{\mathrm{-}}\text{p}\text{→}\text{K}{}^0\text{π}{}^{\mathrm{-}}\text{p}$ at 4.2 GeV/c

Abstract

An analysis is presented of the reaction $\text{K}{}^{\mathrm{-}}\text{p}\text{→}\text{K}{}^0\text{π}{}^{\mathrm{-}}\text{p at}\text{4.2}\text{GeV}\text{/c}$ incident momentum, using analytical techniques in fully dimensional phase space. This methods allows to isolate the contributions of the 0⁺, 1⁻ and 2⁺ (Kπ) partial waves in various helecity Separating well-understood contributions from the rest, the method is particularly useful for the detection of small effects (≈1% of the total final-state cross section) not visible in the mass distributions: (i) small cross-section contributions of 3⁻ (Kπ partial waves, K^∗(1780), are unambiguously isolated; (ii) 3.5σ evidence is given for Σ(1480) in the (p$\text{K}$⁰) system; (iii) effects due to a second Kπ P-wave or the possible presence of a doubly peripheral mechanism are discussed. The method furthermore allows simultaneous treatment of the (Kπ) partial waves, pπ) partial waves and their interferences and of a Σ(1765) signal (with spin $\text{5}\text{2}$). While interferences within the (Kπ) and within the (pπ) systems are strongly determining the corresponding distributions, no interference between these systems is needed.