Diffractive dissociation into $K_sK^{\pm}\pi^{\mp}\pi^{-}$ final states

TL;DR

This paper reports on the analysis of diffractive dissociation into specific final states at CERN, aiming to identify spin-exotic mesons like the $ ext{π}_1(1600)$ and $ ext{π}_1(2000)$ through partial-wave analysis of the $K_sK^{\pm}\pi^{\mp}\pi^{-}$ system.

Contribution

It presents the first event selection and preliminary analysis of the diffractively produced system, advancing the search for spin-exotic states in COMPASS data.

Findings

Identification of $f_1(1285)$ and $f_1(1420)$ resonances in the data

Initial partial-wave analysis underway for decay channels

Enhanced data set from 2008/09 to clarify spin-exotic states

Abstract

The COMPASS fixed-target experiment at CERN/SPS is dedicated to the study of hadron structure and spectroscopy, especially the search for spin-exotic states. After having started to study the existence of the spin-exotic $\pi_1(1600)$ resonance in the 2004 pilot-run data, the new 2008/09 data will enable us to further clarify the situation. Apart from the $\pi_1(1600)$ resonance, also a spin-exotic $\pi_1(2000)$ was reported in the past in the $f_1(1285)\pi$ decay channel by the E852/BNL experiment, however, this state still lacks confirmation. We present a first event selection of the diffractively produced $(K\bar{K}\pi\pi)^{-}$ system showing clean $f_1(1285)$ and $f_1(1420)$ resonances at competing statistics. A partial-wave analysis started on $f_1(1285)\pi$ and $f_1(1420)\pi$ decay channels will further complete the search for spin-exotics in the 2008/09 COMPASS data.