Study of reaction pi- A --> pi+pi-pi- A at VES setup

TL;DR

This paper presents a partial wave analysis of a three-pion system produced at high energy, introducing a new amplitude analysis method, and investigates exotic waves and t'-dependence without finding narrow resonances around 1.6 GeV.

Contribution

A novel amplitude analysis method based on extracting the largest eigenvalue of the density matrix is proposed for studying three-pion systems.

Findings

No narrow resonance around 1.6 GeV was observed.

An unusually steep t'-dependence for the pi(1300) was detected.

Exotic wave with JPC = 1-+ in rho pi system was studied across four t' regions.

Abstract

The results on partial wave analysis of 3pi system produced at beam momentum 36.6 GeV/c on beryllium target are presented. New method of amplitude analysis is suggested -- extraction of largest eigenvalue of density matrix. Exotic wave with JPC = 1-+ in rho pi system is studied in four t' regions. No narrow object around M = 1.6 GeV is found. Unusually steep t'-dependence for pi(1300) object is detected.