A study of the reaction pim p --> omega pim p at 18 GeV/c: The D and S decay amplitudes for b1(1235) --> omega pi

TL;DR

This study investigates the reaction p̄ p → ω p̄ p at 18 GeV/c, focusing on the decay amplitudes of b1(1235) → ω π, revealing detailed amplitude ratios and phase differences through Partial Wave Analysis.

Contribution

It provides the first detailed measurement of the S-wave and D-wave decay amplitudes and their ratio and phase difference for b1(1235) → ω π at high energy.

Findings

Dominance of b1(1235) in the ω p̄ mass spectrum

Amplitude ratio |D/S| = 0.269 ± 0.009 (stat) ± 0.01 (sys)

Phase difference φ(D-S) = 10.54° ± 2.4° (stat) ± 3.9° (sys)

Abstract

The reaction pim p --> omega pim p, omega --> pip pim pi0 has been studied at 18 GeV/c. The omega pim mass spectrum is found to be dominated by the b1(1235). Partial Wave Analysis shows that b1 production is dominated by natural parity exchange. The S-wave and D-wave amplitudes for b1(1235) --> omega pi have been determined, and it is found that the amplitude ratio, |D/S| = 0.269 +/- (0.009)stat +/- (0.01)sys and the phase difference, phi(D-S) = 10.54 deg +/- (2.4)stat +/- (3.9)sys.