학술논문
Study of a near-threshold scalar resonance in the ωϕ system in pion-Be interaction at momentum of 29 GeV
Document Type
Original Paper
Author
Source
The European Physical Journal A: Hadrons and Nuclei. 60(5)
Subject
Language
English
ISSN
1434-601X
Abstract
The charge-exchange reaction π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) with π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) and π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) is studied with the upgraded VES facility (U-70, Protvino) using a 29 GeV pion beam. The distribution of the π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) invariant mass shows a near-threshold enhancement. Partial-wave analysis reveals that an isoscalar scalar state with π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) dominates in this mass region. Considering the observed signal as an π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) resonance, and using the one-pion-exchange model, the product of the branching fractions into two channels π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) is measured. Based on this value, a large partial width is found for the radiative decay of π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) into this state, which suggests a significant glueball component. The result is discussed under alternative assumptions concerning an identification of the observed signal as π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770) or π-Be→Aω(782)ϕ(1020)ω→π+π-π0ϕ→K+K-ωϕJPC=0++f0Br(f0→ππ)Br(f0→ωϕ)J/ψf0(1710)f0(1770).