Observation of New Resonance Structure in the Invariant Mass Spectrum of Two gamma-Quanta in dC-Interactions at Momentum 2.75 GeV/c per Nucleon

Abraamyan, Kh. U.; Sissakian, A. N.; Sorin, A. S.

Observation of New Resonance Structure in the Invariant Mass Spectrum of Two gamma-Quanta in dC-Interactions at Momentum 2.75 GeV/c per Nucleon

Authors

Abraamyan, Kh. U.

Sissakian, A. N.

Sorin, A. S.

Description

A new resonance structure at M = 355 \pm 6 \pm 9 MeV is observed in the invariant mass spectrum of two gamma-quanta produced in the reaction d + C => gamma + gamma + x at momentum 2.75 GeV/c per nucleon. Preliminary estimates of its width and cross section are Gamma = 41 \pm 12 MeV and sigma_{gamma-gamma} = 0.6 mkb. The collected statistics is 2680 \pm 310 events of 1.5 10^6 triggered interactions of a total number 3 10^{12} dC-interactions.
10 pages, 10 figures, LaTeX