Photon and π⁰ pairs production in proton-nucleus and deuteron-nucleus interactions. Results of experiments on internal beams of the Nuclotron

¹ VBLHEP JINR, 141980 Dubna, Moscow region, Russia
² Yerevan State University, 0025, Yerevan, Armenia
³ Institute of Applied Physics, MD-2028 Kishinev, Moldova
⁴ Institute of Nuclear Physics, Moscow State University, 119992, Moscow, Russia
⁵ Institut für Theoretische Physik, Universität Tübingen, D-72076 Tübingen, Germany
⁶ Moscow State Institute of Radioengineering, Electronics and Automation, 119454 Moscow, Russia
⁷ BLTP JINR, 141980 Dubna, Moscow region, Russia

^* e-mail: abraam@bk.ru

Published online: 27 March 2017

Abstract

The results of experiments on photon and π⁰ pairs production in interactions of 5.5 GeV/c protons, 2.75 and 3.83 GeV/c per nucleon deuterons with carbon and copper nuclei are presented. As previously reported (see. [1] and references therein), along with π⁰ and η mesons, a resonance structure in the invariant mass spectrum of two photons at M_γγ = 360 ± 7 ± 9 MeV is observed in the reaction dC → γ + γ + X at momentum 2.75 GeV/c per nucleon. Here are some results of testing the signal and results of statistical analysis of the experimental data which allow to explain the lack of appearance of the signal in other experiments [2, 3] and make predictions for possible appearances of the signal in upcoming experiments.