π⁰ production in dC- and dCu-interactions at a momentum of 4.5 GeV/c per nucleon

¹ VBLHEP JINR, 141980 Dubna, Moscow region, Russia
² Yerevan State University, 0025, Yerevan, Armenia

^* e-mail: jenaro@mail.ru

Published online: 27 March 2017

Abstract

We report on measurements of neutral pion production in the inclusive reactions d + C → π⁰ + x and d + Cu → π⁰ + x at an incident momentum of 4.5 GeV/c per nucleon. The experiments were performed on the LHE 90-channel lead glass γ-spectrometer. The cross sections were measured over the kinematical region specified by the inequalities θ_π ≤ 16° and E_π ≥ 2 GeV (in the laboratory frame). The cumulative number and transverse momentum dependencies of the exponent n in the invariant cross section parameterization Ed³ σ / d³ p ~ A_tⁿ are investigated by comparing of the observed cross sections for π⁰ production on carbon and copper targets in the intervals 0.6 ≤ X ≤ 1.8 and 0.04 ≤ p_T² ≤ 0.40 (GeV/c)². The double differential cross section for the reaction d + C → π⁰ + x is measured using statistics of about 4.5 · 10⁴π⁰ mesons. On the basis of these data we verified the so-called cluster mechanism of π⁰ production. We have compared our data for the reaction d + C → π⁰ + x, extrapolated to θ_π = 0°, with the data from another experiments on π⁻ production: d + C → π⁻(0°) + x (P = 1.75 and 2.88 GeV/c per nucleon) [1]; p + d → π⁻(180°) + x and p + d → π⁺(180°) + x (P = 8.9 GeV/c per nucleon) [2]; d + p → π⁻(0°) + x (P = 8.9 GeV/c per nucleon) [3]. The invariant cross sections were approximated by an exponential function Ed³ σ / d³ p ~ exp(−X / X₀). The slope parameter X₀ at different kinetic energies of the projectiles in the range of 1.05÷8.0 GeV per nucleon is determined.