Bose-Einstein correlations in pp collisions at 400 GeV/c

Abstract

Bose-Einstein correlations among identically charged pions produced inpp collisions at 400 GeV/c are studied using the EHS spectrometer. Empoying the Kopylov-Podgoretskii parametrization, the average size of the emitting region r_k and its lifetime τ for pion production were determined to be r_k=1.71 ± 0.04 fm and c τ=0.89± 0.05fm. The average sizer g in terms of the Lorentz invariant Goldhaber parametrization was determined to be r_g=1.20±0.03fm. A decrease of the size with increasing momentum of the pions was observed. The size and the incoherence parameter of the pion emitting region were determined as a function of the charged particle multiplicity and the momentum of the pions. Identified charged kaons were used to study Bose-Einstein correlations among identically charged kaons K^± K^± . The average size of the emitting region for kaon production was determined to be r_k=1.87± 0.33fm in terms of the Kopylov-Podgoretskii parametrization. A study of the influence of a reference sample is presented.