Bose-Einstein correlations inpp collisions at 400 GeV/c

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 regionrk and its lifetime τ for pion production were determined to berk=1.71±0.04 fm andcτ=0.89±0.05fm. The average sizerg in terms of the Lorentz invariant Goldhaber parametrization was determined to berg=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 kaonsK±K±. The average size of the emitting region for kaon production was determined to berk=1.87±0.33fm in terms of the Kopylov-Podgoretskii parametrization. A study of the influence of a reference sample is presented.