Study of source size in [ital p[bar p]] collisions at [radical][ital s] =1. 8 TeV using pion interferometry

Experiment E735 collected data for [similar to]10[sup 7] interactions at the C0 intersection of the Fermilab [ital p[bar p]] collider with [radical][ital s] =1.8 TeV. The Bose-Einstein correlations between pairs of identical pions were measured in a limited aperture spectrometer and used to estimate the size and lifetime of the source. The aperture shape limited the sensitivity primarily to the source dimension [ital R] along the incident [ital p[bar p]] direction. Both this dimension and the lifetime appear to depend strongly on pion multiplicity. Efforts were also made to obtain some information on the transverse source size, energy density, and the dependence of source size and strength on dipion momentum. Fits to the entire data sample yielded a value [ital R]=1.06[plus minus]0.07 fm for the average source dimension and a value [tau]=0.74[plus minus]0.06 fm for the average source lifetime with [l angle][ital dN][sub [ital c]]/[ital d][eta][r angle]=14.4.