Analysis of Bose-Einstein correlations at fixed multiplicities in TeV energy $pp$ collisions in the quantum optical approach

The multiplicity distribution and the two-particle Bose-Einstein correlations at fixed multiplicities observed in $pp$ collisions at $\sqrt{s}=7$ TeV by the ALICE Collaboration are analyzed by the formulae obtained in the quantum optical approach. The chaoticity parameters in the inclusive and semi-inclusive events are estimated from the analysis. Multiplicity or $k_T$ dependence of longitudinal and transverse source radii are also estimated.