  Charged multiplicity distribution in a pseudo-rapidity window is formulated
under the assumption that the charge conservation is satisfied in the full
phase space.
  At first, we analyze measured charged particle multiplicity distributions in
pseudo-rapidity windows in LHC by CMS and ALICE collaborations with the two
probability distributions. One is the convolution of negative binomial and
Poisson distributions, and the other is the Glauber-Lachs formula.
  Each distribution is considered as an analogy of the quantum optics. Next, we
analyze the data with the double GL formulae for $|\eta|<2.4$ at 7 TeV by the
CMS collaboration and for $|\eta|<1.5$ at 8 TeV by the ALICE collaboration to
describe the global structure of measured distributions.
