Relaxation-time approximation with pair production and annihilation processes

Pion pair production in e + e − annihilation

We present an analysis of the process ee → γ orZ → ππγ, in the kinematical region where √ s, the c.m. energy of the ee pair, is large but much below the Z-pole. The subprocess γ orZ → ππγ can be described by the convolution of the hard scattering coefficient γ orZ → qq̄γ and the general distribution amplitude of two pions qq̄ → ππ. In the case of neutral pion, the production through γ is the domi...

The pair production spectrum from photon-photon annihilation

We present the first completely analytical computationof the full differentialγ-γ pair production rate fromcompact radiation fields, exact to 2nd order QED, and use this result to investigate the validity of previously known approximations.

THE BOTTOM BARYON PAIR PRODUCTION IN THE e+e−-ANNIHILATION

In the framework of the nonrelativistic diquark model of the heavy baryons and the perturbative approach of QCD we predict the value and energy dependence for the total cross section of the Λband Σ∗b-baryons pair production at the energy range of the KEKB and PEP-II ee-colliders.

Secondary Heavy Quark Pair Production in ee Annihilation

The multiplicity of heavy quarks from gluon splitting in ee annihilation has now been theoretically calculated and experimentally measured at LEP. However, the experimental measurement requires theoretical input for the shape of the multiplicity with respect to an event shape. In this paper we calculate the multiplicity of heavy quarks from gluon splitting in ee annihilation as a function of th...

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