175 research outputs found
Process 3 -> 3 and crossing symmetry violation
Using the Sudakov technique we sum the perturbation series for the process
and obtain the compact analytical expression for the amplitude of this
process, which takes into account all possible Coulomb interactions between
colliding particles. Compare it with the amplitude of the lepton pair
production in heavy ion collision i.e. in the process , we show that
crossing symmetry between this processes holds only if one neglects the
interaction of produced pair with ions (i.e. in the approximation
).Comment: LaTeX2e, 10 pages, 5 eps figure
Final state interaction in kaons decays
The kaons decays to the pairs of charged and neutral pions are considered in
the framework of the non-relativistic quantum mechanics. The general
expressions for the decay amplitudes to the two different channels accounting
for the strong interaction between pions are obtained. The developed approach
allows one to estimate the contribution of terms of any order in strong
interaction and correctly takes into account the electromagnetic interaction
between the pions in the final state.Comment: 8 page
Radiative corrections in decay
The final state interaction of pions in the decay allows to obtain the value of the isospin and angular
momentum zero pion-pion scattering length . To extract this quantity
from experimental data the radiative corrections (RC) have to be taken into
account. Basing on the lowest order results and the factorization hypothesis,
we get the expressions for RC in the leading and next-to leading logarithmical
approximation. It is shown that the decay width dependence on the lepton mass
through the parameter
\sigma=\frac{\alpha}{2\pi}\br{\ln\frac{M^2}{m_e^2}-1} has a standard form of
the Drell-Yan process and is proportional to the Sommerfeld-Sakharov factor.
The numerical estimations are presented.Comment: 11 pages, 5 figures, 1 table, some minor misprints are correcte
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