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Дата изменения: Wed Aug 9 20:40:47 2000 Дата индексирования: Mon Oct 1 22:51:01 2012 Кодировка: |
It is well known that in the Standard Model only the left component
of massless neutrino takes part in interactions.
So one can describe neutrino by a Majorana field which has the
same number of degrees of freedom as a left Dirac one. To realize such a
particle in the framework of CompHEPone should add the
following record to the table of particles:
Full name | A | A+ | 2*spin | mass | width | color | aux |
neutrino | MN | MN | 1 | 0 | 0 | 1 |
In terms of Dirac field a neutrino appears in the Standard Model
Lagrangian in the following way (.19)1:
A1 | A2 | A3 | A4 | Factor | Lorentz part |
MN | MN | Z | -EE/(2*SW*CW) | G(m3)*G5 | |
E1 | MN | W- | EE/(2*Sqrt2*SW) | G(m3)*(1-G5) | |
MN | e1 | W+ | EE/(2*Sqrt2*SW) | G(m3)*(1-G5) |
Let us emphasize that there are two identical neutrino fields in that term of the Lagrangian which describes the interaction of neutrinos with a -boson. It leads to the additional factor and to the symmetry property of the corresponding vertex. One of the typical mistakes in realization of such a vertex is an introduction of the G(m3)*(1-G5) term which breaks the symmetry property. Correct evaluation of the functional derivative (8) with the help of the identity (11) never produces such a term.