Speaker
Jan Stern
(IPN Orsay)
Description
The recent dedicated analysis of K^L_{$\mu$ 3} Dalitz plot by
NA48 reveals a 5
$\sigma$ deviation from the Callan-Treiman low-energy theorem ,
provided standard
electroweak
couplings of quarks are assumed. QCD can hardly tolerate such a
huge violation of its
$ SU(2) X SU(2) $ chiral symmetry. We suggest that , instead, the
observed
discrepancy reflects a small admixture of right - handed quark
currents coupled to W
( as proposed by us one year
ago.) It is argued that this interpretation allows to explain
the observeed size of
the effect and passes all electroweak tests at sub-TeV scales ,
both in the charged
and in the neutral currents sectors. The possible impact on the
tests of CKM
unitarity for light quarks will be
briefly discussed.
Primary author
Jan Stern
(IPN Orsay)
Co-authors
Emilie Passemar
(IPN - Orsay)
Micaela Oertel
(LUTH - Paris - Meudon)
Veronique Bernard
(Laboratoire de Physique theorique , Univ. Strasbourg)
