6,749 research outputs found
Lepton flavor changing in neutrinoless decays
Neutrino oscillations, as recently reported by the Super-Kamiokande
collaboration, imply that lepton numbers could be violated, and are some typical
examples. We point out that in these neutrinoless modes, the GIM cancelation is
much milder with only a logarithmic behavior where
are the neutrino masses. This is in sharp contrast with the vanishingly small
amplitude strongly suppressed by the quadratic
power . In comparison with the hopelessly small
branching ratio B, the
B could be larger than .
The latter mode, if measurable, could give one more constraint to the lepton
mixing angle and the neutrino mass ratio , and
therefore is complementary to neutrino oscillation experiments.Comment: Latex (7 pages) + 3 postscript figure
Possible huge enhancement in the radiative decay of the weal W boson into the charmed meson
We point out that the rare decay mode could be spectacularly enhanced, with a branching ratio around
which is three order of magnitude larger than previous predictions.
Its observation will determine the W boson mass with great accuracy, providing
additional high precision tests of the standard model, as well as reveal
eventual deviation from the trilinear non-abelian gauge coupling.Comment: 14, PAR/LPTHE 93 - 0
Chiral Anomaly Effects and the BaBar Measurements of the Transition Form Factor
The recent BaBar measurements of the transition
form factor show spectacular deviation from perturbative QCD prediction for
large space-like up to . When plotted against ,
shows steady increase with in contrast with the flat
behavior predicted by perturbative QCD, and at is
more than 50% larger than the QCD prediction. Stimulated by the BaBar
measurements, we revisit our previous paper on the cancellation of anomaly
effects in high energy processes , and apply our results to the
transition form factor measured in the
process with one highly virtual photon. We find that, the transition form
factor behaves as and produces a striking agreement with the BaBar data
for with which also reproduces very well the
CLEO data at lower .Comment: v4, LaTeX, 8 pages, one figure, minor changes(references), to appear
in Int. J. Mod. Phys.
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