15 research outputs found
Proton decay and light sterile neutrinos
Within the standard model, non-renormalizable operators at dimension six
() violate baryon and lepton number by one unit and thus lead to proton
decay. Here, we point out that the proton decay mode with a charged pion and
missing energy can be a characteristic signature of operators containing
a light sterile neutrino, if it is not accompanied by the standard
final state. We discuss this effect first at the level of effective operators
and then provide a concrete model with new physics at the TeV scale, in which
the lightness of the active neutrinos and the stability of the proton are
related.Comment: 7 pages, 2 figures, published versio
Lepton flavor violating decays of vector mesons
We estimate the rates of lepton flavor violating decays of the vector mesons
. The theoretical tools are based on an effective
Lagrangian approach without referring to any specific realization of the
physics beyond the standard model responsible for lepton flavor violation
(\Lfv). The effective lepton-vector meson couplings are extracted from the
existing experimental bounds on the nuclear conversion. In
particular, we derive an upper limit for the \Lfv branching ratio which is much more stringent than
the recent experimental result
presented by the SND Collaboration. Very tiny limits on \Lfv decays of vector
mesons derived in this letter make direct experimental observation of these
processes unrealistic.Comment: 3 pages, 1 figure, accepted for publication in Phys. Rev.
New bounds on lepton flavor violating decays of vector mesons and the Z0 boson
We give an estimate for the upper bounds on rates of lepton flavor violating
(LFV) decays M to mu(pm) + e(mp) of vector mesons M = rho0, omega, phi, J/psi,
Upsilon and the Z0 boson in a model independent way, analyzing the
corresponding lowest dimension effective operators. These operators also
contribute to nuclear mu-e-conversion. Based on this observation and using the
existing experimental limits on this LFV nuclear process, we show that the
studied two-body LFV decays of vector bosons are strongly suppressed
independent on the explicit realization of new physics. The upper limits on the
rates of some of these decays are significantly more stringent than similar
limits known in the literature. In view of these results experimental
observation of the two-body LFV decays of vector bosons looks presently
unrealistic.Comment: 4 pages, 1 figur