220,399 research outputs found
Neutrino Mass from Triplet and Doublet Scalars at the TeV Scale
If the minimal standard model of particle interactions is extended to include
a scalar triplet with lepton number and a scalar doublet with ,
neutrino masses eV is possible,
where GeV is the electroweak symmetry breaking scale,
TeV is the typical mass of the new scalars, and GeV is a soft
lepton-number-violating parameter.Comment: 6 pages, no figur
Seeding of Strange Matter with New Physics
At greater than nuclear densities, matter may convert into a mixture of
nucleons, hyperons, dibaryons, and strangelets, thus facilitating the formation
of strange matter even before the onset of the quark-matter phase transition.
From a nonstrange dibaryon condensate, it may even be possible to leapfrog into
strange matter with a certain new interaction, represented by an effective
six-quark operator which is phenomenologically unconstrained.Comment: 7 pages, no figure (Talk given at SQM97
High--Resolution 3D Simulations of Relativistic Jets
We have performed high-resolution 3D simulations of relativistic jets with
beam flow Lorentz factors up to 7, a spatial resolution of 8 cells per beam
radius, and for up to 75 normalized time units to study the morphology and
dynamics of 3D relativistic jets. Our simulations show that the coherent fast
backflows found in axisymmetric models are not present in 3D models. We further
find that when the jet is exposed to non-axisymmetric perturbations, (i) it
does not display the strong perturbations found for 3D classical hydrodynamic
and MHD jets (at least during the period of time covered by our simulations),
and (ii) it does propagate according to the 1D estimate. Small 3D effects in
the relativistic beam give rise to a lumpy distribution of apparent speeds like
that observed in M87. The beam is surrounded by a boundary layer of high
specific internal energy. The properties of this layer are briefly discussed.Comment: 15 pages, 4 figures. Accepted to be publish in the ApJ Letters.
Tar+gzip documen
Spontaneous Supersymmetric Generation of an Indeterminate Mass Scale and a Possible Light Sterile Neutrino
If a global continuous symmetry of a supersymmetric field theory is
spontaneously broken while preserving the supersymmetry, the resulting theory
has a massless superfield. One of its two bosonic degrees of freedom is the
familiar phase rotation of the usual massless Nambu-Goldstone boson, but the
other is a scale transformation. An indeterminate mass scale is thus generated.
In the fermion sector, a seesaw texture appears which may be suitable for a
possible light sterile neutrino. This feature persists even after the gauging
of the continuous symmetry or the breaking of the supersymmetry to resolve the
aforementioned mass-scale ambiguity.Comment: 9 pages, expanded to include the discussion of a possible sterile
neutrin
Baryon and Lepton Number Violation with Scalar Bilinears
We consider all possible scalar bilinears, which couple to two fermions of
the standard model. The various baryon and lepton number violating couplings
allowed by these exotic scalars are studied. We then discuss which ones are
constrained by limits on proton decay (to a lepton and a meson as well as to
three leptons), neutron-antineutron oscillations, and neutrinoless double beta
decay.Comment: 11 pages latex fil
Transverse-Momentum Dependent Factorization for gamma^* pi^0 to gamma
With a consistent definition of transverse-momentum dependent (TMD)
light-cone wave function, we show that the amplitude for the process can be factorized when the virtuality of the initial photon is
large. In contrast to the collinear factorization in which the amplitude is
factorized as a convolution of the standard light-cone wave function and a hard
part, the TMD factorization yields a convolution of a TMD light-cone wave
function, a soft factor and a hard part. We explicitly show that the TMD
factorization holds at one loop level. It is expected that the factorization
holds beyond one-loop level because the cancelation of soft divergences is on a
diagram-by-diagram basis. We also show that the TMD factorization helps to
resum large logarithms of type .Comment: Published version in Phys.Rev.D75:014014,200
Light Unstable Sterile Neutrino
The three massless active (doublet) neutrinos may mix with two heavy and one
\underline {light} sterile (singlet) neutrinos so that the induced masses and
mixings among the former are able to explain the present data on atmospheric
and solar neutrino oscillations. If the LSND result is also to be explained,
one active neutrino mass eigenstate must mix with the light sterile neutrino. A
specific model is proposed with the spontaneous and soft explicit breaking of a
new global symmetry so that a sterile neutrino will decay into an
active antineutrino and a nearly massless pseudo-Majoron.Comment: Discussion and references adde
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