51 research outputs found
Some consequences of a Higgs triplet
We consider an extension of the scalar sector of the Standard Model with a
single complex Higgs triplet . Such extensions are the most economic,
model-independent way of generating neutrino masses through triplet
interactions. We show that a term like \azero\Phi\Phi X^\dag must be included
in the most general potential of such a scenario, in order to avoid a massless
neutral physical scalar. We also demonstrate that \azero must be real, thus
ruling out any additional source of CP-violation. We then examine the
implications of this term in the mass matrices of the singly-and doubly-charged
scalar, neutral scalar and pseudoscalar fields. We find that, for small values
of \azero/\vtwo, where \vtwo is the triplet vev, the spectrum allows the
decay of heavier scalars into lighter ones via gauge interactions. For large
\azero/\vtwo, the doubly-charged, singly-charged and neutral pseudoscalar
bosons become practically degenerate, while the even-parity neutral scalars
remain considerably lighter, thus emphasizing the possibility of decay of the
singly-charged or neutral pseudoscalar states into the neutral scalars.
Constraints from the -parameter are used to find nontrivial limits on the
charged Higgs mass depending on \azero. We also study the couplings of the
various physical states in this scenario. For small values of |\azero|/\vtwo,
we find the lightest neutral scalar field to be triplet-dominated, and thus
having extremely suppressed interactions with fermion as well as gauge boson
pairs.Comment: Revised version, 25 pages, 4 figure
Bulk Higgs field in a Randall-Sundrum model with nonvanishing brane cosmological constant
We consider the possibility of Higgs mechanism in the bulk in a generalised
Randall-Sundrum model, where a nonvanishing cosmological constant is induced on
the visible brane. This scenario has the advantage of accommodating positive
tension of the visible brane and thus ensures stability of the model. It is
shown that several problems usually associated with this mechanism are avoided
if some dimensionful parameters in the bulk are allowed to lie a little below
the Planck mass. The most important of these is keeping the lowest massive mode
in the scale of the standard electroweak model, and at the same time reducing
the gauge coupling of the next excited state, thus ameliorating otherwise
stringent phenomenological constraints.Comment: 7 pages, 2 tables, version accepted for publicatio
WAFERS: AN INNOVATIVE ADVANCEMENT OF ORO-DISPERSIBLE FILMS
The formulation of oral disintegrating films has led to the development of wafers which has modified itself in the recent past years. Wafers are more advantageous over other conventional dosage forms as well as from other oral disintegrating solid dosage forms. The major difficulty in formulating wafers is the choice of drugs to be incorporated. Wafers with low dose of active pharmaceutical ingredient (API) and with a good mouth feel are prepared for making it more patients compliant. The manufacturing procedures are quite similar to oral disintegrating film but the composition of polymers may vary. The wafers requires expensive packaging and care should be taken while handling, storage & transport. In spite of these hardships, wafers have become popular between geriatric and paediatric population because of its ease of administration and bioavailability.
Keywords: Transmucosal route, Oral films, Wafers, Fast dissolving dosage forms, Oral administratio
A Profile of Knee Injuries Suffered by Australian Army Reserve Soldiers
Despite having to perform the same occupational tasks as full-time soldiers, part-time soldiers may have lower levels of physical conditioning and report higher rates of injury per unit exposure to active service. The purpose of this study was to profile the leading body site of injury occurring in part-time soldiers to inform injury prevention strategies. Injury data from the Australian Army Reserve (ARES) spanning a two-year period were obtained from the Department of Defence Workplace Health, Safety, Compensation and Reporting database pertaining to locations, nature, mechanisms, and the activity being performed at the time of injury. Among the 1434 injuries reported by ARES personnel, the knee was the most common injury site (n = 228, 16%). Soft tissue injury due to trauma or unknown causes was the most common nature of knee injury (n = 177, 78%). Combat training was the most common activity being performed when soft tissue injuries occurred at the knee (n = 73, 42%), with physical training the second most common (n = 51, 30%), due to muscular stress (n = 36, 71%) and falls (n = 8, 16%). Targeted intrinsic and extrinsic approaches to injury minimization strategies for soft tissue knee injuries during combat and physical training should be designed
A comparison of ultraviolet sensitivities in universal, nonuniversal, and split extra dimensional models
We discuss the origin of ultraviolet sensitivity in extra dimensional
theories, and compare and contrast the cutoff dependences in universal,
nonuniversal and split five dimensional models. While the gauge bosons and
scalars are in the five dimensional bulk in all scenarios, the locations of the
fermions are different in different cases. In the universal model all fermions
can travel in the bulk, in the nonuniversal case they are all confined at the
brane, while in the split scenario some are in the bulk and some are in the
brane. A possible cure from such divergences is also discussed.Comment: 9 pages, Latex, no figure, v2: further clarifications and references
added, accepted for publication in Phys. Rev.
Unitarity violation in sequential neutrino mixing in a model of extra dimensions
We investigate the possibility of unitarity violation in the sequential
neutrino mixing matrix in a scenario with extra compact spacelike dimensions.
Gauge singlet neutrinos are assumed to propagate in one extra dimension, giving
rise to an infinite tower of states in the effective four-dimensional theory.
It is shown that this leads to small lepton-number violating entries in the
neutrino mass matrix, which can violate unitarity on the order of one per cent.Comment: 16 pages, 2 table
Neutrinos in flat extra dimension: towards a realistic scenario
We consider the simple extension of the Standard Model in which an additional
right handed neutrino propagates along a flat extra dimension, while the
Standard Model fields are confined on a 3-brane. The fifth dimension is
orbifold compactified. In this scenario, the neutrino mass can be
naturally suppressed. By studying systematically the fundamental parameter
space, we show that the strong phenomenological constraints on mixing angles
between active and sterile neutrinos (especially those derived from the SNO
experiment data) do not conflict with the possibility of generating a realistic
neutrino mass spectrum. As a second step, we explore the possibility of a
successful leptogenesis through the decays of the Kaluza-Klein excitations of
the right handed neutrino.Comment: 16 pages, 2 ps figure
Two-loop neutrino masses with large R-parity violating interactions in supersymmetry
We attempt to reconcile large trilinear R-parity violating interactions in a
supersymmetric (SUSY) theory with the observed pattern of neutrino masses and
mixing. We show that, with a restricted number of such interaction terms with
the -type couplings in the range (0.1-1.0), it is possible to forbid
one-loop contributions to the neutrino mass matrix. This is illustrated with
the help of a `working example' where an econnomic choice of SUSY parameters is
made, with three non-vanishing and `large' R-parity violating terms in the
superpotential. The two-loop contributions in such a case can not only generate
the masses in the requisite order but can also lead us to specific allowed
regions of the parameter space.Comment: Revised version, 25 pages, 16 figure
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