8,192 research outputs found
Natural history of therapeutic management in oral cancer
The natural history of a diseases is greatly influenced by the course of therapeutic management. Just after the tissue stage of the disease is aver. The cure rate of diseases, particularly those of cancers, could probably be modified to a greater extent, if the natural history of the therapeutic manageÂment is understood properly, so that the community education programme be organised in the proper direction, to trigger early diagnosis. Home remedy urn the first preference of 76.8% of oral cancer cases, 64.6% preferred traditional unqualified practitioners as their 2nd preference of place of treatment for oral cancer. Thus during the stage of fa stigium a case oj oral cancer gets frustrated with the hospital treatment and awaits death counting his day
Production of qqQQ final states in ee collisions in the left-right symmetric model
We consider the reaction ee ->qqQQ as a test of lepton number
non-conservation in the framework of the left-right-symmetric electroweak
model. The main contributions to this process are due to Majorana neutrino
exchange in t-channel and doubly charged Higgs (Delta{--}) exchange in
s-channel with a pair of right-handed weak bosons (WR) as intermediate state.
We show that in a linear ee collider with the collision energy of 1 TeV (1.5
TeV) the cross section of this process is 0.01 fb (1 fb), and it will, for the
anticipated luminosity of 10**{35} cm**{-2}, be detectable below the WR
threshold. We study the sensitivity of the reaction on the masses of the heavy
neutrino, WR and Delta{--}.Comment: 24 pages, 9 eps figures, uses axodraw.st
Collider Signature of Bulk Neutrinos in Large Extra Dimensions
We consider the collider signature of right-handed neutrinos propagating in
(large) extra dimensions, and interacting with Standard Model fields
only through a Yukawa coupling to the left-handed neutrino and the Higgs boson.
These theories are attractive as they can explain the smallness of the neutrino
mass, as has already been shown. We show that if is bigger than two,
it can result in an enhancement in the production rate of the Higgs boson,
decaying either invisibly or to a anti- quark pair, associated with an
isolated high charged lepton and missing transverse energy at future
hadron colliders, such as the LHC. The enhancement is due to the large number
of Kaluza-Klein neutrinos produced in the final state. The observation of the
signal event would provide an opportunity to distinguish between the normal and
inverted neutrino mass hierarchies, and to determine the absolute scale of
neutrino masses by measuring the asymmetry of the observed event numbers in the
electron and muon channels.Comment: 31 pages, 13 figures. v2: Added discussion on PDF uncertainties,
added reference
Grand unification in the minimal left-right symmetric extension of the standard model
The simplest minimal left-right symmetric extension of the standard model is
studied in the high energy limit, and some consequences of the grand
unification hypothesis are explored assuming that the parity breaking scale is
the only relevant energy between the electro-weak scale and the unification
point. While the model is shown to be compatible with the observed neutrino
phenomenology, the parity breaking scale and the heavy boson masses are
predicted to be above 10^7 TeV, quite far from the reach of nowadays
experiments. Below that scale only an almost sterile right handed neutrino is
allowed with a mass M \approx 100 TeV
Reconciling Supersymmetry and Left-Right Symmetry
We construct the minimal supersymmetric left-right theory and show that at
the renormalizable level it requires the existence of an intermediate
breaking scale. The subsequent symmetry breaking down to MSSM automatically
preserves R-symmetry. Furthermore, unlike in the nonsupersymmetric version of
the theory, the see-saw mechanism takes its canonical form. The theory predicts
the existence of a triplet of Higgs scalars much lighter than the
breaking scale.Comment: 4 pages, revtex, no figure
Vanishing corrections on the intermediate scale and implications for unification of forces
In two-step breaking of a class of grand unified theories including SO(10),we
prove a theorem showing that the scale where the Pati-Salam gauge
symmetry with parity breaks down to the standard gauge group,has vanishing
corrections due to all sources emerging from higher scales such as
the one-loop and all higher loop effects,the GUT-threshold,gravitational
smearing,and string threshold effects. Implications of such a scale for the
unification of gauge couplings with small Majorana neutrino masses are
discussed.In string inspired SO(10) we show that ,needed for neutrino masses,with the GUT scale can
be realized provided certain particle states in the predicted spectum are
light.Comment: 21 pages, Late
Geometric CP Violation with Extra Dimensions
We discuss how CP symmetry can be broken geometrically through orbifold
projections in hidden extra dimensions in the context of D-brane models for
particle unifications. We present a few toy models to illustrate the idea and
suggest ways to incorporate this technique in the context of realistic models.Comment: 6 pages, one figure; references updated and a new model adde
Running neutrino masses and mixing in a SU(4) x SU(2)^2 x U(1)_X model
In this talk, we discuss the implications of the renormalization group
equations for the neutrino masses and mixing angles in a supersymmetric
string-inspired SU(4) x SU(2)_L x SU(2)_R x U(1)_X model with matter in
fundamental and antisymmetric tensor representations only. The quark, charged
lepton and neutrino Yukawa matrices are distinguished by different
Clebsch-Gordan coefficients due to contracting over SU(4) and SU(2)_R indices.
In order to permit for a more realistic, hierarchical light neutrino mass
spectrum with bi-large mixing a second U(1)_X breaking singlet with fractional
charge is introduced. By numerical investigation we find a region in the model
parameter space where the neutrino mass-squared differences and mixing angles
at low energy are consistent with experimental data.Comment: Talk presented at the Corfu Summer Institute, Corfu-Greece, September
4-14, 200
Vector boson pair production in e-e- collisions with polarized beams
The -boson pair production in collisions with polarized beams is
investigated. The helicity amplitudes are derived for general couplings and the
conditions for a good high-energy behaviour of the cross-section are given. The
results are applied to the heavy vector boson production in the context of the
left-right symmetric model. The Ward identities and the equivalence theorem are
also discussed.Comment: 17 pages+ 8 figures(uuencoded compressed ps-file appended), HU-SEFT R
1994-09 (the original version of the file was unreproducable in some
computers
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