19 research outputs found
Axigluon Couplings in the Presence of Extra Color-Octet Spin-One Fields
In this paper, we study how the interaction of the axigluon with quarks is
modified when we introduce new color-octet spin-one fields in a chiral color
model. We show that in this case the strength of this interaction is not
completely determined by the gauge symmetry any more and can be significantly
weaker than the one predicted in the original chiral color model. In this way,
we reinterpret the non-observability of the axigluon at the Tevatron, not as a
limit on the axigluon mass, but as a limit on the strength of the axigluon
coupling to quarks
Realistic constraints on the doubly charged bilepton couplings from Bhabha scattering with LEP data
Upper limits on doubly charged bilepton couplings and masses are extracted
from LEP data for Bhabha scattering at energy range GeV
using standard model program ZFITTER which calculates radiative corrections. We
find that at 95% C.L. for scalar and
vector bileptons.Comment: 5 pages, 1 EPS figur
Explaining the Higgs Decays at the LHC with an Extended Electroweak Model
We show that the recent discovery of a new boson at the LHC, which we assume
to be a Higgs boson, and the observed enhancement in its diphoton decays
compared to the SM prediction, can be explained by a new doublet of charged
vector bosons from an extended electroweak gauge sector model with
SU(3)_C\otimesSU(3)_L\otimesU(1)_X symmetry. Our results show a good
agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs
boson and the experimental significance observed in the diphoton channel at the
8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also
taken into account, in order to anticipate a possible confirmation of deficits
in the branching ratios into , , bottom quarks, and tau leptons.Comment: 16 pages, 5 figure
Two-body decays in the minimal 331 model
The two-body decays of the extra neutral boson Z_2 predicted by the minimal
331 model are analyzed. At the three-level it can decay into standard model
particles as well as exotic quarks and the new gauge bosons predicted by the
model. The decays into a lepton pair are strongly suppressed, with and . In the bosonic
sector, Z_2 would decay mainly into a pair of bilepton gauge bosons, with a
branching ratio below the 0.1 level. The Z_2 boson has thus a leptophobic and
bileptophobic nature and it would decay dominantly into quark pairs. The
anomaly-induced decays and , which occurs
at the one-loop level are studied. It is found that and at most. As for the and decays, with H a relatively light Higgs boson, they
are induced via Z'-Z mixing. It is obtained that
and . We also examine the flavor changing neutral
current decays and , which may have branching
fractions as large as and , respectively, and thus may be of
phenomenological interest.Comment: 14 pages, 3 figures, submitted to Physical Review
Static quantities of the W boson in the SU_L(3) X U_X(1) model with right-handed neutrinos
The static electromagnetic properties of the boson, and
, are calculated in the SU_L(3)} \times U_X(1) model with
right-handed neutrinos. The new contributions from this model arise from the
gauge and scalar sectors. In the gauge sector there is a new contribution from
a complex neutral gauge boson and a singly-charged gauge boson .
The mass of these gauge bosons, called bileptons, is expected to be in the
range of a few hundreds of GeV according to the current bounds from
experimental data. If the bilepton masses are of the order of 200 GeV, the size
of their contribution is similar to that obtained in other weakly coupled
theories. However the contributions to both and are
negligible for very heavy or degenerate bileptons. As for the scalar sector, an
scenario is examined in which the contribution to the form factors is
identical to that of a two-Higgs-doublet model. It is found that this sector
would not give large corrections to and .Comment: New material included. Final version to apppear in Physical Review
Seismology of the Sun : Inference of Thermal, Dynamic and Magnetic Field Structures of the Interior
Recent overwhelming evidences show that the sun strongly influences the
Earth's climate and environment. Moreover existence of life on this Earth
mainly depends upon the sun's energy. Hence, understanding of physics of the
sun, especially the thermal, dynamic and magnetic field structures of its
interior, is very important. Recently, from the ground and space based
observations, it is discovered that sun oscillates near 5 min periodicity in
millions of modes. This discovery heralded a new era in solar physics and a
separate branch called helioseismology or seismology of the sun has started.
Before the advent of helioseismology, sun's thermal structure of the interior
was understood from the evolutionary solution of stellar structure equations
that mimicked the present age, mass and radius of the sun. Whereas solution of
MHD equations yielded internal dynamics and magnetic field structure of the
sun's interior. In this presentation, I review the thermal, dynamic and
magnetic field structures of the sun's interior as inferred by the
helioseismology.Comment: To be published in the proceedings of the meeting "3rd International
Conference on Current Developments in Atomic, Molecular, Optical and Nano
Physics with Applications", December 14-16, 2011, New Delhi, Indi
Patient satisfaction after biofeedback for constipation and pelvic floor dyssynergia.
Patients referred for chronic constipation frequently report symptoms of straining, feeling of incomplete evacuation, or the need to facilitate defecation digitally (dyschezia). When such patients show manometric evidence of inappropriate contraction or failure to relax the pelvic floor muscles during attempts to defecate, they are diagnosed as having pelvic floor dyssynergia (Rome I).
To evaluate long-term satisfaction of patients with pelvic floor dyssynergia after biofeedback.
Forty-one consecutive patients referred for chronic constipation at an outpatient gastrointestinal unit and diagnosed as having pelvic floor dyssynergia who completed a full course of biofeedback.
Data have been collected using a standardised questionnaire. A questionnaire survey of patients' satisfaction rate and requirement of aperients was undertaken.
Mean age and symptom duration were respectively 41 and 20 years. Half of patients reported fewer than 3 bowel motions per week. Patients were treated with a mean of 5 biofeedback sessions. At the end of the therapy pelvic floor dyssynergia was alleviated in 85% of patients and 49% were able to stop all aperients. Satisfaction was maintained at follow-up telephone interviews undertaken after a mean period of 2 years, as biofeedback was helpful for 79% of patients and 47% still abstained from intake of aperients.
Satisfaction after biofeedback is high for patients referred for chronic constipation and diagnosed with pelvic floor dyssynergia. Biofeedback improves symptoms related to dyschezia and reduces use of aperients
Effects of rosuvastatin on progression of stenosis in adult patients with congenital aortic stenosis (PROCAS Trial)
Item does not contain fulltextRecent trials have failed to show that statin therapy halts the progression of calcific aortic stenosis (AS). We hypothesized that statin therapy in younger patients with congenital AS would be more beneficial, because the valve is less calcified. In the present double-blind, placebo-controlled trial, 63 patients with congenital AS (age 18 to 45 years) were randomly assigned to receive either 10 mg of rosuvastatin daily (n = 30) or matched placebo (n = 33). The primary end point was the progression of peak aortic valve velocity. The secondary end points were temporal changes in the left ventricular mass, ascending aortic diameter, and N-terminal pro-brain natriuretic peptide (NT-proBNP). The median follow-up was 2.4 years (interquartile range 1.9 to 3.0). The mean increase in peak velocity was 0.05 +/- 0.21 m/s annually in the rosuvastatin group and 0.09 +/- 0.24 m/s annually in the placebo group (p = 0.435). The annualized change in the ascending aorta diameter (0.4 +/- 1.7 mm with rosuvastatin vs 0.5 +/- 1.6 mm with placebo; p = 0.826) and left ventricular mass (1.1 +/- 15.8 g with rosuvastatin vs -3.7 +/- 30.9 g with placebo; p = 0.476) were not significantly different between the 2 groups. Within the statin group, the NT-proBNP level was 50 pg/ml (range 19 to 98) at baseline and 21 pg/ml (interquartile range 12 to 65) at follow-up (p = 0.638). NT-proBNP increased from 40 pg/ml (interquartile range 20 to 92) to 56 pg/ml (range 26 to 130) within the placebo group (p = 0.008). In conclusion, lipid-lowering therapy with rosuvastatin 10 mg did not reduce the progression of congenital AS in asymptomatic young adult patients. Interestingly, statins halted the increase in NT-proBNP, suggesting a potential positive effect of statins on cardiac function in young patients with congenital AS