6,408 research outputs found
Electroweak Model Independent Tests for SU(3) Symmetry in Hadronic B Decays
We study effects of new physics beyond the Standard Model on SU(3) symmetry
in charmless hadronic two body B decays. It is found that several equalities
for some of the decay amplitudes, such as , , , predicted by SU(3) symmetry in the SM are not affected by new
physics. These relations provide important electroweak model independent tests
for SU(3) symmetry in B decays.Comment: 4 pages, revte
Bitter Taste Receptors for Asthma Therapeutics.
Clinical management of asthma and chronic obstructive pulmonary disease (COPD) has primarily relied on the use of beta 2 adrenergic receptor agonists (bronchodilators) and corticosteroids, and more recently, monoclonal antibody therapies (biologics) targeting specific cytokines and their functions. Although these approaches provide relief from exacerbations, questions remain on their long-term efficacy and safety. Furthermore, current therapeutics do not address progressive airway remodeling (AR), a key pathological feature of severe obstructive lung disease. Strikingly, agonists of the bitter taste receptors (TAS2Rs) deliver robust bronchodilation, curtail allergen-induced inflammatory responses in the airways and regulate airway smooth muscle (ASM) cell proliferation and mitigate features of A
A method for determining CP violating phase
A new way of determining the phases of weak amplitudes in charged decays
based on SU(3) symmetry is proposed. The CP violating phase can now be
determined without the previous difficulty associated with electroweak
penguins.Comment: 9 pages plus one figure, Revte
The Vela Pulsar's Radio Nebula
We have discovered that the radio nebula surrounding the Vela pulsar covers a
much wider extent than previously reported, with two lobes to the North and
South of the pulsar. Indications of this object have been reported previously,
but its symmetric morphology around the pulsar and other details had not been
identified as they were hidden due to poor sensitivity to low spatial
frequencies.
The structure is highly polarised and the polarisation vectors, once
corrected for Faraday rotation, reveal symmetry with respect to the spin axis
of the pulsar. The X-ray emission found by Chandra lies at the centre of this
structure, in a region which has no detectable excess of radio emission. We
estimate total fluxes and regional fluxes from the Northern and Southern lobes,
plus the X-ray region at four radio frequencies; 1.4, 2.4, 5 and 8.5 GHz. We
present the corresponding images in both the total and polarised intensities,
as well as those showing the derotated linear polarisation vectors.Comment: 17 pages, to appear in MNRA
Effects of R-parity violation on direct CP violation in B decays and extraction of
In the standard model, direct CP-violating asymmetries for are roughly 2% based on perturbative calculation. Rescattering effects might
enhance it to at most (20-25)%. We show that lepton-number-violating couplings
in supersymmetric models without R-parity are capable of inducing as large as
100% CP asymmetry in this channel. Such effects drastically modify the allowed
range of the CKM parameter arising from the combinations of the
observed charged and neutral B decays in the modes. With a multichannel
analysis in B decays, one can either discover this exciting new physics, or
significantly improve the existing constraints on it.Comment: Latex, 5 pages; minor changes, to appear in Phys Rev Let
Evaluation of cancer risk in tobacco chewers and smokers: an epidemiologic assessment
A retrospective study of cancer at high risk sites in the region of the head and neck was undertaken at the Bombay Cancer Registry, in 1968, to evaluate the effects of tobacco when chewed or smoked. There is sufficient evidence available today to indict chewing and smoking of tobacco as factors of great importance in the etiology of oral, pharyngeal, laryngeal, and esophageal cancers-the most common sites affected by the disease in Greater Bombay. This cause/effect association is probably as intimate as that of cigarette smoking and lung cancer. The carcinogenic action of chewed tobacco is particularly evident at those sites where the bolus is retained in place for any length of time. Likewise, inhalation of tobacco fumes during the act of smoking produces a stream of gas and of solid particles which impinges directly on the oropharynx and especially on the soft palate initially and exposes smokers to the increased risk of developing cancer at exactly these posterior sites in the oropharynx, rather than more anteriorly in the oral cavity where the tissues do not directly bear the brunt of the onslaught from the smoke. It is revealing to find that the high risk sites involved in tobacco chewers appear to be the least affected in smokers, and vice versa
Spin-Kick Correlation in Neutron Stars: Alignment Conditions and Implications
Recent observations of pulsar wind nebulae and radio polarization profiles
revealed a tendency of the alignment between the spin and velocity directions
in neutron stars. We study the condition for spin-kick alignment using a toy
model, in which the kick consists of many off-centered, randomly-oriented
thrusts. Both analytical considerations and numerical simulations indicate that
spin-kick alignment cannot be easily achieved if the proto-neutron star does
not possess some initial angular momentum, contrary to some previous claims. To
obtain the observed spin-kick misalignment angle distribution, the initial spin
period of the neutron star must be smaller than the kick timescale. Typically,
an initial period of a hundred milliseconds or less is required.Comment: 17 pages, 8 figures. Accepted by Ap
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