7,301 research outputs found
The NLO contributions to the scalar pion form factors and the annihilation corrections to the decays
In this paper, by employing the factorization theorem, we made the
first calculation for the space-like scalar pion form factor at
the leading order (LO) and the next-to-leading order (NLO) level, and then
found the time-like scalar pion form factor by analytic
continuation from the space-like one. From the analytical evaluations and the
numerical results, we found the following points: (a) the NLO correction to the
space-like scalar pion form factor has an opposite sign with the LO one but is
very small in magnitude, can produce at most decrease to LO result in
the considered region; (b) the NLO time-like scalar pion form factor
describes the contribution to the
factorizable annihilation diagrams of the considered decays,
i.e. the NLO annihilation correction; (c) the NLO part of the form factor
is very small in size, and is almost independent with the
variation of cutoff scale , but this form factor has a large strong
phase around and may play an important role in producing large CP
violation for decays; and (d) for and decays, the newly known NLO annihilation correction can produce
only a very small enhancement to their branching ratios, less than in
magnitude, and therefore we could not interpret the well-known -puzzle
by the inclusion of this NLO correction to the factorizable annihilation
diagrams.Comment: 26 pages, 12 figures, 1 Table; Minor correction
Phenomenological discriminations of the Yukawa interactions in two-Higgs doublet models with symmetry
There are four types of two-Higgs doublet models under a discrete
symmetry imposed to avoid tree-level flavour-changing neutral current, i.e.
type-I, type-II, type-X and type-Y models. We investigate the possibility to
discriminate the four models in the light of the flavour physics data,
including mixing, , and
decays, the recent LHC Higgs data, the direct search
for charged Higgs at LEP, and the constraints from perturbative unitarity and
vacuum stability. After deriving the combined constraints on the Yukawa
interaction parameters, we have shown that the correlation between the mass
eigenstate rate asymmetry of and the
ratio could be sensitive probe to discriminate the four models with
future precise measurements of the observables in the
decay at LHCb.Comment: 29 pages, 4 tables, 11 figures. v3: minor corrections included,
matches published version in EPJ
Elucidation of Emergent Regional Mechanisms of Heart Muscle Dysfunction in the Mouse Model of Duchenne Muscular Dystrophy
Cardiac dysfunction is a primary cause of mortality in Duchenne Muscular Dystrophy (DMD), potentially related to elevated cytosolic calcium. However, the regional versus global functional consequences of cellular calcium mishandling have not been defined in the whole heart. Here, we elucidate, for the first time, loci- and age-dependencies between calcium mishandling and myocardial sheet function as a manifestation of dystrophin-deficient cardiomyopathy. We also map calcium transients to illustrate the regional dependence of ion flux disturbances in the dystrophin-deficient (mdx) mouse heart. Furthermore, we elucidate abnormalities in autophagic processes that can be corrected with nanoparticle therapeutics delivering rapamycin to heart tissues to improve ventricular function in affected older mice with incipient cardiomyopathy. We conclude that the rapid reversibility of functional defects by reducing cytosolic calcium or by impacting impaired autophagy points to the significance of regional mechanical factors in the progression of the disease
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