5,177 research outputs found
Echoes of the electroweak phase transition: discovering a second Higgs doublet through A0 → ZH0
The existence of a second Higgs doublet in nature could lead to a cosmological first-order electroweak
phase transition and explain the origin of the matter-antimatter asymmetry in the Universe. We obtain the
spectrum and properties of the new scalars H0, A0, and H� that signal such a phase transition and show that
the observation of the decay A0 → ZH0 at LHC would be a “smoking gun” signature of these scenarios. We
analyze the LHC search prospects for this decay in the llbb¯ and llWþW− final states, arguing that current
data may be sensitive to this signature in the former channel as well as there being great potential for a
discovery in either channel at the very early stages of the 14 TeV run
Energy loss mechanism for suspended micro- and nanoresonators due to the Casimir force
A so far not considered energy loss mechanism in suspended micro- and
nanoresonators due to noncontact acoustical energy loss is investigated
theoretically. The mechanism consists on the conversion of the mechanical
energy from the vibratory motion of the resonator into acoustic waves on large
nearby structures, such as the substrate, due to the coupling between the
resonator and those structures resulting from the Casimir force acting over the
separation gaps. Analytical expressions for the resulting quality factor Q for
cantilever and bridge micro- and nanoresonators in close proximity to an
underlying substrate are derived and the relevance of the mechanism is
investigated, demonstrating its importance when nanometric gaps are involved
Hierarchical versus degenerate 2HDM: the LHC run 1 legacy at the onset of run 2
Current discussions of the allowed two-Higgs-doublet model parameter space after LHC run 1 and the prospects for run 2 are commonly phrased in the context of a quasidegenerate spectrum for the new scalars. Here, we discuss the generic situation of a two-Higgs-doublet model with a nondegenerate spectrum for the new scalars. This is highly motivated from a cosmological perspective since it naturally leads to a strongly first-order electroweak phase transition that could explain the matter-antimatter asymmetry in the Universe. While constraints from measurements of Higgs signal strengths do not change, those from searches of new scalar states get modified dramatically once a nondegenerate spectrum is considered
Interaction and Localization of One-electron Orbitals in an Organic Molecule: Fictitious Parameter Analysis for Multi-physics Simulations
We present a new methodology to analyze complicated multi-physics simulations
by introducing a fictitious parameter. Using the method, we study quantum
mechanical aspects of an organic molecule in water. The simulation is
variationally constructed from the ab initio molecular orbital method and the
classical statistical mechanics with the fictitious parameter representing the
coupling strength between solute and solvent. We obtain a number of
one-electron orbital energies of the solute molecule derived from the
Hartree-Fock approximation, and eigenvalue-statistical analysis developed in
the study of nonintegrable systems is applied to them. Based on the results, we
analyze localization properties of the electronic wavefunctions under the
influence of the solvent.Comment: 4 pages, 5 figures, the revised version will appear in J. Phys. Soc.
Jpn. Vol.76 (No.1
Chiral perturbation theory in a magnetic background - finite-temperature effects
We consider chiral perturbation theory for SU(2) at finite temperature in
a constant magnetic background . We compute the thermal mass of the pions
and the pion decay constant to leading order in chiral perturbation theory in
the presence of the magnetic field. The magnetic field gives rise to a
splitting between and as well as between
and . We also calculate the free energy and the
quark condensate to next-to-leading order in chiral perturbation theory. Both
the pion decay constants and the quark condensate are decreasing slower as a
function of temperature as compared to the case with vanishing magnetic field.
The latter result suggests that the critical temperature for the chiral
transition is larger in the presence of a constant magnetic field. The increase
of as a function of is in agreement with most model calculations but
in disagreement with recent lattice calculations.Comment: 24 pages and 9 fig
An analytical six-dimensional potential energy surface for dissociation of molecular hydrogen on Cu(100).
Bucillamine prevents cisplatin-induced ototoxicity through induction of glutathione and antioxidant genes.
Bucillamine is used for the treatment of rheumatoid arthritis. This study investigated the protective effects of bucillamine against cisplatin-induced damage in auditory cells, the organ of Corti from postnatal rats (P2) and adult Balb/C mice. Cisplatin increases the catalytic activity of caspase-3 and caspase-8 proteases and the production of free radicals, which were significantly suppressed by pretreatment with bucillamine. Bucillamine induces the intranuclear translocation of Nrf2 and thereby increases the expression of γ-glutamylcysteine synthetase (γ-GCS) and glutathione synthetase (GSS), which further induces intracellular antioxidant glutathione (GSH), heme oxygenase 1 (HO-1) and superoxide dismutase 2 (SOD2). However, knockdown studies of HO-1 and SOD2 suggest that the protective effect of bucillamine against cisplatin is independent of the enzymatic activity of HO-1 and SOD. Furthermore, pretreatment with bucillamine protects sensory hair cells on organ of Corti explants from cisplatin-induced cytotoxicity concomitantly with inhibition of caspase-3 activation. The auditory-brainstem-evoked response of cisplatin-injected mice shows marked increases in hearing threshold shifts, which was markedly suppressed by pretreatment with bucillamine in vivo. Taken together, bucillamine protects sensory hair cells from cisplatin through a scavenging effect on itself, as well as the induction of intracellular GSH
The Evershed Effect with SOT/Hinode
The Solar Optical Telescope onboard Hinode revealed the fine-scale structure
of the Evershed flow and its relation to the filamentary structures of the
sunspot penumbra. The Evershed flow is confined in narrow channels with nearly
horizontal magnetic fields, embedded in a deep layer of the penumbral
atmosphere. It is a dynamic phenomenon with flow velocity close to the
photospheric sound speed. Individual flow channels are associated with tiny
upflows of hot gas (sources) at the inner end and downflows (sinks) at the
outer end. SOT/Hinode also discovered ``twisting'' motions of penumbral
filaments, which may be attributed to the convective nature of the Evershed
flow. The Evershed effect may be understood as a natural consequence of thermal
convection under a strong, inclined magnetic field. Current penumbral models
are discussed in the lights of these new Hinode observations.Comment: To appear in "Magnetic Coupling between the Interior and the
Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and
Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200
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