336 research outputs found
Associated production of the heavy charged gauge boson and a top quark at LHC
In the context of topflavor seesaw model, we study the production of the
heavy charged gauge boson associated with a top quark at the LHC.
Focusing on the searching channel , we carry out a full simulation of the signal and the
relevant standard model backgrounds. The kinematical distributions of final
states are presented. It is found that the backgrounds can be significantly
suppressed by sets of kinematic cuts, and the signal of the heavy charged boson
might be detected at the LHC with TeV. With a integrated
luminosity of \LL= 100 , a signal significance can be
achieved for TeV.Comment: 16 pages, 6 figure
Bottom partner B' and Zb production at the LHC
Some new physics models, such as "beautiful mirrors" scenario, predict the
existence of the bottom partner . Considering the constraints from the data
for the branching ratio and the asymmetry
on the relevant free parameters, we calculate the contributions of
to the cross section and the polarization asymmetry
for production at the . We find that the bottom partner
can generate significant corrections to and , which might
be detected in near future.Comment: 15 pages, 5 figures. Version published in Phys. Lett.
Constraints on anomalous quartic gauge couplings via production at the LHC
In this paper, we investigate the contributions of anomalous quartic gauge
couplings (aQGCs) to production at the Large Hadron Collider (LHC)
in the context of Standard Model effective theory (SMEFT). When energy scale is
large, the validity of SMEFT becomes an important issue. To ensure the
validity, the unitarity bound is applied in a model independent approach, which
is found to have significant suppressive effects on the signals of
operators. The kinematic and polarization features of the aQGC signals are also
studied. The polarization effect is useful to highlight the signals of
operators. The sensitivity estimates on dimension-8 operators with
unitarity bounds at TeV are obtained.Comment: 25 pages, 6 figure
Phenanthrothiophene-Triazine Star-Shaped Discotic Liquid Crystals: Synthesis, Self-Assembly, and Stimuli-Responsive Fluorescence Properties
Lipophilic biphenylthiophene- and phenanthrothiophene-triazine compounds, BPTTn and CPTTn, respectively, were prepared by a tandem procedure involving successive Suzuki-Miyaura coupling and Scholl cyclodehydrogenation reactions. These compounds display photoluminescence in solution and in thin film state, solvatochromism with increasing solvent's polarity, as well as acidochromism and metal ion recognition stimuli-responsive fluorescence. Protonation of BPTT10 and CPTT10 by trifluoroacetic acid results in fluorescence quenching, which is reversibly restored once treated with triethylamine (ON-OFF switch). DFT computational studies show that intramolecular charge transfer (ICT) phenomena occurs for both molecules, and reveal that protonation enhances the electron-withdrawing ability of the triazine core and reduces the band gap. This acidochromic behavior was applied to a prototype fluorescent anti-counterfeiting device. They also specifically recognize Fe3+ through coordination, and the recognition mechanism is closely related to the photoinduced electron transfer between Fe3+ and BPTT10/CPTT10. CPTTn self-assemble into columnar rectangular (Colrec) mesophase, which can be modulated by oleic acid via the formation of a hydrogen-bonded supramolecular liquid crystal hexagonal Colhex mesophase. Finally, CPTTn also form organic gels in alkanes at low critical gel concentration (3.0 mg/mL). Therefore, these star-shaped triazine molecules possess many interesting features and thus hold great promises for information processing, liquid crystal semiconductors and organogelators
Calcium-sensing receptors regulate cardiomyocyte Ca2+ signaling via the sarcoplasmic reticulum-mitochondrion interface during hypoxia/reoxygenation
Communication between the SR (sarcoplasmic reticulum, SR) and mitochondria is important for cell survival and apoptosis. The SR supplies Ca2+ directly to mitochondria via inositol 1,4,5-trisphosphate receptors (IP3Rs) at close contacts between the two organelles referred to as mitochondrion-associated ER membrane (MAM). Although it has been demonstrated that CaR (calcium sensing receptor) activation is involved in intracellular calcium overload during hypoxia/reoxygenation (H/Re), the role of CaR activation in the cardiomyocyte apoptotic pathway remains unclear. We postulated that CaR activation plays a role in the regulation of SR-mitochondrial inter-organelle Ca2+ signaling, causing apoptosis during H/Re. To investigate the above hypothesis, cultured cardiomyocytes were subjected to H/Re. We examined the distribution of IP3Rs in cardiomyocytes via immunofluorescence and Western blotting and found that type 3 IP3Rs were located in the SR. [Ca2+]i, [Ca2+]m and [Ca2+]SR were determined using Fluo-4, x-rhod-1 and Fluo 5N, respectively, and the mitochondrial membrane potential was detected with JC-1 during reoxygenation using laser confocal microscopy. We found that activation of CaR reduced [Ca2+]SR, increased [Ca2+]i and [Ca2+]m and decreased the mitochondrial membrane potential during reoxygenation. We found that the activation of CaR caused the cleavage of BAP31, thus generating the pro-apoptotic p20 fragment, which induced the release of cytochrome c from mitochondria and the translocation of bak/bax to mitochondria. Taken together, these results reveal that CaR activation causes Ca2+ release from the SR into the mitochondria through IP3Rs and induces cardiomyocyte apoptosis during hypoxia/reoxygenation
Benchmarking calculations of wavelengths and transition rates with spectroscopic accuracy for W XLVIII through W LVI tungsten ions
Atomic properties of n=3 levels for W47+-W55+ ions (Z=74) are systematically calculated using two different and independent methods, namely, the second-order many-body perturbation theory and the multiconfiguration Dirac-Hartree-Fock method combined with the relativistic configuration interaction approach. Wavelengths and transition rates for electric-and magnetic-dipole transitions involving the n=3 levels of W47+-W55+ are calculated. In addition, we discuss in detail the importance of the valence and core-valence electron correlations, the Breit interaction, the higher-order frequency-dependent retardation correction, and the leading quantum electrodynamical corrections for transition wavelengths. Spectroscopic accuracy is achieved for the present calculated wavelengths, and most of them agree with experimental values within 0.05%. Our calculated wavelengths, combined with collisional radiative model simulations, are used to identify the yet unidentified 25 observed lines in the extremely complex spectrum between 27Ã… and 34Ã… measured by Lennartsson etal. [Phys. Rev. A 87, 062505 (2013)10.1103/PhysRevA.87.062505]. We provide additional data for 472 strong electric-dipole transitions in the wavelength range of 17-50 Ã…, and 185 strong magnetic-dipole transitions between 36Ã… and 4384Ã…, with a line intensity greater than 1photon/s. These can provide benchmark data for future experiments and theoretical calculations
- …