1,258 research outputs found
The extended BLMSSM with a 125 GeV Higgs boson and dark matter
To extend the BLMSSM, we not only add exotic Higgs superfields
to make the exotic lepton heavy, but also introduce
the superfields(,) having couplings with lepton and exotic lepton
at tree level. The obtained model is called as EBLMSSM, which has difference
from BLMSSM especially for the exotic slepton(lepton) and exotic
sneutrino(neutrino). We deduce the mass matrices and the needed couplings in
this model. To confine the parameter space, the Higgs boson mass and
the processes , are
studied in the EBLMSSM. With the assumed parameter space, we obtain reasonable
numerical results according to data on Higgs from ATLAS and CMS. As a cold dark
mater candidate, the relic density for the lightest mass eigenstate of and
mixing is also studied
Cerebral hemodynamic characteristics of acute mountain sickness upon acute high-altitude exposure at 3,700 m in young Chinese men.
PURPOSE: We aimed at identifying the cerebral hemodynamic characteristics of acute mountain sickness (AMS). METHODS: Transcranial Doppler (TCD) sonography examinations were performed between 18 and 24 h after arrival at 3,700 m via plane from 500 m (n = 454). A subgroup of 151 subjects received TCD examinations at both altitudes. RESULTS: The velocities of the middle cerebral artery, vertebral artery (VA) and basilar artery (BA) increased while the pulsatility indexes (PIs) and resistance indexes (RIs) decreased significantly (all p < 0.05). Velocities of BA were higher in AMS (AMS+) individuals when compared with non-AMS (AMS-) subjects (systolic velocity: 66 ± 12 vs. 69 ± 15 cm/s, diastolic velocity: 29 ± 7 vs. 31 ± 8 cm/s and mean velocity, 42 ± 9 vs. 44 ± 10 cm/s). AMS was characterized by higher diastolic velocity [V d_VA (26 ± 4 vs. 25 ± 4, p = 0.013)] with lower PI and RI (both p = 0.004) in VA. Furthermore, the asymmetry index (AI) of VAs was significantly lower in the AMS + group [-5.7 % (21.0 %) vs. -2.5 % (17.8 %), p = 0.016]. The AMS score was closely correlated with the hemodynamic parameters of BA and the V d_VA, PI, RI and AI of VA. CONCLUSION: AMS is associated with alterations in cerebral hemodynamics in the posterior circulation rather than the anterior one, and is characterized by higher blood velocity with lower resistance. In addition, the asymmetry of VAs may be involved in AMS
A probability-box-based method for propagation of multiple types of epistemic uncertainties and its application on composite structural-acoustic system
AT 2023clx: the Faintest and Closest Optical Tidal Disruption Event Discovered in Nearby Star-forming Galaxy NGC 3799
We report the discovery of a faint optical tidal disruption event (TDE) in
the nearby star-forming galaxy NGC 3799. Identification of the TDE is based on
its position at the galaxy nucleus, a light curve declining as t^-5/3, a blue
continuum with an almost constant blackbody temperature of ~12,000K, and broad
(~15,000kms^-1) Balmer lines and characteristic He~II 4686A emission. The light
curve of AT 2023clx peaked at an absolute magnitude of -17.16mag in the g-band
and a maximum blackbody bolometric luminosity of 4.56*10^42 ergs^-1, making it
the faintest TDE discovered to date. With a redshift of 0.01107 and a
corresponding luminosity distance of 47.8Mpc, it is also the closest optical
TDE ever discovered to our best knowledge. Furthermore, our analysis of
Swift/XRT observations of AT 2023clx yields a very tight 3 sigma upper limit of
9.53*10^39 ergs^-1 in the range 0.3--10keV. AT 2023clx, together with very few
other faint TDEs such as AT 2020wey, prove that there are probably a large
number of faint TDEs yet to be discovered at higher redshifts, which is
consistent with the prediction of luminosity functions (LFs). The upcoming
deeper optical time-domain surveys, such as the Legacy Survey of Space and Time
(LSST) and the Wide-Field Survey Telescope (WFST) will discover more TDEs at
even lower luminosities, allowing for a more precise constraint of the low-end
of the LF.Comment: 9 pages, 6 figures; Accepted for ApJL (July, 2023
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