57,824 research outputs found
Natural NMSSM confronting with the LHC7-8
The natural supersymmetry (SUSY) requires that stop, sbottom, and gluino be
around one TeV or lighter. By using the direct SUSY search bounds from both
ATLAS and CMS Collaborations, we examine the constraints on the natural SUSY in
the Next to Minimal Supersymmetric Standard Model (NMSSM). We consider two
cases of interpretations for the Higgs boson data: (1) the Standard Model (SM)
like Higgs boson is the lightest CP-even Higgs boson; (2) the SM like Higgs
boson is the second lightest CP-even Higgs boson. We find that the direct SUSY
searches at the LHC impose a strong constraint on the light gluino scenarios,
and in both cases the gluino can not be lighter than 1.1 TeV with sbottom mass
up to 600 GeV and stop mass up to 550 GeV.Comment: 43 pages, 13 figure
A Non-Mainstream Viewpoint on Apparent Superluminal Phenomena in AGN Jet
The group velocity of light in material around the AGN jet is acquiescently
one (c as a unit), but this is only a hypothesis. Here, we re-derive apparent
superluminal and Doppler formulas for the general case (it is assumed that the
group velocity of light in the uniform and isotropic medium around a jet (a
beaming model) is not necessarily equal to one, e.g., Araudo et al. (2010)
thought that there may be dense clouds around AGN jet base), and show that the
group velocity of light close to one could seriously affect apparent
superluminal phenomena and Doppler effect in the AGN jet (when the viewing
angle and Lorentz factor take some appropriate values).Comment: 4 pages, 2 figures, new version accepted for publication in Journal
of Astrophysics and Astronom
Fighting against fast speckle decorrelation for light focusing inside live tissue by photon frequency shifting
Light focusing inside live tissue by digital optical phase conjugation (DOPC) has drawn increasing interest due to its potential biomedical applications in optogenetics, microsurgery, phototherapy, and deep-tissue imaging. However, fast physiological motions in a live animal, including blood flow and respiratory motions, produce undesired photon perturbation and thus inevitably deteriorate the performance of light focusing. Here, we develop a photon-frequency-shifting DOPC method to fight against fast physiological motions by switching the states of a guide star at a distinctive frequency. Therefore, the photons tagged by the guide star are well detected at the specific frequency, separating them from the photons perturbed by fast motions. Light focusing was demonstrated in both phantoms in vitro and mice in vivo with substantially improved focusing contrast. This work puts a new perspective on light focusing inside live tissue and promises wide biomedical applications
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