分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-09-17
摘要:WIMP dark matter and gauge coupling unification are considered in an R-parity violating MSSM with vector-like matter. Dark matter is contained in an additional vector-like SU(2)L doublet which possesses a new U(1) gauge symmetry. The Higgs fields are extended to be in a 5 ⊕¯5 representation of SU(5). The stability of dark matter is a result of gauge symmetries, and the mass of the dark matter particle is between (1.1-1.5) TeV. Dark matter has a very small cross section with nucleis, thus the model is consistent with current dark matter direct detection experiments such as Xenon100. The model also predicts new charged and colored particles to be observed at LHC.
分类: 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间: 2017-09-17
摘要:LHCb collaboration has recently announced a measurement of the difference of time-integrated CP asymmetries between D → K+K− and D → #25;+#25;−. This result provides the evidence of large direct CP violation in D meson and reveals some important implications on underlying new physics. It is shown that the direct CP violation in D meson can be enhanced by R-parityviolating supersymmetry, while CP violations in K and B mesons are suppressed by this newphysics, which is in consistence with previous experiments. Constraints on the model parametersand some consequences are also discussed.
分类: 物理学 >> 核物理学 提交时间: 2016-09-05
摘要:Future large liquid-scintillator detectors can be implemented to observe neutrinos from a core-collapse supernova (SN) in our galaxy in various reaction channels: (1) The inverse beta decay ν¯¯¯e+p→n+e+; (2) The elastic neutrino-proton scattering ν+p→ν+p; (3) The elastic neutrino-electron scattering ν+e−→ν+e−; (4) The charged-current νe interaction νe+12C→e−+12N; (5) The charged-current ν¯¯¯e interaction ν¯¯¯e+12C→e++12B; (6) The neutral-current interaction ν+12C→ν+12C∗. The less abundant 13C atoms in the liquid scintillator are also considered as a target, and both the charged-current interaction νe+13C→e−+13N and the neutral-current interaction ν+13C→ν+13C∗ are taken into account. In this work, we show for the first time that a global analysis of all these channels at a single {liquid-}scintillator detector, such as Jiangmen Underground Neutrino Observatory (JUNO), is very important to test the average-energy hierarchy of SN neutrinos and how the total energy is partitioned among neutrino flavors. In addition, the dominant channels for reconstructing neutrino spectra and the impact of other channels are discussed in great detail.