119201993
Direct detection and solar capture of dark matter with momentum and velocity dependent elastic scattering
We explore the momentum and velocity dependent elastic scattering between the dark matter (DM) particles and the nuclei in detectors and the Sun. In terms of the non-relativistic effective theory, we phenomenologically discuss ten kinds of momentum and velocity dependent DM nucleus interactions and recalculate the corresponding upper limits on the spin-independent DM nucleon scattering cross section from the current direct detection experiments. The DM solar capture rate is calculated for each interaction. Our numerical results show that the momentum and velocity dependent cases can give larger solar capture rate than the usual contact interaction case for almost the whole parameter space. On the other hand, we deduce the Super-Kamiokande's constraints on the solar capture rate for eight typical DM annihilation channels. In contrast to the usual contact interaction, the Super-Kamiokande and IceCube experiments can give more stringent limits on the DM nucleon elastic scattering cross section than the current direct detection experiments for several momentum and velocity dependent DM nucleus interactions. In addition, we investigate the mediator mass effect on the DM elastic scattering cross section and solar capture rate. (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.
15114555
Rephasing invariants of CP and T violation in the four neutrino mixing models
We calculate the rephasing invariants of CP and T violation in a favorable parametrization of the 4x4 lepton flavor mixing matrix. Their relations with the CP- and T-violating asymmetries in neutrino oscillations are derived, and the matter effects are briefly discussed.
118832699
Enhancement of dark matter annihilation via Breit-Wigner resonance
The Breit-Wigner enhancement of the thermally averaged annihilation cross section is shown to provide a large boost factor when the dark matter annihilation process nears a narrow resonance. We explicitly demonstrate the evolution behavior of the Breit-Wigner enhanced as the function of universe temperature for both the physical and unphysical pole cases. It is found that both of the cases can lead a large enough boost factor to explain the recent PAMELA, ATIC, and PPB-BETS anomalies. We also calculate the coupling of the annihilation process, which is useful for an appropriate model building to give the desired dark matter relic density.
298741
NEUTRINO MASSES, LEPTON FLAVOR MIXING AND LEPTOGENESIS IN THE MINIMAL SEESAW MODEL
We present a review of neutrino phenomenology in the minimal seesaw model (MSM), an economical and intriguing extension of the Standard Model with only two heavy right-handed Majorana neutrinos. Given current neutrino oscillation data, the MSM can predict the neutrino mass spectrum and constrain the effective masses of the tritium beta decay and the neutrinoless double-beta decay. We outline five distinct schemes to parameterize the neutrino Yukawa-coupling matrix of the MSM. The lepton favor mixing and baryogenesis via leptogenesis are investigated in some detail by taking account of possible texture zeros of the Dirac neutrino mass matrix. We derive an upper bound on the CP-violating asymmetry in the decay of the lighter right-handed Majorana neutrino. The effects of the renormalization-group evolution on the neutrino mixing parameters are analyzed, and the correlation between the CP-violating phenomena at low and high energies is highlighted. We show that the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism at the TeV scale. The lepton-flavor-violating rare decays, such as mu -> + gamma are also discussed in the supersymmetric extension of the MSM.
118632568
Searching for dark matter signals in the left-right symmetric gauge model with CP symmetry
We investigate the singlet scalar dark matter (DM) candidate in a left-right symmetric gauge model with two Higgs bidoublets in which the stabilization of the DM particle is induced by the discrete symmetries P and CP. According to the observed DM abundance, we predict the DM direct and indirect detection cross sections for the DM mass range from 10 to 500 GeV. We show that the DM indirect detection cross section is not sensitive to the light Higgs mixing and Yukawa couplings except for the resonance regions. The predicted spin-independent DM-nucleon elastic scattering cross section is found to be significantly dependent on the above two factors. Our results show that the future DM direct search experiments can cover the most parts of the allowed parameter space. The PAMELA antiproton data can only exclude two very narrow regions in the two Higgs bidoublets model. It is very difficult to detect the DM direct or indirect signals in the resonance regions due to the Breit-Wigner resonance effect.
119237588
Exploring the Singlet Scalar Dark Matter from Direct Detections and Neutrino Signals Via Its Annihilation in the Sun
We explore the singlet scalar dark matter (DM) from direct detections and high energy neutrino signals generated by the solar DM annihilation. Two singlet scalar DM models are discussed, one is the real singlet scalar DM model as the simple extension of the standard model (SSDM-SM) with a discrete Z(2) symmetry, and another is the complex singlet scalar DM model as the simple extension of the left-right symmetric two Higgs bidoublet model (SSDM-2HBDM) with P and CP symmetries. To derive the Sun capture rate, we consider the uncertainties in the hadronic matrix elements and calculate the spin-independent DM-nucleon elastic scattering cross section. We find that the predicted neutrino induced upgoing muon fluxes in the region 3.7 GeV <= m(D) <= 4.2 GeV slightly exceed the Super-Kamiokande limit in the SSDM-SM. However, this exceeded region can be excluded by the current DM direct detection experiments. For the SSDM-2HBDM. one may adjust the Yukawa couplings to avoid the direct detection limits and enhance the predicted muon fluxes. For the allowed parameter space of the SSDM-SM and SSDM-2HBDM, the produced muon fluxes in the Super-Kamiokande and muon event rates in the IceCube are less than the experiment upper bound and atmosphere background, respectively. Crown Copyright (C) 2012 Published by Elsevier B.V. All rights reserved.
118716317
Note on entanglement temperature for low thermal excited states in higher derivative gravity
A bstractWe investigate the entanglement temperature of a small scale subsystem in low excited states by using holographic method. Especially, we study the entanglement entropy and entanglement temperature in higher derivative gravities which are considered as low thermal excitation of pure AdS gravity. We find that the entanglement entropy are related to the central charges of CFT living on the boundary. The relation between the variance of entanglement entropy and energy of a small scale subsystem has been also obtained. Furthermore, the relation is consistent with the first law-like relation that is proposed by Phys. Rev. Lett. 110 (2013)091602. Finally, we derive the formula of the variance of entanglement entropy in general excited states in gravity background with the Fefferman-Graham coordinates and the entanglement temperature can be figured out in special case.
119115373
Holographic Rényi entropy and generalized entropy method
In this paper we use the method of generalized gravitational entropy in [6] to construct the dual bulk geometry for a spherical entangling surface, and calculate the Renyi entropy with the dual bulk gravity theory being either Einstein gravity or Lovelock gravity, this approach being closely related to that in [4]. For a general entangling surface we derive the area law of entanglement entropy. The area law is closely related to the local property of the entangling surface. (C) 2014 The Authors. Published by Elsevier B.V.