117860662
New Physics (2HDM) Effects on CP Violation
118710048
Probing the fourth generation Majorana neutrino dark matter
The heavy fourth-generation Majorana neutrino can be stable and contribute to a small fraction of the relic density of dark matter (DM) in the Universe. Because of its strong coupling to the standard model particles, it can be probed by the current direct and indirect DM detection experiments even it is a subdominant component of the whole halo DM. Assuming that it contributes to the same fraction of the local halo DM density as that of the DM relic density in the Universe, we show that the current Xenon100 data constrain the mass of the stable Majorana neutrino to be greater than the mass of the top quark. In the mass range from 200 GeV to a few hundred GeV, the effective spin-independent cross section for the neutrino elastic-scattering off nucleon is insensitive to the neutrino mass and mixing, and is predicted to be similar to 1.5 X 10(-44) cm(2), which can be reached by the direct DM detection experiments soon. In the same mass region the predicted effective spin-dependent cross section for the heavy neutrino scattering off proton is in the range of 2 X 10(-40) cm(2) similar to 2 X 10(-39) cm(2), which is within the reach of the ongoing DM indirect search experiments such as IceCube. We demonstrate such properties of the heavy neutrino DM in a fourth-generation model with the stability of the fourth Majorana neutrino protected by an additional generation-dependent U(1) gauge symmetry.
119263633
Two Higgs bi-doublet left-right model with spontaneous P and CP violation
A left-right symmetric model with two Higgs bi-doublet is shown to be a consistent model for both spontaneous P and CP violation. The flavor changing neutral currents can be suppressed by the mechanism of approximate global U(1) family symmetry. The constraints from neural K meson mass difference ΔmK are calculated and it is demonstrated that a right-handed gauge boson W2 contribution in box-diagrams with mass well below 1 TeV is allowed due to a cancelation caused by a light-charged Higgs boson with a mass range of 150–300 GeV. The W2 contribution to εK can be suppressed from an appropriate choice of additional CP phases appearing in the right-handed Cabbibo-Kobayashi-Maskawa matrix. The model is also found to be fully consistent with B0 mass difference ΔmB and the mixing induced CP violation sin2βJ/ Ψ, which is usually difficult for the model with only one Higgs bi-doublet. The new physics beyond the standard model can be directly searched at the colliders LHC and ILC.
123787607
The Contribution of Reggeon in charge exchange processes
We discuss in this paper The experimental results on maximum psedo-rapidity $\eta_{max}$ distribution in the charge exchange process $e+p\to e+n+X$ in ZEUS Collaboration at HERA. We calculate the contributions of \regg ($\rho$-Reggeon associated with $\rho$ meson) from regge phenomenology and $\pi^{+}$-exchange from pion cloud model. The results show that neither the \regg-exchange nor the pion cloud model alone can explain the experimental data well, but after considering both these two processes together, by using Monte Carlo simulation, a good agreement between theoretical results and experimental data is found. This means that in discussing the large rapidity gap phenomena in deep inelastic scattering, both of the two processes play substantial role.
115775190
More precise determination of V-cb & V-ub and direct CP violation in charmless B decays
More precise extractions on the two important CKM matrix elements \V-cb\ and \V-ub\ are presented up to 1/m(Q)(2) corrections, based on the complete heavy-quark effective field theory (HQEFT) of QCD. The HQEFT as a large component QCD provides us with a complete theoretical framework for correctly and systematically evaluating the subleading and higher-order contributions in 1/m(Q) expansion of heavy quarks. A global analysis on charmless B decays is made, based on the isospin and SU(3) flavor symmetry. An isospin relation is found to be very useful for studying SU(3) symmetry-breaking effects of strong phases and exploring new types of electroweak penguin effects. The direct CP violation in charmless B decays is predicted, and its precise measurement is helpful either for testing SU(3) symmetry breaking effects of strong phases or for probing news physics beyond standard model.
18105043
Chiral couplings of W ′ and top quark polarization at the LHC
If a TeV-scale charged gauge boson (W') is discovered at the Large Hadron Collider (LHC), it will become imperative to determine its chiral couplings to standard model (SM) fermions in order to learn about the underlying theory containing the W'. We describe the reconstruction of the tb decay mode of the W' at the LHC, and identify various kinematic observables such as the angular distributions of the top quark and the lepton resulting from top decay that can be used to disentangle the chiral couplings of the W' to SM fermions. We demonstrate by presenting analytical expressions, numerical simulations, as well as intuitive illustrations for these observables at the LHC that among the SM fermions, the polarized top quark can most directly probe the chirality of such couplings.
118334948
Non-Hermitian perturbations to the Fritzsch textures of lepton and quark mass matrices
Abstract We show that non-Hermitian and nearest-neighbor-interacting perturbations to the Fritzsch textures of lepton and quark mass matrices can make both of them fit current experimental data very well. In particular, we obtain θ 23 ≃ 45 ° for the atmospheric neutrino mixing angle and predict θ 13 ≃ 3 ° to 6° for the smallest neutrino mixing angle when the perturbations in the lepton sector are at the 20% level. The same level of perturbations is required in the quark sector, where the Jarlskog invariant of CP violation is about 3.7 × 10 − 5 . In comparison, the strength of leptonic CP violation is possible to reach about 1.5 × 10 − 2 in neutrino oscillations.
14308322
HOLOGRAPHIC SUPERCONDUCTOR FOR A LIFSHITZ FIXED POINT
We consider the gravity dual of strongly coupled system at a Lifshitz-fixed point and finite temperature, which was constructed in a recent work arXiv:0909.0263. We construct an Abelian-Higgs model in that background and calculate condensation and conductivity using holographic techniques. We find that condensation happens and DC conductivity blows up when temperature turns below a critical value. We also study the zero temperature limit of strongly coupled system at the Lifshitz-fixed point.
119257921
Geometry of the effective Majorana neutrino mass in the $0\nu\beta\beta$ decay
The neutrinoless double-beta (0 nu beta beta) decay is a unique process used to identify the Majorana nature of massive neutrinos, and its rate depends on the size of the effective Majorana neutrino mass (ee). We put forward a novel 'coupling-rod' diagram to describe (ee) in the complex plane, by which the effects of the neutrino mass ordering and CP-violating phases on (ee) are intuitively understood. We show that this geometric language allows us to easily obtain the maximum and minimum of vertical bar (ee)vertical bar. It remains usable even if there is a kind of new physics contributing to (ee), and it can also be extended to describe the effective Majorana masses (e mu), (e tau), (mu mu), (mu tau), and (tau tau) which may appear in some other lepton-number violating processes.
771773
High spin baryon in hot strongly coupled plasma
We consider a strings-junction holographic model of a probe baryon in the finite-temperature supersymmetric Yang-Mills dual of the AdS-Schwarzschild black hole background. In particular, we investigate the screening length for a high spin baryon composed of rotating N-c heavy quarks. To rotate quarks by finite force, we put a hard infrared cutoff in the bulk and give quarks a finite mass. We find that N-c microscopic strings are embedded reasonably in the bulk geometry when they have finite angular velocity omega, similar to the meson case. By defining the screening length as the critical separation of quarks, we compute the omega dependence of the baryon screening length numerically and obtain a reasonable result which shows that baryons with high spin dissociate more easily. Finally, we discuss the relation between J and E-2 for baryons.
119221494
Neutrino masses and flavor mixing in a generalized inverse seesaw model with a universal two-zero texture
A generalized inverse seesaw model, in which the 9 x 9 neutrino mass matrix has vanishing (1,1) and (1,3) submatrices, is proposed. This is similar to the universal two-zero texture which gives vanishing (1,1) and (1,3) elements of the 3 x 3 mass matrices in both the charged lepton and neutrino sectors. We consider the Z(6) x Z(6) group to realize such texture zeros in the framework of the generalized inverse seesaw model. We also analyze the universal two-zero texture in the general case and propose two Ansatze to reduce the number of free parameters. Taking account of the new result of theta(13) from the Daya Bay experiment, we constrain the parameter space of the universal two-zero texture in the general case and in the two Ansatze, respectively. We find that one of the Ansatze works well.