55043401
Enhancements of weak gauge boson scattering processes at the CERN LHC
A bstractCurrent CERN Large Hadron Collider data on the 126 GeV standard model-like Higgs boson suggest the possibility of larger Higgs boson couplings with the weak gauge bosons, ghVV, than those in the standard model. We use the Georgi-Machacek model as an explicit model to realize such a scenario. We find that the ghVV couplings can be larger than the standard model value by a factor of about 1.3 maximally in the parameter region consistent with the current Higgs boson search data and allowed by various other constraints. We then show how the modified ghVV couplings lead to enhancements in various weak boson scattering processes. This can be clearly observed as excesses in the transverse mass distributions at around 126 GeV and also the mass of heavy Higgs bosons.
119109976
Probing leptonic interactions of a family-nonuniversal Z′ boson
A bstractWe explore a Z′ boson with family-nonuniversal couplings to charged leptons. The general effect of Z-Z′ mixing, of both kinetic and mass types, is included in the analysis. Adopting a model-independent approach, we perform a comprehensive study of constraints on the leptonic Z′ couplings from currently available experimental data on a number of flavor-conserving and flavor-changing transitions. Detailed comparisons are made to extract the most stringent bounds on the leptonic couplings. Such information is fed into predictions of various processes that may be experimentally probed in the near future.
118094398
Determining the Unitarity Triangle from Two‐Body Charmless Hadronic B Decays
We performed an updated global fits to charmless Bu,d → PP decays in the framework of flavor SU(3) symmetry, without referring to sin2β measured from the charmonium decay modes. Fit results directly constrain the (ρ, η) vertex of the unitarity triangle. Details regarding the analyses of different schemes of SU(3) breaking in decay amplitude sizes and predictions for the branching ratios and CP asymmetries of Bu,d,s → PP decays are given in Ref. [1].
117495229
Light gluino and the running of alpha(s)
A gluino in the mass range 12--16 GeV combined with a light (2--5.5 GeV) bottom squark, as has been proposed recently to explain an excess of b quark hadroproduction, would affect the momentum-scale dependence (``running'') of the strong coupling constant alpha_s in such a way as to raise its value at M_Z by about 0.014 +/- 0.001. If one combines sources of uncertainty at low (m_b) and high (M_Z) mass scales, one can only distinguish such an effect at slightly more than the 2 sigma level. Prospects for improvement in this situation, which include better lattice QCD simulations and better measurements at M_Z, are discussed.
117055056
A study of CP violation in K and B meson decays
119207675
Phenomenology of large mixing for the CP-even neutral scalars of the Higgs triplet model
The Higgs triplet model contains two CP-even neutral scalar eigenstates, each having components from an isospin doublet and an isospin triplet scalar field. The mixing angle can be maximal if the masses of the scalar eigenstates are close to degeneracy. We quantify the dependence of the mixing angle on the mass splitting and on the vacuum expectation value of the neutral triplet scalar. We determine the parameter space for maximal mixing, and study the observability of both CP-even Higgs bosons at the CERN LHC.
119227092
Dark matter detection with polarized detectors
Abstract We consider the prospects to use polarized dark-matter detectors to discriminate between various dark-matter models. If WIMPs are fermions and participate in parity-violating interactions with ordinary matter, then the recoil-direction and recoil-energy distributions of nuclei in detectors will depend on the orientation of the initial nuclear spin with respect to the velocity of the detector through the Galactic halo. If, however, WIMPS are scalars, the only possible polarization-dependent interactions are extremely velocity-suppressed and, therefore, unobservable. Since the amplitude of this polarization modulation is fixed by the detector speed through the halo, in units of the speed of light, exposures several times larger than those of current experiments will be required to be probe this effect.
12835808
Galaxy redshift surveys with sparse sampling
Survey observations of the three-dimensional locations of galaxies are a powerful approach to measure the distribution of matter in the universe, which can be used to learn about the nature of dark energy, physics of inflation, neutrino masses, etc. A competitive survey, however, requires a large volume (e.g., Vsurvey ~ 10Gpc3) to be covered, and thus tends to be expensive. A ``sparse sampling'' method offers a more affordable solution to this problem: within a survey footprint covering a given survey volume, Vsurvey, we observe only a fraction of the volume. The distribution of observed regions should be chosen such that their separation is smaller than the length scale corresponding to the wavenumber of interest. Then one can recover the power spectrum of galaxies with precision expected for a survey covering a volume of Vsurvey (rather than the volume of the sum of observed regions) with the number density of galaxies given by the total number of observed galaxies divided by Vsurvey (rather than the number density of galaxies within an observed region). We find that regularly-spaced sampling yields an unbiased power spectrum with no window function effect, and deviations from regularly-spaced sampling, which are unavoidable in realistic surveys, introduce calculable window function effects and increase the uncertainties of the recovered power spectrum. On the other hand, we show that the two-point correlation function (pair counting) is not affected by sparse sampling. While we discuss the sparse sampling method within the context of the forthcoming Hobby-Eberly Telescope Dark Energy Experiment, the method is general and can be applied to other galaxy surveys.