15356463
Flavor SU(3) analysis of charmless B meson decays to two pseudoscalar mesons
Global fits to charmless B→PP decays in the framework of flavor SU(3) symmetry are updated and improved without reference to the sin 2β measured from the charmonium decay modes. Fit results directly constrain the (,) vertex of the unitarity triangle, and are used to predict the branching ratios and CP asymmetries of all decay modes, including those of the Bs system. Different schemes of SU(3) breaking in decay amplitude sizes are analyzed. The major breaking effect between strangeness-conserving and strangeness-changing decays can be accounted for by including a ratio of decay constants in tree and color-suppressed amplitudes. The possibility of having a new physics contribution to Kπ decays is also examined from the data fitting point of view.
33469308
Constraint on parity-violating muonic forces.
Using the nonobservance of missing mass events in the leptonic kaon decay K→μX, we place a strong constraint on exotic parity-violating gauge interactions of the right-handed muon. By way of illustration, we apply it to an explanation of the proton size anomaly that invokes such a new force; scenarios in which the gauge boson decays invisibly or is long lived are constrained.
118392807
A six-dimensional gauge-Higgs unification model based on E6 gauge symmetry
Abstract We construct a six-dimensional gauge-Higgs unification model with the enlarged gauge group of E 6 on S 2 / Z 2 orbifold compactification. The standard model particle contents and gauge symmetry are obtained by utilizing a monopole background field and imposing appropriate parity conditions on the orbifold. In particular, a realistic Higgs potential suitable for breaking the electroweak gauge symmetry is obtained without introducing extra matter or assuming an additional symmetry relation between the SU(2) isometry transformation on the S 2 and the gauge symmetry. The Higgs boson is a KK mode associated with the extra-dimensional components of gauge field. We also compute the KK masses of all fields at tree level.
16971592
Flavor symmetry analysis of charmless B ---> VP decays
Based upon flavor SU(3) symmetry, we perform global fits to charmless B decays into one pseudoscalar meson and one vector meson in the final state. We consider different symmetry breaking schemes and find that the one implied by naive scaling, where strangeness-conserving and strangeness-changing amplitudes are related by the ratio of appropriate decay constants, is slightly favored over the exact symmetry case. The ((rho) over bar, (eta) over bar) vertex of the unitarity triangle (UT) constrained by our fits is consistent with other methods within errors. We have found large color-suppressed, electroweak penguin and singlet penguin amplitudes when the spectator quark ends up in the final-state vector meson. Nontrivial relative strong phases are also required to explain the data. The best-fit parameters are used to compute branching ratio and CP asymmetry observables in all of the decay modes, particularly those in the B(s) decays to be measured at the Tevatron and LHC experiments.
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.
15885355
Resumming the color-octet contribution to radiative Upsilon decay
At the upper endpoint of the photon energy spectrum in Upsilon -> X gamma, the standard NRQCD power counting breaks down and the OPE gives rise to color-octet structure functions. Furthermore, in this kinematic regime large Sudakov logarithms appear in the octet Wilson coefficients. The endpoint spectrum can be treated consistently within the framework of a recently developed effective field theory of collinear and soft particles. Here we show that within this approach the octet structure functions arise naturally and that Sudakov logarithms can be summed using the renormalization group equations. We derive an expression for the resummed energy spectrum and, using a model lightcone structure function, investigate the phenomenological importance of the resummation.
54957266
Constraining the detailed balance condition in Hořava gravity with cosmic accelerating expansion
In 2009 Hořava proposed a power-counting renormalizable quantum gravity theory. Afterwards a term in the action that softly violates the detailed balance condition has been considered with the attempt of obtaining a more realistic theory in its IR-limit. This term is proportional to ωR(3), where ω is a constant parameter and R(3) is the spatial Ricci scalar. In this paper we derive constraints on this IR-modified Hořava theory using the late-time cosmic accelerating expansion observations. We obtain a lower bound of |ω| that is nontrivial and depends on ΛW, the cosmological constant of the three dimensional spatial action in the Hořava gravity. We find that to preserve the detailed balance condition, one needs to fine-tune ΛW such that −2.29 × 10−4 < (c2ΛW)/(H20ΩDE)−2 < 0, where H0 and ΩDE are the Hubble parameter and dark energy density fraction in the present epoch, respectively. On the other hand, if we do not insist on the detailed balance condition, then the valid region for ΛW is much relaxed to −0.39 < (c2ΛW)/(H20ΩDE)−2 < 0.12. We find that although the detailed balance condition cannot be ruled out, it is strongly disfavored.
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.