124404039
Space- and time-like kaon electromagnetic form factors in perturbative QCD
We present a phenomenological analysis of the space- and time-like charged kaon electromagnetic form factors in factorized perturbative QCD (pQCD) by employing an analytic model for αs(Q2) and an infrared (IR) finite gluon propagator. In the space-like region, due to the lack of available experimental data above Q2 ~ 0.2 GeV2, we only give our results for intermediate energies and make no comparison. In the time-like region, our results agree reasonably well with the available experimental data at moderate energies, including the CLEO data and the J/ψ result.
118702585
Probe the R-parity Violating Supersymmetry Effects in the $B^0_s-\bar{B}^0_s$ Mixing
The recent measurements of the $B_s$ mass difference $\Delta M_s$ by the CDF and D{\O} collaborations are roughly consistent with the Standard Model predictions, therefore, these measurements will afford an opportunity to constrain new physics scenarios beyond the Standard Model. We consider the impact of the R-parity violating supersymmetry in the $B^0_s-\bar{B}^0_s$ mixing, and use the latest experimental results of $\Delta M_s$ to constrain the size of the R-parity violating tree level couplings in the $B^0_s-\bar{B}^0_s$ mixing. Then, using the constrained R-parity violating parameter space from $\Delta M_s$, we show the R-parity violating effects on the $B_s$ width difference $\Delta\Gamma_{s}$.
118478453
Constraints on anomalous $tcZ$ coupling from $\bar B \to \bar K^* \mu^+ \mu^-$ and $B_s \to \mu^+ \mu^-$ decays
In this paper, we analyze the possible anomalous $tcZ$ coupling effects in the $b \to s $ mediated decays $\bar B \to \bar K^* \mu^+ \mu^-$ and $B_s \to \mu^+ \mu^-$. After exploiting the available experimental data, the combined constraints on the anomalous coupling $X_{ct}^L$ are derived. It is found that, the bound on the magnitude $|X_{ct}^L|$ is dominated by the branching ratios of these two decays. Furthermore, one sign-flipped solution is excluded by the longitudinal fraction of $\bar B \to \bar K^* \mu^+ \mu^-$ at the low dilepton mass region. After considering the combined constraints, for general complex coupling $X_{ct}^L$, the predicted upper bound on $\mathcal B (t \to cZ)$ are compatible with that from the recent CMS direct search. In particular, for the case of real coupling $X_{ct}^L$, the upper bound reads $\mathcal B (t \to cZ)<1.0\times 10^{-4}$, which is much lower than the current CMS bound but still accessible at the LHC. With improved measurements at the LHC, the colser correlations between the $t \to cZ$ and $b \to s$ mediated (semi-) leptonic decays are expected in the near future.
120402686
Perturbative QCD estimation of the Bc exclusive nonleptonic decays
We argue that the B-c exclusive nonleptonic decays are perturbatively calculable. Working in a perturbative QCD model of Brodsky et al, we pay attention to the estimate of the partial widths of the modes B-c --> J/Psi pi(+), J/Psi rho(+), etc., which serve to identify B-c mesons and determine the B-c mass and life time. Our estimations are found to be lower than the other predictions. We note that the spectator ansatz might be misleading in dealing with B-c weak decays. So the results will be potentially important at LHC to measure the B-c meson and to test various models of weak decays of heavy mesons.
118024604
Exclusive radiative B-meson decays within minimal flavor-violating two-Higgs-doublet models
In the "Higgs basis" for a generic two-Higgs-doublet model, only one doublet gets a nonzero vacuum expectation value and, under the criterion of minimal flavor violation, the other one is fixed to be either color-singlet or color-octet, referred to, respectively, as the type-III and type-C models. Both of them can naturally avoid large FCNC transitions and provide very interesting phenomena in some low-energy processes. In this paper, we study their effects on exclusive radiative B-meson decays due to the exchange of colorless or colored charged Higgs. It is found that while constraints from the branching ratios are slightly weaker than the ones from the inclusive B -> X-s gamma decay, the isospin asymmetries in exclusive decays provide very complementary bounds on the model parameters. As the two models predict similar corrections to the dipole coefficient C-7(eff), but similar magnitudes with opposite signs to C-8(eff), the branching ratios cannot discriminate the two models, and we have to resort to the direct CP and isospin asymmetries of b -> s processes, which are more sensitive to C-8(eff). Due to the CKM factors vertical bar lambda((d))(u)vertical bar similar to vertical bar lambda((d))(t)vertical bar, the terms proportional to lambda((d))(u) make the observables of b -> d processes exhibit a different dependence on the possible new physics phase. In addition, correlations between the various observables in the exclusive B -> V gamma and the inclusive B -> X-s,X-d gamma decays are investigated, which could provide further insights into the models with more precise experimental measurements and theoretical predictions for these decays.
119180550
Anomalous tqZ coupling effects in rare B- and K-meson decays
A bstractAs a top-factory, the LHC is performing a direct study of top-quark anomalous FCNC couplings, which are, however, correlated closely with the rare B- and K-meson decays. In this paper, we study the effects of anomalous tqZ (with q = u, c) couplings in the rare decays Bs,d → μ+μ−, B → Xsν$ \overline \nu $, B → K(*)ν$ \overline \nu $, K+ → π+ν$ \overline \nu $, and KL → π0ν$ \overline \nu $. With the up-to-date experimental bounds on the branching ratios of these channels, constraints on the left-handed anomalous couplings $ X_{{ct}}^L $ and $ X_{{ut}}^L $ are derived, respectively. With these low-energy constraints taken into account, we find that, for real couplings $ X_{{ct}}^L $ and $ X_{{ut}}^L $, the indirect upper bounds on B(t → qZ) are much lower than that from the D0 collaboration, but are still compatible with the 5σ discovery potential of ATLAS with an integrated luminosity of 10 fb−1. With refined measurements to be available at the LHCb, the future super-B factories, the NA62 at CERN, and the KOTO at J-PARC, closer correlations between the t → qZ and the rare B- and K-meson decays are expected in the near future, which will be helpful for the searches of the top-quark FCNC decays at the LHC.
119236514
Scalar Glueball in Radiative J/psi Decay on the Lattice
The form factors in the radiative decay of J/psi to a scalar glueball are studied within quenched lattice QCD on anisotropic lattices. The continuum extrapolation is carried out by using two different lattice spacings. With the results of these form factors, the partial width of J/psi radiatively decaying into the pure gauge scalar glueball is predicted to be 0.35(8) keV, which corresponds to a branching ratio of 3.8(9) x 10(-3). By comparing with experiments, out results indicate that f(0)(1710) has a larger overlap with the pure gauge glueball than other related scalar mesons. DOI: 10.1103/PhysRevLett.110.021601
124451852
A STUDY OF O-16+C-12 ELASTIC-SCATTERING AT E/A = 10-MEV IN THE ALPHA-PARTICLE MODEL
Using a folding model based on the alpha-particle model, the differential cross sections for O-16+C-12 elastic scattering at 168 MeV have been calculated. This folding model, having no need of the renormalization, provides a good description of the experimental data.
117973255
A New Approach to the Yang-Mills Gauge Theory of Gravity and It's Applications
We shall give dynamics to our spacetime manifold by first identifying the local affine symmetry as the characterizing symmetry for our geometryla Felix Klein, this symmetry is imposed on us by the Law of Inertia and the Law of Causality. We then prescribe 16 gauge vector bosons to this symmetry ´ ala Yang and Mills. The locally affine symmetric Yang-Mills Lagrangian in the presence of a background world metric, and the corresponding equations of motion, are respectively constructed and derived. Spontaneous breaking of the local affine symmetry to the local Lorentz symmetry is achieved by classical solutions to the equations of motion. In these classical solutions, the 16 gauge vector bosons are shown to select the Schwarzschild metric as one among the admissible background world metrics. Classical gravity is thus be expressed by a spontaneously broken Erlangen program. We shall also show that this Yang-Mills gauge theory of gravity can give an explanation of the form of the galactic rotation curves, of the amount of intergalactic gravitational lensing, and of the accelerating expansion of the Universe.
118950998
Are the X(4160) and X(3915) charmonium states
Inspired by the newly observed states X(4160) and X(3915), we analyze the mass spectra of these states in different quark models and calculate their strong decay widths by the {sup 3}P{sub 0} model. According to the mass spectra of charmonium states predicted by the potential model, the states {chi}{sub 0}(3{sup 3}P{sub 0}), {chi}{sub 1}(3{sup 3}P{sub 1}), {eta}{sub c2}(2{sup 1}D{sub 2}), {eta}{sub c}(4{sup 1}S{sub 0}) all can be candidates for the X(4160). However, only the decay width of the state {eta}{sub c2}(2{sup 1}D{sub 2}) in our calculation is in good agreement with the data reported by Belle, and the decay of {eta}{sub c2}(2{sup 1}D{sub 2}){yields}DD, which is not seen in experiment, is also forbidden. Therefore, it is reasonable to interpret the charmonium state {eta}{sub c2}(2{sup 1}D{sub 2}) as the state X(4160). For the state X(3915), although the mass of {chi}{sub 0}(2{sup 3}P{sub 0}) is compatible with the experimental value, the calculated strong decay width is much larger than experimental data. Hence, the assignment of X(3915) to the charmonium state {chi}{sub 0}(2{sup 3}P{sub 0}) is disfavored in our calculation.
121575220
Elastic O-16+Ne-20 scattering from a folding model analysis
A folding potential for elastic O-16+Ne-20 scattering is constructed based on the four-alpha-particle model for the O-16 nucleus and the alpha+O-16 model for the Ne-20 nucleus. The elastic scattering angular distributions of the O-16+Ne-20 system in the energy range of E-c.m. = 24.5-35.5 MeV are calculated by use of the alpha-folding potential obtained. The calculations show that the experimental data can be reasonably well described. The surface term in the imaginary potential has a significant effect on the calculations of the cross section at large angles for the energies considered.