119340219
B ---> phi pi and B0 ---> phi phi in the standard model and new bounds on R parity violation
We study the pure penguin decays $B \to \phi\pi$ and $B^0 \to \phi\phi$. Using QCD factorization, we find ${\cal B}(B^\pm \to\phi\pi^{\pm} )=2.0^{+0.3}_{-0.1}\times 10^{-8}$. For the pure penguin annihilation process $B^0 \to \phi\phi$, analyzed here for the first time, ${\cal B}(B^0 \to\phi\phi)=2.1^{+1.6}_{-0.3}\times 10^{-9}$. The smallness of these decays in the Standard Model makes them sensitive probes for new physics. From the upper limit of $B\to \phi\pi$,we find constraints on R parity violating couplings, $| \lambda{''}_{i23}\lambda{''}_{i21}|<6\times10^{-5}$, $| \lambda'_{i23}\lambda'_{i21}|<4\times10^{-4}$ and $| \lambda'_{i32}\lambda'_{i12}|<4\times10^{-4}$ for $i=1,2,3$. Our new bounds on $|\lambda{''}_{i23}\lambda{''}_{i21}|$ are one order of magnitude stronger than before. Within the available upper bounds for $| \lambda{''}_{i23}\lambda{''}_{i21}|$, $|\lambda'_{i23}\lambda'_{i21}|$ and $|\lambda'_{i32}\lambda'_{i12}|$, we find that ${\cal B}(B\to\phi\phi)$ could be enhanced to $10^{-8}\sim 10^{-7}$. Experimental searches for these decays are strongly urged.
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.
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.
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.
119227930
Baryonia and near-threshold enhancements
The baryon-antibaryon spectrum consisting of strange, charm and bottom quarks is studied in the color flux-tube model with a multi-body confinement interaction. Numerical results indicate that many low-spin baryon-antibaryon states can form compact hexaquark states and are stable against the decay into a baryon and an antibaryon. The multi-body confinement interaction as a binding mechanism plays an important role in the formation of the states. They can be searched in the $e^+e^-$ annihilation and charmonium or bottomonium decay if they really exist. The newly reported states, X(1835), X(2370), Y(2175), Y(4360) and Y_b(10890), may be interpreted as $N\bar{N}$, $\Delta\bar{\Delta}$, $\Lambda\bar{\Lambda}$, $\Lambda_c\bar{\Lambda}_c$ and $\Lambda_b\bar{\Lambda}_b$ states, respectively.
119228688
The GL(4 R) Yang-Mills Theory of Gravity Predicts An Inflationary Scenario For The Evolution of The Primordial Universe
We show that the GL(4 R) gauge theory of gravity will admit an exponentially expanding solution for the primordial evolution of the Universe. This inflationary phase of the Universe is driven by a rapidly changing GL(4 R) gauge field configuration. No cosmological constant and no rolling scalar field is required. This inflationary expansion will then be shown to slow down to a much slower expansion rate during the late time evolution of the Universe.
119232831
Prediction for the mass spectra of resonance mesons in the soft-wall AdS/QCD model with a modified 5D metric
A soft-wall anti-de Sitter/QCD model with a modified five-dimensional metric at the infrared region is constructed to obtain a nontrivial dilaton solution, which incorporates the chiral symmetry breaking and linear confinement. By taking the pion mass and decay constant as two input mass scales, the resulting predictions for the resonance states of pseudoscalar, scalar, vector, and axial-vector mesons agree remarkably with the experimentally confirmed resonance states. The effects of the quartic interaction term are investigated by taking an appropriate sign and magnitude for maintaining the stability of the bulk scalar potential. It is shown that such a simply modified soft-wall anti-de Sitter/QCD model can lead to a consistent prediction for the mass spectra of resonance states in the pseudoscalar, scalar, vector, and axial-vector mesons; the agreement with the experimental data is found to be better than 10% for the excited meson states. The resulting pion form factor also agrees well with the experimental data.
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.
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