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.
124146558
The Annihilation decay B(c)- ---> eta-prime lepton- anti-neutrino
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 $\Delta\Gamma_{s}$.
1542336
Extracting Cabibbo-Kobayashi-Maskawa elements in Bc semileptonic decays and heavy quark spin symmetry.
We discuss the extraction of \ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{s}}$/${\mathit{V}}_{\mathit{c}\mathit{d}}$\ensuremath{\Vert},\ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{s}}$/${\mathit{V}}_{\mathit{u}\mathit{b}}$\ensuremath{\Vert}, and \ensuremath{\Vert}${\mathit{V}}_{\mathit{c}\mathit{d}}$/${\mathit{V}}_{\mathit{u}\mathit{b}}$\ensuremath{\Vert} from semileptonic ${\mathit{B}}_{\mathit{c}}$ decay in the heavy quark limit. The first corrections to the corresponding ratios of the differential rates of ${\mathit{B}}_{\mathit{c}}$ semileptonic decays are calculated in the zero recoil point within HQET combined with the results of QCD sum rules and chiral perturbation theory, and within the quark model. Special attention is paid to minimize the theoretical uncertainties in the procedure of extracting the ratios. We find many uncertainties can be canceled naturally in the leading level. The ratios also are insensitive to the QCD energy scale \ensuremath{\mu} in the next-to-leading level. The result is potentially important for extracting CKM elements from future measurements at the CERN LHC.
15654773
Probe new physics in leptonic Bc decays at CERN LHC
With respect to large samples of B-c mesons expected to be produced at CERN Large Hadron Collider (LHC) and the large branching ratios Br(B-c --> tau ) and Br(B-c --> mu ), we suggest that, purely leptonic decays could offer an unique probe of the standard model and its extensions such as two Higgs doublet models and models involving supersymmetry, and also the structure of charged weak currents. (C) 1997 Published by Elsevier Science B.V.
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
119114673
Charmonium States in QCD-Inspired Quark Potential Model Using Gaussian Expansion Method
We investigate the mass spectrum and electromagnetic processes of charmonium system with the nonperturbative treatment for the spin-dependent potentials, comparing the pure scalar and scalar-vector mixing linear confining potentials. It is revealed that the scalar-vector mixing confinement would be important for reproducing the mass spectrum and decay widths, and therein the vector component is predicted to be around 22 %. With the state wave functions obtained via the full-potential Hamiltonian, the long-standing discrepancy in M1 radiative transitions of J/ψ and ψ′ are alleviated. This work also provides an inspection and suggestion for the possible cc̄ states among the copious higher charmonium-like states. Particularly, the newly observed X(4160) and X(4350) are found in the charmonium family mass spectrum as M(21D2) = 4164.9 MeV and M(33P2) = 4352.4 MeV, which strongly favor the JPC = 2−+, 2++ assignments respectively. The corresponding radiative transitions, leptonic and two-photon decay widths have been also predicted theoretically for the further experimental search.
119272630
Charmless B-s -> PP, PV, VV decays based on the six-quark effective Hamiltonian with strong phase effects II
We provide a systematic study of charmless B-s -> PP, PV, VV decays (P and V denote pseudoscalar and vector mesons, respectively) based on an approximate six-quark operator effective Hamiltonian from QCD. The calculation of the relevant hard-scattering kernels is carried out, the resulting transition form factors are consistent with the results of QCD sum-rule calculations. By taking into account important classes of power corrections involving "chirally enhanced" terms and the vertex corrections as well as weak annihilation contributions with non-trivial strong phase, we present predictions for the branching ratios and CP asymmetries of B-s decays into PP, PV and VV final states, and also for the corresponding polarization observables in VV final states. It is found that the weak annihilation contributions with non-trivial strong phase have remarkable effects on the observables in the color-suppressed and penguin-dominated decay modes. In addition, we discuss the SU(3) flavor symmetry and show that the symmetry relations are generally respected.
118602451
QCD FACTORIZATION BASED ON SIX-QUARK OPERATOR EFFECTIVE HAMILTONIAN FROM PERTURBATIVE QCD AND CHARMLESS BOTTOM MESON DECAYS B((s)) -> pi pi, pi K, KK
The charmless bottom meson decays are systematically investigated based on an approximate six-quark operator effective Hamiltonian from perturbative QCD. It is shown that within this framework the naive QCD factorization method provides a simple way to evaluate the hadronic matrix elements of two-body mesonic decays. The singularities caused by on mass-shell quark propagator and gluon exchanging interaction are appropriately treated. Such a simple framework allows us to make theoretical predictions for the decay amplitudes with reasonable input parameters. The resulting theoretical predictions for all the branching ratios and CP asymmetries in the charmless B0, B+, Bs → ππ, πK, KK decays are found to be consistent with the current experimental data except for a few decay modes. The observed large branching ratio in B→π0π0 decay remains a puzzle though the predicted branching ratio may be significantly improved by considering the large vertex corrections in the effective Wilson coefficients. More precise measurements of charmless bottom meson decays, especially on CP violations in B → KK and Bs → ππ, πK, KK decay modes, will provide a useful test and guide us to a better understanding on perturbative and nonperturbative QCD.
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.