118478034
NNLO vertex corrections to non-leptonic B decays: Tree amplitudes
Abstract The colour-suppressed tree amplitude in non-leptonic B decays is particularly sensitive to perturbative and non-perturbative corrections. We calculate the two-loop (NNLO) vertex corrections to the colour-suppressed and colour-allowed tree amplitudes in QCD factorization. Our results are given completely analytically, including the full dependence on the charm quark mass. We then update theoretical predictions for a range of interesting observables derived from ππ, πρ and ρρ final states that do not depend (significantly) on penguin contributions, and hence are now available with NNLO accuracy. We observe good agreement with experimental data within experimental and theoretical errors, except for observables involving the π 0 π 0 branching fraction.
53695340
Exclusive radiative B-meson decays within the aligned two-Higgs-doublet model
A bstractIn the aligned two-Higgs-doublet model, the alignment of Yukawa matrices in flavour space guarantees the absence of tree-level flavour-changing neutral currents, while allowing at the same time for new sources of CP violation, implying potentially large effects in many low-energy processes. In this work we study the constraints from exclusive radiative B → V γ decays, where V denotes a light vector meson. The current experimental data on the CP-averaged branching ratios and the direct CP and isospin asymmetries are analyzed. It is found that, while the branching ratios and direct CP asymmetries do not constrain the parameter space much further compared to the inclusive B → Xs,d γ decays, complementary constraints can be obtained from the isospin asymmetries Δ(K*γ) and Δ(ργ). In addition, correlations between the various observables in exclusive B → V γ and inclusive B → Xs,d γ decays are investigated in detail, and predictions are made for several so far unmeasured observables.
125172218
Charmless anti-B(s) ---> VV decays in QCD factorization
12071441
The folding deuteron optical model potentials
In this paper we construct a kind of deuteron optical potential with the folding model. For the nucleon optical potential, we choose two kinds of forms: the phenomenological global nucleon optical potential and the microscopic nucleon optical potential based on the nuclear-matter approach. We use our folding and global deuteron optical potential to calculate the reaction cross-sections, elastic scattering angular distributions, and the $ \chi^{2}_{}$ values for 64 target nuclei.
119233306
Single-nucleon potential decomposition of the nuclear symmetry energy
The nuclear symmetry energy $E_{sym}(\rho)$ and its density slope $L(\rho)$ can be decomposed analytically in terms of the single-nucleon potential in isospin asymmetric nuclear matter. Using three popular nuclear effective interaction models which have been extensively used in nuclear structure and reaction studies, namely, the isospin and momentum dependent MDI interaction model, the Skyrme Hartree-Fock approach and the Gogny Hartree-Fock approach, we analyze the contribution of different terms in the single-nucleon potential to the $E_{sym}(\rho)$ and $L(\rho)$. Our results show that the observed different density behaviors of $E_{sym}(\rho)$ for different interactions are essentially due to the variation of the symmetry potential $U_{sym,1}(\rho,k)$. Furthermore, we find that the contribution of the second-order symmetry potential $U_{sym,2}(\rho,k)$ to the $L(\rho)$ generally cannot be neglected. Moreover, our results demonstrate that the magnitude of the $U_{sym,2}(\rho,k)$ is generally comparable with that of $U_{sym,1}(\rho,k)$, indicating the second-order symmetry potential $U_{sym,2}(\rho,k)$ may have significant corrections to the widely used Lane approximation to the single-nucleon potential in extremely neutron(proton)-rich nuclear matter.
98875889
Isospin dependent global neutronnucleus optical model potential
Abstract In this paper, we construct a new phenomenological isospin dependent global neutron–nucleus optical model potential. Based on the existing experimental data of elastic scattering angular distributions for neutron as projectile, we obtain a set of the isospin dependent global neutron–nucleus optical model potential parameters, which can basically reproduce the experimental data for target nuclei from 24 Mg to 242 Pu with the energy region up to 200 MeV.
17450923
Anisotropic Lattice Calculation of Pion Scattering Using an Asymmetric Box
Pion-pion elastic scattering phase shifts in the I = 2, J = 0 channel are calculated within quenched approximation using improved gauge and Wilson fermion actions on anisotropic lattices in an asymmetric box. Using the modified Lüscher’s formula applicable in an asymmetric volume, we are able to access more low-momentum modes than a cubic box with similar volume. The calculation is performed at three lattice spacings at β = 2.080, β = 2.215 and β = 2.492. For each lattice spacing, several valence quark mass values are taken in the quenched approximation which enable us to extrapolate the results to the chiral limit. Continuum limit extrapolation is then performed and the extrapolated results are compared with the known results from both theory and experiment. We find that our lattice results for the scattering phase shifts in this channel are consistent with the experimental data when the three-momentum of the pion is below 300MeV. The results are Preprint submitted to Elsevier 2 March 2008 also consistent with previous lattice calculations and other theoretical calculations using Chiral Perturbation Theory or dispersion relations. We have also given the pion-pion scattering length in the chiral and continuum limit.
118410842
$p$-wave chiral superfluidity from an $s$-wave interacting atomic Fermi gas
X iv :1 40 2. 59 95 v1 [ co nd -m at .q ua nt -g as ] 24 F eb 2 01 4 p-wave chiral superfluidity from an s-wave interacting atomic Fermi gas Bo Liu , Xiaopeng Li , Biao Wu, and W. Vincent Liu Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260, USA 2 Condensed Matter Theory Center, University of Maryland, Co llege Park, MD 20742, USA Joint Quantum Institute, University of Maryland, College P ark, MD 20742, USA International Center for Quantum Materials, Peking University, Beijing 100871, China Collaborative Innovation Center of Quantum Matter, Beijin g, China (Dated: February 26, 2014) Abstract Chiralp-wave superfluids are fascinating topological quantum stat e of matter that have been found in the liquid 3He-A phase and arguably in the electronic Sr 2RuO4 superconductor. They are shown fundamentally related to the fractional 5/2 quantum Hall state which supports fractional exotic excita tions. A common understanding is that such states require spin-triplet pai ring of fermions due top-wave interaction. Here we report by controlled theoretical approximation that a cent er-of-mass Wannier p-wave chiral superfluid state can arise from spin-singlet pairing for an s-wave interacting atomic Fermi gas in an optical lattice. De spite a conceptually different origin, it shows topological prop erties similar to the conventional chiral p-wave state. These include a non-zero Chern number and the appeara nc of chiral fermionic zero modes bounded to domain walls. Several signature quantities are calculat ed for the cold atom experimental condition.