118563627
DEFORMED RELATIVISTIC HARTREE-BOGOLIUBOV MODEL FOR EXOTIC NUCLEI
A deformed relativistic Hartree-Bogoliubov (DRHB) model is developed aiming at a proper description of exotic nuclei, particularly deformed ones with large spatial extension. In order to give an adequate description of both the contribution of the continuum and the large spatial distribution in exotic nuclei, the DRHB equations are solved in a Woods-Saxon basis in which the radial wave functions have proper asymptotic behaviors at large distance from the nuclear center which is crucial for the formation of halo. The formalism and the numerical procedure of the DRHB model in a Woods-Saxon basis are briefly presented.
121545824
A Light-Cone QCD Inspired Meson Model with a Relativistic Confining Potential in Momentum Space
For describing the radial excited states a relativistic confining potential in momentum space is included in the meson effective light-cone Hamiltonian. The meson eigen equations are transformed from the front form to the instant form and formulated in total angular representation. Details about numerically solving these equations are discussed, mainly focusing on treating singularities arising from one-gluon exchange interactions and confinement. The results of pseudo-scalar mesons indicate that the improved meson effective light-cone Hamiltonian can describe the ground states and radial excited states well. Some radial excited states are also predicted and waiting for experimental test.
115438513
High-spin states in 152Gd
124229961
A light-cone QCD inspired effective Hamiltonian model for pseudoscalar and scalar mesons
Considering the one-gluon exchange interaction and phenomenological quark confinement potential, an improved light-cone effective Hamiltonian for mesons and the corresponding radial mass eigen equations in angular momentum representation is obtained. Solving the J = 0 eigen equations numerically and using a set of adjustable parameters, the obtained solutions for ground states and radial excited states can simultaneously describe both pseudoscalar and scalar flavour-off-diagonal mesons. Some radial excited states are also predicted and wait for experimental test. More results for the vector and axial vector mesons are expected.
18203445
Theoretical study of the two-proton halo candidate 17Ne including contributions from resonant continuum and pairing correlations
Abstract.With the relativistic Coulomb wave function boundary condition, the energies, widths and wave functions of the single-proton resonant orbitals for 17Ne are studied by the analytical continuation in the coupling constant (ACCC) approach within the framework of the relativistic mean field (RMF) theory. Pairing correlations and contributions from the single-particle resonant orbitals in the continuum are taken into consideration by the resonant Bardeen-Cooper-Schrieffer (BCS) approach, in which the constant pairing strength is used. It can be seen that the fully self-consistent calculations with NL3 and NLSH effective interactions mostly agree with the latest experimental measurements, such as binding energies, matter radii, charge radii and densities. The energy of the $ \pi2s_{1/2}$ orbital is slightly higher than that of the $ \pi1d_{5/2}$ orbital, and the occupation probability of the $ (\pi2s_{1/2})^2$ orbital is about 20%, which is in accordance with the shell model calculation and three-body model estimation.
121230661
On the physical contents of the light-cone QCD effective Hamiltonian on meson sector
To explore the physical contents of the light-cone QCD effective Hamiltonian on meson sector, the mass spectra of flavour off-diagonal mesons consisting of (u,d,s,c,b) quarks and mesons consisting of heavy quarks c and b are calculated relativistically and nonperturbatively. Numerical results show that the present light-cone QCD effective Hamiltonian without confining potentials and flavour mixing interactions can well describe the ground states but can not apply for the excited states of the mesons. This result may imply that (i) the confining potential is indispensable for the excited states of mesons, (ii) the valence quark q subspace is only valid for ground states but not for excited states. The above information may be significant for improving the light-cone QCD effective Hamiltonian approach, especially showing the urgent need to implement a confining potential and to enlarge the subspace of the meson sector for a more appropriate description of the excited states of the mesons.
118136973
The Glashow resonance as a discriminator of UHE cosmic neutrinos originating from p-gamma and p-p collisions
We re-examine the interesting possibility of utilizing the Glashow resonance (GR) channel nu_ebar + e^- to W^- to anything to discriminate between the UHE cosmic neutrinos originating from p-gamma and pp collisions in an optically thin source of cosmic rays. We propose a general parametrization of the initial neutrino flavor composition by allowing the ratios Phi^{p gamma}_{pi^-}/Phi^{p gamma}_{pi^+} and Phi^{pp}_{pi^-}/Phi^{pp}_{pi^+} to slightly deviate from their conventional values. A relationship between the typical source parameter kappa = (Phi^{p gamma}_{pi^+} + Phi^{p gamma}_{pi^-})/(Phi^{pp}_{pi^+} + Phi^{pp}_{pi^-} + Phi^{p gamma}_{pi^+} + Phi^{p gamma}_{pi^-}) and the working observable of the GR R_0 = Phi^T_{nu_ebar}/ (Phi^T_{nu_mu} + Phi^T_{nu_mu}) at a neutrino telescope is derived, and the numerical dependence of R_0 on kappa is illustrated by taking account of the latest experimental data on three neutrino mixing angles. It is shown that a measurement of R_0 is in principle possible to identify the pure p-gamma interaction (kappa =1), the pure pp interaction (kappa =0) or a mixture of both of them (0 < kappa < 1) at a given source of UHE cosmic neutrinos. The event rate of the GR signal against the background is also estimated.
118506210
Testing the realistic seesaw model with two heavy Majorana neutrinos at the CERN Large Hadron Collider
In the conventional type-(I+II) seesaw model, the effective mass matrix of three known light neutrinos is given by M(v) = M(L) - M(D)M(R)(-1)M(D)(T) in the leading-order approximation. We propose an intriguing scenario, in which the structural cancellation condition M(D)M(R)(-1)M(D)(T) = 0 is guaranteed by the A(4) x Z(2) flavor symmetry. As a consequence, neutrino masses are mainly generated by the Higgs triplet M(v) = M(L), while the neutrino mixing matrix is non-unitary and takes on the nearly tri-bimaximal pattern. A discriminating feature of this scenario from the pure type-II seesaw model is that the lepton-number-violating signatures induced by the heavy Majorana neutrinos can be discovered at the CERN Large Hadron Collider. We calculate the total cross section of the same-sign dilepton events pp -> l(alpha)(+/-)N(i) -> l(alpha)(+/-)l(beta)(+/-)jj (for i = 1, 2 and alpha, beta = e, mu, tau), and emphasize the significant interference of the contributions from two different heavy Majorana neutrinos. The background from the standard model and the kinematic cuts used to reduce it have been considered. The possible way to distinguish between the signals from heavy Majorana neutrinos and those from doubly-charged Higgs bosons is briefly discussed. (C) 2009 Elsevier B.V. All rights reserved.
118709874
Neutrinos in Particle Physics, Astronomy and Cosmology
Neutrinos: Past, Present and Future.- Neutrinos within the Standard Model.- Neutrinos beyond the Standard Model.- Phenomenology of Neutrino Oscillations.- Neutrinos from Stars.- Neutrinos from Supernovae.- Ultrahigh Energy Cosmic Neutrinos.- Neutrinos and Big Bang Nucleosynthesis.- Neutrinos and Cosmological Perburbations.- Neutrinos and Matter-Antimatter Asymmetry.- Other Topics of Neutrino Astrophysics.
118724442
Measuring the speed of cosmological gravitational waves
In general relativity gravitational waves propagate at the speed of light, however in alternative theories of gravity that might not be the case. We study the effects of a modified speed of gravity, $c_T^2$, on the B-modes of the Cosmic Microwave Background (CMB) anisotropy in polarisation. We find that a departure from the light speed value would leave a characteristic imprint on the BB spectrum part induced by tensors, manifesting as a shift in the angular scale of its peaks. We derive constraints by using the available {\it Planck} and BICEP2 datasets showing how $c_T^2$ can be measured, albeit obtaining weak constraints due to the overall poor accuracy of the current BB power spectrum measurements. The present constraint corresponds to $c_T^2 = 1.30 \pm 0.79$ and $c_T^2< 2.85$ at $95%$ C.L. by assuming a power law primordial tensor power spectrum and $c_T^2<2.33$ at $95%$ C.L. if the running of the spectral index is allowed. We derive forecasts for the next generation CMB satellites, which we find capable of tightly constraining $c_T^2$ at percent level, comparable with bounds from binary pulsar measurements, largely due to the absence of degeneracy with other cosmological parameters.
7963478
Multiple seesaw mechanisms of neutrino masses at the TeV scale
In pursuit of a balance between theoretical naturalness and experimental testability, we propose two classes of multiple seesaw mechanisms at the TeV scale to understand the origin of tiny neutrino masses. They are novel extensions of the canonical and double seesaw mechanisms, respectively, by introducing even and odd numbers of gauge-singlet fermions and scalars. It is thanks to a proper implementation of the global U(1) x Z(2N) symmetry that the overall neutrino mass matrix in either class has a suggestive nearest-neighbor-interaction pattern. We briefly discuss possible consequences of these TeV-scale seesaw scenarios, which can hopefully be explored in the upcoming Large Hadron Collider and precision neutrino experiments, and present a simple but instructive example of model building. (C) 2009 Elsevier B.V. All rights reserved.