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.
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.
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.
121138194
A Light-Cone QCD Inspired Effective Hamiltonian Model with SU(3) Flavor Mixing
The effective light-cone Hamiltonian is extended to include the SU(3) flavor mixing interaction besides the confining potential. Solving the coupled J = 0 mass eigen equations for the up, down, and strange quark components numerically, the masses of pi(0) and eta their radial wave functions, and rms radii are obtained in agreement with the experimental data.
118498370
A partial μ – τ symmetry and its prediction for leptonic CP violation
We find that the lepton flavor mixing matrix Ushould possess a partial mu-tau permutation symmetry vertical bar U-mu 1 vertical bar =vertical bar U-tau 1 vertical bar, and the latter predicts a novel correlation between the Dirac CP-violating phase delta and three flavor mixing angles theta(12), theta(13) and theta(23) in the standard parametrization. Inputting the best-fit values of these angles reported by Capozzi et al., we obtain the prediction delta similar or equal to 255 degrees. in the normal neutrino mass ordering, which is in good agreement with the best-fit result delta similar or equal to 250 degrees. In this connection the inverted neutrino mass ordering is slightly disfavored. If this partial mu-tau symmetry is specified to be vertical bar U-mu 1 vertical bar = vertical bar U-tau 1 vertical bar = 1/root 6, one can reproduce the phenomenologically-favored relation sin(2)theta(12) = (1 - 2 tan(2)theta(13))/3 and a viable two-parameter description of U which were first uncovered in 2006. Moreover, we point out that the octant of theta(23) and the quadrant of delta can be resolved due to the slight violation of vertical bar U-mu 2 vertical bar = vertical bar U-tau 2 vertical bar and vertical bar U-mu 3 vertical bar = vertical bar U-tau 3 vertical bar either at the tree level or from radiative corrections. (C) 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license.
118418835
Mass-varying massive gravity
It has recently been shown that the graviton can consistently gain a constant mass without introducing the Boulware-Deser ghost. We propose a gravity model where the graviton mass is set by a scalar field and prove that this model is free of the Boulware-Deser ghost by analyzing its constraint system and showing that two constraints arise. We also initiate the study of the model's cosmic background evolution and tentatively discuss possible cosmological implications of this model. In particular, we consider a simple scenario where the scalar field setting the graviton mass is identified with the inflaton and the graviton mass evolves from a high to a low energy scale, giving rise to the current cosmic acceleration.
121706213
TeV LEPTOGENESIS IN THE MINIMAL SEESAW MODEL
We present a particularly economical and suggestive neutrino mass model, in which there are only two right-handed Majorana neutrinos of O(1) TeV and their masses are highly degenerate. Its novel Yukawa-coupling texture together with the seesaw mechanism allows us to achieve the normal neutrino mass hierarchy with ml = 0 and a nearly tri-bimaximal neutrino mixing pattern with the maximal CP-violating phase: eZ3 = n/4, 161 = ~ / 2 and sin2 = (1 -2 tan' eI3)/3. One may also obtain the inverted neutrino mass hierarchy with m3 = 0 and the corresponding neutrino mixing pattern with eZ3 = n/4 and eI3 = S = 0. In both cases, the observed matter-antimatter asymmetry of the Universe can naturally be interpreted through the resonant leptogenesis mechanism. An experimental test of this TeV-scale neutrino mass model might not be impossible at LHC and ILC in the near future.
119195344
The Minimal Type-II Seesaw Model and Flavor-dependent Leptogenesis
In this talk, we first give a brief review of the so-called minimal seesaw models and then concentrate on the minimal type-I seesaw model with two almost degenerate right-handed Majorana neutrinos of $\mathcal{O}(1 \,{\rm TeV})$. A specific texture of the neutrino Yukawa coupling matrix is proposed to achieve the nearly tri-bimaximal neutrino mixing pattern. This ansatz predicts (1) θ23 = π/4, |δ| = π/2 and sin2θ12 = (1 − 2tan2θ13)/3 in the m1 = 0 case; and (2) θ23 = π/4 and θ13 = 8 = 0 in the m3 = 0 case. In both cases, the cosmological baryon number asymmetry can be explained via the resonant leptogenesis mechanism. Finally, we demonstrate the significance of flavor-dependent effects in our leptogenesis scenario.
119352062
Tri-bimaximal neutrino mixing and flavor-dependent resonant leptogenesis
We propose a particularly economical neutrino mass model, in which there are only two right-handed Majorana neutrinos of O(l) TeV and their masses are highly degenerate. Its novel Yukawa-coupling texture together with the seesaw mechanism allows us to achieve the normal neutrino mass hierarchy with m(1) = 0 and a nearly tri-bimaiimal neutrino mixing pattern with the maximal CP-violating phase: theta(23) = pi/4, \delta\ = pi/2 and sin(2) theta(12) = (1 - 2tan(2) theta(13))/3. One may also obtain the inverted neutrino mass hierarchy with m(3) = 0 and the corresponding neutrino mixing pattern with theta(23) = pi/4 and theta(13) = delta = 0. In both cases, it is possible to interpret the cosmological baryon number asymmetry eta(B) approximate to 6.1 x 10(-10) through the resonant leptogenesis mechanism. We demonstrate the significance of flavor-dependent effects in this leptogenesis scenario: they can either flip the sign of the flavor-independent prediction for eta(B) in the m(1) = 0 case or magnify the magnitude of the flavor-independent prediction for eta(B) about 50 times in the m(3) = 0 case. (C) 2007 Elsevier BN. All rights reserved.