9205467
The relativistic continuum Hartree–Bogoliubov description of charge-changing cross section for C, N, O and F isotopes
Abstract The ground state properties including radii, density distribution and one neutron separation energy for C, N, O and F isotopes up to the neutron drip line are systematically studied by the self-consistent microscopic Relativistic Continuum Hartree–Bogoliubov (RCHB) theory. With the proton density distribution thus obtained, the charge-changing cross sections for C, N, O and F isotopes are calculated using the Glauber model. Good agreement with the data has been achieved. The charge changing cross sections change only slightly with the neutron number except for proton-rich nuclei. Similar trends of variations of proton radii and of charge changing cross sections for each isotope chain is observed which implies that the proton density plays important role in determining the charge-changing cross sections.
119477279
Pseudospin symmetry and its approximation in real nuclei
The origin of pseudospin symmetry and its broken in real nuclei are discussed in the relativistic mean field theory. In the exact pseudospin symmetry, even the usual intruder orbits have degenerate partners. In real nuclei, pseudospin symmetry is approximate, and the partners of the usual intruder orbits will disappear. The difference is mainly due to the pseudo spin-orbit potential and the transition between them is discussed in details. The contribution of pseudospin-orbit potential for intruder orbits is quite large, compared with that for pseudospin doublets. The disappearance of the pseudospin partner for the intruder orbit can be understood from the properties of its wave function.
17321794
Relativistic continuum Hartree Bogoliubov theory for ground-state properties of exotic nuclei
The Relativistic Continuum Hartree-Bogoliubov (RCHB) theory, which properly takes into account the pairing correlation and the coupling to (discretized) continuum via Bogoliubov transformation in a microscopic and self-consistent way, has been reviewed together with its new interpretation of the halo phenomena observed in light nuclei as the scattering of particle pairs into the continuum, the prediction of the exotic phenomena - giant halos in nuclei near neutron drip line, the reproduction of interaction cross sections and charge-changing cross sections in light exotic nuclei in combination with the Glauber theory, better restoration of pseudo-spin symmetry in exotic nuclei, predictions of exotic phenomena in hypernuclei, and new magic numbers in superheavy nuclei, etc. Recent investigations on new effective interactions, the density dependence of the interaction strengths, the RMF theory on the Woods-Saxon basis, the single-particle resonant states, and the resonant BCS (rBCS) method for the pairing correlation, etc. are also presented in some detail. (c) 2005 Elsevier B.V. All rights reserved.
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.
119220585
Systematic investigation of the rotational bands in nuclei with Z approximate to 100 using a particle-number conserving method based on a cranked shell model
The rotational bands in nuclei with Z approximate to 100 are investigated systematically by using a cranked shell model (CSM) with the pairing correlations treated by a particle-number conserving (PNC) method, in which the blocking effects are taken into account exactly. By fitting the experimental single-particle spectra in these nuclei, a new set of Nilsson parameters (kappa and mu) and deformation parameters (epsilon(2) and epsilon(4)) are proposed. The experimental kinematic moments of inertia for the rotational bands in even-even, odd-A, and odd-odd nuclei, and the band-head energies of the one-quasiparticle bands in odd-A nuclei, are reproduced quite well by the PNC-CSM calculations. By analyzing the omega dependence of the occupation probability of each cranked Nilsson orbital near the Fermi surface and the contributions of valence orbitals in each major shell to the angular momentum alignment, the upbending mechanism in this region is understood clearly.
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.
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.
15746471
Neutrino decays and neutrino-electron elastic scattering in unparticle physics
Following Georgi's unparticle scheme, we examine the effective couplings between neutrinos and unparticle operators. As an immediate consequence, neutrinos become unstable and can decay into the unparticle stuff. Assuming the dimension transmutation scale is around Lambda(u) - 1 TeV, we implement the cosmological limit on the neutrino lifetime to constrain the neutrino-unparticle couplings for different scaling dimensions d. In addition, provided that the electron-unparticle coupling is restricted due to the precise measurement of the anomalous magnetic moment of electron, we calculate the unparticle contribution to the neutrino-electron elastic scattering. It is more important to jointly deal with the couplings of the unparticle to the standard model particles rather than separately. Taking into account both electron- and neutrino-unparticle couplings, we find that the scaling dimension of the scalar unparticle should lie in the narrow range 1 < d < 2 by requiring the observables to be physically meaningful. However, there is no consistent range of d for the vector unparticle operator. (C) 2007 Elsevier B.V. All rights reserved.
119269679
Two-zero textures of the Majorana neutrino mass matrix and current experimental tests
In view of the latest T2K and MINOS neutrino oscillation data which hint at a relatively large θ13, we perform a systematic study of the Majorana neutrino mass matrix Mν with two independent texture zeros. We show that three neutrino masses (m1, m2, m3) and three CP-violating phases (δ, ρ, σ) can fully be determined from two neutrino mass-squared differences (δm2, ∆m2) and three flavor mixing angles (θ12, θ23, θ13). We find that seven patterns of Mν (i.e., A1,2, B1,2,3,4 and C) are compatible with current experimental data at the 3σ level, but the parameter space of each pattern is more strictly constrained than before. We demonstrate that the texture zeros of Mν are stable against the one-loop quantum corrections, and there exists a permutation symmetry between Patterns A1 and A2, B1 and B2 or B3 and B4. Phenomenological implications of Mν on the neutrinoless double-beta decay and leptonic CP violation are discussed, and a realization of those texture zeros by means of the Zn flavor symmetries is illustrated.
119230665
TeV-scale Type-II Seesaw Models and Possible Collider Signatures
A natural extension of the standard model to accommodate massive neutrinos is to introduce one Higgs triplet and three right-handed Majorana neutrinos, leading to a 6×6 neutrino mass matrix. We show that three light Majorana neutrinos (i.e., the mass eigenstates of νe, νμ and ντ) are exactly massless, if and only if $M_{L} = M_{\rm D}M^{-1}_{\rm R}M^{T}_{\rm D}$ exactly holds in this seesaw model. We propose three simple Type-II seesaw scenarios with broken A4 × U(1)x flavor symmetry to interpret the observed neutrino mass spectrum and neutrino mixing pattern. Such a TeV-scale neutrino model can be tested in two complementary ways: (1) searching for possible collider signatures of lepton number violation induced by the right-handed Majorana neutrinos and doubly-charged Higgs particles; and (2) searching for possible consequences of unitarity violation of the 3 × 3 neutrino mixing matrix in the future long-baseline neutrino oscillation experiments.
13176056
Updated values of running quark and lepton masses
Reliable values of quark and lepton masses are important for model building at a fundamental energy scale, such as the Fermi scale M-Z approximate to 91.2 GeV and the would-be GUT scale Lambda(GUT) similar to 2 x 10(16) GeV. Using the latest data given by the Particle Data Group, we update the running quark and charged-lepton masses at a number of interesting energy scales below and above M-Z. In particular, we take into account the possible new physics scale (mu similar to 1 TeV) to be explored by the CERN LHC and the typical seesaw scales (mu similar to 10(9) GeV and mu similar to 10(12) GeV) which might be relevant to the generation of neutrino masses. For illustration, the running masses of three light Majorana neutrinos are also calculated. Our up-to-date tables of running fermion masses are expected to be very useful for the study of flavor dynamics at various energy scales.