118529921
Microscopic description of large-amplitude shape-mixing dynamics with local QRPA inertial functions
We introduce a microscopic approach to derive all the inertial functions in the five-dimensional quadrupole collective Hamiltonian. Local normal modes are evaluated on the constrained mean field in the quasiparticle random-phase approximation in order to derive the inertial functions. The collective Hamiltonians for neutron-rich Mg isotopes are determined with use of this approach, and the shape coexistence/mixing around the N = 20 region is analyzed.
106401285
Shape evolution of giant resonances in Nd and Sm isotopes
Giant multipole resonances in Nd and Sm isotopes are studied by employing the quasiparticle-random-phase approximation on the basis of the Skyrme energy-density-functional method. Deformation effects on giant resonances are investigated in these isotopes, which manifest a typical nuclear shape change from spherical to prolate shapes. The peak energy, the broadening, and the deformation splitting of the isoscalar giant monopole (ISGMR) and quadrupole (ISGQR) resonances agree well with measurements. The magnitude of the peak splitting and the fraction of the energy-weighted strength in the lower peak of the ISGMR reflect the nuclear deformation. The experimental data on ISGMR, isoscalar giant dipole (ISGDR), and ISGQR are consistent with the nuclear-matter incompressibility K � 210‐230 MeV and the effective mass m ∗/m � 0.8‐0.9. However, the high-energy octupole resonance (HEOR) in 144 Sm seems to indicate a smaller effective mass, m ∗ /m � 0.7‐0.8. A further precise measurement of HEOR is desired to determine the effective mass.
119110617
Spin–isospin response of deformed neutron-rich nuclei in a self-consistent Skyrme energy-density-functional approach
We develop a new framework of the self-consistent deformed proton-neutron quasiparticle-random-phase approximation (pnQRPA), formulated in the Hartree-Fock-Bogoliubov (HFB) single-quasiparticle basis. The same Skyrme force is used in both the HFB and pnQRPA calculations except in the proton-neutron particle-particle channel, where an S=1 contact force is employed. Numerical application is performed for Gamow-Teller (GT) strength distributions and $\beta$-decay rates in the deformed neutron-rich Zr isotopes located around the path of the rapid-neutron-capture process nucleosynthesis. It is found that the GT strength distributions are fragmented due to deformation. Furthermore we find that the momentum-dependent terms in the particle-hole residual interaction leads to a stronger collectivity of the GT giant resonance. The T=0 pairing enhances the low-lying strengths cooperatively with the T=1 pairing correlation, which shortens the $\beta$-decay half lives by at most an order of magnitude. The new calculation scheme reproduces well the observed isotopic dependence of the $\beta$-decay half lives of deformed $^{100-110}$Zr isotopes.
123690671
Non-local representation of (2+1)-dimensional quantum gravity with spinor field
Non-local representation of(2+1)-dimensional quantum gravity coupled with the spinor field is considered. We first introduce non-local variables and obtain non-local quantities that are equivalent to the local constraints in some limit. The quantization of these non-local variables is executed in a non-local representation that is similar to the loop representation of pure gravity. The contribution of spinor fields in the state functionals depends not only on the space of loops but also on the space of lines. A state functional which is the solution of all constraint equations is also obtained.
119114995
Holographic description of the Schwinger effect in electric and magnetic field
A bstractWe consider a generalization of the holographic Schwinger effect proposed by Semenoff and Zarembo to the case with constant electric and magnetic fields. There are two ways to turn on magnetic fields, i) the probe D3-brane picture and ii) the string world-sheet picture. In the former picture, magnetic fields both perpendicular and parallel to the electric field are activated by a Lorentz transformation and a spatial rotation. In the latter one, the classical solutions of the string world-sheet corresponding to circular Wilson loops is generalized to contain two additional parameters encoding the presence of magnetic fields.
14982566
A semiclassical string description of Wilson loop with local operators
Abstract We discuss a semiclassical string description to circular Wilson loops without/with local operator insertions. Type IIB string theory on AdS 5 × S 5 is expanded around the corresponding classical solutions with respect to fluctuations and semiclassical quadratic actions are computed. Then the dual corresponding operators describing the fluctuations are discussed from the point of view of a small deformation of the Wilson loops. The result gives new evidence for AdS/CFT correspondence.
15908581
Noncommutative D-branes from covariant AdS superstring
Abstract We study noncommutative (NC) D-branes on AdS 5 × S 5 from κ -invariance of covariant Green–Schwarz action of an open string with a non-trivial world-volume flux. Finding boundary conditions to ensure the κ -invariance, we can see possible configurations of the NC D-branes. With this method 1/4 BPS NC D-branes are discussed. The resulting NC D p -branes are 1/4 BPS at arbitrary position other than the p = 1 case. The exceptional D-string is 1/2 BPS at the origin and 1/4 BPS outside the origin. Those are reduced to possible 1/4 BPS or 1/2 BPS AdS D-branes in the commutative limit. The same analysis is applied to an open superstring in a pp-wave and leads to 1/4 BPS configurations of NC D-branes. These D-branes are consistently obtained from AdS D-branes via the Penrose limit.
3197539
Type IIA string and matrix string on pp-wave
Abstract We study type IIA string theories on the pp -waves with 24 supercharges. The type IIA pp -wave backgrounds are derived from the maximally supersymmetric pp -wave solution in eleven dimensions through the toroidal compactification on the spatial isometry directions. The associated actions of type IIA strings are obtained by using these metrics and other background fields of the type IIA supergravities on the one hand. On the other hand, we derive these theories from D =11 supermembrane on the pp -wave via double-dimensional reduction for the spatial isometry directions. The resulting actions agree with those of type IIA strings obtained in the study of the supergravities. Also, the action of the matrix string is written down. Moreover, the quantization of closed and open strings is discussed. In particular, we study D p -branes allowed in one of the type IIA theories.