Restrictions of generalized Verma modules to symmetric pairs

We initiate a new line of investigation on branching problems for generalized Verma modules with respect to complex reductive symmetric pairs (g,k). Here we note that Verma modules of g may not contain any simple module when restricted to a reductive subalgebra k in general. In this article, using the geometry of K_C orbits on the generalized flag variety G_C/P_C, we give a necessary and sufficient condition on the triple (g,k, p) such that the restriction X|_k always contains simple k-modules for any g-module $X$ lying in the parabolic BGG category O^p attached to a parabolic subalgebra p of g. Formulas are derived for the Gelfand-Kirillov dimension of any simple k-module occurring in a simple generalized Verma module of g. We then prove that the restriction X|_k is multiplicity-free for any generic g-module X \in O if and only if (g,k) is isomorphic to a direct sum of (A_n,A_{n-1}), (B_n,D_n), or (D_{n+1},B_n). We also see that the restriction X|_k is multiplicity-free for any symmetric pair (g, k) and any parabolic subalgebra p with abelian nilradical and for any generic g-module X \in O^p. Explicit branching laws are also presented.Comment: 31 pages, To appear in Transformation Group

A Component-based Software Development and Execution Framework for CAx Applications

Digitalization of the manufacturing process and technologies is regarded as the key to increased competitive ability. The MZ-Platform infrastructure is a component-based software development framework, designed for supporting enterprises to enhance digitalized technologies using software tools and CAx components in a self-innovative way. In the paper we show the algorithm, system architecture, and a CAx application example on MZ-Platform. We also propose a new parametric data structure based on MZ-Platform

Model independent approach to studies of the confining dual Abrikosov vortex in SU(2) lattice gauge theory

We address the problem of determining the type I, type II or borderline dual superconductor behavior in maximal Abelian gauge SU(2) through the study of the dual Abrikosov vortex. We find that significant electric currents in the simulation data call into question the use of the dual Ginzburg Landau Higgs model in interpreting the data. Further, two definitions of the penetration depth parameter take two different values. The splitting of this parameter into two is intricately connected to the existence of electric currents. It is important in our approach that we employ definitions of flux and electric and magnetic currents that respect Maxwell equations exactly for lattice averages independent of lattice spacings. Applied to specific Wilson loop sizes, our conclusions differ from those that use the dual GLH model.Comment: 18 pages, 14 figures, change title, new anaylysis with more figure

Spectroscopy of Heavy Mesons Expanded in 1/m_Q

Operating just once with the naive Foldy-Wouthuysen-Tani transformation on the relativistic Fermi-Yang equation for $Q\bar q$ bound states described by the semi-relativistic Hamiltonian which includes Coulomb-like as well as confining scalar potentials, we have calculated heavy meson mass spectra of D and B together with higher spin states. Based on the formulation recently proposed, their masses and wave functions are expanded up to the second order in $1/m_Q$ with a heavy quark mass $m_Q$ and the lowest order equation is examined carefully to obtain a complete set of eigenfunctions for the Schr\"odinger equation. Heavy quark effective theory parameters, $\bar\Lambda$, $\lambda_1$, and $\lambda_2$, are also determined at the first and second order in $1/m_Q$.Comment: 49 pages, 5 epsf figure

Dynamical Casimir effect for TE and TM modes in a resonant cavity bisected by a plasma sheet

Parametric photon creation via the dynamical Casimir effect (DCE) is evaluated numerically, in a three-dimensional rectangular resonant cavity bisected by a semiconductor diaphragm (SD), which is irradiated by a pulsed laser with frequency of GHz order. The aim of this paper is to determine some of the optimum conditions required to detect DCE photons relevant to a novel experimental detection system. We expand upon the thin plasma sheet model [Crocce et al., Phys. Rev. A 70 033811 (2004)] to estimate the number of photons for both TE and TM modes at any given SD position. Numerical calculations are performed considering up to 51 inter-mode couplings by varying the SD location, driving period and laser power without any perturbations. It is found that the number of photons created for TE modes strongly depends on SD position, where the strongest enhancement occurs at the midpoint (not near the cavity wall); while TM modes have weak dependence on SD position. Another important finding is the fact that significant photon production for TM$_{111}$ modes still takes place at the midpoint even for a low laser power of 0.01 micro J/pulse, although the number of TE$_{111}$ photons decreases almost proportionately with laser power. We also find a relatively wide tuning range for both TE and TM modes that is correlated with the frequency variation of the instantaneous mode functions caused by the interaction between the cavity photons and conduction electrons in the SD excited by a pulsed laser.Comment: 9 pages, 8 figure files; version 2, minor grammatical changes and two references added; version 4 agrees with version in Phys. Rev. A; DOI no. adde

Termination of Electron Acceleration in Thundercloud by Intra/Inter-cloud Discharge

An on-ground observation program for high energy atmospheric phenomena in winter thunderstorms along Japan Sea has been performed via measurements of gamma-ray radiation, atmospheric electric field and low-frequency radio band. On February 11, 2017, the radiation detectors recorded gamma-ray emission lasting for 75 sec. The gamma-ray spectrum extended up to 20 MeV and was reproduced by a cutoff power-law model with a photon index of $1.36^{+0.03}_{-0.04}$, being consistent with a Bremsstrahlung radiation from a thundercloud (as known as a gamma-ray glow and a thunderstorm ground enhancement). Then the gamma-ray glow was abruptly terminated with a nearby lightning discharge. The low-frequency radio monitors, installed $\sim$50 km away from the gamma-ray observation site recorded leader development of an intra/inter-cloud discharge spreading over $\sim$60 km area with a $\sim$300 ms duration. The timing of the gamma-ray termination coincided with the moment when the leader development of the intra/inter-cloud discharge passed 0.7 km horizontally away from the radiation monitors. The intra/inter-cloud discharge started $\sim$15 km away from the gamma-ray observation site. Therefore, the glow was terminated by the leader development, while it did not trigger the lightning discharge in the present case.Comment: 12 pages, 4 figures, accepted for publication in Geophysical Research Letter

The exclusive B_s -> phi mu+ mu- process in a constituent quark model

We consider the exclusive B_s -> phi mu+ mu- process in the standard model using a constituent quark loop model approach together with a simple parameterization of the quark dynamics. The model allows to compute the decay form factors and therefore can give predictions for the decay rates, the invariant mass spectra and the asymmetries. This process is suppressed in the standard model but can be enhanced if new physics beyond the standard model is present, such as flavor-violating supersymmetric models. It constitutes therefore an interesting precision test of the standard model at forthcoming experiments.Comment: 17 pages, 6 figures, 5 tables, LaTeX; minor changes to the introduction, table III and figure 3. Few references adde

Effects of S-wave thresholds

The opening of a new S-wave threshold is frequently accompanied by an abrupt dip in the magnitude of an amplitude for an already-open channel. One familiar example is the behavior of the I=0 S-wave $\pi \pi$ scattering amplitude at $K \bar K$ threshold. Numerous other examples of this phenomenon in recent data are noted, and a unified description of the underlying dynamics is sought.Comment: 17 pages, 2 figures. Two additional references; typographic correction. To be published in Phys. Rev.

Reversible defects in natural killer and memory CD8 T cell lineages in interleukin 15-deficient mice

C57BL/6 mice genetically deficient in interleukin 15 (IL-15(-/-) mice) were generated by gene targeting. IL-15(-/-) mice displayed marked reductions in numbers of thymic and peripheral natural killer (NK) T cells, memory phenotype CD8+ T cells, and distinct subpopulations of intestinal intraepithelial lymphocytes (IELs). The reduction but not absence of these populations in IL-15(-/-) mice likely reflects an important role for IL-15 for expansion and/or survival of these cells. IL-15(-/-) mice lacked NK cells, as assessed by both immunophenotyping and functional criteria, indicating an obligate role for IL-15 in the development and functional maturation of NK cells. Specific defects associated with IL-15 deficiency were reversed by in vivo administration of exogenous IL-15. Despite their immunological defects, IL-15(-/-) mice remained healthy when maintained under specific pathogen-free conditions. However, IL-l5(-/-) mice are likely to have compromised host defense responses to various pathogens, as they were unable to mount a protective response to challenge with vaccinia virus. These data reveal critical roles for IL-15 in the development of specific lymphoid lineages. Moreover, the ability to rescue lymphoid defects in IL-15(-/-) mice by IL-15 administration represents a powerful means by which to further elucidate the biological roles of this cytokine

Spontaneous Chiral-Symmetry Breaking in Three-Dimensional QED with a Chern--Simons Term

In three-dimensional QED with a Chern--Simons term we study the phase structure associated with chiral-symmetry breaking in the framework of the Schwinger--Dyson equation. We give detailed analyses on the analytical and numerical solutions for the Schwinger--Dyson equation of the fermion propagator, where the nonlocal gauge-fixing procedure is adopted to avoid wave-function renormalization for the fermion. In the absence of the Chern--Simons term, there exists a finite critical number of four-component fermion flavors, at which a continuous (infinite-order) chiral phase transition takes place and below which the chiral symmetry is spontaneously broken. In the presence of the Chern--Simons term, we find that the spontaneous chiral-symmetry-breaking transition continues to exist, but the type of phase transition turns into a discontinuous first-order transition. A simple stability argument is given based on the effective potential, whose stationary point gives the solution of the Schwinger-Dyson equation.Comment: 34 pages, revtex, with 9 postscriptfigures appended (uuencoded