5,414 research outputs found

    Study on Decays of DsJ(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) in terms of the CQM Model

    Full text link
    Based on the assumption that DsJ(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) are the (0+,1+)(0^+, 1^+) chiral partners of DsD_{s} and DsD^*_s, we evaluate the strong pionic and radiative decays of DsJ(2317)D_{sJ}^{*}(2317) and DsJ(2460)D_{sJ}(2460) in the Constituent Quark Meson (CQM) model. Our numerical results of the relative ratios of the decay widths are reasonably consistent with data.Comment: 12 pages, 2 figures, 4 tables, a few references adde

    Calcium oscillations coordinate feather mesenchymal cell movement by SHH dependent modulation of gap junction networks

    Get PDF
    Collective cell migration mediates multiple tissue morphogenesis processes. Yet how multi-dimensional mesenchymal cell movements are coordinated remains mostly unknown. Here we report that coordinated mesenchymal cell migration during chicken feather elongation is accompanied by dynamic changes of bioelectric currents. Transcriptome profiling and functional assays implicate contributions from functional voltage-gated Ca^(2+) channels (VGCCs), Connexin-43 based gap junctions, and Ca^(2+) release activated Ca^(2+) (CRAC) channels. 4-Dimensional Ca^(2+) imaging reveals that the Sonic hedgehog-responsive mesenchymal cells display synchronized Ca^(2+) oscillations, which expand progressively in area during feather elongation. Inhibiting VGCCs, gap junctions, or Sonic hedgehog signaling alters the mesenchymal Ca^(2+) landscape, cell movement patterns and feather bud elongation. Ca^(2+) oscillations induced by cyclic activation of opto-cCRAC channels enhance feather bud elongation. Functional disruption experiments and promoter analysis implicate synergistic Hedgehog and WNT/β-Catenin signaling in activating Connexin-43 expression, establishing gap junction networks synchronizing the Ca^(2+) profile among cells, thereby coordinating cell movement patterns

    Spin dynamics in semiconductors

    Full text link
    This article reviews the current status of spin dynamics in semiconductors which has achieved a lot of progress in the past years due to the fast growing field of semiconductor spintronics. The primary focus is the theoretical and experimental developments of spin relaxation and dephasing in both spin precession in time domain and spin diffusion and transport in spacial domain. A fully microscopic many-body investigation on spin dynamics based on the kinetic spin Bloch equation approach is reviewed comprehensively.Comment: a review article with 193 pages and 1103 references. To be published in Physics Reports

    Physics searches at the LHC

    Full text link
    With the LHC up and running, the focus of experimental and theoretical high energy physics will soon turn to an interpretation of LHC data in terms of the physics of electroweak symmetry breaking and the TeV scale. We present here a broad review of models for new TeV-scale physics and their LHC signatures. In addition, we discuss possible new physics signatures and describe how they can be linked to specific models of physics beyond the Standard Model. Finally, we illustrate how the LHC era could culminate in a detailed understanding of the underlying principles of TeV-scale physics.Comment: 184 pages, 55 figures, 14 tables, hundreds of references; scientific feedback is welcome and encouraged. v2: text, references and Overview Table added; feedback still welcom

    The quark axial vector coupling and heavy meson decays

    Get PDF
    Form factors and decay widths for DDγD^{\ast}\rightarrow D \gamma and DDπD^{\ast}\rightarrow D \pi decays are estimated in a relativistic constituent quark model. Relativistic corrections due to light quarks are found to be substantial and to suppress the vector and axial vector form factors. The CLEO experimental value of Rγ0Γ(D0D0γ)/Γ(D0D0π0)=0.572±0.057±0.081R^0_{\gamma}\equiv \Gamma (D^{\ast 0}\rightarrow D^{0} \gamma)/ \Gamma (D^{\ast 0}\rightarrow D^{0} \pi^{0})=0.572\pm 0.057\pm 0.081 is used to determine the quark axial vector coupling gAg_A, which is found to be 0.60.80.6-0.8 for mu=(350200)MeVm_u=(350-200) MeV correspondingly, as compared with the chiral model result gA=0.80.9g_{A}= 0.8-0.9. The heavy meson-pion strong coupling gg is found to be 0.40.60.4-0.6, much smaller than g=1g=1 which is expected in the large NCN_{C} and nonrelativistic limit, but consistent with some heavy hadron chiral theory and QCD sum rule results. The failure of nonrelativistic treatment for the light quark in the heavy meson decays is also emphasized.Comment: 11 pages in Late

    Muon anomalous magnetic moment in the standard model with two Higgs doublets

    Get PDF
    The muon anomalous magnetic moment is investigated in the standard model with two Higgs doublets (S2HDM) motivated from spontaneous CP violation. Thus all the effective Yukawa couplings become complex. As a consequence of the non-zero phase in the couplings, the one loop contribution from the neutral scalar bosons could be positive and negative relying on the CP phases. The interference between one and two loop diagrams can be constructive in a large parameter space of CP-phases. This will result in a significant contribution to muon anomalous magnetic moment even in the flavor conserving process with a heavy neutral scalar boson (mhm_h \sim 200 GeV) once the effective muon Yukawa coupling is large (ξμ50|\xi_\mu|\sim 50). In general, the one loop contributions from lepton flavor changing scalar interactions become more important. In particular, when all contributions are positive in a reasonable parameter space of CP phases, the recently reported 2.6 sigma experiment vs. theory deviation can be easily explained even for a heavy scalar boson with a relative small Yukawa coupling in the S2HDM.Comment: 8 pages, RevTex file, 5 figures, published version Phys. Rev. D 54 (2001) 11501

    Probing exotic phenomena at the interface of nuclear and particle physics with the electric dipole moments of diamagnetic atoms: A unique window to hadronic and semi-leptonic CP violation

    Full text link
    The current status of electric dipole moments of diamagnetic atoms which involves the synergy between atomic experiments and three different theoretical areas -- particle, nuclear and atomic is reviewed. Various models of particle physics that predict CP violation, which is necessary for the existence of such electric dipole moments, are presented. These include the standard model of particle physics and various extensions of it. Effective hadron level combined charge conjugation (C) and parity (P) symmetry violating interactions are derived taking into consideration different ways in which a nucleon interacts with other nucleons as well as with electrons. Nuclear structure calculations of the CP-odd nuclear Schiff moment are discussed using the shell model and other theoretical approaches. Results of the calculations of atomic electric dipole moments due to the interaction of the nuclear Schiff moment with the electrons and the P and time-reversal (T) symmetry violating tensor-pseudotensor electron-nucleus are elucidated using different relativistic many-body theories. The principles of the measurement of the electric dipole moments of diamagnetic atoms are outlined. Upper limits for the nuclear Schiff moment and tensor-pseudotensor coupling constant are obtained combining the results of atomic experiments and relativistic many-body theories. The coefficients for the different sources of CP violation have been estimated at the elementary particle level for all the diamagnetic atoms of current experimental interest and their implications for physics beyond the standard model is discussed. Possible improvements of the current results of the measurements as well as quantum chromodynamics, nuclear and atomic calculations are suggested.Comment: 46 pages, 19 tables and 16 figures. A review article accepted for EPJ

    First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

    Get PDF
    Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far
    corecore