Charmed hadron interactions

title: Excited spectroscopy of mesons containing charm quarks from lattice QCD
abstract: We present highly excited spectra of charmonium, charm-light and charm-strange mesons using the dynamical anisotropic lattices of the Hadron Spectrum Collaboration. The use of novel techniques has allowed us to extract these spectra with a high degree of statistical precision, while also enabling us to observe states as high as spin-4, states with exotic quantum numbers and candidate gluonic excitations. We discuss the phenomenology of these spectra, and also present preliminary results of Dp scattering considering only the lowest partial wave in the isospin-3=2 channel.

title: A NUMERICAL STUDY OF IMPROVED QUARK ACTIONS ON ANISOTROPIC LATTICES
abstract: Tadpole improved Wilson quark actions with clover terms on anisotropic lattices are studied numerically. Using asymmetric lattice volumes, the pseudoscalar meson dispersion relations are measured for eight lowest lattice momentum modes with quark mass values ranging from the strange to the charm quark with various values of the gauge coupling β and three different values of the bare speed of light parameter ν. These results can be utilized to extrapolate or interpolate to obtain the optimal value for the bare speed of light parameter νopt(m) at a given gauge coupling for all bare quark mass values m. In particular, the optimal values of ν at the physical strange and charm quark mass are given for various gauge couplings. The lattice action with these optimized parameters can then be used to study physical properties of hadrons involving either light or heavy quarks.

title: Charmonium spectroscopy from an anisotropic lattice study
abstract: We present a progress report on our study of the charmonium spectrum in full QCD on anisotropic lattices generated by the Hadron Spectrum Collaboration. We adopt a large basis of interpolating operators to extract the excited charmonium states using the variational method. A detailed spectrum of excited charmonium mesons in many J PC channels is obtained. Hybrid states with exotic and non-exotic quantum numbers are determined and preliminary results from a study of disconnected contributions to the hc are presented.

title: New results for charmonium spectroscopy from lattice QCD
abstract: We study the charmonium spectrum in full QCD on anisotropic lattices generated by Hadron Spectrum Collaboration. We adopt a large basis of interpolating operators to extract the excited charmonium states using the variational method. A detailed spectrum of excited charmonium mesons in many JPC channels is obtained. Some exotic hybrid states (with JPC = 0+−, 2−+) are also studied.

title: Quenched charmed meson spectra using tadpole improved quark action on anisotropic lattices
abstract: Charmed meson charmonium spectra are studied with improved quark actions on anisotropic lattices. We measured the pseudo-scalar and vector meson dispersion relations for four lowest lattice momentum modes with quark mass values ranging from the strange quark to charm quark with three different values of gauge coupling β and four different values of bare speed of light ν. With the bare speed of light parameter ν tuned in a mass-dependent way, we study the mass spectra of D, Ds, ηc, D*, Ds* and J/ψ mesons. The results extrapolated to the continuum limit are compared with the experiment, and a qualitative agreement is found.

title: PHENOMENOLOGY OF GOLDSTINO COUPLINGS
abstract: A general coupling of the Goldstino to the matter field and the weak gravitational field is constructed based on the standard and nonlinear Volkov–Akulov realization of SUSY. The resulting Lagrangian, which is invariant under SUSY transformations, can give rise to explicit interactions which couple the helicity ±1/2 states of the gravitino with the gravitational field as well as the matter field.

title: Nonlinear realization and Weyl scale invariant p=2 brane
abstract: The action of Weyl scale invariant p=2 brane which breaks the target super-Weyl scale symmetry in the N=1, D=4 superspace down to the lower dimensional Weyl symmetry W(1,2) is derived by the approach of nonlinear realization. The dual form action for the Weyl scale invariant supersymmetric D2 brane is also constructed. The interactions of localized matter fields on the brane with the Nambu-Goldstone fields associated with the breaking of the symmetries in the superspace and one spatial translation directions are obtained through the Cartan one-forms of the Coset structures. The covariant derivatives for the localized matter fields are also obtained by introducing Weyl gauge field as the compensating field corresponding to the local scale transformation on the brane world volume.

title: Thermodynamics of de Sitter universes
abstract: It is shown that the first law of thermodynamics can be applied to the de Sitter universe to relate its vacuum energy, pressure, entropy of horizon, chemical potential, etc., when the cosmological constant changes due to the fluctuation of the vacuum or other reasons. The second law should be reformulated in the form that the spontaneous decay of the vacuum never makes the entropy of the de Sitter universe decrease. The third law of thermodynamics, applying to the de Sitter universe, implies that the cosmological constant cannot reach zero by finite physical processes. The relation to the holographic principle is also briefly discussed.

title: Evolution of the CKM matrix in the universal extra dimension model
abstract: The evolution of the Cabibbo-Kobayashi-Maskawa matrix and the quark Yukawa couplings is performed for the one-loop renormalization group equations in the universal extra dimension model. It is found that the evolution of mixing angles and the CP violation measure J may rapidly vary in the presence of the Kaluza-Klein modes, and this variation becomes dramatic as the energy approaches the unification scale.

title: GRAVITATIONAL THERMODYNAMICS OF SPACETIME FOAM IN ONE-LOOP APPROXIMATION
abstract: We show from one-loop quantum gravity and statistical thermodynamics that the thermodynamics of quantum foam in flat spacetime and Schwarzschild spacetime is exactly the same as that of Hawking–Unruh radiation in thermal equilibrium. This means we show unambiguously that Hawking–Unruh thermal radiation should contain thermal gravitons or the contribution of quantum spacetime foam. As a by-product, we give also the quantum gravity correction in one-loop approximation to the classical black hole thermodynamics.