3159463
Heavy-baryon spectroscopy from lattice QCD
We use a four-dimensional lattice calculation of the full-QCD (quantum chromodynamics, the non-abliean gauge theory of the strong interactions of quarks and gluons) path integrals needed to determine the masses of the charmed and bottom baryons. In the charm sector, our results are in good agreement with experiment within our systematics, except for the spin-1/2 $$\Xi_{cc}$$, for which we found the isospin-averaged mass to be $$\Xi_{cc}$$ to be $$3665\pm17\pm14^{+0}_{-78}$$ MeV. We predict the mass of the (isospin-averaged) spin-1/2 $$\Omega_{cc}$$ to be $$3763\pm19\pm26^{+13}_{-79}$$ {MeV}. In the bottom sector, our results are also in agreement with experimental observations and other lattice calculations within our statistical and systematic errors. In particular, we find the mass of the $$\Omega_b$$ to be consistent with the recent CDF measurement. We also predict the mass for the as yet unobserved $$\Xi^\prime_b$$ to be 5955(27) MeV.
54947351
Excited spectroscopy of mesons containing charm quarks from lattice QCD
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.
11641258
Charmed Hadron Interactions
We compute the scattering lengths of charmed mesons and charmonia scattering with light hadrons in full QCD. We use Fermilab formulation for the charm quark and domain-wall fermions for the light quarks and staggered sea quarks. Four different light-quark masses are used to extrapolate to the physical point. The charmed baryon spectrum is also presented.
119269752
Singly and Doubly Charmed $J=1/2$ Baryon Spectrum from Lattice QCD
We compute the masses of the singly and doubly charmed baryons in full QCD using the relativistic Fermilab action for the charm quark. For the light quarks we use domain-wall fermions in the valence sector and improved Kogut-Susskind sea quarks. We use the low-lying charmonium spectrum to tune our heavy-quark action and as a guide to understanding the discretization errors associated with the heavy quark. Our results are in good agreement with experiment within our systematics. For the {Xi}{sub cc}, we find the isospin-averaged mass to be M{sub {Xi}{sub c{sub c}}}=3665{+-}17{+-}14{sub -78}{sup +0} MeV; the three given uncertainties are statistical, systematic, and an estimate of lattice discretization errors, respectively. In addition, we predict the mass splitting of the (isospin-averaged) spin-1/2 {Omega}{sub cc} with the {Xi}{sub cc} to be M{sub {Omega}{sub c{sub c}}}-M{sub {Xi}{sub c{sub c}}}=98{+-}9{+-}22{+-}13 MeV (in this mass splitting, the leading discretization errors are also suppressed by SU(3) symmetry). Combining this splitting with our determination of M{sub {Xi}{sub c{sub c}}} leads to our prediction of the spin-1/2 {Omega}{sub cc} mass, M{sub {Omega}{sub c{sub c}}}=3763{+-}19{+-}26{sub -79}{sup +13} MeV.
204005840
Quenched charmed meson spectra using tadpole improved quark action on anisotropic lattices
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.
209955454
Charmed hadron interactions
119247484
Evolution of the CKM matrix in the universal extra dimension model
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.
17624140
Nonlinear realization and Weyl scale invariant p=2 brane
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.
16274144
On the Gravitational Wave in de Sitter Spacetime
For there is always a wrong sign in the mass of graviton in the so-called perturbation expansion approximation of both Minkowski and de Sitter spacetimes, the existence of gravitational wave from the metric perturbation of de Sitter spacetime is doubtful. We try another way to start from the assumption that the gravitational wave equation should be both general covariant and conformal invariant and find that graviton is no longer a part of metric field, it has an effective mass of $m_g=\sqrt{R/6}=% \sqrt{2\Lambda/3}$ with correct sign in de Sitter spacetime, though it's intrinsic mass remains zero.
467723
Detecting the neutral top-pion at future muon colliders
The signals of the neutral top-pion $\pi^{0}_{t}$ at the first muon collider (FMC) are discussed by calculating its contributions to the processes $\mu^{+}\mu^{-}\longrightarrow b\bar{b}$ and $\mu^{+}\mu^{-}\longrightarrow \bar{t}c$. We find that the contributions to the process $\mu^{+}\mu^{-}\longrightarrow b\bar{b}$ are very small and the ratio of signal over square root of the background ($S/\sqrt{B})$ is smaller than 0.2. However, in most of the parameter space, the $\pi^{0}_{t}$ can generate 36 and up to 649 observable $\bar{t}c$ events at the FMC. The signals of the neutral top-pion $\pi^{0}_{t}$ may be detected via the process $\mu^{+}\mu^{-}\longrightarrow \bar{t}c$ at the FMC.
121633455
The quantized Schwarzschild Black Hole and the possible origin of Dark Matter