相关论文: Hyperfine splittings in the $b\bar{b}$ system
The ground state hyperfine splitting of positronium $\Delta_{\mathrm{HFS}}$ is sensitive to high order corrections of quantum electrodynamics (QED) in bound state. The theoretical prediction and the averaged experimental value for…
We present results for the spectrum of b-bbar bound states in the quenched approximation for three different values of the lattice spacing, in the range 0.05fm to 0.15fm. We find our results for spin-independent splittings in physical units…
We calculate the mass difference between the $\Upsilon$ and $\eta_b$ and the $\Upsilon$ leptonic width from lattice QCD using the Highly Improved Staggered Quark formalism for the $b$ quark and including $u$, $d$, $s$ and $c$ quarks in the…
We have systematically investigated the ground-state hyperfine structure for alkali-metal atoms ^{87}Rb, ^{133}Cs, ^{211}Fr and alkali-metal-like ions ^{135}Ba^+, ^{225}Ra^+, which are of particular interest for parity violation studies.…
In the last twenty years, the theory of hyperfine splitting in muonium developed without any experimental input. Finally, this situation is changing and a new experiment on measuring hyperfine splitting in muonium is now in progress at…
We present a lattice investigation of heavy-light mesons in the quenched approximation, using non-relativistic QCD for the heavy quark and a clover improved Wilson formulation for the light quark. A comprehensive calculation of the…
We explore the effect of higher order operators in the non-relativistic formulation of QCD (NRQCD). We calculated masses in the b \bar b spectrum using quenched gauge configurations at beta = 6.0 and two different NRQCD actions which have…
A method for computing electromagnetic properties of hadrons in lattice QCD is described. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing enhanced electric charges, the dependence of the…
We present the first observation of the bottomonium ground state eta_b(1S) in the photon energy spectrum using a sample of 109+/-1 million of Upsilon(3S) events recorded at the Upsilon(3S) energy with the BaBar detector at the PEP-II B…
We outline a partial-fractions decomposition method for determining the one-particle spectral function and single-particle density of states of a correlated electronic system on a finite lattice in the non self-consistent T-matrix…
The electronic structure of heavily overdoped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ is investigated by angle-resolved photoemission spectroscopy. The long-sought bilayer band splitting in this two-plane system is observed in both normal and…
In the framework of phenomenological static and QCD-motivated model potentials for heavy quarkonium, we compute the $\bar{b}c$ mass spectrum as well as its $\QTR{rm}{1S}$ hyperfine splitting using the recently introduced shifted $l$-…
We show how string breaking on the lattice, treated as a mixing effect, can be related to decay rates for heavy quark systems. We use this to make a preliminary calculation of the energy split at maximum mixing for static quarks in QCD from…
We extract directly (for the first time) the charmed (C=1) and bottom (B=-1) heavy-baryons (spin 1/2 and 3/2) mass-splittings due to SU(3) breaking using double ratios of QCD spectral sum rules (QSSR) in full QCD, which are less sensitive…
We present an improved measurement of the eta' meson energy spectrum in Upsilon(1S) decays, using 1.2 fb^{-1}} of data taken at the Upsilon(1S) center-of-mass energy with the CLEO III detector. We compare our results with models of eta'…
A method for computing electromagnetic properties of hadrons in lattice QCD is described and preliminary numerical results are presented. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing…
In the framework of potential models for heavy quarkonium, we compute the mass spectrum of the bottom-charmed $B_{c}$ meson system and spin-dependent splittings from the Schr\"{o}dinger equation using the shifted-large-N expansion…
Recently a new state of the b - anti b system has been observed by the ATLAS Collaboration, with a mass of 10530 +/- 5 +/- 9 MeV. This state has been identified with the n=3 P-wave radial excitations of the b - anti b system with parallel…
The data for 9.3 million Upsilon(2S) and 20.9 million Upsilon(1S) taken with the CLEO III detector has been used to study the radiative population of states identified by their decay into twenty six different exclusive hadronic final…
We report a preliminary numerical study by kinetic Monte Carlo simulation of the dynamics of phase separation following a quench from high to low temperature in a system with a single, conserved, scalar order parameter (a kinetic Ising…