620 research outputs found
Bottom and charmed hadron spectroscopy from lattice QCD
A survey of recent lattice QCD simulations for the mass spectrum of bottom
and charmed hadrons is presented.Comment: 4 pages, 5 figures, 12th International Conference on Meson-Nucleon
Physics (MENU2010), College of William and Mary, 31 May to 4 June 201
Multi-boson spectrum of the SU(2)-Higgs model
Lattice simulations are used to compute the spectrum of energy levels for all
angular momentum and parity quantum numbers in the SU(2)-Higgs model, with
parameters chosen to match experimental data from the Higgs-W boson sector of
the standard model. Creation operators are constructed for all lattice
irreducible representations, and a correlation matrix is formed from which the
spectrum is extracted using a variational analysis. Many multi-boson states are
observed and careful analysis reveals that all are consistent with
weakly-interacting Higgs and W bosons.Comment: 7 pages, 5 figures, presented at the 31st International Symposium on
Lattice Field Theory (Lattice 2013), 29 July - 3 August 2013, Mainz, German
More about excited bottomonium radiative decays
Radiative decays of bottomonium are revisited, focusing on contributions from
higher-order relativistic effects. The leading relativistic correction to the
magnetic spin-flip operator at the photon vertex is found to be particularly
important. The combination of O(v^6) effects in the nonrelativistic QCD action
and in the transition operator moves previous lattice results for excited
Upsilon decays into agreement with experiment.Comment: 4 pages, 3 figures, published versio
Isospin violation in the vector form factors of the nucleon
A quantitative understanding of isospin violation is an increasingly
important ingredient for the extraction of the nucleon's strange vector form
factors from experimental data. We calculate the isospin violating electric and
magnetic form factors in chiral perturbation theory to leading and
next-to-leading order respectively, and we extract the low-energy constants
from resonance saturation. Uncertainties are dominated largely by limitations
in the current knowledge of some vector meson couplings. The resulting bounds
on isospin violation are sufficiently precise to be of value to on-going
experimental studies of the strange form factors.Comment: 13 pages, 8 figures, uses RevTe
- …