Browsing by Subject "Lattice QCD"
Now showing items 120 of 39

Article
The 4D SU(3) gauge theory with an imaginary θ term
(2011)We study the scaling behavior of the 4D SU(3) lattice gauge theory in the presence of a θ term, by Monte Carlo simulations computing the topological properties at imaginary θ. The numerical results provide a good evidence ...

Article
Baryon structure from Lattice QCD
(2009)We present recent lattice results on the baryon spectrum, nucleon electromagnetic and axial form factors, nucleon to Δ transition form factors as well as the Δ electromagnetic form factors. The masses of the low lying ...

Conference Object
Calculation of the decay width of decuplet baryons
(Proceedings of Science (PoS), 2015)We calculate the coupling constant and decay width of the decuplet to octet baryon transitions in lattice QCD using the transfer matrix method. The transition amplitude is related to the coupling constant and via the Fermi's ...

Conference Object
Computation of correlation matrices for tetraquark candidates with Jp = 0+ and flavor structure q1q2q3q3
(Proceedings of Science (PoS), 2015)The conjecture that several recently observed mesons have a structure, which is not dominated by an ordinary quarkAntiquark pair, but by a fourquark structure, is being actively investigated both theoretical and ...

Conference Object
Determination of the Δ resonance width from lattice QCD
(Proceedings of Science (PoS), 2013)A method suitable for extracting resonance parameters of unstable baryons in lattice QCD is examined. The method is applied to the strong decay of the Δ to a pionnucleon state, extracting the pND coupling constant and Δ ...

Article
Direct Evaluation of the Quark Content of Nucleons from Lattice QCD at the Physical Point
(2016)We evaluate the light, strange, and charm scalar content of the nucleon using one lattice QCD ensemble generated with two degenerate light quarks with mass fixed to their physical value. We use improved techniques to ...

Article
Evaluation of disconnected quark loops for hadron structure using GPUs
(2014)A number of stochastic methods developed for the calculation of fermion loops are investigated and compared, in particular with respect to their efficiency when implemented on Graphics Processing Units (GPUs). We assess ...

Article
Evaluation of fermion loops applied to the calculation of the η ′ mass and the nucleon scalar and electromagnetic form factors
(2012)The exact evaluation of the disconnected diagram contributions to the flavorsinglet pseudoscalar meson mass, the nucleon σterm and the nucleon electromagnetic form factors is carried out utilizing GPGPU technology with ...

Article
First moment of the flavour octet nucleon parton distribution function using lattice QCD
(2015)Abstract: We perform a lattice computation of the flavour octet contribution to the average quark momentum in the nucleon, (Formula presented.). In particular, we fully take the disconnected contributions into account in ...

Conference Object
Hadron deformation and form factors from lattice QCD
(2007)We review the current status of lattice QCD studies of the nucleon system. In particular, we focus on the determination of the shape of the nucleon by probing its wave function as well as by evaluating the N to Δ transition ...

Conference Object
Hadron physics and lattice QCD
(2013)A review of recent lattice QCD hadron structure calculations is presented. Important hadronic properties such as the axial charge and spin content of the nucleon, as well as, the mass and axial charge of hyperons and charmed ...

Article
Hadron properties from lattice QCD
(2014)We discuss the status of current dyanmical lattice QCD simulations in connection to the emerging results on the lowlying baryon spectrum, excited states of the nucleon and the investigation of the structure of scalar ...

Article
Hadron structure from lattice QCD
(2015)We review results for hadron masses and hadron structure using maximally twisted mass fermions for our nonperturbative studies of lattice QCD. We demonstrate that hadron masses can be computed reliably in this setup and ...

Article
Hadron structure in lattice QCD
(2012)Recent progress in hadron structure calculations within lattice QCD is reviewed. Results on key observables such as the axial charge, the quark momentum fraction and the spin content of the nucleon are discussed with focus ...

Article
Higher representations on the lattice: Perturbative studies
(2008)We present analytical results to guide numerical simulations with Wilson fermions in higher representations of the colour group. The ratio of Λ parameters, the additive renormalization of the fermion mass, and the ...

Conference Object
Importance of closed quark loops for lattice QCD studies of tetraquarks
(Proceedings of Science (PoS), 2016)To investigate the light scalar tetraquark candidate a0(980) (quantum numbers JP =0+), a correlation matrix including a variety of two and fourquark interpolating operators has to be computed. We discuss efficient ...

Article
Investigating efficient methods for computing fourquark correlation functions
(2017)We discuss and compare the efficiency of various methods, combinations of pointtoall propagators, stochastic timeslicetoall propagators, the oneend trick and sequential propagators, to compute twopoint correlation ...

Article
Investigation of light and heavy tetraquark candidates using lattice QCD
(2014)We review the status of an ongoing longterm lattice investigation of the spectrum and structure of tetraquark candidates. We focus on the light scalar meson a0(980). First steps regarding the study of a possibly existing ...

Article
Large Wilson loops with overlap and clover fermions: Twoloop evaluation of the bquark mass shift and the quarkantiquark potential
(2008)We compute, to two loops in perturbation theory, the fermionic contribution to rectangular R × T Wilson loops, for different values of R and T. We use the overlap fermionic action. We also employ the clover action, for ...

Conference Object
A lattice calculation of parton distributions
(Proceedings of Science (PoS), 2016)We present results for the x dependence of the unpolarized, helicity, and transversity isovector quark distributions in the proton using lattice QCD, employing the method of quasidistributions proposed by Ji in 2013. ...