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A calculational scheme for obtaining the electric polarizability of the neutron in lattice QCD with dynamical quarks is developed, using the background field approach. The scheme differs substantially from methods previously used in the…

High Energy Physics - Lattice · Physics 2008-11-26 Michael Engelhardt

We will discuss here an indirect lattice evaluation of the baryon axial singlet current matrix element. This quantity may be related to the fraction of nucleon spin carried by the quarks. The appropriate structure function has recently been…

High Energy Physics - Lattice · Physics 2011-04-15 R. Altmeyer , M. Goeckeler , R. Horsley , E. Laermann , G. Schierholz

The form factor that yields the light-by-light scattering contribution to the muon anomalous magnetic moment is computed in lattice QCD+QED and QED. A non-perturbative treatment of QED is used and is checked against perturbation theory. The…

High Energy Physics - Lattice · Physics 2015-01-14 Thomas Blum , Saumitra Chowdhury , Masashi Hayakawa , Taku Izubuchi

We present results on the quark unpolarized, helicity and transversity parton distributions functions of the nucleon. We use the quasi-parton distribution approach within the lattice QCD framework and perform the computation using an…

High Energy Physics - Lattice · Physics 2021-09-22 Constantia Alexandrou , Martha Constantinou , Kyriakos Hadjiyiannakou , Karl Jansen , Floriano Manigrasso

We present results for the moments of nucleon isovector vector and axial generalised parton distribution functions computed within lattice QCD. Three ensembles of maximally twisted mass clover-improved fermions simulated with a physical…

The dependence of thermodynamic properties of QCD on the number of quark flavours is investigated. Lattice results for the equation of state are presented for 2, 2+1 and 3 quark flavours. The simulations have been performed with the…

High Energy Physics - Lattice · Physics 2015-06-25 F. Karsch , E. Laermann , A. Peikert

We consider QCD with valence and sea quarks obeying different boundary conditions. We point out that the energy of low lying two hadron states do not depend on the boundary condition of the sea quarks (up to exponentially small…

High Energy Physics - Lattice · Physics 2010-04-05 Paulo F. Bedaque , Jiunn-Wei Chen

Precision experimental tests of the Standard Model of particle physics (SM) are one of our best hopes for discovering what new physics lies beyond the SM (BSM). Key in the search for new physics is the connection between theory and…

We calculate---for the first time in three-flavor lattice QCD---the hadronic matrix elements of all five local operators that contribute to neutral $B^0$- and $B_s$-meson mixing in and beyond the Standard Model. We present a complete error…

I give a brief introduction to the scope of lattice QCD calculations in our effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First I discuss the extraction of CKM matrix elements…

High Energy Physics - Lattice · Physics 2007-05-23 Rajan Gupta

Developments in lattice field theory and computer technology have led to dramatic advances in the use of lattice QCD to explore the quark structure of hadrons. This talk will describe selected examples, including structure functions,…

High Energy Physics - Lattice · Physics 2017-08-23 J. W. Negele

Lattice QCD with background magnetic fields is used to calculate the magnetic moments and magnetic polarizabilities of the nucleons and of light nuclei with $A\le4$, along with the cross-section for the $M1$ transition $np\rightarrow…

High Energy Physics - Lattice · Physics 2015-12-16 Emmanuel Chang , William Detmold , Kostas Orginos , Assumpta Parreno , Martin J. Savage , Brian C. Tiburzi , Silas R. Beane

We argue that no notion of flavour is necessary when performing amplitude calculations in perturbative QCD with massless quarks. We show this explicitly at tree-level, using a flavour recursion relation to obtain multi-flavoured QCD from…

High Energy Physics - Phenomenology · Physics 2014-10-29 Tom Melia

Lattice QCD results relevant to heavy quark physics are reviewed. In particular new results will be shown that, for the first time, include dynamical quarks in the QCD vacuum which are close enough to being realistic to allow accurate…

High Energy Physics - Phenomenology · Physics 2010-11-23 Christine Davies

We present results from a lattice hadron spectrum calculation using three flavors of dynamical quarks - two light and one strange, and quenched simulations for comparison. These simulations were done using a one-loop Symanzik improved gauge…

Flavour symmetries are fundamental tools in the search for an explanation to the flavour puzzle: fermion mass hierarchies, the neutrino mass ordering, the differences between the mixing matrices in the quark and lepton sector, can all find…

High Energy Physics - Phenomenology · Physics 2015-03-12 Luca Merlo

We present, for the first time, an \textit{ab initio} calculation of the individual up, down and strange quark helicity parton distribution functions for the proton. The calculation is performed within the twisted mass clover-improved…

High Energy Physics - Lattice · Physics 2021-03-17 C. Alexandrou , M. Constantinou , K. Hadjiyiannakou , K. Jansen , F. Manigrasso

We perform the first Lattice calculation about the charmed hadron spin decomposition using overlap fermions on a 2+1 flavor RBC/UKQCD domain-wall gauge configurations at 0.083 fm with 300 MeV pion mass. It is found that the contributions of…

High Energy Physics - Lattice · Physics 2024-10-11 Fangcheng He , Jian Liang , Yi-Bo Yang

The scaling of the Schr"odinger functional coupling is studied numerically and perturbatively for an SU(3) lattice gauge field coupled to an O(a) improved bosonic spinor field. This corresponds to QCD with minus two light flavours and is…

High Energy Physics - Lattice · Physics 2015-06-25 Bernd Gehrmann , Juri Rolf , Stefan Kurth , Ulli Wolff

Using the Schr\"odinger functional (SF) with a single staggered fermion field we calculate the SF coupling in four-flavour QCD for a wide range of energies and lattice sizes up to $L/a=16$. Preliminary results for the continuum…

High Energy Physics - Lattice · Physics 2010-12-01 Paula Pérez-Rubio , Stefan Sint