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Related papers: Axial and pseudoscalar form-factors of the Delta^+…

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We present a lattice QCD calculation of the $\Delta(1232)$ matrix elements of the axial-vector and pseudoscalar currents. The decomposition of these matrix elements into the appropriate Lorentz invariant form factors is carried out and the…

High Energy Physics - Lattice · Physics 2013-08-09 C. Alexandrou , E. B. Gregory , T. Korzec , G. Koutsou , J. W. Negele , T. Sato , A. Tsapalis

We present the first calculation on the $\Delta$ axial-vector and pseudoscalar form factors using lattice QCD. Two Goldberger-Treiman relations are derived and examined. A combined chiral fit is performed to the nucleon axial charge, N to…

High Energy Physics - Lattice · Physics 2015-05-28 C. Alexandrou , E. B. Gregory , T. Korzec , G. Koutsou , J. W. Negele , T. Sato , A. Tsapalis

Lattice results on the N to Delta electromagnetic, axial-vector and pseudoscalar form factors are evaluated using dynamical staggered sea quarks and domain wall valence quarks for pion masses in the range of 580-350 MeV, as well as,…

High Energy Physics - Lattice · Physics 2017-08-23 C. Alexandrou

We investigate the isovector axial vector and pseudoscalar form factors of $\Delta$ baryon by employing light-cone QCD sum rules. Numerical calculations show that the form factors can be well fitted by the exponential form. We make a…

High Energy Physics - Phenomenology · Physics 2015-06-22 A. Kucukarslan , U. Ozdem , A. Ozpineci

We compute the nucleon axial and induced pseudoscalar form factors using three ensembles of gauge configurations, generated with dynamical light quarks with mass tuned to approximately their physical value. One of the ensembles also…

We develop techniques to calculate the four Delta electromagnetic form factors using lattice QCD, with particular emphasis on the sub-dominant electric quadrupole form factor that probes deformation of the Delta. Results are presented for…

High Energy Physics - Lattice · Physics 2010-04-21 C. Alexandrou , T. Korzec , G. Koutsou , Th. Leontiou , C. Lorcé , J. W. Negele , V. Pascalutsa , A. Tsapalis , M. Vanderhaeghen

We evaluate the N to Delta axial transition form factors in lattice QCD in the quenched theory, with two degenerate flavors of dynamical Wilson fermions and using domain wall valence fermions with staggered sea quark configurations. We…

High Energy Physics - Lattice · Physics 2008-11-26 C. Alexandrou , Th. Leontiou , J. W. Negele , A. Tsapalis

We calculate the electromagnetic, axial and pseudo-scalar form factors of the Nucleon to $\Delta(1232)$ transition using two dynamical light degenerate quarks and a dynamical strange quark simulated with the domain wall fermion action.…

High Energy Physics - Lattice · Physics 2011-02-25 C. Alexandrou , G. Koutsou , J. W. Negele , Y. Proestos , A. Tsapalis

Vector and axial form factors in the quark resonance model are analyzed with a combination of theoretical and phenomenological arguments. The new form of form factors is deduced from $\Delta$(1232) excitation models and available data. The…

High Energy Physics - Phenomenology · Physics 2014-11-18 K. M. Graczyk , J. T. Sobczyk

The electromagnetic nucleon to Delta transition form factors are evaluated using two degenerate flavors of dynamical Wilson fermions and using dynamical sea staggered fermions with domain wall valence quarks. The two subdominant quadrupole…

High Energy Physics - Lattice · Physics 2008-11-26 C. Alexandrou , G. Koutsou , H. Neff , J. W. Negele , W. Schroers , A. Tsapalis

We present results on the nucleon axial and induced pseudo-scalar form factors using an ensemble of two degenerate twisted mass clover-improved fermions generated at the physical value of the pion mass. We evaluate the isovector and the…

The electromagnetic, axial and pseudoscalar nucleon to Delta form factors are calculated using dynamical domain wall fermions at a lattice spacing of a = 0.114 fm on a lattice of spatial size 2.74 fm and pion mass of 331 MeV. Pion pole…

High Energy Physics - Lattice · Physics 2010-11-05 C. Alexandrou , G. Koutsou , J. W. Negele , A. O'Cais , Y. Proestos , A. Tsapalis

A covariant quark model, based both on the spectator formalism and on vector meson dominance, and previously calibrated by the physical data, is here extended to the unphysical region of the lattice data by means of one single extra…

High Energy Physics - Phenomenology · Physics 2010-04-30 G. Ramalho , M. T. Pena

We present a study of the pseudoscalar and vector meson form factors, calculated using the Fat-Link Irrelevant Clover (FLIC) action in the framework of Quenched Lattice QCD. Of particular interest is the determination of a negative…

High Energy Physics - Lattice · Physics 2008-11-26 J. N. Hedditch , W. Kamleh , B. G. Lasscock , D. B. Leinweber , A. G. Williams , J. M. Zanotti

We discuss the techniques to extract the electromagnetic Delta form factors in Lattice QCD. We evaluate these form factors using dynamical fermions with smallest pion mass of about 350 MeV. We pay particular attention to the extraction of…

High Energy Physics - Lattice · Physics 2010-02-05 C. Alexandrou , T. Korzec , G. Koutsou , C. Lorcé , V. Pascalutsa , M. Vanderhaeghen , J. W. Negele , A. Tsapalis

During the last year, analytic expressions for the two-loop QCD corrections to the form factors for the vector, axial-vector, scalar and pseudo-scalar vertices involving a pair of heavy quarks, $Q \bar{Q}$, were calculated. The results are…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Bernreuther , R. Bonciani , T. Gehrmann , R. Heinesch , T. Leineweber , P. Mastrolia , E. Remiddi

We compute non-perturbatively the renormalization coefficients of scalar and pseudoscalar operators, local vector and axial currents, conserved vector and axial currents, and $O^{\Delta S=2}_{LL}$ over a wide range of energy scales using a…

High Energy Physics - Lattice · Physics 2009-10-31 Yuriy Zhestkov

With the advent of chiral fermion formulations, the simulation of light valence quarks has finally become realistic for numerical simulations of lattice QCD. The simulation of light dynamical quarks, however, remains one of the major…

High Energy Physics - Lattice · Physics 2019-08-14 D. B. Renner , W. Schroers , R. Edwards , G. T. Fleming , Ph. Hagler , J. W. Negele , K. Orginos , A. V. Pochinski , D. Richards

We present a lattice calculation of the nucleon iso-vector axial and induced pseudoscalar form factors on the CLS ensembles using $N_{\rm f}=2$ dynamical flavours of non-perturbatively $\mathcal{O}(a)$-improved Wilson fermions and an…

Nucleon form factors have been extensively studied both experimentally and theoretically for many years. We report here on new results of a high statistics quenched lattice QCD calculation of vector and axial-vector nucleon form factors at…

High Energy Physics - Lattice · Physics 2008-11-26 S. Capitani , M. Gockeler , R. Horsley , B. Klaus , H. Oelrich , H. Perlt , D. Petters , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , P. Stephenson
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