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Related papers: Basis Light-Front Quantization for a Chiral Nucleo…

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A unified description of spacelike and timelike hadron form factors within a light-front model was successfully applied to the pion. The model is extended to the nucleon to study the role of $q \bar q$ pair production and of nonvalence…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Pace , G. Salme` , T. Frederico , S. Pisano , J. P. B. C. de Melo

The light-front approach is a relativistic quark model and offers many insights to the internal structures of the hadronic bound states. In this study, we apply the covariant light-front approach to ground-state heavy quarkonium. The…

High Energy Physics - Phenomenology · Physics 2008-11-26 Chien-Wen Hwang , Zheng-Tao Wei

A model for the pionic components of nuclear wave functions is obtained from light front dynamical calculations of binding energies and densities. The pionic effects are small enough to be consistent with measured nuclear di-muon production…

Nuclear Theory · Physics 2009-11-07 Gerald A. Miller

We calculate the phase shifts in the pion-nucleon scattering using the heavy baryon formalism. We consider phase shifts for the pion energy range of 140 to $200 $ MeV. We employ two different methods for calculating the phase shifts - the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Alakabha Datta , Sandip Pakvasa

A general strategy is described for deriving a constituent approximation to QCD, inspired by the constituent quark model and based on light-front quantization. Some technical aspects of the approach are discussed, including a mechanism for…

High Energy Physics - Theory · Physics 2007-05-23 Kenneth G. Wilson , David G. Robertson

We develop a formalism to calculate form factor and charge density distribution of pion in the chiral limit using the holographic dual model of QCD with hard-wall cutoff. We introduce two conjugate pion wave functions and present analytic…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. R. Grigoryan , A. V. Radyushkin

We study the electromagnetic structure of the pion in terms of the quantum cromodynamic~(QCD) model on the Breit-frame. We calculated the observables, such as the electromagnetic form factor. The priori to have a calculation covariant need…

High Energy Physics - Phenomenology · Physics 2016-05-17 Clayton Santos Mello , J. P. B. C. de Melo , T. Frederico

We show that the masses of the lowest-lying heavy baryons can be very well described in a pion mean-field approach. We consider a heavy baryon as a system consisting of the $N_c-1$ light quarks that induce the pion mean field, and a heavy…

High Energy Physics - Phenomenology · Physics 2016-11-02 Ghil-Seok Yang , Hyun-Chul Kim , Maxim V. Polyakov , Michał Praszałowicz

We investigate the parton distribution functions (PDFs) of the pion and kaon from the eigenstates of a light-front effective Hamiltonian in the constituent quark-antiquark representation suitable for low-momentum scale applications. By…

High Energy Physics - Phenomenology · Physics 2020-09-07 Jiangshan Lan , Chandan Mondal , Shaoyang Jia , Xingbo Zhao , James P. Vary

We investigate the properties of octet and decuplet baryons in a light-front holographic model. By taking into account the effect of nonvanishing quark mass, we obtain the modified light-front wave functions which are applicable at both low…

High Energy Physics - Phenomenology · Physics 2015-11-18 Tianbo Liu , Bo-Qiang Ma

We calculate the mass spectrum and the structure of the positronium system at a strong coupling in a basis light-front approach. We start from the light-front QED Hamiltonian and retain one dynamical photon in our basis. We perform the…

High Energy Physics - Phenomenology · Physics 2021-03-12 Xingbo Zhao , Kaiyu Fu , Hengfei Zhao , James P. Vary

Longitudinal and transverse quark momentum distributions in the nucleon are calculated from a phenomenological quark-nucleon vertex function obtained through an investigation of the nucleon electromagnetic form factors within a light-front…

High Energy Physics - Phenomenology · Physics 2014-11-20 E. Pace , J. P. B. C. de Melo , T. Frederico , S. Pisano , G. Salme'

A systematic calculation of nuclear matter is performed which includes the long-range correlations between nucleons arising from one- and two-pion exchange. Three-body effects from $2\pi$-exchange with excitations of virtual…

Nuclear Theory · Physics 2008-11-26 N. Kaiser , M. Mühlbauer , W. Weise

The static electric polarizability of the neutron is evaluated using domain-wall valence quarks on a MILC asqtad sea quark ensemble corresponding to a pion mass of m_pi = 357 MeV. Both connected as well as disconnected contributions are…

High Energy Physics - Lattice · Physics 2010-01-29 Michael Engelhardt

We calculate the finite volume effects for the pion and nucleon mass. For the pion mass we present the results of a full two-loop calculation in chiral perturbation theory. The outcome shows that the resummed version of the Luscher formula…

High Energy Physics - Lattice · Physics 2009-11-11 Gilberto Colangelo , Andreas Fuhrer , Christoph Haefeli

We present model predictions of Collins asymmetries for proton in the SIDIS process for $\pi^+$ and $\pi^-$ channels. We use a recently proposed light-front quark-diquark model for proton with the light-front wave functions predicted in…

High Energy Physics - Phenomenology · Physics 2018-01-08 Tanmay Maji , Dipankar Chakrabarti

We study pion--nucleon scattering with a chiral lagrangian of pions, nucleons, and $\Delta$-isobars. The scattering amplitude is evaluated to one-loop $Q^3$ order, where $Q$ is a generic small momentum, using a new approach which is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Paul J. Ellis , Hua-Bin Tang

We present new results for light quark masses. The calculations are performed using two flavours of $O(a)$ improved Wilson fermions. We have reached lattice spacings as small as $a \sim 0.07$fm and pion masses down to $m_{\pi} \sim 340$MeV…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , Y. Nakamura , D. Pleiter , P. E. L. Rakow , G. Schierholz , T. Streuer , H. Stüben , J. M. Zanotti

We construct a chiral Lagrangian containing besides the usual pion field (pi) also its first radial excitation (pi'). The Lagrangian is derived by bosonization of a Nambu--Jona-Lasinio quark model with separable non-local interactions, with…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. K. Volkov , C. Weiss

We study light-quark observables by means of dynamical lattice QCD simulations using two flavours of twisted mass fermions at maximal twist. We employ chiral perturbation theory to describe our data for the pion mass and decay constant. In…

High Energy Physics - Lattice · Physics 2019-08-13 P. Dimopoulos , R. Frezzotti , G. Herdoiza , K. Jansen , C. Michael , C. Urbach