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Related papers: The spin structure of the pion

200 papers

We investigate the internal structure of the pion using generalized transverse momentum-dependent parton distributions (GTMDs) within the light-cone quark model. By solving the quark-quark correlator, we derive the twist-$2$, $3$, and $4$…

High Energy Physics - Phenomenology · Physics 2025-09-19 Satyajit Puhan , Shubham Sharma , Narinder Kumar , Harleen Dahiya

We present recent results on generalized parton distributions from dynamical lattice QCD calculations. Our set of twelve different combinations of couplings and quark masses allows for a preliminary study of the pion mass dependence of the…

High Energy Physics - Lattice · Physics 2019-08-14 M. Göckeler , Ph. Hägler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , J. M. Zanotti

Being the fountainhead of transverse distortion and asymmetries in accordance to $``SSA=GPD \ast FSI\,"$, we study the spin flip generalized parton distribution. We demonstrate this transverse deformation by using the quark-scalar diquark…

High Energy Physics - Phenomenology · Physics 2024-09-27 Navpreet Kaur , Harleen Dahiya

We perform the first full decomposition of the pion momentum into its gluon and quark contributions. We employ an ensemble generated by the Extended Twisted Mass Collaboration with $N_f=2 + 1 +1$ Wilson twisted mass clover fermions at…

We study the single-spin (left-right) asymmetry in single-inclusive pion production in hadronic scattering. This asymmetry is power-suppressed in the transverse momentum of the produced pion and can be analyzed in terms of twist-three…

High Energy Physics - Phenomenology · Physics 2008-11-26 Chris Kouvaris , Jian-Wei Qiu , Werner Vogelsang , Feng Yuan

We present a lattice-QCD calculation of the pion distribution amplitudes using large-momentum effective theory (LaMET). Our calculation is carried out using five ensembles with 2+1+1 flavors of highly improved staggered quarks (HISQ),…

High Energy Physics - Lattice · Physics 2021-08-11 Nicholas Juliano , Rui Zhang , Carson Honkala , Huey-Wen Lin

We consider mechanism for one-spin asymmetries observed in inclusive hadron production. The main role belongs to the orbital angular momentum of the quark-antiquark cloud in the internal structure of constituent quarks. We argue that the…

High Energy Physics - Phenomenology · Physics 2016-09-01 S. M. Troshin , N. E. Tyurin

We review recent progress of field theory on a transverse lattice including: realistic calculations of pion structure in large-N_c QCD; fermion doubling and chiral symmetry; a new strong coupling limit; supersymmetry on the transverse…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Dalley , B. van de Sande

We calculate pion mass, pion decay constant, PCAC quark mass and nucleon mass in two flavour lattice QCD with unimproved Wilson fermion and gauge actions. Simulations are performed using DD-HMC algorithm at two lattice spacings and two…

High Energy Physics - Lattice · Physics 2015-06-12 Abhishek Chowdhury , Asit K. De , Sangita De Sarkar , A. Harindranath , Jyotirmoy Maiti , Santanu Mondal , Anwesa Sarkar

A single-spin asymmetry in the azimuthal distribution of neutral pions relative to the lepton scattering plane has been measured for the first time in deep-inelastic scattering of positrons off longitudinally polarized protons. The…

High Energy Physics - Experiment · Physics 2010-05-28 HERMES Collaboration , A. Airapetian

Using mean--field improved gauge field configurations, we compare the results obtained for the quark propagator from Wilson fermions and Overlap fermions on a $\3$ lattice at a spacing of $a=0.125(2)$ fm.

High Energy Physics - Lattice · Physics 2010-03-04 F. D. R. Bonnet , D. B. Leinweber , A. G. Williams , J. M. Zanotti , J. B. Zhang

We present results of a lattice simulation of quantum chromodynamics with two degenerate flavors of dynamic Wilson fermions at $6/g^2=5.3$ at each of two dynamical fermion hopping parameters, $\kappa=0.1670$ and 0.1675, corresponding to…

High Energy Physics - Lattice · Physics 2009-10-22 K. M. Bitar

I discuss the properties of pions in ``partially quenched'' theories, i.e. those in which the valence and sea quark masses, $m_V$ and $m_S$, are different. I point out that for lattice fermions which retain some chiral symmetry on the…

High Energy Physics - Lattice · Physics 2014-11-17 Stephen R. Sharpe

Previous Lattice QCD calculations of nucleon transverse momentum-dependent parton distributions (TMDs) focused on the case of transversely polarized nucleons, and thus did not encompass two leading-twist TMDs associated with longitudinal…

High Energy Physics - Lattice · Physics 2023-01-18 M. Engelhardt , N. Hasan , T. Izubuchi , C. Kallidonis , S. Krieg , S. Meinel , J. Negele , A. Pochinsky , G. Silvi , S. Syritsyn

We present a first Wilson twisted mass fermion calculation of the matrix element between pion states of the twist-2 operator, which is related to the the lowest moment < x > of the valence quark parton distribution function in a pion. Using…

High Energy Physics - Lattice · Physics 2009-11-11 S. Capitani , K. Jansen , M. Papinutto , A. Shindler , C. Urbach , I. Wetzorke

We evaluate pseudoscalar, vector, spin 1/2 and spin 3/2 baryon masses predicted by lattice QCD with Wilson quarks in the valence (quenched) approximation for a range of different values of lattice spacing, lattice volume and quark mass.…

High Energy Physics - Lattice · Physics 2009-10-22 F. Butler , H. Chen , J. Sexton , A. Vaccarino , D. Weingarten

Using Nf=2+1+1 lattice QCD, we determine the fermionic connected contributions to the second and third moment of the pion PDF. Based on gauge configurations from the European Twisted Mass Collaboration, chiral and continuum extrapolations…

High Energy Physics - Lattice · Physics 2021-02-22 M. Oehm , C. Alexandrou , M. Constantinou , K. Jansen , G. Koutsou , B. Kostrzewa , F. Steffens , C. Urbach , S. Zafeiropoulos

Low and high energy properties of the pion are reviewed in the framework of chiral quark models. Particular emphasis is put on the simplest version of the SU(2) NJL model as prototype. The role of gauge invariance in this kind of…

High Energy Physics - Phenomenology · Physics 2007-05-23 E. Ruiz Arriola

We present the first lattice QCD calculation of the rapidity anomalous dimension of transverse-momentum-dependent distributions (TMDs), i.e. the Collins-Soper (CS) kernel, employing the recently proposed Coulomb-gauge-fixed quasi-TMD…

High Energy Physics - Lattice · Physics 2024-07-16 Swagato Mukherjee , Dennis Bollweg , Xiang Gao , Yong Zhao

We extend the formalism relating electromagnetic form factors to transverse quark charge densities in the light-front frame to the case of a spin-3/2 baryon and calculate these transverse densities for the $\Delta(1232)$ isobar using…