相关论文: Unveiling the inner structure of the pion first ex…
We investigate the internal structure of the ground ($1S$) and the first two radially excited ($2S,3S$) states of the pion within the light-front quark model. The valence Fock sector is described using pure harmonic-oscillator eigenstates…
The parton distribution of the pion is obtained for the first time from the solution of a dynamical equation in Minkowski space. The adopted equation is the homogeneous Bethe-Salpeter one with a ladder kernel, described in terms of i)…
We present an exploratory lattice QCD investigation of the differences between the valence quark structure of pion and its radial excitation $\pi(1300)$ in a fixed finite volume using the leading-twist factorization approach. We present…
We extend the investigation of the Generalized Parton Distribution for a charged pion within a fully covariant constituent quark model, in two respects: (i) calculating the tensor distribution and (ii) adding the treatment of the evolution,…
A nonperturbatively-improved, symmetry-preserving approximation to the quantum field equations relevant in calculations of meson masses and interactions is used to deliver predictions for all distribution functions (DFs) of the ground state…
The study of the spectrum of excited states of the nucleon is vital to our understanding of how QCD is realized in the baryon spectrum. Using a simultaneous analysis of the pion nucleon scattering data up to 2 GeV as well as the results of…
An overview of the vector and tensor Generalized Parton Distributions for a charged pion is presented. Such observables, belonging to the set of quantities fundamental for a detailed investigation of the hadronic inner dynamics, have been…
The pion structure function is investigated in a simple model, where the pion and its constituent quark fields are coupled through the simplest pseudoscalar coupling. The imaginary part of the forward gamma* pi -> gamma* pi scattering…
The chirally improved (CI) fermion action allows us to obtain results for pion masses down to 320 MeV on (in lattice units) comparatively small lattices with physical extent of 2.4 fm. We use differently smeared quarks sources to build sets…
We investigate the excitation spectrum and momentum distribution of the ionic Bose-Hubbard model by the standard basis operator method. We derive Green's functions in the random phase approximation in Mott insulator, superfluid, charge…
We apply the eigenvectors from a variational analysis to successfully extract the wave functions of even-parity excited states of the nucleon, including the Roper. We explore the first four states in the spectrum excited by the standard…
The excitation spectrum of the nucleon with the spin 1/2 is examined by using the Friedberg-Lee model containing the constituent quark and the scalar meson. An appropriate way of quantization for the non-linear meson field is employed by…
The partonic structure of hadrons plays an important role in a vast array of high-energy and nuclear physics experiments. It also underpins the theoretical understanding of hadron structure. Recent developments in lattice QCD offer new…
We present the first lattice-QCD calculation of the pion distribution amplitude using the large- momentum effective field theory (LaMET) approach, which allows us to extract lightcone parton observables from a Euclidean lattice. The mass…
Using the constrained-fitting method based on Bayesian priors, we extract the masses of the two lowest states of octet and decuplet baryons with both parities. The calculation is done on quenched 16^3x28 lattices of a=0.2 fm using an…
We study hadronic wave functions using an instanton model for the QCD vacuum. The wave functions are defined in terms of gauge invariant Bethe Salpeter amplitudes which we have determined numerically using a Monte Carlo simulation of the…
We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a…
A simple model of a composite nucleon is developed in which a fermion and a boson, representing quark and diquark constituents of the nucleon, form a bound state owing to a contact interaction. Photon and pion couplings to the quark provide…
Highly excited states for isospin 1/2 baryons are calculated for the first time using lattice QCD with two flavors of dynamical quarks. Anisotropic lattices are used with two pion masses: 416(36) MeV and 578(29) MeV. The lowest four…
Using exact Bethe ansatz solution, we rigorously study excitation spectra of the spin-1/2 Fermi gas (called Yang-Gaudin model) with an attractive interaction. Elementary excitations of this model involve particle-hole excitations, hole…