Related papers: Pion form factor from a contact interaction
Recent results on pion physics from lattice QCD are reviewed. We discuss quark mass dependences of pion mass and decay constant and compare them with the predictions from chiral perturbation theory. In particular we focus on the convergence…
We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…
We compute the electromagnetic form factor of a "pion" with mass m_pi=330MeV at low values of Q^2\equiv -q^2, where q is the momentum transfer. The computations are performed in a lattice simulation using an ensemble of the RBC/UKQCD…
The $^{1}$H($e,e^\prime \pi^+$)n cross section was measured for a range of four-momentum transfer up to $Q^2$=3.91 GeV$^2$ at values of the invariant mass, $W$, above the resonance region. The $Q^2$-dependence of the longitudinal component…
We study CP violation and the contribution of the strong pion-pion interactions in the three-body B+- --> pi+- pi-+ pi+- decays within a quasi two-body QCD factorization approach. The short distance interaction amplitude is calculated in…
It has been pointed out that the recent BaBar data on the pi gamma^* -> gamma transition form factor F_{pi gamma}(Q^2) at low (high) momentum transfer squared Q^2 indicate an asymptotic (flat) pion distribution amplitude. These seemingly…
We use the world data on the pion form factor for space-like kinematics and a technique previously used to extract the proton transverse densities to extract the transverse pion charge density and its uncertainty due the incomplete…
A continuum approach to quark-antiquark bound-states is used to determine the electromagnetic form factors of pion-like mesons with masses $m_{0^-}/{\rm GeV}=0.14$, $0.47$, $0.69$, $0.83$ on a spacelike domain that extends to $Q^2 \lesssim…
A novel method is employed to compute the pion electromagnetic form factor, F_\pi(Q^2), on the entire domain of spacelike momentum transfer using the Dyson-Schwinger equation (DSE) framework in quantum chromodynamics (QCD). The DSE…
A variety of strong and electroweak interaction properties of the pion and the light scalar sigma meson are computed in a relativistic quark model. Under the assumption that the resulting coupling of these mesons to the constituent quarks…
In a study of the elastic pion form factor for large momentum transfers based on a modified perturbative QCD (PQCD) approach we have included helicity components that are customarily neglected. Along with the inclusion of transverse…
Using the field-theory-inspired expression for the pion electromagnetic form factor F_\pi, a good description of the data in the range -10<s<1 GeV^2 is obtained upon taking into account the pseudoscalar-pseudoscalar (PP) loops. When the…
The pion decay constants of the lowest orbitally excited states of the nucleon and the $\Delta(1232)$ along with the corresponding axial transition form factors are calculated with Poincar\'e covariant constituent-quark models with instant,…
The pion form factor is calculated using quenched twisted mass QCD with beta=6.0 and maximal twisting angle omega=pi/2. Two pion masses and several values of momentum transfer are considered. The momentum averaging procedure of Frezzotti…
Motivated by the planned measurements of the time-like electromagnetic proton form factors an exploratory study of the time-like electromagnetic pion form factor is presented in a formalism which describes mesons as Poincar\'e-invariant…
The charged pion form factor, Fpi(Q^2), is an important quantity which can be used to advance our knowledge of hadronic structure. However, the extraction of Fpi from data requires a model of the 1H(e,e'pi+)n reaction, and thus is…
In this work, the self energies of $\pi^0$ and $\pi^{\pm}$ up to one loop order have been calculated in the limit of weak external magnetic field. The effective masses are explicitly dependent on the magnetic field which are modified…
The two-photon-exchange (TPE) effects in the process $e^+e^- \rightarrow \pi^+\pi^-$ at large momentum transfer are discussed within the perturbative QCD (pQCD). The contributions from the twist-2 and twist-3 distribution amplitudes (DAs)…
Pion structure functions are considered in the framework of QCD sum rules at the next to leading order. The 2-loop diargam, representing the gluon exchange between the struck quark and spectator, is calculated for space-like pion momentum…
Octet baryon axial, induced pseudoscalar, and pseudoscalar form factors are computed using a symmetry-preserving treatment of a vector$\,\times\,$vector contact interaction (SCI), thereby unifying them with an array of other baryon…