English
Related papers

Related papers: Pion form factor from a contact interaction

200 papers

We extend recently developed methods used for determining the electromagnetic charge radius and $a_\mu^{\pi\pi}$ to obtain a determination of the electromagnetic form factor of the pion, $F_\pi^V(t)$, in several significant kinematical…

High Energy Physics - Phenomenology · Physics 2019-01-02 B. Ananthanarayan , Irinel Caprini , Diganta Das

We adopt a non-perturbative relativistic constituent-quark model for the pi-meson electromagnetic form factor, which have successfully predicted experimental results, and supplement it with the effective momentum-dependent quark mass to…

High Energy Physics - Phenomenology · Physics 2013-11-19 S. V. Troitsky , V. E. Troitsky

The implications of the pion (meson) degrees of freedom for baryon properties, taken at the constituent quark and baryon levels are compared. It is shown that there is a dramatic qualitative difference between two approaches.

Nuclear Theory · Physics 2011-02-01 L. Ya. Glozman , D. O. Riska

Holographic QCD provides a unique framework in which to compute QCD observables. In this talk we summarize recent numerical work on computing the pion electromagnetic form factor using an AdS/QCD action that includes both spontaneous and…

High Energy Physics - Phenomenology · Physics 2017-08-23 Herry J. Kwee , Richard F. Lebed

The structure of the pion wave function in the relativistic constituent quark model is investigated in the explicitly covariant formulation of light-front dynamics. We calculate the two relativistic components of the pion wave function in a…

High Energy Physics - Phenomenology · Physics 2011-09-13 O. Leitner , J. -F. Mathiot , N. A. Tsirova

We discuss the evaluation of the transition form factor (TFF) $F^{\gamma*\gamma\pi^0}(Q^2)$ by means of QCD theory and by state-space reconstruction from topological data analysis. We first calculate this quantity in terms of quark-gluon…

High Energy Physics - Phenomenology · Physics 2019-06-21 N. G. Stefanis

Recent experiment indicates that the behavior exhibited by the ratios $E_{1^+}/M_{1^+}$ and $S_{1^+}/M_{1^+}$ of the $\gamma^* N \leftrightarrow \Delta$ transition remain small and negative for $Q^2 \le 4.0 GeV^2$. It implies that the…

Nuclear Theory · Physics 2010-04-06 S. S. Kamalov , Shin Nan Yang

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 transition form factors of the light mesons in the kinematics, where one photon is real and other is virtual. Using the dispersive approach to axial anomaly we show that the axial anomaly in this case reveals itself as a…

High Energy Physics - Phenomenology · Physics 2010-12-23 Yaroslav N. Klopot , Armen G. Oganesian , Oleg V. Teryaev

We study a model-independent parameterization of the vector pion form factor that arises from the constraints of analyticity and unitarity. Our description should be suitable up to sqrt(s) ~ 1.2 GeV and allows a model-independent…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Pich , J. Portoles

Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Xing-Gang Wu , Tao Huang

The experimental situation with regard to measurements of the pion charge form factor is reviewed. Both existing data and planned experiments are discussed.

Nuclear Experiment · Physics 2007-05-23 H. P. Blok , G. M. Huber , D. J. Mack

We perform a perturbative QCD analysis of the quark transverse momentum effect on the pion-photon transition form factors $F_{\pi \gamma}$ and $F_{\pi \gamma^*}$ in the standard light-cone formalism, with two phenomenological models of…

High Energy Physics - Phenomenology · Physics 2009-10-28 Fu-Guang Cao , Tao Huang , Bo-Qiang Ma

A lattice determination of the form factor and decay constants for the semileptonic decay of heavy pseudoscalar (PS) mesons at zero recoil is presented from which the soft pion relation is satisfied. Chiral extrapolation of the form factor…

High Energy Physics - Lattice · Physics 2015-06-25 UKQCD Collaboration , K. C. Bowler , C. M. Maynard , L. Lellouch , J. Nieves , D. G. Richards , L. Del Debbio , J. M. Flynn , V. I. Lesk

The pion wave function is discussed in the light of the recent CLEO data on the pion gamma transition form factor. It turns out that the wave function is close to the asymptotic form whereas wave functions strongly concentrated in the…

High Energy Physics - Phenomenology · Physics 2009-08-25 P. Kroll , M. Raulfs

We try to understand the recently observed anomalous behavior of the photon-to-pion transition form factor in the holographic QCD approach. First the holographic description of the anomalous \gamma^*\gamma^*\pi^0 form factor is reviewed and…

High Energy Physics - Phenomenology · Physics 2012-02-01 Fen Zuo , Tao Huang

We consider the pion-photon transition form factor at low to intermediate spacelike momenta within the theoretical framework of light-cone sum rules. We derive predictions which take into account all currently known contributions stemming…

High Energy Physics - Phenomenology · Physics 2017-03-24 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. Mateu , J. Portoles

We propose a simple method to calculate the pion form factor at not very large momentum transfers, which combines the technique of the QCD sum rules with the description of the pion in terms of the set of wave functions of increasing twist.…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. M. Braun , I. Halperin

We analyse the perturbative contributions from the higher helicity ($\lambda_{1}+\lambda_{1}=\pm 1$) components, which should be naturally contained in the light-cone wave function for the pion as a consequence of the Wigner rotation, in…

High Energy Physics - Phenomenology · Physics 2009-10-28 Bo-Qiang Ma , Tao Huang