English
Related papers

Related papers: The Pion Form Factor Within the Hidden Local Symme…

200 papers

We study $e^+e^-\to\pi^+\pi^-$ cross section and phase shift of $I=l=1$ $\pi-\pi$ scattering below 1GeV in framework of chiral constituent quark model. The results including all order contribution of the chiral perturbation expansion and…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xiao-Jun Wang , Mu-Lin Yan

We write down some relevant matrix elements for the scattering and decay processes of the pion by considering a quark-meson vertex function. The pion charge and transition form factors $F_\pi$, $F_{\pi\gamma}$, and $F_{\pi\gamma^*}$ are…

High Energy Physics - Phenomenology · Physics 2009-11-07 Chien-Wen Hwang

The NLO Brodsky-Lepage-Mackenzie (BLM) scale for the pion transition form factor has been determined. To achieve that, a consistent calculation up to nf-proportional NNLO contributions to both the hard-scattering amplitude and the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Blazenka Melic , Bene Nizic , Kornelija Passek

Employing the standard hard-scattering approach and the running coupling method we calculate a class of power-suppressed corrections $\sim 1/Q^{2n},n=1,2,3,...$ to the electromagnetic $\pi^0\gamma$ transition form factor (FF)…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. S. Agaev

We discuss the role that Higgs coupling measurements can play in differentiating supersymmetric extensions of the Standard Model. Fitting current LHC data to the Higgs couplings, we find that the likelihood fit shows a preference in the…

High Energy Physics - Phenomenology · Physics 2013-03-11 Aleksandr Azatov , Spencer Chang , Nathaniel Craig , Jamison Galloway

We use the Omnes representation to obtain the q-squared dependence of the form factors f+ and f0 for semileptonic H -> pi decays from the elastic pi H -> pi H scattering amplitudes, where H denotes a B or D meson. The scattering amplitudes…

High Energy Physics - Phenomenology · Physics 2014-11-17 J. M. Flynn , J. Nieves

We propose a new conjectural way to calculate the local $L$-factor $L=L_\chi(\pi,\rho,s)$ where $\pi$ is a representation of a $p$-adic group $G$, $\rho$ is an algebraic representation of the dual group $G^{\vee}$ and $\chi$ is an algebraic…

Representation Theory · Mathematics 2024-05-21 Roman Bezrukavnikov , Alexander Braverman , Michael Finkelberg , David Kazhdan

The Standard Model provides an excellent description of the observables measured at high energy lepton and hadron colliders. However, measurements of the forward-backward asymmetry of the bottom quark at LEP suggest that the effective…

High Energy Physics - Phenomenology · Physics 2009-10-07 D. E. Morrissey , C. E. M. Wagner

It may be possible to approximate the full pion wave function in light-front QCD using only $q \qbar$ and $q \qbar g$ Fock space components. Removing zero modes and using invariant-mass cutoffs that make a constituent approximation possible…

High Energy Physics - Phenomenology · Physics 2009-10-31 Robert J. Perry

We calculate the pion transition form factor ${\cal F}_{\pi^0\gamma^*\gamma^*}(q_1^2,q_2^2)$, which describe the interaction of an on-shell pion with two off-shell photons, using lattice QCD simulations with two degenerate flavors of…

High Energy Physics - Lattice · Physics 2016-12-07 Antoine Gérardin , Harvey B. Meyer , Andreas Nyffeler

The calculation of the hadronic light-by-light scattering contribution to the muon g-2 currently relies entirely on models. Measurements of the form factors which describe the interactions of hadrons with photons can help to constrain the…

High Energy Physics - Phenomenology · Physics 2013-06-26 Andreas Nyffeler

We analyze the sigma meson mass and width together with the pion-pion scattering parameters in the context of non-local chiral quark models with wave-function renormalization (WFR). We consider both non-local interactions based on the…

High Energy Physics - Phenomenology · Physics 2008-12-18 S. Noguera , N. N. Scoccola

We report preliminary results from an analysis of the pion scalar form factor computed on a set of the $\mathrm{tr}[M]=\mathrm{const}$ CLS gauge ensembles with $N_f=2+1$ Wilson Clover-improved sea quarks. The calculations are carried out…

High Energy Physics - Lattice · Physics 2024-01-17 Konstantin Ottnad , Georg von Hippel

We show that processes involving pions that remain very near their mass-shell can be reliably computed in the pionless effective field theory, with the pion integrated in as a heavy field. As an application, we compute the pion-deuteron…

Nuclear Theory · Physics 2009-11-07 Silas R. Beane , Martin J. Savage

In this contribution to the proceedings, we present our recent analysis on the chiral symmetry restoration in the generalized hidden local symmetry (GHLS) which incorporates the rho meson, $A_1$ meson and the pion consistently with the…

High Energy Physics - Phenomenology · Physics 2017-08-23 Masayasu Harada , Chihiro Sasaki

We describe the present status of the pion distribution amplitude (DA) as it originated from several sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates, (ii) an O(\alpha_s) QCD analysis of the CLEO…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. P. Bakulev

Compared in this work are a few sets of results, obtained from the pion-nucleon ($\pi N$) data at low energy (pion laboratory kinetic energy up to $100$ MeV) on the basis of the modelling of the $s$- and $p$-wave $K$-matrix elements (or of…

Nuclear Theory · Physics 2022-06-07 Evangelos Matsinos

The dimensionless parameter $\xi = M_\pi^2/(16 \pi^2 F_\pi^2)$, where $F_\pi$ is the pion decay constant and $M_\pi$ is the pion mass, is expected to control the convergence of chiral perturbation theory applicable to QCD. Here we…

High Energy Physics - Lattice · Physics 2008-11-26 D. J. Cecile , Shailesh Chandrasekharan

The pion electromagnetic form factor at spacelike momentum transfer is calculated in relativistic impulse approximation using the Covariant Spectator Theory. The same dressed quark mass function and the equation for the pion bound-state…

High Energy Physics - Phenomenology · Physics 2014-01-09 Elmar P. Biernat , Franz Gross , M. T. Peña , Alfred Stadler

It is shown that the threshold productions of $\pi^0 pp$, $\pi^+ np$ and $\pi^+ d$ from $pp$ collisions can be consistently described by a model consisting of a pion s-wave rescattering and $N\bar N$ pair-terms of heavy-meson exchanges. The…

Nuclear Theory · Physics 2016-09-08 T. -S. H. Lee