English
Related papers

Related papers: The pion form factor from first principles

200 papers

The exact decomposition of the proton spin has been a much debated topic, on the experimental as well as the theoretical side. In this talk we would like to report on recent non-perturbative results and ongoing efforts to explore the proton…

We present our calculations of the electromagnetic form factor of pions. We explore the properties of pion form factor at momentum transfer larger than previous studies by including more combinations of source and sink momenta and using…

High Energy Physics - Lattice · Physics 2010-12-13 Pai-hsien Jennifer Hsu , George T. Fleming

We present a construction of the pion electromagnetic form factor where the transition from large-Nc Regge vector meson dominance models with infinitely many resonances to perturbative QCD is built in explicitly. The construction is based…

High Energy Physics - Phenomenology · Physics 2008-11-26 Enrique Ruiz Arriola , Wojciech Broniowski

We present our preliminary results concerning the charged/neutral pion mass difference $M_{\pi^{+}} - M_{\pi^{0}}$ at order $\mathcal{O}(\alpha_{em})$ in the QED interactions, and for $M_{\pi^{+}} - M_{\pi^{0}}$ at order $\mathcal{O}\left(…

High Energy Physics - Lattice · Physics 2021-12-03 R. Frezzotti , G. Gagliardi , V. Lubicz , G. Martinelli , F. Sanfilippo , S. Simula

We present a lattice QCD calculation of the charged-neutral pion mass splitting $M_{\pi^+} - M_{\pi^0}$ at $\mathcal{O}(\alpha_\mathrm{em})$ using a recently proposed framework based on a Pauli-Villars (PV) regulated photon propagator…

High Energy Physics - Lattice · Physics 2026-05-29 Alessandro De Santis , Dominik Erb , Harvey B. Meyer

In this work we present the analysis of the energy spectrum from a recent two-flavor ($N_f=2$) lattice QCD calculation for pion-pion scattering in the scalar, isoscalar channel (the $\sigma$-meson). The lattice simulation was performed for…

High Energy Physics - Lattice · Physics 2018-07-31 R. Molina , D. Guo , A. Alexandru , M. Mai , M. Döring

A calculation for the one-loop pion vector form-factor in Resonance Chiral Theory is provided in this talk. The amplitude is computed up to next-to-leading order in 1/Nc and, by means of high-energy constraints, we are able to produce a…

High Energy Physics - Phenomenology · Physics 2011-02-01 J. J. Sanz-Cillero

A method for computing electromagnetic properties of hadrons in lattice QCD is described and preliminary numerical results are presented. The electromagnetic field is introduced dynamically, using a noncompact formulation. Employing…

High Energy Physics - Lattice · Physics 2009-10-28 A. Duncan , E. Eichten , H. Thacker

We present a study of chiral behavior of light meson form factors in QCD with three flavors of overlap quarks. Gauge ensembles are generated at single lattice spacing 0.12 fm with pion masses down to 300 MeV. The pion and kaon…

High Energy Physics - Lattice · Physics 2016-01-29 JLQCD Collaboration , T. Kaneko , S. Aoki , G. Cossu , X. Feng , H. Fukaya , S. Hashimoto , J. Noaki , T. Onogi

We present results for the electromagnetic form factors of the proton and neutron computed on the $(2 + 1)$-flavor Coordinated Lattice Simulations (CLS) ensembles including both quark-connected and -disconnected contributions. The $Q^2$-,…

High Energy Physics - Lattice · Physics 2024-09-27 Miguel Salg , Dalibor Djukanovic , Georg von Hippel , Harvey B. Meyer , Konstantin Ottnad , Hartmut Wittig

The $\pi NN$ form factor $g_{\pi NN}(q^2)$ is obtained from a quenched lattice QCD calculation of the pseudoscalar form factor $g_P(q^2)$ of the proton with pion pole dominance. We find that $g_{\pi NN}(q^2)$ fitted with the monopole form…

High Energy Physics - Lattice · Physics 2009-09-25 K. F. Liu , S. J. Dong , Terrence Draper , Walter Wilcox

We consider a bottom-up AdS/QCD model with a conformal exponential deformation $e^{k\,z^2}$ on a Lorentz invariant AdS background. In this model, we assume the conformal dimension associated with the operator that creates pions at the…

High Energy Physics - Phenomenology · Physics 2022-03-29 Miguel Angel Martin Contreras , Eduardo Folco Capossoli , Danning Li , Alfredo Vega , Henrique Boschi-Filho

For obtaining the spin space wave function of the pion meson in the light-cone formalism from the naive quark model, it is necessary to take into account Wigner rotation. Consequently there are higher helicity ($\lambda_1+\lambda_2=\pm 1$)…

High Energy Physics - Phenomenology · Physics 2010-11-19 Fuguang Cao , J. Cao , T. Huang , B. Q. Ma

We determine generalized form factors of the nucleon from lattice simulations with $N_f = 2$ mass-degenerate non-perturbatively improved Wilson-Sheikholeslami-Wohlert fermions down to a pion mass of 150 MeV. We also present the resulting…

High Energy Physics - Lattice · Physics 2016-01-20 Gunnar Bali , Sara Collins , Meinulf Göckeler , Rudolf Rödl , Andreas Schäfer , Andre Sternbeck

We present a calculation of the pion quark momentum fraction, $\langle x \rangle$, and its third Mellin moment $\langle x^2 \rangle$. We also obtain directly, for the first time, $\langle x \rangle$ and $\langle x^2 \rangle$ for the kaon…

We present a lattice QCD calculation of $B\to \pi l \nu$ semileptonic decay form factors in the small pion recoil momentum region. The calculation is performed on a quenched $16^3 \times 48$ lattice at $\beta=5.9$ with the NRQCD action…

The parameters in the pseudoscalar meson mass formula in quenched chiral perturbation theory to one-loop order are determined by quenched lattice QCD with overlap Dirac operator, and from which the light quark masses are determined with the…

High Energy Physics - Lattice · Physics 2008-11-26 Ting-Wai Chiu , Tung-Han Hsieh

The hadron mass can be obtained through the calculation of the trace of the energy-momentum tensor in the hadron which includes the trace anomaly and sigma terms. The anomaly due to conformal symmetry breaking is believed to be an important…

High Energy Physics - Lattice · Physics 2024-05-10 Bigeng Wang , Fangcheng He , Gen Wang , Terrence Draper , Jian Liang , Keh-Fei Liu , Yi-Bo Yang

A model is developed for electromagnetic form factor of the pion. One-loop corrections are included in the linear sigma-model. The rho-meson contribution is added in an extended VMD model. The form factor, calculated without fitting…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. K. Dubinsky , A. Yu. Korchin , N. P. Merenkov

We compute the $J/\psi \pi\to {charmed mesons}$ cross section using QCD sum rules. This cross section is important to distinguish the suppression in the production of $J/\psi$ through the dissociation by comoving pions and through the…

Nuclear Theory · Physics 2009-11-07 Francisco O. Durães , Su Houng Lee , Fernando S. Navarra , Marina Nielsen