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Related papers: Pion form factor at very large $Q^2$

200 papers

We consider the cross section of the deep inelastic pion electroproduction on a proton target at threshold for Q^2 in the region 5-10 GeV^2. The corresponding amplitudes are described in terms of two form factors which we calculate using…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. M. Braun , D. Yu. Ivanov , A. Lenz , A. Peters

A ratio of lattice correlation functions is identified from which the pion form factor can be obtained directly. Preliminary results from quenched Wilson simulations are presented.

High Energy Physics - Lattice · Physics 2014-11-17 Frederic D. R. Bonnet , Robert G. Edwards , George T. Fleming , Randy Lewis , David G. Richards

In a Poincare'-covariant vector-boson-exchange theory, the pion possesses components of pseudovector origin, which materially influence its observable properties. For a range of such quantities, we explore the consequences of a…

Nuclear Theory · Physics 2010-11-11 L. X. Gutierrez-Guerrero , A. Bashir , I. C. Cloet , C. D. Roberts

We present a lattice calculation of the vector form factor of the pion for two flavours of non-perturbatively O(a) improved Wilson fermions. For the measurements we utilise the CLS ensembles which include various lattice spacings and pion…

High Energy Physics - Lattice · Physics 2011-09-02 Bastian B. Brandt , Andreas Juttner , Hartmut Wittig

We calculate the electromagnetic form factor of the pion in quenched lattice QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is used together with the ${\mathcal O}(a)$ improved current. We calculate form factor…

High Energy Physics - Lattice · Physics 2009-11-10 Jan van der Heide

We present a formula that allows one to calculate the pion form factor in the timelike region 2mpi <= sqrt{s} <= 4mpi in lattice QCD. The form factor quantifies the contribution of two-pion states to the vacuum polarization. It must be…

High Energy Physics - Lattice · Physics 2012-04-04 Harvey B. Meyer

We comment on the results of a complete leading-twist next-to-leading order QCD analysis of the spacelike pion electromagnetic form factor at large-momentum transfer Q. For the asymptotic distribution amplitude, we have examined the…

High Energy Physics - Phenomenology · Physics 2009-08-25 B. Melic , B. Nizic , K. Passek

Some predictions concerning possible results of the future JLab experiments on the pion form factor F_pi(Q^2) are made. The calculations exploit the method proposed previously by the authors and based on the instant-form Poincare invariant…

Nuclear Theory · Physics 2009-12-14 A. F. Krutov , V. E. Troitsky , N. A. Tsirova

We compute two-photon exchange corrections to the electromagnetic form factor of the pion, taking into account the finite size of the pion. Compared to the soft-photon approximation for the infrared divergent contribution which neglects…

Nuclear Theory · Physics 2010-02-02 P. G. Blunden , W. Melnitchouk , J. A. Tjon

Pion transition form factor for the process $\gamma*\gamma*\to \pi^0$ at space-like values of photon momenta is calculated within the effective quark-meson model with the interaction induced by instanton exchange. The leading and…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. E. Dorokhov

The $\gamma^\ast \gamma \to \pi^0$ transition form factor, $G(Q^2)$, is computed on the entire domain of spacelike momenta using a continuum approach to the two valence-body bound-state problem in relativistic quantum field theory: the…

The pion distribution amplitude (DA) can be related to the fundamental QCD Green's functions as a function of the quark self-energy and the quark-pion vertex, which in turn are associated with the pion wave function through the…

High Energy Physics - Phenomenology · Physics 2015-06-23 E. G. S. Luna , A. A. Natale

Separated longitudinal and transverse structure functions for the reaction 1H(e,eprime pi+)n were measured in the momentum transfer region Q2=0.6-1.6 (GeV/c)**2 at a value of the invariant mass W=1.95 GeV. New values for the pion charge…

Nuclear Experiment · Physics 2009-04-15 J. Volmer

We report a measurement of the process gamma gamma* --> pi0 with a 759 fb^{-1} data sample recorded with the Belle detector at the KEKB asymmetric-energy e+e- collider. The pion transition form factor, F(Q^2), is measured for the…

High Energy Physics - Experiment · Physics 2012-11-15 The Belle Collaboration , S. Uehara , Y. Watanabe , H. Nakazawa , I. Adachi , H. Aihara , D. M. Asner , T. Aushev , A. M. Bakich , K. Belous , V. Bhardwaj , B. Bhuyan , M. Bischofberger , A. Bondar , G. Bonvicini , A. Bozek , M. Bracko , T. E. Browder , M. -C. Chang , A. Chen , P. Chen , B. G. Cheon , K. Chilikin , I. -S. Cho , K. Cho , Y. Choi , J. Dalseno , Z. Dolezal , Z. Drasal , S. Eidelman , D. Epifanov , J. E. Fast , M. Feindt , V. Gaur , N. Gabyshev , Y. M. Goh , B. Golob , J. Haba , K. Hayasaka , H. Hayashii , Y. Horii , Y. Hoshi , W. -S. Hou , H. J. Hyun , T. Iijima , A. Ishikawa , R. Itoh , M. Iwabuchi , Y. Iwasaki , T. Iwashita , T. Julius , J. H. Kang , T. Kawasaki , C. Kiesling , H. J. Kim , H. O. Kim , J. B. Kim , J. H. Kim , K. T. Kim , M. J. Kim , Y. J. Kim , B. R. Ko , S. Koblitz , P. Kodys , S. Korpar , R. T. Kouzes , P. Krizan , P. Krokovny , A. Kuzmin , Y. -J. Kwon , J. S. Lange , S. -H. Lee , J. Li , Y. Li , J. Libby , C. -L. Lim , C. Liu , Y. Liu , Z. Q. Liu , D. Liventsev , R. Louvot , D. Matvienko , K. Miyabayashi , H. Miyata , Y. Miyazaki , G. B. Mohanty , A. Moll , T. Mori , N. Muramatsu , Y. Nagasaka , E. Nakano , M. Nakao , Z. Natkaniec , S. Nishida , K. Nishimura , O. Nitoh , S. Ogawa , T. Ohshima , S. Okuno , S. L. Olsen , Y. Onuki , P. Pakhlov , G. Pakhlova , H. K. Park , K. S. Park , T. K. Pedlar , R. Pestotnik , M. Petric , L. E. Piilonen , K. Prothmann , M. Rohrken , S. Ryu , H. Sahoo , K. Sakai , Y. Sakai , T. Sanuki , Y. Sato , V. Savinov , O. Schneider , C. Schwanda , R. Seidl , K. Senyo , O. Seon , M. E. Sevior , M. Shapkin , C. P. Shen , T. -A. Shibata , J. -G. Shiu , B. Shwartz , A. Sibidanov , F. Simon , J. B. Singh , P. Smerkol , Y. -S. Sohn , A. Sokolov , E. Solovieva , M. Staric , T. Sumiyoshi , Y. Teramoto , K. Trabelsi , T. Tsuboyama , M. Uchida , Y. Unno , S. Uno , Y. Usov , P. Vanhoefer , G. Varner , A. Vinokurova , V. Vorobyev , C. H. Wang , P. Wang , M. Watanabe , K. M. Williams , E. Won , Y. Yamashita , C. Z. Yuan , C. C. Zhang , Z. P. Zhang , V. Zhilich , V. Zhulanov , A. Zupanc

The charge form factor of the pion is calculated in lattice QCD. The non-perturbatively improved Sheikholeslami-Wohlert action is used together with the $\mathcal{O}(a)$ improved vector current. Other choices for the current are examined.…

High Energy Physics - Lattice · Physics 2009-11-10 J. van der Heide , J. Koch , E. Laermann

We show that in fully-self-consistent treatments of the pion; namely, its static properties and elastic and transition form factors, the asymptotic limit of the product Q^2 G_{\gamma * \gamma \pi ^0}(Q^2), determined a priori by the…

Nuclear Theory · Physics 2010-12-24 H. L. L. Roberts , C. D. Roberts , A. Bashir , L. X. Gutierrez-Guerrero , P. C. Tandy

Considering, as a limit case, an approximately flat pion distribution amplitude, which is determined from the hardest, in momentum space, solution of the Bethe-Salpeter equation for the pion wave function, we compute the pion transition…

High Energy Physics - Phenomenology · Physics 2020-01-22 D. A. Fagundes , E. G. S. Luna , A. A. Natale , M. Pelaez

We present a calculation of the pion form factor using overlap fermions on 2+1-flavor domain-wall configurations on a $24^3\times 64$ lattice with $a=0.11 \, {\rm{fm}}$ and on a $32^3 \times 64$ lattice with $a=0.143 \, {\rm{fm}}$ generated…

High Energy Physics - Lattice · Physics 2018-10-31 Gen Wang , Jian Liang , Terrence Draper , Keh-Fei Liu , Yi-Bo Yang

The pion electromagnetic form factor is investigated by using the dispersion relation with the superconvergence condition, which was proposed to synthesize the vector meson dominance model and QCD. The absorptive part is given as an…

High Energy Physics - Phenomenology · Physics 2007-05-23 Keiji Watanabe , Hirohisa Ishikawa , Masami Nakagawa

We present results of a calculation of the electromagnetic pion form factor within a framework of QCD Sum Rules with nonlocal condensates and using a perturbative spectral density which includes \mathcal{O}(\alpha_s) contributions.

High Energy Physics - Phenomenology · Physics 2014-11-18 A. P. Bakulev , A. V. Pimikov , N. G. Stefanis