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Related papers: Pion vector and scalar form factors with dynamical…

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We use light-cone QCD sum rules to calculate the pion-photon transition form factor, taking into account radiative corrections up to the next-to-next-to-leading order of perturbation theory. We compare the obtained predictions with all…

High Energy Physics - Phenomenology · Physics 2015-05-14 S. V. Mikhailov , N. G. Stefanis

We use a version of the instant-form relativistic quantum mechanics of composite systems to obtain the gravitational form factors of the pion in a common approach to its electroweak and gravitational properties. In the preceding work…

High Energy Physics - Phenomenology · Physics 2022-09-16 A. F. Krutov , V. E. Troitsky

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 present the most accurate calculation for the pion and kaon electromagnetic form factors in the framework of perturbative QCD, where the power corrections up to twist-4 of the meson distribution amplitudes and the next-to-leading-order…

High Energy Physics - Phenomenology · Physics 2019-08-07 Shan Cheng

We present a two-flavor QCD calculation of $B_K$ on a $16^3 \times 32$ lattice at $a\sim 0.12$ fm (or equivalently $a^{-1}\sim$1.67 GeV). Both valence and sea quarks are described by the overlap fermion formulation. The matching factor is…

High Energy Physics - Lattice · Physics 2019-08-13 S. Aoki , H. Fukaya , S. Hashimoto , J. Noaki , T. Kaneko , H. Matsufuru , T. Onogi , N. Yamada

We study the pion electromagnetic form factor in the modulus squared dispersion relation, and do the model independent extraction of the most important nonperturbative parameters in pion light-cone distribution amplitude. The motivation of…

High Energy Physics - Phenomenology · Physics 2023-07-26 Jian Chai , Shan Cheng , Jun Hua

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

We investigate the spin structure of the pion within the framework of the nonlocal chiral quark model from the instanton vacuum. We first evaluate the tensor form factors of the pion for the first and second moment (n=1,2) and compare it…

High Energy Physics - Phenomenology · Physics 2011-06-07 Seung-il Nam , Hyun-Chul Kim

We calculate axial vector and vector form factors for the semileptonic decay Ds to phi using HISQ valence quarks on MILC ensembles with 2+1 flavours of asqtad sea quarks. Using twisted boundary conditions to tune the quarks' momenta, we…

High Energy Physics - Lattice · Physics 2011-11-02 Gordon Donald , Christine Davies , Jonna Koponen

The first three coefficients of the Taylor's series expansion of the vector pion form factor as a function of the momentum transfer are evaluated using experimental data on the pion form factor and the P-wave pi pi phase shifts. The real…

High Energy Physics - Phenomenology · Physics 2007-05-23 Tran N. Truong

I review the lattice formulations of vector-like gauge theories (e.g. QCD) with domain-wall/overlap fermions, and discuss how to optimize the chiral symmetry for any finite $ N_s $ (sites in the fifth dimension). In this formulation, quark…

High Energy Physics - Lattice · Physics 2011-02-16 Ting-Wai Chiu

We study the electromagnetic form factor of the pion and kaons at low-energies with the use of Chiral Perturbation Theory. The analysis is performed within the three flavour framework and at next-to-next-to-leading order. We explain…

High Energy Physics - Phenomenology · Physics 2011-03-22 Johan Bijnens , Pere Talavera

We present the results of an investigation of a mixed action approach of overlap valence and maximally twisted mass sea quarks. Employing a particular matching condition on the pion mass, we analyze the continuum limit scaling of the pion…

High Energy Physics - Lattice · Physics 2010-11-03 Krzysztof Cichy , Vincent Drach , Elena Garcia-Ramos , Gregorio Herdoiza , Karl Jansen

Quantum loops in the Resonance Chiral Theory are needed to improve the implementation of non-perturbative QCD. Furthermore, the one-loop computations can predict chiral low-energy couplings at next-to-leading order, a very appealing task.…

High Energy Physics - Phenomenology · Physics 2009-11-11 I. Rosell

The effective interaction between a quark and an anti-quark as obtained previously with by the method of iterated resolvents is replaced by the so called up-down-model and applied to flavor off-diagonal mesons including the pion. The only…

High Energy Physics - Phenomenology · Physics 2007-05-23 Hans-Christian Pauli

We present a comparison of a number of iterative solvers of linear systems of equations for obtaining the fermion propagator in lattice QCD. In particular, we consider chirally invariant overlap and chirally improved Wilson (maximally)…

High Energy Physics - Lattice · Physics 2015-10-27 T. Chiarappa , K. Jansen , K. -I. Nagai , M. Papinutto , L. Scorzato , A. Shindler , C. Urbach , U. Wenger , I. Wetzorke

Using the Resonance Chiral Theory lagrangian, we perform a calculation of the vector form factor of the pion at the next-to-leading order (NLO) in the $1/N_C$ expansion. Imposing the correct QCD short-distance constraints, one determines it…

High Energy Physics - Phenomenology · Physics 2011-02-15 Ignasi Rosell

Recent BaBaR data on the pion transition form factor, whose Q^2 dependence is much steeper then predicted by asymptotic Quantum Chromodynamics (QCD), have caused a renewed interest in its theoretical description. We present here a formalism…

High Energy Physics - Phenomenology · Physics 2010-12-09 S. Noguera , V. Vento

Using quenched and unquenched chiral perturbation theory we compute vector and axial current two-point functions at finite volume and fixed gauge field topology, in the so-called \epsilon-regime of QCD. A comparison of these results with…

High Energy Physics - Lattice · Physics 2009-11-10 P. H. Damgaard , P. Hernandez , K. Jansen , M. Laine , L. Lellouch

Strange quark content of the nucleon is calculated in dynamical lattice QCD employing the overlap fermion formulation. For this quantity, exact chiral symmetry guaranteed by the Ginsparg-Wilson relation is crucial to avoid large…

High Energy Physics - Lattice · Physics 2011-06-21 JLQCD collaboration , K. Takeda , S. Aoki , S. Hashimoto , T. Kaneko , J. Noaki , T. Onogi