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Related papers: On the second Gegenbauer moment of $\rho$-meson di…

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We present the results of a lattice study of the second moment of the light-cone pion distribution amplitude using two flavors of dynamical (clover) fermions on lattices of different volumes and pion masses down to $m_\pi\sim 150 \, \mathrm…

High Energy Physics - Lattice · Physics 2015-07-29 V. M. Braun , S. Collins , M. Göckeler , P. Pérez-Rubio , A. Schäfer , R. W. Schiel , A. Sternbeck

We present preliminary results from the QCDSF/UKQCD collaborations for the second moment of the pion's distribution amplitude with two flavours of dynamical fermions. We use nonperturbatively determined renormalisation coefficients to…

High Energy Physics - Lattice · Physics 2008-11-26 M. Göckeler , R. Horsley , D. Pleiter , P. E. L. Rakow , A. Schäfer , G. Schierholz , W. Schroers , J. M. Zanotti

In this paper, we investigate the distribution amplitudes (DAs) of pseudoscalar mesons within the light-front quark model (LFQM), and the $n$-th Gegenbauer moment $a_n(\mu)$, $\xi$-moment $\langle \xi^n\rangle$ and transverse moment…

High Energy Physics - Phenomenology · Physics 2026-01-06 Xiao-Nan Li , Shuai Xu , Qin Chang

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

We have calculated the second moment of the pion light-cone distribution amplitude using two flavors of dynamical (clover) fermions on lattices of different volumes, lattice spacings between $0.06 \, \mathrm {fm}$ and $0.08 \, \mathrm {fm}$…

High Energy Physics - Lattice · Physics 2015-10-27 V. M. Braun , S. Collins , M. Göckeler , P. Pérez-Rubio , A. Schäfer , R. W. Schiel , A. Sternbeck

We suggest to probe the pion light-cone distribution amplitude, applying a dispersion relation for the pion electromagnetic form factor. Instead of the standard dispersion relation, we use the equation between the spacelike form factor…

High Energy Physics - Phenomenology · Physics 2020-11-04 Shan Cheng , Alexander Khodjamirian , Aleksey V. Rusov

We calculate the two-pion light-cone distribution amplitudes in the effective low-energy theory based on the instanton vacuum. These generalized distribution amplitudes describe the soft (non-perturbative) part of the process…

High Energy Physics - Phenomenology · Physics 2009-12-30 M. V. Polyakov , C. Weiss

We fitted the pi-pi mass distribution in the range 0.5 < mpipi < 1.1 GeV measured in hard exclusive positron-proton reactions at HERA by the form dictated by QCD at leading twist level. Extracted parameters are related to valence quark…

High Energy Physics - Phenomenology · Physics 2009-10-31 B. Clerbaux , M. V. Polyakov

Based on lattice simulations with two flavours of dynamical, O(a)-improved Wilson fermions we present results for the first two moments of the distribution amplitudes of pseudoscalar mesons at several values of the valence quark masses. By…

High Energy Physics - Lattice · Physics 2008-11-26 V. M. Braun , M. Göckeler , R. Horsley , H. Perlt , D. Pleiter , P. E. L. Rakow , G. Schierholz , A. Schiller , W. Schroers , H. Stüben , J. M. Zanotti

We present the results of a lattice study of the normalization constants and second moments of the light-cone distribution amplitudes of longitudinally and transversely polarized $\rho$ mesons. The calculation is performed using two flavors…

In this paper, we study the pion leading-twist distribution amplitude $\phi_{2;\pi}(x,\mu)$ by improving the traditional light-cone harmonic oscillator model within the reconstruction of the function $\varphi_{2;\pi}(x)$. In order to…

High Energy Physics - Phenomenology · Physics 2021-07-28 Tao Zhong , Zhi-Hao Zhu , Hai-Bing Fu , Xing-Gang Wu , Tao Huang

The CLEO experimental data on the $\pi\gamma$ transition are analyzed to next-to-leading order accuracy in QCD perturbation theory using light-cone QCD sum rules. By processing these data along the lines proposed by Schmedding and Yakovlev,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexander P. Bakulev , S. V. Mikhailov , N. G. Stefanis

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

We discuss the status of the pion distribution amplitude (DA) from analyzing the CLEO experimental data in the context of QCD sum-rule techniques and QCD perturbation theory at the NLO accuracy. The constraints extracted this way for the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander P. Bakulev , S. V. Mikhailov , N. G. Stefanis

We investigate the leading-twist light-cone distribution amplitudes for the pion and kaon, based on the nonlocal chiral quark model from the instanton vacuum. Effects of explicit flavor SU(3)-symmetry breaking are taken into account. The…

High Energy Physics - Phenomenology · Physics 2009-11-11 Seung-il Nam , Hyun-Chul Kim , Atsushi Hosaka , M. M. Musakhanov

We revisit the $\rho$-meson longitudinal leading-twist distribution amplitude (DA) $\phi_{2;\rho}^\|$ by using the QCD sum rules approach within the background field theory. To improve the accuracy of the sum rules for its moments…

High Energy Physics - Phenomenology · Physics 2016-10-05 Hai-Bing Fu , Xing-Gang Wu , Wei Cheng , Tao Zhong

We revisit the hard QCD contributions to the pion gravitational form factors (GFFs), in terms of the twist-2,3 pion distribution amplitudes (DA), including novel semi-hard contributions from the instantons. The pion DAs are evaluated in the…

High Energy Physics - Phenomenology · Physics 2024-10-16 Wei-Yang Liu , Edward Shuryak , Ismail Zahed

We present a calculation of the quark distribution amplitudes(DAs), the Gegenbauer moments, and decay constants for $\pi,\rho,K$ and $K^*$ mesons using the light-front quark model. While the quark DA for $\pi$ is somewhat broader than the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ho-Meoyng Choi , Chueng-Ryong Ji

We present a quantitative analysis of the electromagnetic pion form factor in the light-cone sum rule approach, including radiative corrections and higher-twist effects. The comparison to the existing data favors the asymptotic profile of…

High Energy Physics - Phenomenology · Physics 2011-05-05 V. M. Braun , A. Khodjamirian , M. Maul

We perform a global analysis of three-body charmless hadronic decays $B\to VP_3\to P_1P_2P_3$ in the perturbative QCD (PQCD) approach, where $V$ denotes an intermediate vector resonance, and $P_i$, $i=1,2,3$, denote final-state pseudoscalar…

High Energy Physics - Phenomenology · Physics 2021-11-23 Ya Li , Da-Cheng Yan , Jun Hua , Zhou Rui , Hsiang-nan Li
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