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Power corrections to hadronic event shapes are estimated using a recently suggested relationship between perturbative and non-perturbative effects in QCD. The infrared cutoff dependence of perturbative calculations is related to…

High Energy Physics - Phenomenology · Physics 2009-10-28 B. R. Webber

The perturbative pion form factor with Sudakov suppression is re-examined. Taking into account the multi-gluon exchange in the law $Q^2$ regions, we suggest that the running coupling constant should be frozen at $\alpha_s(t=\sqrt{<{\bf…

High Energy Physics - Phenomenology · Physics 2016-09-01 Fu-guang Cao , Tao Huang , Chuan-wang Luo

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

We employ non-perturbative flow equations to compute the equation of state for two flavor QCD within an effective quark meson model. Our treatment covers both the chiral perturbation theory domain of validity and the domain of validity of…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. Berges

We present predictions for the pion-photon transition form factor, derived with the help of light-cone sum rules and including the main part of the NNLO radiative corrections. We show that, when the Bakulev-Mikhailov-Stefanis (BMS) pion…

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

The transition pion-photon form factor is studied within the framework of Light-Cone QCD Sum Rules. The spectral density for the next-to-leading order corrections is calculated for any Gegenbauer harmonic. At the level of the…

High Energy Physics - Phenomenology · Physics 2011-05-13 S. V. Mikhailov , N. G. Stefanis

We study the implications of several recent high-precision measurements of the pion form factor in the region of the rho-omega interference "shoulder" for (i) the extraction of the rho-omega mixing matrix element, Pi_{\rho\omega}(m_rho^2),…

High Energy Physics - Phenomenology · Physics 2010-04-30 C. E. Wolfe , K. Maltman

We examine the role of O(\alpha_s) perturbative corrections to the pion elastic form factor F_\pi(Q^2). We express the quark current three-point function in terms of light cone variables and use Borel transformation to simultaneously model…

High Energy Physics - Phenomenology · Physics 2014-11-17 Adam Szczepaniak , Anatoly Radyushkin , Chueng-Ryong Ji

We indicate how consistent heterotic orbifold compactifications, including non perturbative information, can be constructed. We first analyse the situation in six dimensions, N=1, where strong coupling effects, implying the presence of five…

High Energy Physics - Phenomenology · Physics 2007-05-23 G. Aldazabal

Various classical counterparts for the two-level pairing model in a many-fermion system are presented in the Schwinger boson representation. It is shown that one of the key ingredients giving the classical descriptions for quantal system is…

Nuclear Theory · Physics 2008-11-26 Y. Tsue , C. Providencia , J. da Providencia , M. Yamamura

Scientists and practitioners increasingly rely on machine learning to model data and draw conclusions. Compared to statistical modeling approaches, machine learning makes fewer explicit assumptions about data structures, such as linearity.…

In many years ago, Isgur and Llewellyn Smith addressed that PQCD is inapplicable to exclusive processes, such as the pion form factor.The main problem is that the asymptotic of PQCD is only about one fourth of the experimental value. We…

High Energy Physics - Phenomenology · Physics 2009-08-25 Tsung-Wen yeh

We investigate the pion electromagnetic half off-shell form factors, which parametrize the matrix element of the charged pion electromagnetic current with one leg off-mass-shell and the other leg on-mass-shell, using an exactly solvable…

High Energy Physics - Phenomenology · Physics 2020-01-01 Ho-Meoyng Choi , T. Frederico , Chueng-Ryong Ji , J. P. B. C. de Melo

In present note the arguments in favour of future high statistical measurements of the formfactors that describe pi-meson decays into lepton-antilepton pair and photon are presented. It is shown that these formfactors Q^2 dependence…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. B. Skachkov

In my talk I discuss the theoretical and experimental status of the pion distribution amplitude (DA). I show that the QCD sum rule method with nonlocal condensates (NLC) for the pion DA gives us admissible sets (bunches) of DAs for each…

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

Existing effect measures for compositional features are inadequate for many modern applications, for example, in microbiome research, since they display traits such as high-dimensionality and sparsity that can be poorly modelled with…

Methodology · Statistics 2025-06-02 Anton Rask Lundborg , Niklas Pfister

We develop a gauge-invariant formalism to describe metric perturbations in five-dimensional brane-world theories. In particular, this formalism applies to models originating from heterotic M-theory. We introduce a generalized longitudinal…

High Energy Physics - Theory · Physics 2008-11-26 C. van de Bruck , M. Dorca , R. H. Brandenberger , A. Lukas

The form factors for the $B-->\pi$ transition are evaluated in the entire momentum transfer range by using the constraints obtained in the framework combining the heavy quark expansion and chiral symmetry for light quarks and the quark…

High Energy Physics - Phenomenology · Physics 2009-10-31 Riazuddin , T. A. Al-Aithan , Amjad Hussain Shah Gilani

Two-jet event shape distributions, traditionally studied in the language of perturbative QCD, can be described naturally in soft-collinear effective theory. In this language, we demonstrate factorization of event shape distributions into…

High Energy Physics - Phenomenology · Physics 2010-10-27 Christopher Lee

We consider the electromagnetic and transition pion form factors. Using dispersion relations we simultaneously describe both the hadronic, time-like region and the asymptotic region of large energy-momentum transfer. For the latter we…

High Energy Physics - Phenomenology · Physics 2011-06-28 Mikhail Gorchtein , Peng Guo , Adam P. Szczepaniak