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相关论文: QCD Sum Rule and Perturbative QCD Approaches to Pi…

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We use the method of QCD sum rules in the presence of an external pion field to investigate isospin symmetry breakings in pion-nucleon couplings. Possible manifestations of such isospin symmetry breaking are examined in the context of…

核理论 · 物理学 2009-09-25 W-Y. P. Hwang , Ze-sen Yang , Y. S. Zhong , Z. N. Zhou , Shi-lin Zhu

QCD sum rules are used to compute the first few moments of the mesonic quark momentum. Transverse, longitudinal and mixed transverse-longitudinal components are examined. The transverse size of the pion is shown to be dictated by the gluon…

高能物理 - 唯象学 · 物理学 2009-10-22 Su H. Lee , T. Hatsuda , G. A. Miller

Detailed predictions for the scaled pion-photon transition form factor are given, derived with the method of light-cone sum rules and using pion distribution amplitudes with two and three Gegenbauer coefficients obtained from QCD sum rules…

高能物理 - 唯象学 · 物理学 2014-03-03 S. V. Mikhailov , A. V. Pimikov , N. G. Stefanis

Resummation of large QCD radiative corrections, including leading and next-to-leading logarithms, in pion electromagnetic form factor is reviewed. Similar formalism is applied to exclusive processes involving heavy mesons, and leads to…

高能物理 - 唯象学 · 物理学 2009-09-25 Hsiang-nan Li , Hoi-Lai Yu

In a recent Physical Review Letter, Kondo and Morimatsu present a QCD sum rule calculation of nucleon-nucleon scattering lengths. They also relate the empirical scattering lengths to the nucleon mass shift in nuclear matter to cast doubt on…

高能物理 - 唯象学 · 物理学 2009-10-22 R. J. Furnstahl , T. Hatsuda

We scrutinize recent findings on the charged-pion elastic form factor and the form factors entering in neutral-meson-to-photons transition amplitudes within the framework of QCD sum rules.

高能物理 - 唯象学 · 物理学 2015-06-05 Irina Balakireva , Wolfgang Lucha , Dmitri Melikhov

The pion-baryon sigma terms and the strange-quark condensates of the octet and the decuplet baryons are calculated by employing the method of quantum chromodynamics (QCD) sum rules. We evaluate the vacuum-to-vacuum transition matrix…

高能物理 - 唯象学 · 物理学 2010-04-21 G. Erkol , M. Oka , G. Turan

We evaluate the forward Compton scattering off the proton, based on Kramers-Kronig kind of relations which express the Compton amplitudes in terms of integrals of total photoabsorption cross sections. We obtain two distinct fits to the…

核理论 · 物理学 2015-10-28 Oleksii Gryniuk , Franziska Hagelstein , Vladimir Pascalutsa

Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s = 5-11 and -t = 2-7 GeV2 with statistical accuracy of a few percent. The scaling power for the s-dependence of the cross…

核实验 · 物理学 2008-11-26 A. Danagoulian , V. H. Mamyan , M. Roedelbronn , the Hall A Collaboration

The pion electromagnetic form factor with leading and next-to-leading twist corrections are studied in the framework of pQCD approach. We find that, at small momentum transfer regions, Sudakov effects cannot provide a strong enough…

高能物理 - 唯象学 · 物理学 2007-05-23 Zheng-Tao Wei , Mao-Zhi Yang

We describe the present status of the pion distribution amplitude as it originated from two sources: (i) a nonperturbative approach, based on QCD sum rules with nonlocal condensates and (ii) a NLO QCD analysis of the CLEO data on…

高能物理 - 唯象学 · 物理学 2015-06-25 A. P. Bakulev , A. V. Pimikov

The quantum electrodynamical (QED) process of Compton scattering in strong magnetic fields is commonly invoked in atmospheric and inner magnetospheric models of x-ray and soft gamma-ray emission in high-field pulsars and magnetars. A major…

In a study of the elastic pion form factor for large momentum transfers based on a modified perturbative QCD (PQCD) approach we have included helicity components that are customarily neglected. Along with the inclusion of transverse…

高能物理 - 唯象学 · 物理学 2009-10-28 Siwen Wang , Leonard S. Kisslinger

Motivated by recent work on three-point QCD sum rules in heavy quark physics, we use the simple quantum mechanical models to study the basic issue of duality in three-point sum rules. We show that while in all of these models the duality in…

高能物理 - 唯象学 · 物理学 2014-11-17 B. Blok , M. Lublinsky

We discuss the QCD sum-rule approach for the spacelike electromagnetic pion form factor in the $O(\alpha_s)$ approximation. We show that the nonlocality of the condensates is a key point to include nonperturbative contributions to the pion…

高能物理 - 唯象学 · 物理学 2010-02-18 Alexander P. Bakulev , A. V. Pimikov , N. G. Stefanis

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…

高能物理 - 唯象学 · 物理学 2015-05-14 S. V. Mikhailov , N. G. Stefanis

We use the Endpoint model for exclusive hadronic processes to study Compton scattering of the proton. The parameters of the Endpoint model are fixed using the data for $F_1$ and the ratio of Pauli and Dirac form factors ($F_2/F_1$) and then…

高能物理 - 唯象学 · 物理学 2016-11-02 Sumeet Dagaonkar

We derive two sum rules by studying the low energy Compton scattering on a target of arbitrary (nonzero) spin j. In the first sum rule, we consider the possibility that the intermediate state in the scattering can have spin |j \pm 1| and…

高能物理 - 理论 · 物理学 2012-10-11 Hovhannes R. Grigoryan , Massimo Porrati

The masses of octet baryons are calculated by the method of QCD sum rules. Using generalized interpolating fields, three independent sets of QCD sum rules are derived which allow the extraction of low-lying N* states with spin-parity 1/2+,…

核理论 · 物理学 2014-11-18 Frank X. Lee , Xinyu Liu

We show that the one-loop QCD correction to deeply-virtual Compton scattering can be factorized into the finite perturbative contributions and the collinearly-divergent terms, which correspond to the matrix elements of the off-forward…

高能物理 - 唯象学 · 物理学 2009-12-30 Xiangdong Ji , Jonathan Osborne