1,569 research outputs found

    Comment on "Remark on the external-field method in QCD sum rules"

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    It is proved, that suggested by Jin modified formalism in the external-field method in QCD sum rules exactly coincides with the formalism used before. Therefore, unlike the claims of ref.1, this formalism cannot improve the predictability and reliability of external-field sum rule calculations in comparison with those, done by the standard approach. PACS number(s): 12.38.Lg, 11.55.HxComment: 5 pages, RevTe

    Quark distributions in QCD sum rules: unexpected features and paradoxes

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    Some very unusual features of the hadron structure functions, obtained in the generalized QCD sum rules, like the surprisingly strong difference between longitudinally and transversally polarized ρ\rho mesons structure functions and the strong suppression of the gluon sea in longitudinally polarized ρ\rho mesons are discussed. Also the problem of exact zero contribution of gluon condensates to pion and longitudinally polarized ρ\rho meson quark distributions is discussed.Comment: 9 pages, 5 fig

    Weak interaction contribution to the inclusive hadron-hadron scattering cross sections at high pTp_T

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    It is demonstrated that the strong power-like scaling violation in the transverse momentum distribution of inclusive hadron production, observed by CDF Collaboration in pˉp\bar{p}p collisions at Tevatron is caused by contribution of weak interaction. The contribution of weak interaction is increasing with energy at high energies.Comment: Talk presented at Gribov-80 Memorial Workshop, Trieste, May 26-28, 2010 and International seminar Quarks-2010, Colomna, June 6-12, 2010, 6 pages, 3 figures, it is accounted the weak boson formfactor, caused by strong interactio

    Chiral effective theory of strong interactions

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    The review of chiral effective theory (CET) is given. CET is based on quantum chromodynamics and describes the processes of strong interaction at low energies. It is proved, that CET comes as a consequence of the spontaneous violation of chiral symmetry in QCD - the appearance of chiral symmetry violating vacuum condensates. The Goldstone theorem for the case of QCD is proved and the existence of the octet of massless Goldstone bosons (pi, K, eta) is demonstrated in the limit of massless u,d,s quarks (or the triplet of massless pions in the limit m_u,m_d->0). It is shown, that the same phenomenon - the appearance of quark condensate in QCD - which causes the Goldstone bosons, results in appearance of violating chiral symmetry massive baryons. The general form of CET Lagrangian is derived. Few examples of higher order corrections to tree diagrams in CET are given. The Wess-Zumino term (of order p^4 term in CET Lagrangian) is presented. Low energy sum rules are presented. QCD and CET at finite temperature are discussed. In the framework of CET the T^2 correction to quark condensate in QCD at finite temperature T is calculated and the results of higher order temperature corrections are demonstrated. These results indicate on phase transition in QCD at T \sim 150-200 MeV. The mixing of current correlators in order T^2 is proved.Comment: 36 pages, 7 figure