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Author (up) Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title The gluon mass generation mechanism: A concise primer Type Journal Article
Year 2016 Publication Frontiers of Physics Abbreviated Journal Front. Phys.
Volume 11 Issue 2 Pages 111203 - 18pp
Keywords nonperturbative physics; Schwinger-Dyson equations; dynamical mass generation
Abstract We present a pedagogical overview of the nonperturbative mechanism that endows gluons with a dynamical mass. This analysis is performed based on pure Yang-Mills theories in the Landau gauge, within the theoretical framework that emerges from the combination of the pinch technique with the background field method. In particular, we concentrate on the Schwinger-Dyson equation satisfied by the gluon propagator and examine the necessary conditions for obtaining finite solutions within the infrared region. The role of seagull diagrams receives particular attention, as do the identities that enforce the cancellation of all potential quadratic divergences. We stress the necessity of introducing nonperturbative massless poles in the fully dressed vertices of the theory in order to trigger the Schwinger mechanism, and explain in detail the instrumental role of these poles in maintaining the Becchi-Rouet-Stora-Tyutin symmetry at every step of the mass-generating procedure. The dynamical equation governing the evolution of the gluon mass is derived, and its solutions are determined numerically following implementation of a set of simplifying assumptions. The obtained mass function is positive definite, and exhibits a power law running that is consistent with general arguments based on the operator product expansion in the ultraviolet region. A possible connection between confinement and the presence of an inflection point in the gluon propagator is briefly discussed.
Address [Aguilar, A. C.] Univ Campinas UNICAMP, Gleb Wataghin Inst Phys, BR-13083859 Campinas, SP, Brazil, Email: Joannis.Papavassiliou@uv.es
Corporate Author Thesis
Publisher Higher Education Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0462 ISBN Medium
Area Expedition Conference
Notes WOS:000387550300001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2859
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Author (up) Wang, Y.F.; Yao, D.L.; Zheng, H.Q.
Title On the existence of N*(890) resonance in S-11 channel of N scatterings Type Journal Article
Year 2019 Publication Frontiers of Physics Abbreviated Journal Front. Phys.
Volume 14 Issue 2 Pages 24501 - 6pp
Keywords dispersion relations; N scatterings; nucleon resonance
Abstract Low-energy partial-wave N scattering data is reexamined with the help of the production representation of partial-wave S matrix, where branch cuts and poles are thoroughly under consideration. The left-hand cut contribution to the phase shift is determined, with controlled systematic error estimates, by using the results of O(p(3)) chiral perturbative amplitudes obtained in the extended-onmass- shell scheme. In S-11 and P-11 channels, severe discrepancies are observed between the phase shift data and the sum of all known contributions. Statistically satisfactory fits to the data can only be achieved by adding extra poles in the two channels. We find that a S-11 resonance pole locates at zr = (0:895-0:081)-(0:164-0:023)i GeV, on the complex s-plane. On the other hand, a P-11 virtual pole, as an accompanying partner of the nucleon bound-state pole, locates atzv = (0:966-0:018) GeV, slightly above the nucleon pole on the real axis below threshold. Physical origin of the two newly established poles is explored to the best of our knowledge. It is emphasized that the O(p(3)) calculation greatly improves the fit quality comparing with the previous O(p(2)) one.
Address [Wang, Yu-Fei; Zheng, Han-Qing] Peking Univ, Dept Phys, Beijing 100871, Peoples R China, Email: deliang.yao@ific.uv.es
Corporate Author Thesis
Publisher Higher Education Press Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2095-0462 ISBN Medium
Area Expedition Conference
Notes WOS:000454564100001 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3857
Permanent link to this record