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Author (up) Aguilar, A.C.; Binosi, D.; Figueiredo, C.T.; Papavassiliou, J.
Title Unified description of seagull cancellations and infrared finiteness of gluon propagators Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 94 Issue 4 Pages 045002 - 22pp
Keywords
Abstract We present a generalized theoretical framework for dealing with the important issue of dynamical mass generation in Yang-Mills theories, and, in particular, with the infrared finiteness of the gluon propagators, observed in a multitude of recent lattice simulations. Our analysis is manifestly gauge invariant, in the sense that it preserves the transversality of the gluon self-energy, and gauge independent, given that the conclusions do not depend on the choice of the gauge-fixing parameter within the linear covariant gauges. The central construction relies crucially on the subtle interplay between the Abelian Ward identities satisfied by the nonperturbative vertices and a special integral identity that enforces a vast number of “seagull cancellations” among the one-and two-loop dressed diagrams of the gluon Schwinger-Dyson equation. The key result of these considerations is that the gluon propagator remains rigorously massless, provided that the vertices do not contain (dynamical) massless poles. When such poles are incorporated into the vertices, under the pivotal requirement of respecting the gauge symmetry of the theory, the terms comprising the Ward identities conspire in such a way as to still enforce the total annihilation of all quadratic divergences, inducing, at the same time, residual contributions that account for the saturation of gluon propagators in the deep infrared.
Address [Aguilar, A. C.; Figueiredo, C. T.] Univ Campinas UNICAMP, Inst Phys Gleb Wataghin, BR-13083859 Campinas, SP, Brazil
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2470-0010 ISBN Medium
Area Expedition Conference
Notes WOS:000380962400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2772
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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) Aguilar-Saavedra, J.A.; Bernabeu, J.
Title Breaking down the entire W boson spin observables from its decay Type Journal Article
Year 2016 Publication Physical Review D Abbreviated Journal Phys. Rev. D
Volume 93 Issue 1 Pages 011301 - 6pp
Keywords
Abstract We discuss the eight independent spin observables for the W boson in terms of its vector and tensor polarizations and identify the angular distributions and asymmetries able to separate them in collider experiments. The results are applied to the study of polarized top quark decays and diboson resonances. These novel observables are of great value for disentangling new physics mechanisms in W boson production.
Address [Aguilar-Saavedra, J. A.] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain
Corporate Author Thesis
Publisher Amer Physical Soc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000368324500001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2538
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Author (up) Albaladejo, M.; Fernandez-Soler, P.; Nieves, J.
Title Z(c)(3900): confronting theory and lattice simulations Type Journal Article
Year 2016 Publication European Physical Journal C Abbreviated Journal Eur. Phys. J. C
Volume 76 Issue 10 Pages 573 - 9pp
Keywords
Abstract We consider a recent T -matrix analysis by Albaladejo et al. (Phys Lett B 755: 337, 2016), which accounts for the J/psi pi and D*(D) over bar coupled-channels dynamics, and which successfully describes the experimental information concerning the recently discovered Z(c)(3900)(+/-). Within such scheme, the data can be similarly well described in two different scenarios, where Z(c)(3900) is either a resonance or a virtual state. To shed light into the nature of this state, we apply this formalism in a finite box with the aim of comparing with recent Lattice QCD (LQCD) simulations. We see that the energy levels obtained for both scenarios agree well with those obtained in the single-volume LQCD simulation reported in Prelovsek et al. (Phys Rev D 91: 014504, 2015), thus making it difficult to disentangle the two possibilities. We also study the volume dependence of the energy levels obtained with our formalism and suggest that LQCD simulations performed at several volumes could help in discerning the actual nature of the intriguing Z(c)(3900) state.
Address [Albaladejo, Miguel; Fernandez-Soler, Pedro; Nieves, Juan] Univ Valencia, Inst Fis Corpuscular IFIC, Ctr Mixto CSIC, Inst Invest Paterna, Aptdo 22085, Valencia 46071, Spain, Email: miguelalbaladejo@gmail.com
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1434-6044 ISBN Medium
Area Expedition Conference
Notes WOS:000388981700001 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ pastor @ Serial 2877
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Author (up) Albaladejo, M.; Guo, F.K.; Hidalgo-Duque, C.; Nieves, J.
Title Z(c)(3900): What has been really seen? Type Journal Article
Year 2016 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 755 Issue Pages 337-342
Keywords
Abstract The Z(c)(+/-)(3900)/Z(c)(+/-)(3885) resonant structure has been experimentally observed in the Y(4260) -> J/Psi pi pi and Y(4260) -> (D) over bar* D pi decays. This structure is intriguing since it is a prominent candidate of an exotic hadron. Yet, its nature is unclear so far. In this work, we simultaneously describe the (D) over bar* D and J/Psi pi invariant mass distributions in which the Z(c) peak is seen using amplitudes with exact unitarity. Two different scenarios are statistically acceptable, where the origin of the Z(c) state is different. They correspond to using energy dependent or independent (D) over bar *D S-wave interaction. In the first one, the Z(c) peak is due to a resonance with a mass around the D (D) over bar* threshold. In the second one, the Z(c) peak is produced by a virtual state which must have a hadronic molecular nature. In both cases the two observations, Z(c)(+/-)(3900) and Z(c)(+/-)(3885), are shown to have the same common origin, and a (D) over bar *D bound state solution is not allowed. Precise measurements of the line shapes around the D (D) over bar* threshold are called for in order to understand the nature of this state.
Address [Albaladejo, Miguel; Hidalgo-Duque, Carlos; Nieves, Juan] Ctr Mixto CSIC Univ Valencia, Inst Invest Paterna, Inst Fis Corpuscular, Aptd 22085, E-46071 Valencia, Spain, Email: Miguel.Albaladejo@ific.uv.es
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000373568100047 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 2711
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