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Author Binosi, D.; Chang, L.; Ding, M.H.; Gao, F.; Papavassiliou, J.; Roberts, C.D.
Title Distribution amplitudes of heavy-light mesons Type Journal Article
Year 2019 Publication Physics Letters B Abbreviated Journal (up) Phys. Lett. B
Volume 790 Issue Pages 257-262
Keywords B-meson decays; Heavy-light mesons; Nonperturbative continuum methods in quantum field theory; Parton distribution amplitudes; Quantum chromodynamics
Abstract A symmetry-preserving approach to the continuum bound-state problem in quantum field theory is used to calculate the masses, leptonic decay constants and light-front distribution amplitudes of empirically accessible heavy-light mesons. The inverse moment of the B-meson distribution is particularly important in treatments of exclusive B-decays using effective field theory and the factorisation formalism; and its value is therefore computed: lambda(B) = (zeta = 2GeV) = 0.54(3) GeV. As an example and in anticipation of precision measurements at new-generation B-factories, the branching fraction for the rare B -> gamma (E-gamma)l nu(l) radiative decay is also calculated, retaining 1/m(B)(2), and 1/E-gamma(2) corrections to the differential decay width, with the result Gamma(B -> gamma l nu l) /Gamma(B) = 0.47 (15) on E-gamma > 1.5 GeV.
Address [Binosi, Daniele; Ding, Minghui] European Ctr Theoret Studies Nucl Phys & Related, Str Tabarelle 286, I-38123 Villazzano, TN, Italy, Email: binosi@ectstar.eu;
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:000460118200030 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 3934
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Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title Nonperturbative gluon and ghost propagators for d=3 Yang-Mills theory Type Journal Article
Year 2010 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 81 Issue 12 Pages 125025 - 13pp
Keywords
Abstract We study a manifestly gauge-invariant set of Schwinger-Dyson equations to determine the non-perturbative dynamics of the gluon and ghost propagators in d = 3 Yang-Mills theory. The use of the well-known Schwinger mechanism, in the Landau gauge leads to the dynamical generation of a mass for the gauge boson (gluon in d = 3), which, in turn, gives rise to an infrared finite gluon propagator and ghost dressing function. The propagators obtained from the numerical solution of these nonperturbative equations are in very good agreement with the results of SU(2) lattice simulations.
Address [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes ISI:000279165900006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 422
Permanent link to this record
 

 
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title Dynamical equation of the effective gluon mass Type Journal Article
Year 2011 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 84 Issue 8 Pages 085026 - 19pp
Keywords
Abstract In this article, we derive the integral equation that controls the momentum dependence of the effective gluon mass in the Landau gauge. This is accomplished by means of a well-defined separation of the corresponding “one-loop dressed” Schwinger-Dyson equation into two distinct contributions, one associated with the mass and one with the standard kinetic part of the gluon. The entire construction relies on the existence of a longitudinally coupled vertex of nonperturbative origin, which enforces gauge invariance in the presence of a dynamical mass. The specific structure of the resulting mass equation, supplemented by the additional requirement of a positive-definite gluon mass, imposes a rather stringent constraint on the derivative of the gluonic dressing function, which is comfortably satisfied by the large-volume lattice data for the gluon propagator, both for SU(2) and SU(3). The numerical treatment of the mass equation, under some simplifying assumptions, is presented for the aforementioned gauge groups, giving rise to a gluon mass that is a nonmonotonic function of the momentum. Various theoretical improvements and possible future directions are briefly discussed.
Address [Aguilar, AC] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil, Email: Arlene.Aguilar@ufabc.edu.br
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:000296889200007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 814
Permanent link to this record
 

 
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
Title Unquenching the gluon propagator with Schwinger-Dyson equations Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 86 Issue 1 Pages 014032 - 24pp
Keywords
Abstract In this article we use the Schwinger-Dyson equations to compute the nonperturbative modifications caused to the infrared finite gluon propagator (in the Landau gauge) by the inclusion of a small number of quark families. Our basic operating assumption is that the main bulk of the effect stems from the "one-loop dressed'' quark loop contributing to the full gluon self-energy. This quark loop is then calculated, using as basic ingredients the full quark propagator and quark-gluon vertex; for the quark propagator we use the solution obtained from the quark-gap equation, while for the vertex we employ suitable Ansatze, which guarantee the transversality of the answer. The resulting effect is included as a correction to the quenched gluon propagator, obtained in recent lattice simulations. Our main finding is that the unquenched propagator displays a considerable suppression in the intermediate momentum region, which becomes more pronounced as we increase the number of active quark families. The influence of the quarks on the saturation point of the propagator cannot be reliably computed within the present scheme; the general tendency appears to be to decrease it, suggesting a corresponding increase in the effective gluon mass. The renormalization properties of our results, and the uncertainties induced by the unspecified transverse part of the quark-gluon vertex, are discussed. Finally, the gluon propagator is compared with the available unquenched lattice data, showing rather good agreement.
Address [Aguilar, A. C.] Univ Estadual Campinas, UNICAMP, Inst Fis 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 1550-7998 ISBN Medium
Area Expedition Conference
Notes WOS:000306929400003 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1127
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Author Binosi, D.; Ibañez, D.; Papavassiliou, J.
Title All-order equation of the effective gluon mass Type Journal Article
Year 2012 Publication Physical Review D Abbreviated Journal (up) Phys. Rev. D
Volume 86 Issue 8 Pages 085033 - 21pp
Keywords
Abstract We present the general derivation of the full nonperturbative equation that governs the momentum evolution of the dynamically generated gluon mass, in the Landau gauge. The entire construction hinges crucially on the inclusion of longitudinally coupled vertices containing massless poles of nonperturbative origin, which preserve the form of the fundamental Slavnov-Taylor identities of the theory. The mass equation is obtained from a previously unexplored version of the Schwinger-Dyson equation for the gluon propagator, particular to the pinch technique-background field method formalism, which involves a reduced number of two-loop dressed diagrams, thus simplifying the calculational task considerably. The two-loop contributions turn out to be of paramount importance, modifying the qualitative features of the full mass equation and enabling the emergence of physically meaningful solutions. Specifically, the resulting homogeneous integral equation is solved numerically, subject to certain approximations, for the entire range of physical momenta, yielding positive-definite and monotonically decreasing gluon masses.
Address [Binosi, D.] European Ctr Theoret Studies Nucl Phys & Related, I-38123 Villazzano, Trento, Italy
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:000309999700007 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 1196
Permanent link to this record