IFIC Home

IFIC Literature Database

Home |  Show All |  Simple Search |  Advanced Search
Quick Search:
221-230 of 2404 records found matching your query:
toggle visibility Search & Display Options
Select All    Deselect All [11–20] << 21 22 23 24 25 26 27 28 29 30 >> [31–40]
List View
 | 
Citations
 | 
Details
   print
  Records Links
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J. url  doi
openurl 
  Title QCD effective charges from lattice data Type Journal Article
  Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 002 - 24pp  
  Keywords Nonperturbative Effects; QCD  
  Abstract We use recent lattice data on the gluon and ghost propagators, as well as the Kugo-Ojima function, in order to extract the non-perturbative behavior of two particular definitions of the QCD effective charge, one based on the pinch technique construction, and one obtained from the standard ghost-gluon vertex. The construction relies crucially on the definition of two dimensionful quantities, which are invariant under the renormalization group, and are built out of very particular combinations of the aforementioned Green's functions. The main non-perturbative feature of both effective charges, encoded in the infrared finiteness of the gluon propagator and ghost dressing function used in their definition, is the freezing at a common finite (non-vanishing) value, in agreement with a plethora of theoretical and phenomenological expectations. We discuss the sizable discrepancy between the freezing values obtained from the present lattice analysis and the corresponding estimates derived from several phenomenological studies, and attribute its origin to the difference in the gauges employed. A particular toy calculation suggests that the modifications induced to the non-perturbative gluon propagator by the gauge choice may indeed account for the observed deviation of the freezing values.  
  Address (up) [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil, Email: arlene.aguilar@ufabc.edu.br  
  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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281504500002 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 384  
Permanent link to this record
 
 
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J. url  doi
openurl 
  Title Gluon mass through ghost synergy Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 01 Issue 1 Pages 050 - 32pp  
  Keywords Nonperturbative Effects; QCD  
  Abstract In this work we compute, at the “one-loop-dressed” level, the nonperturbative contribution of the ghost loops to the self-energy of the gluon propagator, in the Landau gauge. This is accomplished within the PT-BFM formalism, where the contribution of the ghost-loops is inherently transverse, by virtue of the QED-like Ward identities satisfied in this framework. At the level of the “one-loop dressed” approximation, the ghost transversality is preserved by employing a suitable gauge-technique Ansatz for the longitudinal part of the full ghost-gluon vertex. Under the key assumption that the undetermined transverse part of this vertex is numerically subleading in the infrared, and using as nonperturbative input the available lattice data for the ghost dressing function, we show that the ghost contributions have a rather sizable effect on the overall shape of the gluon propagator, both for d = 3, 4. Then, by exploiting a recently introduced dynamical equation for the effective gluon mass, whose solutions depend crucially on the characteristics of the gluon propagator at intermediate energies, we show that if the ghost loops are removed from the gluon propagator then the gluon mass vanishes. These findings suggest that, at least at the level of the Schwinger-Dyson equations, the effects of gluons and ghosts are inextricably connected, and must be combined suitably in order to reproduce the results obtained in the recent lattice simulations.  
  Address (up) [Aguilar, A. C.] Fed Univ ABC, CCNH, BR-09210170 Santo Andre, Brazil, Email: arlene.aguilar@ufabc.edu.br  
  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 1126-6708 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000300181800050 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 969  
Permanent link to this record
 
 
Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J. url  doi
openurl 
  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 (up) [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  
Permanent link to this record
 
 
Author Aguilar, A.C.; De Soto, F.; Ferreira, M.N.; Papavassiliou, J.; Pinto-Gomez, F.; Roberts, C.D.; Rodriguez-Quintero, J. url  doi
openurl 
  Title Schwinger mechanism for gluons from lattice QCD Type Journal Article
  Year 2023 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 841 Issue Pages 137906 - 8pp  
  Keywords Continuum Schwinger function methods; Emergence of mass; Gluons; Lattice Schwinger function methods; Quantum chromodynamics; Schwinger mechanism of gauge boson mass; generation  
  Abstract Continuum and lattice analyses have revealed the existence of a mass-scale in the gluon two-point Schwinger function. It has long been conjectured that this expresses the action of a Schwinger mechanism for gauge boson mass generation in quantum chromodynamics (QCD). For such to be true, it is necessary and sufficient that a dynamically-generated, massless, colour-carrying, scalar gluon+gluon correlation emerges as a feature of the dressed three-gluon vertex. Working with results on elementary Schwinger functions obtained via the numerical simulation of lattice-regularised QCD, we establish with an extremely high level of confidence that just such a feature appears; hence, confirm the conjectured origin of the gluon mass scale.  
  Address (up) [Aguilar, A. C.] Univ Estadual Campinas, Inst Phys Gleb Wataghin, UNICAMP, BR-13083859 Campinas, SP, Brazil, Email: cristina.aguilar@unicamp.br;  
  Corporate Author Thesis  
  Publisher Elsevier 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:000984221700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 5530  
Permanent link to this record
 
 
Author ANTARES Collaboration (Aguilar, J.A. et al); Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Ruiz-Rivas, J.; Salesa, F.; Sanchez-Losa, A.; Toscano, S.; Yepes, H.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title A method for detection of muon induced electromagnetic showers with the ANTARES detector Type Journal Article
  Year 2012 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 675 Issue Pages 56-62  
  Keywords Neutrino telescope; Electromagnetic shower identification; High energy muons; Energy reconstruction  
  Abstract The primary aim of ANTARES is neutrino astronomy with upward going muons created in charged current muon neutrino interactions in the detector and its surroundings. Downward going muons are background for neutrino searches. These muons are the decay products of cosmic-ray collisions in the Earth's atmosphere far above the detector. This paper presents a method to identify and count electromagnetic showers induced along atmospheric muon tracks with the ANTARES detector. The method is applied to both cosmic muon data and simulations and its applicability to the reconstruction of muon event energies is demonstrated.  
  Address (up) [Aguilar, J. A.; Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J. P.; Hernandez-Rey, J. J.; Mangano, S.; Rostovtsev, A.; Ruiz-Rivas, J.; Salesa, F.; Sanchez-Losa, A.; Toscano, S.; Yepes, H.; Zornoza, J. D.; Zuniga, J.] Univ Valencia, IFIC, Inst Fis Corpuscular, CSIC, Valencia 46071, Spain, Email: manganos@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 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000302973600011 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 988  
Permanent link to this record
 
 
Author ANTARES Collaboration (Aguilar, J.A. et al); Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Salesa, F.; Toscano, S.; Yepes, H.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title Time calibration of the ANTARES neutrino telescope Type Journal Article
  Year 2011 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.  
  Volume 34 Issue 7 Pages 539-549  
  Keywords Time calibration; Neutrino telescopes; ANTARES  
  Abstract The ANTARES deep-sea neutrino telescope comprises a three-dimensional array of photomultipliers to detect the Cherenkov light induced by upgoing relativistic charged particles originating from neutrino interactions in the vicinity of the detector. The large scattering length of light in the deep sea facilitates an angular resolution of a few tenths of a degree for neutrino energies exceeding 10 TeV. In order to achieve this optimal performance, the time calibration procedures should ensure a relative time calibration between the photomultipliers at the level of similar to 1 ns. The methods developed to attain this level of precision are described.  
  Address (up) [Aguilar, J. A.; Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J. P.; Hernandez-Rey, J. J.; Mangano, S.; Salesa, F.; Toscano, S.; Yepes, H.; Zornoza, J. D.; Zuniga, J.] Univ Valencia, CSIC, Inst Fis Corpuscular, IFIC, Valencia 46071, Spain, Email: zornoza@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 0927-6505 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000287955500004 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 560  
Permanent link to this record
 
 
Author ANTARES Collaboration (Aguilar, J.A. et al); Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Mangano, S.; Salesa, F.; Toscano, S.; Yepes, H.; Zornoza, J.D.; Zuñiga, J. url  doi
openurl 
  Title Performance of the front-end electronics of the ANTARES neutrino telescope Type Journal Article
  Year 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A  
  Volume 622 Issue 1 Pages 59-73  
  Keywords Neutrino telescope; Photomultiplier tube; Front-end electronics; ASIC  
  Abstract ANTARES is a high-energy neutrino telescope installed in the Mediterranean Sea at a depth of 2475 m. It consists of a three-dimensional array of optical modules, each containing a large photomultiplier tube. A total of 2700 front-end ASICs named analogue ring samplers (ARS) process the phototube signals, measure their arrival time, amplitude and shape as well as perform monitoring and calibration tasks. The ARS chip processes the analogue signals from the optical modules and converts information into digital data. All the information is transmitted to shore through further multiplexing electronics and an optical link. This paper describes the performance of the ARS chip: results from the functionality and characterization tests in the laboratory are summarized and the long-term performance in the apparatus is illustrated.  
  Address (up) [Aguilar, J. A.; Bigongiari, C.; Dornic, D.; Emanuele, U.; Gomez-Gonzalez, J. P.; Hernandez-Rey, J. J.; Mangano, S.; Salesa, F.; Toscano, S.; Yepes, H.; Zornoza, J. D.; Zuniga, J.] Univ Valencia, IFIC, CSIC, Valencia 46071, Spain, Email: s.loucatos@cea.fr  
  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 0168-9002 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000282530300009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 363  
Permanent link to this record
 
 
Author Aguilar-Saavedra, J.A.; Casas, J.A.; Quilis, J.; Ruiz de Austri, R. url  doi
openurl 
  Title Multilepton dark matter signals Type Journal Article
  Year 2020 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 04 Issue 4 Pages 069 - 24pp  
  Keywords Beyond Standard Model; Gauge Symmetry  
  Abstract The signatures of dark matter at the LHC commonly involve, in simplified scenarios, the production of a single particle plus large missing energy, from the undetected dark matter. However, in Z ' -portal scenarios anomaly cancellation requires the presence of extra dark leptons in the dark sector. We investigate the signatures of the minimal scenarios of this kind, which involve cascade decays of the extra Z ' boson into the dark leptons, identifying a four-lepton signal as the most promising one. We estimate the sensitivity to this signal at the LHC, the high-luminosity LHC upgrade, a possible high-energy upgrade, as well as a future circular collider. For Z ' couplings compatible with current dijet constraints the multilepton signals can reach the 5 sigma level already at Run 2 of the LHC. At future colliders, couplings two orders of magnitude smaller than the electroweak coupling can be probed with 5 sigma sensitivity.  
  Address (up) [Aguilar-Saavedra, J. A.; Casas, J. A.; Quilis, J.] Univ Autonoma Madrid, IFT, CSIC, E-28049 Madrid, Spain, Email: jaas@ugr.es;  
  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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000528689700001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4384  
Permanent link to this record
 
 
Author Aguilar-Saavedra, J.A.; Bernabeu, J. url  doi
openurl 
  Title W polarisation beyond helicity fractions in top quark decays Type Journal Article
  Year 2010 Publication Nuclear Physics B Abbreviated Journal Nucl. Phys. B  
  Volume 840 Issue 1-2 Pages 349-378  
  Keywords  
  Abstract We calculate the density matrix for the decay of a polarised top quark into a polarised W boson and a massive 17 quark, for the most general Wth vertex arising from dimension-six gauge-invariant effective operators. We show that, in addition to the well-known W helicity fractions, for polarised top decays it is worth defining and studying the transverse and normal W polarisation fractions, that is, the W polarisation alone two directions orthogonal to its momentum. In particular, a rather simple forward-backward asymmetry in the normal direction is found to be very sensitive to complex phases in one of the Wth anomalous couplings. This asymmetry, which indicates a normal W polarisation, can be generated for example by a P-odd. T-odd transition electric dipole moment. We also investigate the angular distribution of decay products in the top quark rest frame, calculating the spin analysing powers for a general Wth vertex. Finally we show that, using a combined fit to top decay observables and the t W cross section, at LHC it will be possible to obtain model-independent measurements of all the (complex) Wth couplings as well as the single top polarisation. Implications for spin correlations in top pair production are also discussed.  
  Address (up) [Aguilar-Saavedra, J. A.] Univ Granada, Dept Fis Teor & Cosmos, E-18071 Granada, Spain, Email: jaas@ugr.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 0550-3213 ISBN Medium  
  Area Expedition Conference  
  Notes ISI:000281832900013 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 370  
Permanent link to this record
 
 
Author Aguilera-Verdugo, J.J.; Driencourt-Mangin, F.; Plenter, J.; Ramirez-Uribe, S.; Rodrigo, G.; Sborlini, G.F.R.; Torres Bobadilla, W.J.; Tracz, S. url  doi
openurl 
  Title Causality, unitarity thresholds, anomalous thresholds and infrared singularities from the loop-tree duality at higher orders Type Journal Article
  Year 2019 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 12 Issue 12 Pages 163 - 12pp  
  Keywords Duality in Gauge Field Theories; Perturbative QCD; Scattering Amplitudes  
  Abstract We present the first comprehensive analysis of the unitarity thresholds and anomalous thresholds of scattering amplitudes at two loops and beyond based on the loop- tree duality, and show how non-causal unphysical thresholds are locally cancelled in an efficient way when the forest of all the dual on-shell cuts is considered as one. We also prove that soft and collinear singularities at two loops and beyond are restricted to a compact region of the loop three-momenta, which is a necessary condition for implementing a local cancellation of loop infrared singularities with the ones appearing in real emission; without relying on a subtraction formalism.  
  Address (up) [Aguilera-Verdugo, J. Jesus; Driencourt-Mangin, Felix; Plenter, Judith; Ramirez-Uribe, Selomit; Rodrigo, German; Sborlini, German F. R.; Torres Bobadilla, William J.; Tracz, Szymon] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular, Parc Cient, E-46980 Valencia, Spain, Email: jesus.aguilera@ific.uv.es;  
  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 1029-8479 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000513535500003 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 4288  
Permanent link to this record
Select All    Deselect All [11–20] << 21 22 23 24 25 26 27 28 29 30 >> [31–40]
List View
 | 
Citations
 | 
Details
   print
toggle visibility
Save Citations:
Export Records:
Home CQL Search  |  Library Search  |  Show Record  |  Extract Citations Help
ific federMinisterio de Ciencia e InnovaciónAgencia Estatal de Investigaciongva