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Author Binosi, D.; Papavassiliou, J.
Title Gauge invariant Ansatz for a special three-gluon vertex Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 03 Issue 3 Pages 121 - 23pp
Keywords Nonperturbative Effects; QCD
Abstract We construct a general Ansatz for the three-particle vertex describing the interaction of one background and two quantum gluons, by simultaneously solving the Ward and Slavnov-Taylor identities it satisfies. This vertex is known to be essential for the gauge-invariant truncation of the Schwinger-Dyson equations of QCD, based on the pinch technique and the background field method. A key step in this construction is the formal derivation of a set of crucial constraints (shown to be valid to all orders), relating the various form factors of the ghost Green's functions appearing in the aforementioned Slavnov-Taylor identity. When inserted into the Schwinger-Dyson equation for the gluon propagator, this vertex gives rise to a number of highly non-trivial cancellations, which are absolutely indispensable for the self-consistency of the entire approach.
Address [Binosi, D.] European Ctr Theoret Studies Nucl Phys & Related, I-38123 Villazzano, TN, Italy, Email: binosi@ect.it
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language (up) 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:000289295300049 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 624
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Author Perez-Ramos, R.; Mathieu, V.; Sanchis-Lozano, M.A.
Title Heavy quark flavour dependence of multiparticle production in QCD jets Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 08 Issue 8 Pages 047 - 24pp
Keywords Jets; Hadronic Colliders; QCD
Abstract After inserting the heavy quark mass dependence into QCD partonic evolution equations, we determine the mean charged hadron multiplicity and second multiplicity correlators of jets produced in high energy collisions. We thereby extend the so-called dead cone effect to the phenomenology of multiparticle production in QCD jets and find that the average multiplicity of heavy-quark initiated jets decreases significantly as compared to the massless case, even taking into account the weak decay products of the leading primary quark. We emphasize the relevance of our study as a complementary check of b-tagging techniques at hadron colliders like the Tevatron and the LHC.
Address [Perez-Ramos, Redamy] Univ Valencia, CSIC, Dept Fis Teor, E-46100 Burjassot, Spain, Email: redamy.perez@uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language (up) 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:000282368500019 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 356
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Author Jung, M.; Pich, A.; Tuzon, P.
Title Charged-Higgs phenomenology in the aligned two-Higgs-doublet model Type Journal Article
Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 11 Issue 11 Pages 003 - 45pp
Keywords Higgs Physics; Beyond Standard Model; CP violation
Abstract The alignment in flavour space of the Yukawa matrices of a general two-Higgs-doublet model results in the absence of tree-level flavour-changing neutral currents. In addition to the usual fermion masses and mixings, the aligned Yukawa structure only contains three complex parameters zeta(f), which are potential new sources of CP violation [1]. For particular values of these three parameters all known specific implementations of the model based on discrete Z(2) symmetries are recovered. One of the most distinctive features of the two-Higgs-doublet model is the presence of a charged scalar H-+/-. In this work, we discuss its main phenomenological consequences in flavour-changing processes at low energies and derive the corresponding constraints on the parameters of the aligned two-Higgs-doublet model.
Address [Jung, Martin; Pich, Antonio; Tuzon, Paula] Univ Valencia, Inst Fis Corpuscular IFIC, CSIC, E-46071 Valencia, Spain, Email: jung@ific.uv.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language (up) 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:000284963400078 Approved no
Is ISI yes International Collaboration no
Call Number IFIC @ elepoucu @ Serial 317
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Author Donini, A.; Gomez-Cadenas, J.J.; Meloni, D.
Title The tau-contamination of the golden muon sample at the Neutrino Factory Type Journal Article
Year 2011 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.
Volume 02 Issue 2 Pages 095 - 16pp
Keywords Neutrino Physics; Beyond Standard Model; CP violation
Abstract We study the contribution of nu(e) -> nu(tau) -> tau -> μtransitions to the wrong-sign muon sample of the golden channel of the Neutrino Factory. Muons from tau decays are not really a background, since they contain information from the oscillation signal, and represent a small fraction of the sample. However, if not properly handled they introduce serious systematic error, in particular if the detector/analysis are sensitive to muons of low energy. This systematic effect is particularly troublesome for large theta(13) >= 1 degrees and prevents the use of the Neutrino Factory as a precision facility for large theta(13). Such a systematic error disappears if the tau contribution to the golden muon sample is taken into account. The fact that the fluxes of the Neutrino Factory are exactly calculable permits the knowledge of the tau sample due to the nu(e) -> nu(tau) oscillation. We then compute the contribution to the muon sample arising from this sample in terms of the apparent muon energy. This requires the computation of a migration matrix M-ij which describes the contributions of the tau neutrinos of a given energy E-i, to the muon neutrinos of an apparent energy E-j. We demonstrate that applying M-ij to the data permits the full correction of the otherwise intolerable systematic error.
Address [Donini, A.] Univ Autonoma Madrid, CSIC, IFT, E-28049 Madrid, Spain, Email: andrea.donini@uam.es
Corporate Author Thesis
Publisher Springer Place of Publication Editor
Language (up) 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:000287939200023 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 621
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Author Aguilar, A.C.; Binosi, D.; Papavassiliou, J.
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 [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 (up) 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