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Author Bierenbaum, I.; Catani, S.; Draggiotis, P.; Rodrigo, G. url  doi
openurl 
  Title A tree-loop duality relation at two loops and beyond Type Journal Article
  Year 2010 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 10 Issue 10 Pages 073 - 22pp  
  Keywords NLO Computations; QCD  
  Abstract The duality relation between one-loop integrals and phase-space integrals, developed in a previous work, is extended to higher-order loops. The duality relation is realized by a modification of the customary +i0 prescription of the Feynman propagators, which compensates for the absence of the multiple-cut contributions that appear in the Feynman tree theorem. We rederive the duality theorem at one-loop order in a form that is more suitable for its iterative extension to higher-loop orders. We explicitly show its application to two-and three-loop scalar master integrals, and we discuss the structure of the occurring cuts and the ensuing results in detail.  
  Address [Bierenbaum, Isabella; Draggiotis, Petros; Rodrigo, German] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular, E-46071 Valencia, Spain, Email: isabella.bierenbaum@ific.uv.es  
  Corporate Author Thesis (up)  
  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:000284147000016 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ elepoucu @ Serial 326  
Permanent link to this record
 
 
Author Gomez Dumm, D.; Noguera, S.; Scoccola, N.N. url  doi
openurl 
  Title Pion radiative weak decays in nonlocal chiral quark models Type Journal Article
  Year 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B  
  Volume 698 Issue 3 Pages 236-242  
  Keywords Nonlocal quark models; Pion radiative weak decays  
  Abstract We analyze the radiative pion decay pi(+) -> e(+) nu(e)gamma within nonlocal chiral quark models that include wave function renormalization. In this framework we calculate the vector and axial-vector form factors F-V and F-A at q(2) = 0 – where q(2) is the e(+) nu(e) squared invariant mass – and the slope a of F-V (q(2)) at q(2) -> 0. The calculations are carried out considering different nonlocal form factors, in particular those taken from lattice QCD evaluations, showing a reasonable agreement with the corresponding experimental data. The comparison of our results with those obtained in the (local) NJL model and the relation of F-V and a with the form factor in pi(0) -> gamma*gamma decays are discussed.  
  Address [Gomez Dumm, D.] Univ Nacl La Plata, CONICET, Dept Fis, IFLP, RA-1900 La Plata, Buenos Aires, Argentina, Email: dumm@fisica.unlp.edu.ar  
  Corporate Author Thesis (up)  
  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 ISI:000289543700008 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 609  
Permanent link to this record
 
 
Author Catani, S.; de Florian, D.; Rodrigo, G. url  doi
openurl 
  Title Space-like (vs. time-like) collinear limits in QCD: is factorization violated? Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 026 - 88pp  
  Keywords NLO Computations; Hadronic Colliders  
  Abstract We consider the singular behaviour of QCD scattering amplitudes in kinematical configurations where two or more momenta of the external partons become collinear. At the tree level, this behaviour is known to be controlled by factorization formulae in which the singular collinear factor is universal (process independent). We show that this strict (process-independent) factorization is not valid at one-loop and higher-loop orders in the case of the collinear limit in space-like regions (e. g., collinear radiation from initial-state partons). We introduce a generalized version of all-order collinear factorization, in which the space-like singular factors retain some dependence on the momentum and colour charge of the non-collinear partons. We present explicit results on one-loop and two-loop amplitudes for both the two-parton and multiparton collinear limits. At the level of squared amplitudes and, more generally, cross sections in hadron-hadron collisions, the violation of strict collinear factorization has implications on the non-abelian structure of logarithmically-enhanced terms in perturbative calculations (starting from the next-to-next-to-leading order) and on various factorization issues of mass singularities (starting from the next-to-next-to-next-to-leading order).  
  Address [Catani, Stefano] Univ Florence, Sez Firenze, Ist Nazl Fis Nucl, I-50019 Florence, Italy, Email: catani@fi.infn.it;  
  Corporate Author Thesis (up)  
  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:000307298400026 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1160  
Permanent link to this record
 
 
Author Alioli, S.; Fuster, J.; Irles Quiles, A.; Moch, S.; Uwer, P.; Vos, M. doi  openurl
  Title A new observable to measure the top quark mass at hadron colliders Type Journal Article
  Year 2012 Publication Pramana-Journal of Physics Abbreviated Journal Pramana-J. Phys.  
  Volume 79 Issue 4 Pages 809-812  
  Keywords Top quark; mass; pole mass; NLO; cross-section; t(t)over-bar plus jet; POWHEG; perturbative QCD  
  Abstract The t (t) over bar + jet + X differential cross-section in proton-proton collisions at 7 TeV centre of mass energy is investigated with respect to its sensitivity to the top quark mass. The analysis includes higher order QCD corrections at NLO. The impact of the renormalization scale (mu(R)), the factorization (mu(F)) scale and of the choice of different proton's PDF (parton distribution function) has been evaluated. In this study it is concluded that differential jet rates offer a promising option for alternative mass measurements of the top quark, with theoretical uncertainties below 1 GeV.  
  Address [Fuster, Juan; Irles, Adrian; Vos, Marcel] Univ Valencia, Ctr Mixte, CSIC, IFIC, E-46071 Valencia, Spain, Email: airqui@ific.uv.es  
  Corporate Author Thesis (up)  
  Publisher Indian Acad Sciences Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-4289 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000310875900021 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1200  
Permanent link to this record
 
 
Author Kleiss, R.H.P.; Malamos, I.; Papadopoulos, C.G.; Verheyen, R. url  doi
openurl 
  Title Counting to one: reducibility of one- and two-loop amplitudes at the integrand level Type Journal Article
  Year 2012 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 12 Issue 12 Pages 038 - 24pp  
  Keywords QCD Phenomenology; NLO Computations  
  Abstract Calculation of amplitudes in perturbative quantum field theory involve large loop integrals. The complexity of those integrals, in combination with the large number of Feynman diagrams, make the calculations very difficult. Reduction methods proved to be very helpful, lowering the number of integrals that need to be actually calculated. Especially reduction at the integrand level improves the speed and set-up of these calculations. In this article we demonstrate, by counting the numbers of tensor structures and independent coefficients, how to write such relations at the integrand level for one-and two-loop amplitudes. We clarify their connection to the so-called spurious terms at one loop and discuss their structure in the two-loop case. This method is also applicable to higher loops, and the results obtained apply to both planar and non-planar diagrams.  
  Address [Kleiss, Ronald H. P.; Verheyen, Rob] Radboud Univ Nijmegen, NL-6525 ED Nijmegen, Netherlands, Email: R.Kleiss@science.ru.nl;  
  Corporate Author Thesis (up)  
  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:000313123800038 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1346  
Permanent link to this record
 
 
Author Bierenbaum, I.; Buchta, S.; Draggiotis, P.; Malamos, I.; Rodrigo, G. url  doi
openurl 
  Title Tree-loop duality relation beyond single poles Type Journal Article
  Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 03 Issue 3 Pages 025 - 24pp  
  Keywords QCD Phenomenology; NLO Computations  
  Abstract We develop the Tree-Loop Duality Relation for two- and three-loop integrals with multiple identical propagators (multiple poles). This is the extension of the Duality Relation for single poles and multi-loop integrals derived in previous publications. We prove a generalization of the formula for single poles to multiple poles and we develop a strategy for dealing with higher-order pole integrals by reducing them to single pole integrals using Integration By Parts.  
  Address Univ Hamburg, Inst Theoret Phys 2, D-22761 Hamburg, Germany, Email: isabella.bierenbaum@desy.de;  
  Corporate Author Thesis (up)  
  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:000317521200025 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1418  
Permanent link to this record
 
 
Author Mateu, V.; Rodrigo, G. url  doi
openurl 
  Title Oriented event shapes at (NLL)-L-3 + O(alpha(2)(S)) Type Journal Article
  Year 2013 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 11 Issue 11 Pages 030 - 29pp  
  Keywords Jets; NLO Computations  
  Abstract We analyze oriented event-shapes in the context of Soft-Collinear Effective Theory (SCET) and in fixed-order perturbation theory. Oriented event-shapes are distributions of event-shape variables which are differential on the angle theta(T) that the thrust axis forms with the electron-positron beam. We show that at any order in perturbation theory and for any event shape, only two angular structures can appear: F-0 = 3/8 (1+cos(2) theta(T)) and F-1 = (1 – 3 cos(2) theta(T)). When integrating over theta(T) to recover the more familiar event-shape distributions, only F-0 survives. The validity of our proof goes beyond perturbation theory, and hence only these two structures are present at the hadron level. The proof also carries over massive particles. Using SCET techniques we show that singular terms can only arise in the F-0 term. Since only the hard function is sensitive to the orientation of the thrust axis, this statement applies also for recoil-sensitive variables such as Jet Broadening. We show how to carry out resummation of the singular terms at (NLL)-L-3 for Thrust, Heavy-Jet Mass, the sum of the Hemisphere Masses and C-parameter by using existing computations in SCET. We also compute the fixed-order distributions for these event-shapes at O(alpha(S)) analytically and at O(alpha(2)(S)) with the program Event2.  
  Address [Mateu, Vicent; Rodrigo, German] Univ Valencia, Consejo Super Invest Cient, Inst Fis Corpuscular, E-46980 Paterna, Valencia, Spain, Email: mateu@ific.uv.es;  
  Corporate Author Thesis (up)  
  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:000326699400001 Approved no  
  Is ISI yes International Collaboration no  
  Call Number IFIC @ pastor @ Serial 1675  
Permanent link to this record
 
 
Author Sborlini, G.F.R.; de Florian, D.; Rodrigo, G. url  doi
openurl 
  Title Double collinear splitting amplitudes at next-to-leading order Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 01 Issue 1 Pages 018 - 55pp  
  Keywords NLO Computations; Hadronic Colliders  
  Abstract We compute the next-to-leading order (NLO) QCD corrections to the 1 -> 2 splitting amplitudes in different dimensional regularization (DREG) schemes. Besides recovering previously known results, we explore new DREG schemes and analyze their consistency by comparing the divergent structure with the expected behavior predicted by Catani's formula. Through the introduction of scalar-gluons, we show the relation among splittings matrices computed using different schemes. Also, we extended this analysis to cover the double collinear limit of scattering amplitudes in the context of QCD+QED.  
  Address [Sborlini, German F. R.; de Florian, Daniel] Univ Buenos Aires, FCEyN, Dept Fis, RA-1428 Buenos Aires, Argentina, Email: gfsborlini@df.uba.ar;  
  Corporate Author Thesis (up)  
  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:000329617800009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1698  
Permanent link to this record
 
 
Author Davesne, D.; Pastore, A.; Navarro, J. url  doi
openurl 
  Title Fitting (NLO)-L-3 pseudo-potentials through central plus tensor Landau parameters Type Journal Article
  Year 2014 Publication Journal of Physics G Abbreviated Journal J. Phys. G  
  Volume 41 Issue 6 Pages 065104 - 12pp  
  Keywords Landau parameters; (NLO)-L-3; phenomenological interactions; fitting methods  
  Abstract Landau parameters determined from phenomenological finite-range interactions are used to get an estimation of next-to-next-to-next-to-leading order ((NLO)-L-3) pseudo-potentials parameters. The parameter sets obtained in this way are shown to lead to consistent results concerning saturation properties. The uniqueness of this procedure is discussed, and an estimate of the error induced by the truncation at (NLO)-L-3 is given.  
  Address [Davesne, D.] Univ Lyon, F-69622 Lyon, France, Email: davesne@inpl.in2p3.fr  
  Corporate Author Thesis (up)  
  Publisher Iop Publishing Ltd Place of Publication Editor  
  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0954-3899 ISBN Medium  
  Area Expedition Conference  
  Notes WOS:000338425100009 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1838  
Permanent link to this record
 
 
Author Campanario, F.; Kerner, M.; Ninh, D.L.; Zeppenfeld, D. url  doi
openurl 
  Title Next-to-leading order QCD corrections to ZZ production in association with two jets Type Journal Article
  Year 2014 Publication Journal of High Energy Physics Abbreviated Journal J. High Energy Phys.  
  Volume 07 Issue 7 Pages 148 - 14pp  
  Keywords NLO Computations; Hadronic Colliders  
  Abstract We present a calculation of next-to-leading order QCD corrections to QCD-induced ZZ production in association with two jets at hadron colliders. Both Z bosons decay leptonically with all off-shell effects, virtual photon contributions and spin-correlation effects fully taken into account. This process is an important background to weak boson scattering and to searches for signals of new physics beyond the Standard Model. As expected, the next-to-leading order corrections reduce significantly the scale uncertainty and show a non-trivial phase space dependence in kinematic distributions. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO.  
  Address [Campanario, Francisco] Univ Valencia, CSIC, Div Theory, IFIC, E-46980 Valencia, Spain, Email: francisco.campanario@ific.uv.es;  
  Corporate Author Thesis (up)  
  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:000340051900001 Approved no  
  Is ISI yes International Collaboration yes  
  Call Number IFIC @ pastor @ Serial 1882  
Permanent link to this record
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