Agustin Sabio Vera

Universidad Autónoma de Madrid, Madrid, Madrid, Spain

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Publications (54)161.82 Total impact

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    Agustin Sabio Vera, Miguel A. Vazquez-Mozo
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    ABSTRACT: The subleading corrections to factorization theorems for soft bremsstrahlung in nonabelian gauge theories and gravity are investigated. Building on recent results, we write the action of the angular momentum operators on scattering amplitudes as derivatives with respect to the Mandelstam invariants to uncover a double copy structure in the contribution of the soft graviton to the amplitude, both in the leading term and the first correction. Using our approach, we study Gribov's theorem as extended to nonabelian gauge theories and gravity by Lipatov, and find that subleading corrections can be obtained from those to Low's theorem by dropping the terms with derivatives with respect to the center-of-mass energy, which are suppressed at high energies. In this case, the emitted gravitons are not necessarily soft.
    Journal of High Energy Physics 12/2014; 2015(3). DOI:10.1007/JHEP03(2015)070 · 6.22 Impact Factor
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    ABSTRACT: We present the calculation of the forward jet vertex associated to a rapidity gap (coupling of a hard pomeron to the jet) in the BFKL formalism at next-to-leading order (NLO). Real emission contributions are computed via Lipatov's effective action. The NLO jet vertex turns out to be finite within collinear factorization and allows, together with the NLO non-forward gluon Green's function, to perform NLO studies of jet production in diffractive events (e.g. Mueller-Tang dijets).
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    ABSTRACT: In this talk we review the work in [1,2,3] where we have studied the applicability of the color-kinematics duality to the scattering of two distinguishable scalar matter particles with one gluon emission in QCD, or one graviton emission in Einstein gravity. We have shown that the duality works well in the Regge limit under two different extensions of the gauge theory: the introduction of a new scalar contact interaction and the relaxation of the distinguishability of the scalars. Both modifications correspond to theories obtained by dimensional reduction from higher-dimensional pure gauge theories.
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    ABSTRACT: In this note we study the applicability of the color-kinematics duality to the scattering of two distinguishable scalar matter particles with gluon emission in QCD, or graviton emission in Einstein gravity. Previous analysis suggested that direct use of the Bern-Carrasco-Johansson double-copy prescription to matter amplitudes do not reproduce the gravitational amplitude in multi-Regge kinematics. However, minimal extensions of the calculation cure this obstacle. Here we present two approaches: introduction of a scalar contact interaction, or relaxing distinguishability of the scalars. In both cases new diagrams allow for a full reconstruction of the correct Regge limit on the gravitational side. Both modifications correspond to theories obtained by dimensional reduction from higher-dimensional gauge theories.
    Journal of High Energy Physics 07/2013; DOI:10.1007/JHEP10(2013)215 · 6.22 Impact Factor
  • 04/2013; DOI:10.1063/1.4802102
  • M. Hentschinski, Agustin Sabio Vera, Clara Salas
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    ABSTRACT: We show that it is possible to describe the effective Pomeron intercept, determined from the HERA Deep Inelastic Scattering data at small values of Bjorken x, using next-to-leading order BFKL evolution together with collinear improvements. To obtain a good description over the whole range of Q2 we use a non-Abelian physical renormalization scheme with BLM optimal scale, combined with a parametrization of the running coupling in the infrared region.
    04/2013; DOI:10.1063/1.4802116
  • 04/2013;
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    Martin Hentschinski, Agustín Sabio Vera, Clara Salas
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    ABSTRACT: We show that it is possible to describe the effective Pomeron intercept, determined from the HERA deep inelastic scattering data at small values of Bjorken x, by using next-to-leading order Balitsky-Fadin-Kuraev-Lipatov evolution together with collinear improvements. To obtain a good description over the whole range of Q2, we use a non-Abelian physical renormalization scheme with the Brodsky-Lepage-Mackenzie optimal scale, combined with a parametrization of the running coupling in the infrared region.
    Physical Review Letters 01/2013; 110(4). DOI:10.1103/PhysRevLett.110.041601 · 7.73 Impact Factor
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    Martin Hentschinski, Agustin Sabio Vera, Clara Salas
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    ABSTRACT: We present a detailed description of the Q(2) and x dependence of the structure functions F-2 and F-L as extracted from the deep inelastic scattering data at HERA in the small Bjorken x region. Making use of a collinearly improved Balitsky-Fadin-Kuraev-Lipatov equation at next-to-leading order and a treatment of the running of the coupling using non-Abelian physical renormalization together with the Brodsky-Lepage-Mackenzie scale choice allows us to reach low values of Q(2). We also provide some predictions for future lepton-hadron colliders. DOI: 10.1103/PhysRevD.87.076005
    Physical review D: Particles and fields 01/2013; 87(7). DOI:10.1103/PhysRevD.87.076005 · 4.86 Impact Factor
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    ABSTRACT: We determine both real and virtual next-to-leading order corrections to the gluon induced forward jet vertex, from the high energy effective action proposed by Lipatov. For these calculations we employ the same regularization and subtraction formalism developed in our previous work on the quark-initiated vertex. We find agreement with previous results in the literature.
    Physical review D: Particles and fields 12/2012; 87(7). DOI:10.1103/PhysRevD.87.076009 · 4.86 Impact Factor
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    ABSTRACT: We investigate tree-level five-point amplitudes in scalar-QCD expressed in terms of Sudakov variables and find the equivalent "gravitational" counterparts using the color-kinematics duality proposed by Bern, Carrasco, and Johannson. Taking the multi-Regge limit in the gravitational amplitudes, we show that those pieces in the coupling of two reggeized gravitons to one on-shell graviton directly stemming from the double copy of the vertex for two reggeized gluons to one on-shell gluon are universal and properly reproduced by the duality.
    Journal of High Energy Physics 12/2012; 2013(4). DOI:10.1007/JHEP04(2013)086 · 6.22 Impact Factor
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    Jochen Bartels, Lev N. Lipatov, Agustin Sabio Vera
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    ABSTRACT: We study the interplay between graviton reggeization and double-logarithmic in energy contributions to four-graviton scattering in theories with and without supersymmetry. Predictions to all orders in the gravitational coupling are given for these double-logarithms. As the number of supersymmetries grows these terms generate a convergent behaviour for the amplitudes at very high energies. At two-loop level, we find agreement with previous exact results for N=8 supergravity and with those of Boucher-Veronneau and Dixon, who studied the N=4,5,6 supergravities using a conjectured double-copy structure of gravity.
    Journal of High Energy Physics 08/2012; 2014(7). DOI:10.1007/JHEP07(2014)056 · 6.22 Impact Factor
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    ABSTRACT: Lipatov's high-energy effective action is a useful tool for computations in the Regge limit beyond leading order. Recently, a regularisation/subtraction prescription has been proposed that allows to apply this formalism to calculate next-to-leading order corrections in a consistent way. We illustrate this procedure with the computation of the gluon Regge trajectory at two loops.
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    ABSTRACT: We investigate dijet production at large rapidity separation in QCD and N = 4 SYM, showing that both theories give similar predictions for observables only sensitive to conformal properties of the scattering such as ratios of azimuthal angle correlations. Renormalization prescriptions are important in this comparison.
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    Martin Hentschinski, Agustín Sabio Vera
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    ABSTRACT: Real and virtual contributions to the quark-initiated forward jet vertex in QCD are calculated at next-to-leading logarithmic accuracy using Lipatov’s effective action, valid in the high-energy multi-Regge limit. A regularization of longitudinal divergencies is proposed which allows for the determination of jet observables. Agreement with previous results in the literature is found.
    Physical review D: Particles and fields 03/2012; 85(5). DOI:10.1103/PhysRevD.85.056006 · 4.86 Impact Factor
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    ABSTRACT: The five-point amplitude for the scattering of two distinct scalars with the emission of one graviton in the final state is calculated in exact kinematics for Einstein-Hilbert gravity. The result, which satisfies the Steinmann relations, is expressed in Sudakov variables, finding that it corresponds to the sum of two gauge invariant contributions written in terms of a new two scalar - two graviton effective vertex. A similar calculation is carried out in Quantum Chromodynamics (QCD) for the scattering of two distinct quarks with one extra gluon in the final state. The effective vertices which appear in both cases are then evaluated in the multi-Regge limit reproducing the well-known result obtained by Lipatov where the Einstein-Hilbert graviton emission vertex can be written as the product of two QCD gluon emission vertices, up to corrections to preserve the Steinmann relations.
    Journal of High Energy Physics 12/2011; 2012(3). DOI:10.1007/JHEP03(2012)005 · 6.22 Impact Factor
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    Alberto Romagnoni, Agustin Sabio Vera
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    ABSTRACT: A new mapping between the BFKL equation and Beisert's representation of the XXX Heisenberg ferromagnet with spin s = - 1/2 is given. The action of the Hamiltonian operator of a spin chain with SL(2) invariance on a symmetric double copy of a harmonic oscillator excited state is shown to be identical to the action of the BFKL Hamiltonian on the gluon Green function for the azimuthal-angle averaged forward scattering case. A natural mapping between the gluon Green function, discretized in virtuality space, and the double harmonic oscillator excited state emerges.
  • Martin Hentschinski, Agustin Sabio Vera
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    ABSTRACT: Ratios of azimuthal angle correlations for Mueller-Navelet jets are compared in QCD and N = 4 SYM. Such observables are well suited to study the effects of Moebius invariance in the Regge limit. The role of the renormalization prescription and the size of conformal contributions is addressed, showing that the BLM procedure best reproduces the N = 4 SYM results.
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    César Gómez, Johan Gunnesson, Agustín Sabio Vera
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    ABSTRACT: A dual conformal symmetry, analogous to the dual conformal symmetry observed for the scattering amplitudes of N=4 Super Yang–Mills theory, is identified in the Regge limit of QCD. Combined with the original two-dimensional conformal symmetry of the theory, this dual symmetry can potentially explain the integrability of the BFKL Hamiltonian. We also give evidence that the symmetry survives when a subset of unitarity corrections are taken into account by studying briefly the non-planar 2 to m reggeon transition vertices.
    Physics Letters B 06/2010; 690(1-690):78-82. DOI:10.1016/j.physletb.2010.04.077 · 6.02 Impact Factor

Publication Stats

538 Citations
161.82 Total Impact Points

Institutions

  • 2010–2013
    • Universidad Autónoma de Madrid
      • Department of Theoretical physics
      Madrid, Madrid, Spain
  • 2006–2012
    • CERN
      • Physics Department (PH)
      Genève, Geneva, Switzerland
    • Kennesaw State University
      Кеннесо, Georgia, United States
  • 2004–2005
    • University of Hamburg
      • II. Institut für Theoretische Physik
      Hamburg, Hamburg, Germany
  • 2000–2004
    • University of Cambridge
      • Department of Physics: Cavendish Laboratory
      Cambridge, England, United Kingdom
  • 1998–1999
    • The University of Manchester
      • School of Physics and Astronomy
      Manchester, England, United Kingdom