Ignacio Fabre

Bio: Ignacio Fabre is an academic researcher from National University of General San Martín. The author has contributed to research in topics: Higgs boson & Quantum chromodynamics. The author has an hindex of 5, co-authored 7 publications receiving 204 citations. Previous affiliations of Ignacio Fabre include Mayo Clinic.

Les Houches 2019: Physics at TeV Colliders: Standard Model Working Group Report

Abstract: This Report summarizes the proceedings of the 2019 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments for high precision Standard Model calculations, (II) the sensitivity of parton distribution functions to the experimental inputs, (III) new developments in jet substructure techniques and a detailed examination of gluon fragmentation at the LHC, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, and (V) Monte Carlo event generator studies relating to PDF evolution and comparisons of important processes at the LHC.

QCD ⊕QED NNLO corrections to Drell-Yan production

Abstract: We compute the $\mathrm{QCD}\ifmmode\times\else\texttimes\fi{}\mathrm{QED}$ [$\mathcal{O}({\ensuremath{\alpha}}_{s}\ensuremath{\alpha})$] mixed and ${\mathrm{QED}}^{2}$ [$\mathcal{O}({\ensuremath{\alpha}}^{2})$] corrections to the production of an on-shell $Z$ boson in hadronic collisions. We obtain them by profiting from the calculation of the pure QCD terms after taking the corresponding Abelian limits. Therefore, we extend the available knowledge up to complete next-to-next-to-leading-order precision in $\mathrm{QCD}\ensuremath{\bigoplus}\mathrm{QED}$. We present explicit results for the perturbative coefficients and perform the phenomenological analysis at different collider energies with particular emphasis on the mixed corrections. We study the contribution from the different channels and discuss the scale dependence stabilization effect. We find that the contributions compete with the pure QCD NNLO ones under relevant kinematical conditions for the LHC, despite the fact that they are small, typically at the few per mille level.

Higgs boson pair production at NNLO in QCD including dimension 6 operators

Abstract: In this paper we present the computation of the Higgs boson pair production cross section, both inclusive as well as differential on the invariant mass distribution, at next-to-next-to-leading order (NNLO) in QCD including effects of new physics beyond the standard model. We parametrize the effects of new physics with the relevant dimension 6 operators in a standard model effective field theory (EFT) approach, and examine their phenomenology. The dependence of the NNLO K-factor on the EFT couplings is analysed, finding that, while rather flat for a number of EFT coefficients, it can considerable differ from the standard model value in some particular regions of the parameter space. We present explicit examples of (almost) degeneracy in the NNLO cross-section with respect to the anomalous couplings, showing that the invariant mass distribution has a much larger sensitivity to phenomena beyond the standard model and can be used as a tool to discriminate their effect.

Les Houches 2019: Physics at TeV Colliders: Standard Model Working Group Report

Abstract: This Report summarizes the proceedings of the 2019 Les Houches workshop on Physics at TeV Colliders. Session 1 dealt with (I) new developments for high precision Standard Model calculations, (II) the sensitivity of parton distribution functions to the experimental inputs, (III) new developments in jet substructure techniques and a detailed examination of gluon fragmentation at the LHC, (IV) issues in the theoretical description of the production of Standard Model Higgs bosons and how to relate experimental measurements, and (V) Monte Carlo event generator studies relating to PDF evolution and comparisons of important processes at the LHC.

Higgs boson pair production at NNLO in QCD including dimension 6 operators

Abstract: In this paper, we present the computation of the Higgs boson pair production cross section, both inclusive as well as differential on the invariant mass distribution, at next-to-next-to-leading order (NNLO) in QCD including effects of new physics beyond the standard model. We parametrize the effects of new physics with the relevant dimension 6 operators in a standard model effective field theory (EFT) approach and examine their phenomenology. The dependence of the NNLO $K$-factor on the EFT couplings is analysed, finding that, while rather flat for a number of EFT coefficients, it can considerably differ from the standard model value in some particular regions of the parameter space. We present explicit examples of (almost) degeneracy in the NNLO cross-section with respect to the anomalous couplings, showing that the invariant mass distribution has a much larger sensitivity to phenomena beyond the standard model and can be used as a tool to discriminate their effect.

Parton distributions for the LHC

Abstract: We present a preliminary set of updated NLO parton distributions. For the first time we have a quantitative extraction of the strange quark and antiquark distributions and their uncertainties determined from CCFR and NuTeV dimuon cross sections. Additional jet data from HERA and the Tevatron improve our gluon extraction. Lepton asymmetry data and neutrino structure functions improve the flavour separation, particularly constraining the down quark valence distribution.

Electron Ion Collider: The next QCD frontier

Abstract: Abstract.This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of workshops on EIC physics over the past decades and, in particular, the focused ten-week program on “Gluons and quark sea at high energies” at the Institute for Nuclear Theory in Fall 2010. It contains a brief description of a few golden physics measurements along with accelerator and detector concepts required to achieve them. It has been benefited profoundly from inputs by the users’ communities of BNL and JLab. This White Paper offers the promise to propel the QCD science program in the US, established with the CEBAF accelerator at JLab and the RHIC collider at BNL, to the next QCD frontier.

Higgs boson production at the LHC

Abstract: After the discovery at the LHC, the main goal of the Higgs boson measurements at ATLAS and CMS is to fully elucidate the nature of this new particle. In this contribution we will discuss the Higgs boson production and decay properties at the LHC and the main analyses which build the foundation for the current Higgs boson property measurements. Inclusive rates as well as differential measurements in the main bosonic and fermionic channels, and searches for rarer decay modes will be presented.

Next-to-leading order QCD predictions for W+3-jet distributions at hadron colliders

Abstract: U.S. Department of Energy (Contract Nos. DE-FG03-91ER40662, DE-AC02- 76SF00515, and DE-FC02-94ER40818)