arXiv subjects

Francisco Campanario

Publications and source records attributed to Francisco Campanario.

At least 37 records · Page 2Linked to original sources

arXiv2014

Higgs boson CP-properties of the gluonic contributions in Higgs plus three jet production via gluon fusion at the LHC

In high energy hadronic collisions, a general CP-violating Higgs boson $Φ$ with accompanying jets can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. In this letter we study the dominant sub-channel $ gg \to Φggg$ of the gluon fusion production process with triple real emission corrections at order $α_s^5$. We go beyond the heavy top limit approximation and include the full mass dependence of the top- and bottom-quark contributions. Furthermore, we show within a toy-model scenario that bottom-quark loop contributions in combination with large values of $\tan β$ can modify visibly the differential distributions sensitive to $\mathcal{CP}$-measurements of the Higgs boson particle.

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arXiv2014

Next-to-leading order QCD corrections to $W^+W^+$ and $W^-W^-$ production in association with two jets

We present a study of $W^+W^+jj$ and $W^-W^-jj$ production including leptonic decays in hadron-hadron collisions. The full electroweak and QCD induced contributions and their interferences are calculated at leading order. We find that, for inclusive cuts, the interference effects can be large if the jets are produced with large transverse momentum where, however, the production rate is suppressed. We also discuss the vector-boson-fusion (VBF) cuts and show the validity of the VBF approximation. The NLO QCD corrections to the QCD-induced channels are also calculated. Compared to the previous calculation, we allow the intermediate $W$ bosons to be off-shell. For on-shell $W$ production, we obtain an excellent agreement with previous results. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO.

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arXiv2014

Next-to-leading order QCD corrections to $W γ$ production in association with two jets

The QCD-induced $W^\pm γ$ production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonicly and full off-shell and finite width effects as well as spin correlations are taken into account. These processes are important backgrounds to beyond Standard Model physics searches and also relevant to test the nature of the quartic gauge couplings of the Standard Model. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence. Our code will be publicly available as part of the parton level Monte Carlo program VBFNLO.

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arXiv2013

WW production at high transverse momenta beyond NLO

Pair production of W gauge bosons is an important process at the LHC entering many experimental analyses, both as background in new-physics searches or Higgs measurements and as signal in precision studies and tests of the Standard Model. Therefore, accurate predictions for this class of processes are of great interest in order to exploit the full potential of LHC measurements. We use the LoopSim method to combine NLO QCD results for WW and WW+jet, as well as the loop-squared gluon-fusion contribution, to obtain approximate NNLO predictions for WW production. The cross sections are calculated with VBFNLO and include leptonic decays of the W bosons as well as finite-width and off-shell effects. We find that the size of the additional corrections beyond NLO can be significant and well outside of the NLO error bands given by renormalization and factorization scale variation. Applying a jet veto, we observe further negative corrections at NNLO, which we relate to the presence of large Sudakov logarithms.

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arXiv2013

NLO QCD Corrections to Electroweak Higgs Boson Plus Three Jet Production at the LHC

The implementation of the full next-to-leading order (NLO) QCD corrections to electroweak Higgs boson plus three jet production at hadron colliders such as the LHC within the Matchbox NLO framework of the Herwig++ event generator is discussed. We present numerical results for integrated cross sections and kinematic distributions.

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arXiv2013

NLO QCD corrections to WZjj production at the LHC

We present a summary of the first calculation of NLO QCD corrections to WZjj production with leptonic decays at the LHC. Our results show that the next-to-leading order corrections reduce significantly the scale uncertainties.

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arXiv2013

W γ production in vector boson fusion at NLO in QCD

The next-to-leading order QCD corrections to W gamma production in association with two jets via vector boson fusion are calculated, including the leptonic decay of the W with full off-shell effects and spin correlations. The process lends itself to a test of quartic gauge couplings. The next-to-leading order corrections reduce the scale uncertainty significantly and show a non-trivial phase space dependence.

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arXiv2013

Di-boson and Tri-boson production at the LHC

The status of di-boson and tri-boson production is shortly review. Using the VBFNLO and the LOOPSIM package, approximated results at NNLO QCD are given for WZ production. Results for waa + jet at NLO QCD are also shown.

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arXiv2013

Higgs boson production in association with three jets via gluon fusion at the LHC: Gluonic contributions

Higgs production in association with three jets via gluon fusion (GF) is an important channel for the measurement of the CP-properties of the Higgs particle at the LHC. In this letter, we go beyond the heavy top effective theory approximation and include at LO the full mass dependence of the top- and bottom-quark contributions. We consider the dominant sub-channel gg -> H ggg which involves the manipulation of massive rank-5 hexagon integrals. Furthermore, we present results for several differential distributions and show deviations from the effective theory as large as 100% at high pT for light Higgs masses.

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arXiv2013

WZ production in association with two jets at NLO in QCD

We report on the calculation of $W^\pm Zjj$ production with leptonic decays at hadron-hadron colliders at next-to-leading order in QCD. These processes are important both to test the quartic gauge couplings of the Standard Model and because they constitute relevant backgrounds to beyond standard model physics searches. Our results show that the next-to-leading order corrections reduce significantly the scale uncertainties and have a non-trivial phase space dependence.

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arXiv2012

ZZ+jet production via gluon fusion at the LHC

Pair production of Z bosons in association with a hard jet is an important background for Higgs particle or new physics searches at the LHC. The loop-induced gluon-fusion process gg > ZZg contributes formally only at the next-to-next-to-leading order. Nevertheless, it can get enhanced by the large gluon flux at the LHC, and thus should be taken into account in relevant experimental searches. We provide the details and results of this calculation, which involves the manipulation of rank-5 pentagon integrals. Our results show that the gluon-fusion process can contribute more than 10% to the next-to-leading order QCD result and increases the overall scale uncertainty. Moreover, interference effects between Higgs and non-Higgs contributions can become large in phase-space regions where the Higgs is far off-shell.

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arXiv2012

WZ production beyond NLO for high-pT observables

We use the LoopSim and VBFNLO packages to investigate a merged sample of partonic events that is accurate at NLO in QCD simultaneously for the WZ and WZ+jet production processes. In certain regions of phase space such a procedure is expected to account for the dominant part of the NNLO QCD corrections to the WZ production process. For a number of commonly used experimental observables, we find that these corrections are substantial, in the 30-100% range, and in some cases their inclusion can reduce scale uncertainties by a factor of two. As in the underlying VBFNLO calculations, we include the leptonic decays of the vector bosons and all off-shell and finite-width effects.

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arXiv2011

Results in Precision Multiboson+Jet Phenomenology

We review recent results in precision multiboson+jet phenomenology at the LHC. We discuss strategies how to compute these processes at NLO QCD and examine the impact of the perturbative corrections on the expected phenomenology, especially in the context of anomalous gauge boson couplings searches.

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arXiv2011

Precise predictions for W γγ+jet production at hadron colliders

In this letter we report on a calculation of W gamma gamma + jet production at next-to-leading order QCD. We include the leptonic decays of the W and take into account all off-shell and finite width effects. This is the first computation which falls into the category of triboson+jet production at next-to-leading order QCD. In total we find sizable corrections with nontrivial phase space dependencies. Therefore, our results are important for phenomenological analyses such as the extraction of anomalous electroweak quartic couplings from inclusive hadron collider data.

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arXiv2011

Towards pp -> VVjj at NLO QCD: Bosonic contributions to triple vector boson production plus jet

In this work, some of the NLO QCD corrections for pp -> VVjj + X are presented. A program in Mathematica based on the structure of FeynCalc which automatically simplifies a set of amplitudes up to the hexagon level of rank 5 has been created for this purpose. We focus on two different topologies. The first involves all the virtual contributions needed for quadruple electroweak vector boson production, i.e. pp -> VVVV + X. In the second, the remaining "bosonic" corrections to electroweak triple vector boson production with an additional jet (pp -> VVV j + X) are computed. We show the factorization formula of the infrared divergences of the bosonic contributions for VVVV and VVVj production with V=(W,Z,gamma). Stability issues associated with the evaluation of the hexagons up to rank 5 are studied. The CPU time of the FORTRAN subroutines rounds the 2 milliseconds and seems to be competitive with other more sophisticated methods. Additionally, in Appendix A the master equations to obtain the tensor coefficients up to the hexagon level in the external momenta convention are presented including the ones needed for small Gram determinants.

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arXiv2011

Precise predictions for (non-standard) W+photon+jet production

We report on a detailed investigation of the next-to-leading order (NLO) QCD corrections to $Wγ$+jet production at the Tevatron and the LHC using a fully-flexible parton-level Monte Carlo program. We include the full leptonic decay of the $W$, taking into account all off-shell and finite width effects, as well as non-standard $WWγ$ couplings. We find particularly sizable corrections for the currently allowed parameter range of anomalous couplings imposed by LEP data. In total the NLO differential distributions reveal a substantial phase space dependence of the corrections, leaving considerable sensitivity to anomalous couplings beyond scale uncertainty at large momentum transfers in the anomalous vertex.

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arXiv2010

Gluon-fusion contributions to Phi + 2 Jet production

In high energy hadronic collisions a scalar or pseudoscalar Higgs boson, Phi=H,A, can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. We here consider double real emission corrections to Phi=A production, which lead to a Higgs plus two-jet final state, at order alpha_s^4. Full quark mass effects are considered in the calculation of scattering amplitudes for the CP-odd Higgs boson A, as induced by quark triangle-, box- and pentagon-diagrams. They complement the analogous results for a CP-even Higgs boson H in Ref.[1]. Interference effects between loops with top and bottom quarks as well as between CP-even and CP-odd couplings of the heavy quarks are fully taken into account.

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arXiv2010

QCD corrections to non-standard WZ+jet production with leptonic decays at the LHC

We discuss the impact of anomalous WW$γ$ and WWZ couplings on WZ+jet production at next-to-leading order QCD, including full leptonic decays of the electroweak gauge bosons. While the inclusive hadronic cross sections do not exhibit any particular sensitivity to anomalous couplings once the residual QCD scale uncertainties are taken into account, the transverse momentum distributions show substantial deviations from the Standard Model, provided that the anomalous vertices are probed at large enough momentum transfers.

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