Campanario, F., Kerner, M., Ninh, L. D., & Zeppenfeld, D. (2014). Z gamma production in association with two jets at next-to-leading order QCD. Eur. Phys. J. C, 74(9), 3085–7pp.
Abstract: Next-to-leading order QCD corrections to the QCD-induced pp -> l(+)l(-)gamma j j + X and pp -> <(nu)lover bar>(l)nu(l)gamma(jj) + X processes are presented. The latter is used to find an optimal cut to reduce the contribution of radiative photon emission off the charged leptons in the first channel. As expected, the scale uncertainties are significantly reduced at NLO and the QCD corrections are phase-space dependent and important for precise measurements at the LHC.
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Campanario, F., & Kubocz, M. (2014). Higgs boson CP-properties of the gluonic contributions in Higgs plus three jet production via gluon fusion at the LHC. J. High Energy Phys., 10(10), 173–16pp.
Abstract: in high energy hadronic collisions, a general CP-violating Higgs boson Phi with accompanying jets can be efficiently produced via gluon fusion, which is mediated by heavy quark loops. In this article, we study the dominant sub-channel gg -> ggg Phi of the gluon fusion production process with triple real emission corrections at order alpha(5)(s). We go beyond the heavy top-quark approximation and include the full mass dependence of the top- and bottom-quark contributions. Furthermore, in a specific model we demonstrate the features of our program and show the impact of bottom-quark loop contributions in combination with large values of tan beta on differential distributions sensitive to CP-rneasurements of the Higgs boson.
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Campanario, F., Kerner, M., Ninh, L. D., & Zeppenfeld, D. (2014). Next-to-leading order QCD corrections to Wgamma production in association with two jets. Eur. Phys. J. C, 74(5), 2882–9pp.
Abstract: The QCD-induced production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonically 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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Campanario, F., Kerner, M., Ninh, D. L., & Zeppenfeld, D. (2014). Next-to-leading order QCD corrections to ZZ production in association with two jets. J. High Energy Phys., 07(7), 148–14pp.
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.
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Campanario, F., Kerner, M., Ninh, L. D., & Zeppenfeld, D. (2014). Next-to-leading order QCD corrections to W+W+ and W-W- production in association with two jets. Phys. Rev. D, 89(5), 054009–11pp.
Abstract: 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 cuts and show the validity of the vector-boson-fusion approximation. The next-to-leading order 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 VBFLNO.
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Campanario, F., Rauch, M., & Sapeta, S. (2014). W+W- production at high transverse momenta beyond NLO. Nucl. Phys. B, 879, 65–79.
Abstract: 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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Campanario, F., Czyz, H., Gluza, J., Gunia, M., Riemann, T., Rodrigo, G., et al. (2014). Complete QED NLO contributions to the reaction e(+)e(-) -> mu(+)mu(-)gamma and their implementation in the event generator PHOKHARA. J. High Energy Phys., 02(2), 114–27pp.
Abstract: KLOE and Babar have an observed discrepancy of 2% to 5% in the invariant pion pair production cross section. These measurements are based on approximate NLO mu(+)mu(-)gamma cross section predictions of the Monte Carlo event generator PHOKHARA7.0. In this article, the complete NLO radiative corrections to mu(+)mu(-)gamma production are calculated and implemented in the Monte Carlo event generator PHOKHARA9.0. Numerical reliability is guaranteed by two independent approaches to the real and the virtual corrections. The novel features include the contribution of pentagon diagrams in the virtual corrections, which form a gauge-invariant set when combined with their box diagram partners. They may contribute to certain distributions at the percent level. Also the real emission was complemented with two-photon final state emission contributions not included in the generator PHOKHARA7.0. We demonstrate that the numerical influence reaches, for realistic charge-averaged experimental setups, not more than 0.1% at KLOE and 0.3% at BaBar energies. As a result, we exclude the approximations in earlier versions of PHOKHARA as origin of the observed experimental discrepancy.
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Campanario, F., Kaiser, N., & Zeppenfeld, D. (2014). W gamma production in vector boson fusion at NLO in QCD. Phys. Rev. D, 89(1), 014009–5pp.
Abstract: 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 nontrivial phase space dependence.
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Campanario, F., Figy, T. M., Platzer, S., & Sjodahl, M. (2013). Electroweak Higgs Boson Plus Three Jet Production at Next-to-Leading-Order QCD. Phys. Rev. Lett., 111(21), 211802–4pp.
Abstract: We calculate next-to-leading order (NLO) QCD corrections to electroweak Higgs boson plus three jet production. Both vector boson fusion (VBF) and Higgs-strahlung type contributions are included along with all interferences. The calculation is implemented within the MATCHBOX NLO framework of the HERWIG++ event generator.
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Campanario, F., & Kubocz, M. (2013). Higgs-boson production in association with three jets via gluon fusion at the LHC: Gluonic contributions. Phys. Rev. D, 88(5), 054021–5pp.
Abstract: Higgs production in association with three jets via gluon fusion is an important channel for the measurement of the CP properties of the Higgs particle at the LHC. In this paper, 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 subchannel gg -> Hggg 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 p(T) for light Higgs masses.
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