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Related papers: One-loop phi-MHV amplitudes using the unitarity bo…

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We calculate the corrections to the Higgs wave-function renormalization constant arising from modified cubic, quartic, and quintic Higgs self-couplings up to the two-loop level. Using our analytic results, we derive two-dimensional…

High Energy Physics - Phenomenology · Physics 2025-05-28 Ulrich Haisch , Aparna Sankar , Giulia Zanderighi

We develop an algorithm of polynomial complexity for evaluating one-loop amplitudes with an arbitrary number of external particles. The algorithm is implemented in the Rocket program. Starting from particle vertices given by Feynman rules,…

High Energy Physics - Phenomenology · Physics 2009-05-05 W. T. Giele , G. Zanderighi

We compute renormalized vertices of the 125 GeV Higgs boson $h$ with the weak gauge bosons ($hVV$), fermions ($hf\bar{f}$) and itself ($hhh$) in the Georgi-Machacek model at one-loop level. The renormalization is performed based on the…

High Energy Physics - Phenomenology · Physics 2018-08-01 Cheng-Wei Chiang , An-Li Kuo , Kei Yagyu

We study constraints on one-loop neutral naturalness at the LHC by considering gluon partners which are required to ameliorate the tuning in the Higgs mass-squared arising at two loops. This is done with a simple orbifold model of folded…

High Energy Physics - Phenomenology · Physics 2022-09-09 Tony Gherghetta , Minh Nguyen , Zoe Thomas

We discuss the amplitudes describing N-gluon scattering in type I superstring theory, on a disk world-sheet. After reviewing the general structure of amplitudes and the complications created by the presence of a large number of vertices at…

High Energy Physics - Theory · Physics 2008-11-26 Stephan Stieberger , Tomasz R. Taylor

We study the factorisation properties of one-loop scattering amplitudes in the triple collinear limit and extract the universal splitting amplitudes for processes initiated by a gluon. The splitting amplitudes are derived from the analytic…

High Energy Physics - Phenomenology · Physics 2015-07-20 Simon Badger , Francesco Buciuni , Tiziano Peraro

We examine the constraints on the trilinear Higgs coupling $\lambda$ that originate from associated ($Vh$) and vector boson fusion (VBF) Higgs production in $pp$ collisions in the context of the Standard Model effective field theory. The…

High Energy Physics - Phenomenology · Physics 2017-10-12 Wojciech Bizon , Martin Gorbahn , Ulrich Haisch , Giulia Zanderighi

We consider the multi-collinear limit of multi-gluon QCD amplitudes at tree level. We use the MHV rules for constructing colour ordered tree amplitudes and the general collinear factorization formula to derive timelike splitting functions…

High Energy Physics - Phenomenology · Physics 2009-11-11 T. G. Birthwright , E. W. N. Glover , V. V. Khoze , P. Marquard

We calculate the four-top quark operator contributions to Higgs production via gluon fusion in the Standard Model Effective Field Theory. The four-top operators enter for the first time via two-loop diagrams. Due to their chiral structure…

High Energy Physics - Phenomenology · Physics 2024-03-26 Stefano Di Noi , Ramona Gröber , Gudrun Heinrich , Jannis Lang , Marco Vitti

We use an effective field theory (EFT) which includes all possible gluon-Higgs dimension-5 and dimension-7 operators to study Higgs boson plus jet production in next-to-leading order QCD. The EFT sheds light on the effect of a finite top…

High Energy Physics - Phenomenology · Physics 2014-11-27 S. Dawson , I. M. Lewis , Mao Zeng

We present a calculation of the two-loop quark-squark-gluino contributions to pseudoscalar Higgs boson production via gluon fusion in the MSSM. We regularize the loop integrals using the Pauli-Villars method, and obtain explicit and compact…

High Energy Physics - Phenomenology · Physics 2011-09-02 G. Degrassi , S. Di Vita , P. Slavich

We revisit the hadronic production of the four-lepton final state, e^- e^+ \mu^- \mu^+, through the fusion of initial state gluons. This process is mediated by loops of quarks and we provide first full analytic results for helicity…

High Energy Physics - Phenomenology · Physics 2015-06-17 John M. Campbell , R. Keith Ellis , Ciaran Williams

We present a precise and efficient computation of the two-loop amplitudes entering the Higgs boson pair production process via gluon fusion. Our approach is based on the small-Higgs-mass expansion while keeping the full dependence on the…

High Energy Physics - Phenomenology · Physics 2021-09-29 Guoxing Wang , Yuxuan Wang , Xiaofeng Xu , Yongqi Xu , Li Lin Yang

We calculate the complete matrix of two-body scattering amplitudes for the scattering of longitudinally polarized gauge bosons $W_L^\pm$, $Z_L$ and Higgs bosons to two loops in the high-energy, heavy-Higgs limit $\sqrt{s}\gg M_H\gg M_W$.…

High Energy Physics - Phenomenology · Physics 2014-11-17 Peter N. Maher , Loyal Durand , Kurt Riesselmann

We compute the next-to-MHV one-loop n-gluon amplitudes in N=4 super-Yang-Mills theory. These amplitudes contain three negative-helicity gluons and an arbitrary number of positive-helicity gluons, and are the first infinite series of…

High Energy Physics - Theory · Physics 2010-04-06 Zvi Bern , Lance J. Dixon , David A. Kosower

A c++ implementation of the D_s-dimensional unitarity cut algorithm for the numerical evaluation of the virtual contribution to NLO QCD amplitudes is presented. The current version includes an arbitrary number of external gluons with…

High Energy Physics - Phenomenology · Physics 2008-12-17 A. Lazopoulos

In an extension of the Standard Model with one extra dimension and N=1 supersymmetry compactified on R^1/(Z_2 x Z'_2), we compute the Higgs boson decay width into two gluons, relevant to Higgs production in hadronic collisions. At one loop,…

High Energy Physics - Phenomenology · Physics 2009-11-07 Giacomo Cacciapaglia , Marco Cirelli , Giampaolo Cristadoro

The factorisation of QCD matrix elements in the limit of two external partons becoming collinear is described by process-independent splitting amplitudes, which can be expanded systematically in perturbation theory. Working in conventional…

High Energy Physics - Phenomenology · Physics 2015-06-23 Claude Duhr , Thomas Gehrmann , Matthieu Jaquier

We present an ansatz for all one-loop amplitudes in pure Einstein gravity for which the n external gravitons have the same outgoing helicity. These loop amplitudes, which are rational functions of the momenta, also arise in the quantization…

High Energy Physics - Theory · Physics 2010-11-15 Z. Bern , L. Dixon , M. Perelstein , J. S. Rozowsky

One and two-jet observables of dimension-7 Higgs-gluon coupling operators are studied as probes of possible deviations from the top-loop induced gluon-Higgs coupling. We discuss the case of both a scalar as well as a pseudo-scalar Higgs…

High Energy Physics - Phenomenology · Physics 2013-10-17 Robert V. Harlander , Tobias Neumann