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Related papers: Two-loop virtual QCD correction to the B -> X_s l+…

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We present the status of on-going efforts to compute the two-loop virtual corrections to $pp\to t\bar{t} j$ in the leading colour approximation. We review the recent study of the master integrals and their differential equations and present…

High Energy Physics - Phenomenology · Physics 2024-05-20 Simon Badger

We compute the amplitudes for the two-body decay of $B$ mesons into longitudinally polarized light vector mesons at next-to-leading order in QCD. We give the explicit expressions in QCD factorization for all 34 transitions of a heavy-light…

High Energy Physics - Phenomenology · Physics 2008-10-02 Matthaeus Bartsch , Gerhard Buchalla , Christina Kraus

I report on three recent topics from the field of two-body nonleptonic decays of $B_{(s)}$ mesons. The computation of two-loop NNLO corrections to the leading penguin amplitudes in QCD factorisation, puzzles that have emerged in…

High Energy Physics - Phenomenology · Physics 2022-04-14 Tobias Huber

The two--loop ${\cal O}(\alpha_s G_F m_t^2)$ corrections to the $b\bar b$ decay rate of the Standard Model Higgs boson as well as its production via $e^+e^- \to ZH$ will be presented. These QCD corrections are obtained by using a low-energy…

High Energy Physics - Phenomenology · Physics 2007-05-23 Michael Spira

Higher-order corrections to the MSSM Higgs-boson masses are desirable for accurate predictions currently testable at the LHC. By comparing the prediction with the measured value of the discovered Higgs signal, viable parameter regions can…

High Energy Physics - Phenomenology · Physics 2020-12-11 Sophia Borowka , Sebastian Paßehr , Georg Weiglein

We present a leading colour computation of the double virtual contributions to top-quark pair production in association with a jet at a hadron collider at next-to-next-to-leading order in QCD. The finite remainders of the two-loop…

High Energy Physics - Phenomenology · Physics 2026-05-15 Simon Badger , Matteo Becchetti , Colomba Brancaccio , Michał Czakon , Heribertus Bayu Hartanto , Rene Poncelet , Simone Zoia

In this talk, a wide range of recently published results on rare B decays from BABAR and Belle are covered. The decays of B->XsGamma, B->K(*)l+l-, and lepton-number violation in B decays are measured for new physics searches.

High Energy Physics - Experiment · Physics 2019-08-13 Liang Sun

We present the analytic calculation of the two-loop QCD corrections to the decay width of a Higgs boson into a photon and a $Z$ boson. The calculation is carried out using integration-by-parts identities for the reduction to master…

High Energy Physics - Phenomenology · Physics 2015-09-30 R. Bonciani , V. Del Duca , H. Frellesvig , J. M. Henn , F. Moriello , V. A. Smirnov

We report on the first complete computation of the mixed QCD$-$electroweak (EW) corrections to the neutral-current Drell$-$Yan process. Superseding previously applied approximations, our calculation provides the first result at this order…

High Energy Physics - Phenomenology · Physics 2022-01-19 Roberto Bonciani , Luca Buonocore , Massimiliano Grazzini , Stefan Kallweit , Narayan Rana , Francesco Tramontano , Alessandro Vicini

We derive the triply differential spectrum for the inclusive rare decay B -> Xs l+ l- in the shape function region, in which Xs is jet-like with $mX^2 \lesssim mb \Lambda_QCD$. Experimental cuts make this a relevant region. The perturbative…

High Energy Physics - Phenomenology · Physics 2008-11-26 Keith S. M. Lee , Iain W. Stewart

We present an algorithm to compute arbitrary multi-loop massive Feynman diagrams in the region where the typical energy scale \sqrt{s} is much larger than the typical mass scale M, i.e. s>>M^2, while various different energy and mass…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , S. Pozzorini

We compute the full three-loop coefficient functions for the structure functions F_2 and F_L in massless perturbative QCD. The results for F_L complete the next-to-next-to-leading order description of unpolarized electromagnetic…

High Energy Physics - Phenomenology · Physics 2008-11-26 J. A. M. Vermaseren , A. Vogt , S. Moch

We show that the calculation of L-loop Feynman integrals in D dimensions can be reduced to a series of matrix multiplications in D times L dimensions. This gives rise to a new type of expansions for the critical exponents in three…

High Energy Physics - Theory · Physics 2009-10-31 Hagen Kleinert

A model-independent analysis for the exclusive, rare B -> K^* l^+ l^- decay is presented. Systematically studied are the experimentally measured quantities, such as, branching ratio, forward-backward asymmetry, longitudinal polarization of…

High Energy Physics - Phenomenology · Physics 2011-03-23 T. M. Aliev , C. S. Kim , Y. G. Kim

We study the radiative decay B -> gamma l nu_l in the framework of QCD factorization. We demonstrate explicitly that, in the heavy-quark limit and at one-loop order in perturbation theory, the amplitude does factorize, i.e. that it can be…

High Energy Physics - Phenomenology · Physics 2009-10-09 S. Descotes-Genon , C. T. Sachrajda

For the calculation of multi-loop Feynman integrals, a novel numerical method, the Direct Computation Method (DCM) is developed. It is a combination of a numerical integration and a series extrapolation. In principle, DCM can handle…

High Energy Physics - Phenomenology · Physics 2012-01-31 K. Kato , E. de Doncker , N. Hamaguchi , T. Ishikawa , T. Koike , Y. Kurihara , Y. Shimizu , F. Yuasa

The angular analysis of exclusive rare B-meson decays via intermediate vector mesons V into 4-body final states of two pseudo-scalars P_1, P_2 and a pair of light leptons l = e, mu offers a large set of observables. They can be used to test…

High Energy Physics - Phenomenology · Physics 2015-05-28 Christoph Bobeth , Gudrun Hiller , Danny van Dyk

We update the branching ratios for the inclusive decays $B\to X_s \ell^+ \ell^-$ and the exclusive decays $B\to (K,K^*) \ell^+ \ell^-$, with $\ell=e, \m$, in the standard model by including the explicit $O(\a_s)$ and $\Lambda_{\hbox{\tiny…

High Energy Physics - Phenomenology · Physics 2011-01-05 A. Ali , E. Lunghi , C. Greub , G. Hiller

The decay $B \to X_s \gamma$ is studied at the Next to Leading Order in QCD in a class of models containing at least two Higgs doublets and with only one charged Higgs boson non-decoupled at low-energy. The two-loop matching condition is…

High Energy Physics - Phenomenology · Physics 2011-01-05 F. Borzumati , C. Greub

We present a full account of the two-loop electroweak, two-photon mediated short-distance dispersive $K_L \to\mu^+\mu^-$ decay amplitude. QCD corrections change the sign of this amplitude and reduce it by an order of magnitude. Thus, the…

High Energy Physics - Phenomenology · Physics 2011-09-13 J. O. Eeg , K. Kumericki , I. Picek