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Related papers: Approximate NNLO Threshold Resummation in Heavy Fl…

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Within NRQCD factorization framework, in this work we compute, at the lowest order in velocity expansion, the next-to-leading-order (NLO) perturbative corrections to the short-distance coefficients associated with heavy quark fragmentation…

High Energy Physics - Phenomenology · Physics 2021-07-28 Feng Feng , Yu Jia , Wen-Long Sang

We present an extension of the antenna subtraction formalism at NLO to include massive final state fermions. The basic ingredients to the subtraction terms, the NLO massive final-final antenna functions are derived and integrated over the…

High Energy Physics - Phenomenology · Physics 2009-07-22 A. Gehrmann-De Ridder , M. Ritzmann

We study the electromagnetic on-shell form factor of quarks in massless perturbative QCD. We derive the complete pole part in dimensional regularization at three loops, and extend the resummation of the form factor to the…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. Moch , J. A. M. Vermaseren , A. Vogt

We develop perturbative QCD factorization theorems for the exclusive semileptonic heavy baryon decay $\Lambda_b \to pl{\bar\nu}$, in which the relevant hadronic form factor is expressed as the convolution of a hard subamplitude with the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Hsien-Hung Shih , Shih-Chang Lee , Hsiang-nan Li

We include nonfactorizable soft gluon corrections into the perturbative QCD formalism for exclusive nonleptonic heavy meson decays, which combines factorization theorems and effective field theory. These corrections are classified according…

High Energy Physics - Phenomenology · Physics 2011-07-19 Hsiang-nan Li , B. Tseng

We resum distributions that are singular at partonic threshold (the elastic limit) in heavy quark production, in terms of logarithmic behavior in moment space. The method may be applied to a variety of cross sections sensitive to the edge…

High Energy Physics - Phenomenology · Physics 2014-11-17 Nikolaos Kidonakis , George Sterman

We have computed the complete next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of unpolarized parton densities in perturbative QCD. Our results agree with all partial results available in…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. Moch , J. A. M. Vermaseren , A. Vogt

We consider the diphoton production in hadronic collisions at the next-to-next-to-leading order (NNLO) in perturbative QCD, taking into account for the first time the full top quark mass dependence. We present the computation of the…

High Energy Physics - Phenomenology · Physics 2023-10-23 Federico Coro

We evaluate in the framework of QCD factorization the two-loop vertex corrections to the decays $\bar{B}_{(s)}\to D_{(s)}^{(\ast)+} \, L^-$ and $\Lambda_b \to \Lambda_c^+ \, L^-$, where $L$ is a light meson from the set…

High Energy Physics - Phenomenology · Physics 2016-10-12 Tobias Huber , Susanne Kränkl , Xin-Qiang Li

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

In this contribution we provide further details to the recent calculation of QCD corrections to massive three-loop form factors presented in Ref. [1].

High Energy Physics - Phenomenology · Physics 2018-07-26 Roman N. Lee , Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

We compute the NNLO QCD corrections for the hadroproduction of a pair of off-shell photons in the limit of a large number of quark flavors. We perform a reduction of the two-loop amplitude to master integrals and calculate the latter…

High Energy Physics - Phenomenology · Physics 2015-06-22 Charalampos Anastasiou , Julian Cancino , Federico Chavez , Claude Duhr , Achilleas Lazopoulos , Bernhard Mistlberger , Romain Mueller

Many present lattice QCD approaches to calculate the parton distribution functions (PDFs) rely on a factorization formula or effective theory expansion of certain Euclidean matrix elements in boosted hadron states. In the quasi- and…

High Energy Physics - Phenomenology · Physics 2021-05-28 Xiang Gao , Kyle Lee , Swagato Mukherjee , Charles Shugert , Yong Zhao

We summarize our recent results on small x resummation in full QCD with n_f quark flavours and discuss their phenomenological impact in the extraction of parton distributions from present day structure function data and their extrapolation…

High Energy Physics - Phenomenology · Physics 2009-04-14 Guido Altarelli , Richard D Ball , Stefano Forte

In this work, we discuss both relativistic and perturbative QCD corrections to the transition form-factor ${\cal F}_{\eta_Q}{(t_1,t_2)}$ for the process $\gamma^*(q_1) \gamma^*(q_2) \leftrightarrow \eta_Q(P)$ with dependencies on the…

High Energy Physics - Phenomenology · Physics 2026-01-07 Izabela Babiarz , Chris A. Flett , Melih A. Ozcelik , Wolfgang Schäfer , Antoni Szczurek

We compute the next-to-next-to-leading order (NNLO) contributions to the splitting functions governing the evolution of the unpolarized flavour-singlet parton densities in perturbative QCD. The exact expressions are presented in both…

High Energy Physics - Phenomenology · Physics 2010-04-05 A. Vogt , S. Moch , J. A. M. Vermaseren

We review semi-inclusive charmless B decays, focussing on threshold logarithmic resumming and on universality of QCD dynamics in radiative and semileptonic decays.

High Energy Physics - Phenomenology · Physics 2007-05-23 Giulia Ricciardi

We discuss recent results on the three-loop (next-to-next-to-leading order, NNLO) time-like splitting functions of QCD and the two-loop (NNLO) coefficient functions in one-particle inclusive e+e- annihilation. These results form the basis…

High Energy Physics - Phenomenology · Physics 2009-11-11 A. Mitov , S. Moch , A. Vogt

We present the first exact analytic result for all partonic channels contributing to the total cross section for the production of a pair of heavy flavors in hadronic collisions in NLO QCD. Our calculation is an essential step in the…

High Energy Physics - Phenomenology · Physics 2009-10-06 M. Czakon , A. Mitov

We present new results on the summation of nonpower-series expansions in QCD Analytic Perturbation Theory (APT) in the one-loop approximation. We show how to generalize the approach suggested by one of us earlier to the cases of APT and…

High Energy Physics - Phenomenology · Physics 2008-03-27 A. P. Bakulev , S. V. Mikhailov