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Related papers: Massive quark form factors

200 papers

We calculate the form factors for weak decays of $B_{(s)}$ and $D_{(s)}$ mesons to light pseudoscalar and vector mesons within a relativistic dispersion approach based on the constituent quark picture. This approach gives the form factors…

High Energy Physics - Phenomenology · Physics 2007-05-23 Dmitri Melikhov , Berthold Stech

We calculate four-loop QCD corrections to the electroweak $\rho$ parameter with a non-vanishing $b$ quark mass. At three loops, it was observed that elliptic integrals contribute to this observable. This prompts the question of which…

High Energy Physics - Phenomenology · Physics 2024-08-01 Samuel Abreu , Arnd Behring , Andrew McLeod , Ben Page

We calculate the two-loop QCD correction to the form factors of on-shell b-quark decay to an energetic massless quark, which constitutes the last missing piece required for an O(alpha_s^2) determination of |V_ub| from inclusive…

High Energy Physics - Phenomenology · Physics 2014-11-18 M. Beneke , T. Huber , Xin-Qiang Li

The paper is devoted to the calculation of additional two-loop O(\alpha_s^2) MSSM corrections to the relation between the pole mass of the t-quark and its running mass in the DR scheme. The value of the second order contribution from large…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Bednyakov , D. I. Kazakov , A. Sheplyakov

We compute the planar three-loop Quantum Chromodynamics (QCD) corrections to the helicity amplitudes involving a vector boson $V=Z,W^\pm,\gamma^*$, two quarks and a gluon. These amplitudes are relevant to vector-boson-plus-jet production at…

High Energy Physics - Phenomenology · Physics 2023-12-07 Thomas Gehrmann , Petr Jakubčík , Cesare Carlo Mella , Nikolaos Syrrakos , Lorenzo Tancredi

We compute the two-loop QCD corrections to amplitudes for processes $g g \to H g, q g \to H q$ and $q \bar{q} \to H g$ in the limit when the Higgs transverse momentum is larger than the top quark mass, $p_\perp \gg m_t$. These amplitudes…

High Energy Physics - Phenomenology · Physics 2018-04-04 Kirill Kudashkin , Kirill Melnikov , Christopher Wever

We present recent results on newly calculated 2- and 3-loop contributions to the heavy quark parts of the structure functions in deep-inelastic scattering due to charm and bottom.

High Energy Physics - Phenomenology · Physics 2016-09-21 J. Ablinger , A. Behring , J. Blümlein , G. Falcioni , A. De Freitas , A. Hasselhuhn , A. von Manteuffel , M. Round , C. Schneider , F. Wißbrock

I present results for soft anomalous dimensions through three loops for many QCD processes. In particular, I give detailed expressions for soft anomalous dimensions in various processes with electroweak and Higgs bosons as well as single…

High Energy Physics - Phenomenology · Physics 2022-08-08 Nikolaos Kidonakis

We present the one-loop QCD amplitudes for two external massless quarks and three external gluons ($\bar{q}qggg$). This completes the set of one-loop amplitudes needed for the next-to-leading-order corrections to three-jet production at…

High Energy Physics - Phenomenology · Physics 2010-11-15 Z. Bern , L. Dixon , D. A. Kosower

We construct approximate formulas for the O(\alpha_s^3) QCD contributions to vector, axial-vector, scalar and pseudo-scalar quark current correlators, which are valid for arbitrary values of momenta and masses. The derivation is based on…

High Energy Physics - Phenomenology · Physics 2009-10-02 Y. Kiyo , A. Maier , P. Maierhoefer , P. Marquard

We perform a perturbative QCD analysis of the gravitational form factors (GFFs) of nucleon at large momentum transfer. We derive the explicit factorization formula of the GFFs in terms of twist-3 and twist-4 light-cone distribution…

High Energy Physics - Phenomenology · Physics 2022-10-26 Xuan-Bo Tong , Jian-Ping Ma , Feng Yuan

We compute the two-loop QCD corrections to $q g \to H q$ and $q \bar{q} \to H g$ amplitudes mediated by loops of nearly massless quarks. These amplitudes provide the last missing ingredient required to compute the NLO QCD corrections to the…

High Energy Physics - Phenomenology · Physics 2017-03-22 Kirill Melnikov , Lorenzo Tancredi , Christopher Wever

We complete the investigation of loop corrections to hard spectator-scattering in exclusive B meson to light meson transitions by computing the short-distance coefficient (jet-function) from the hard-collinear scale. Adding together the two…

High Energy Physics - Phenomenology · Physics 2010-04-05 M. Beneke , D. Yang

Sudakov form factors appear ubiquitously in factorized cross sections where they allow one to resum large logarithms to all orders in perturbation theory. Their exact evaluation requires numerical integrals over anomalous dimensions, which…

High Energy Physics - Phenomenology · Physics 2022-02-22 Markus A. Ebert

In this note, we propose a factorization formula for gauge-theory scattering amplitudes up to two loops in the high-energy boosted limit. Our formula extends existing results in the literature by incorporating the contributions from massive…

High Energy Physics - Phenomenology · Physics 2023-12-20 Guoxing Wang , Tianya Xia , Li Lin Yang , Xiaoping Ye

This talk presents details of the calculation of two-loop corrections to heavy baryon currents containing one heavy quark in leading order of the $1/m_Q$-expansion, i.e. in the limit of Heavy Quark Symmetry (HQS). The calculations lead to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Stefan Groote

The 1/m corrections to heavy baryon masses are calculated from the QCD sum rules within the framework of the heavy quark effective theory. Numerical results for the heavy baryons are obtained. The implications of the results are discussed.

High Energy Physics - Phenomenology · Physics 2015-06-25 Yuan-ben Dai , Chao-shang Huang , Chun Liu , Cai-dian Lü

We perform an analytic calculation of the one-loop amplitude for the W-boson mediated process 0 \to d u-bar Q Q-bar l-bar l, retaining the mass for the quark Q. The momentum of each of the massive quarks is expressed as the sum of two…

High Energy Physics - Phenomenology · Physics 2011-03-18 Simon Badger , John M. Campbell , R. K. Ellis

The form factors relevant to $B_{q}\to D^{\ast}_{q}(J^{P}=1^{-})\ell\nu$ $(q=s, d, u)$ decays are calculated in the framework of the three point QCD sum rules approach. The heavy quark effective theory prediction of the form factors are…

High Energy Physics - Phenomenology · Physics 2009-11-13 M. Bayar , K. Azizi

We compute squared matrix elements at next-to-next-to-leading order in perturbative quantum chromodynamics for the production of two or three (on- or off-shell) photons mediated via (light or heavy) quark loops. Our method handles all cases…

High Energy Physics - Phenomenology · Physics 2025-10-22 Dario Kermanschah , Matilde Vicini