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Related papers: The two-mass contribution to the three-loop pure s…

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Second- and third-order results are presented for the structure functions of charged-current deep-inelastic scattering in the framework of massless perturbative QCD. We write down the two-loop differences between the corresponding…

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

We calculate the massive two--loop pure singlet Wilson coefficients for heavy quark production in the unpolarized case analytically in the whole kinematic region and derive the threshold and asymptotic expansions. We also recalculate the…

High Energy Physics - Phenomenology · Physics 2019-06-12 J. Blümlein , A. De Freitas , C. G. Raab , K. Schönwald

The two-loop massive operator matrix elements for the fermionic local twist--2 operators with external massive fermion lines in Quantum Electrodynamics (QED) are calculated up to the constant terms in the dimensional parameter $\epsilon = D…

High Energy Physics - Phenomenology · Physics 2011-11-02 Johannes Blümlein , Abilio De Freitas , Wilhelmus van Neerven

We present the two-loop corrected operator matrix elements calculated in N-dimensional regularization up to the finite terms which survive in the limit $\epsilon = N - 4 \to 0 $. The anomalous dimensions of the local operators have been…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. Matiounine , J. Smith , W. L. van Neerven

The new theoretical input to the analysis of the experimental data of the CCFR collaboration for $F_3$ structure function of $\nu N$ deep inelastic scattering is considered. This input comes from the next-to-next-to-leading order…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. L. Kataev , G. Parente , A. V. Sidorov

The relation between the on-shell quark mass and the mass defined in the modified minimal subtraction scheme is computed up to order \alpha_s^3. Implications for the numerical values of the top and bottom quark masses are discussed. We show…

High Energy Physics - Phenomenology · Physics 2010-04-06 K. G. Chetyrkin , M. Steinhauser

A physically defined QCD coupling parameter naturally incorporates massive quark flavor thresholds in a gauge invariant, renormalization scale independent and analytical way. In this paper we summarize recent results for the finite-mass…

High Energy Physics - Phenomenology · Physics 2009-10-31 Michael Melles

In the framework of analytic approach to QCD, which has been recently intensively developed, the dependence of nonperturbative contributions in a running coupling of strong interaction on initial perturbative approximation to 3-loop order…

High Energy Physics - Phenomenology · Physics 2007-05-23 Aleksey I. Alekseev

Extending the method successful for one-loop integrals, the computation of two-loop diagrams with general internal masses is discussed. For the two-loop vertex of non-planar type, as an example, we show a calculation related to…

High Energy Physics - Phenomenology · Physics 2011-03-02 J. FUJIMOTO , Y. SHIMIZU , K. KATO , T. KANEKO

We calculate massive 5-propagator 2-loop integrals for operator matrix elements in the light-cone expansion, using Mellin-Barnes techniques and representations through generalized hypergeometric functions.

High Energy Physics - Phenomenology · Physics 2009-11-11 I. Bierenbaum , J. Blümlein , S. Klein

I discuss the status of the computation of the two-loop QCD corrections to top-quark pair production associated with a jet at hadron colliders. This amplitude is a missing ingredient for next-to-next-to-leading order (NNLO) QCD predictions.…

High Energy Physics - Phenomenology · Physics 2024-11-19 Colomba Brancaccio

The perturbative result for the quark-mass conversion factor between the $\overline{\mathrm{MS}}$ and regularization-independent symmetric-momentum subtraction scheme (RI/SMOM) away from the chiral limit, i.e. at non-zero quark masses…

High Energy Physics - Phenomenology · Physics 2025-11-10 Long Chen , Marco Niggetiedt

We present the results of our QCD analysis for nonsinglet unpolarized quark distributions and structure function $F_2(x,Q^2)$. New parameterizations are derived for the nonsinglet quark distributions for the kinematic wide range of $x$ and…

High Energy Physics - Phenomenology · Physics 2008-12-25 Ali N. Khorramian , S. Atashbar Tehrani

During the last year, analytic expressions for the two-loop QCD corrections to the form factors for the vector, axial-vector, scalar and pseudo-scalar vertices involving a pair of heavy quarks, $Q \bar{Q}$, were calculated. The results are…

High Energy Physics - Phenomenology · Physics 2007-05-23 W. Bernreuther , R. Bonciani , T. Gehrmann , R. Heinesch , T. Leineweber , P. Mastrolia , E. Remiddi

We calculate the three-loop master integrals of Ref. [1] [arXiv:1709.02160] in analytic form. This allows us to present the fermionic contributions to the $\Delta B=2$ Wilson coefficients of the $B$-$\bar B$ decay matrix in…

High Energy Physics - Phenomenology · Physics 2022-07-06 Artyom Hovhannisyan , Ulrich Nierste

We calculate the contributions arising at order $\alpha_s$ in the QCD sum rule for the spin-symmetry violating universal function $\chi_3(v\cdot v')$, which appears at order $1/m_Q$ in the heavy quark expansion of meson form factors. In…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Neubert , Z. Ligeti , Y. Nir

In the asymptotic limit $Q^2 \gg m^2$, the non-power corrections to the heavy flavour Wilson coefficients in deep--inelastic scattering are given in terms of massless Wilson coeffcients and massive operator matrix elements. We start…

High Energy Physics - Phenomenology · Physics 2008-12-19 I. Bierenbaum , J. Blümlein , S. Klein

We present analytical results for the $O(\alpha _s ^2)$ contributions to the functions $\eta _A$ and $\eta _V$ which parameterize QCD corrections to semileptonic $b \to c$ transitions at zero recoil. Previously obtained approximate results…

High Energy Physics - Phenomenology · Physics 2011-01-25 Andrzej Czarnecki , Kirill Melnikov

The resummation of soft gluon exchange for QCD hard scattering requires a matrix of anomalous dimensions. We compute this matrix directly for arbitrary 2 to n massless processes for the first time at two loops. Using color generator…

High Energy Physics - Phenomenology · Physics 2009-04-06 S. Mert Aybat , Lance J. Dixon , George Sterman

The quark-connected leading-order hadronic contributions to the running of the electromagnetic fine structure constant, $\alpha_{\rm QED}$, and the weak mixing angle, $\theta_W$, are determined by a four-flavour lattice QCD computation with…

High Energy Physics - Lattice · Physics 2015-12-09 Florian Burger , Karl Jansen , Marcus Petschlies , Grit Pientka