# ZEU-THEO

 2017-09-1910:04 [PUBDB-2017-10870] Report/Journal Article et al The two-loop electroweak bosonic corrections to $\sin^2\theta_{\textrm{eff}}^{\textrm{b}}$ [DESY-16-119; KW-16-002; arXiv:1607.08375] Physics letters / B 762, 184 - 189 (2016) [10.1016/j.physletb.2016.09.012]   The prediction of the effective electroweak mixing angle $\sin^2\theta_{\rm eff}^{\rm b}$ in the Standard Model at two-loop accuracy has now been completed by the first calculation of the bosonic two-loop corrections to the $Z{\bar b}b$ vertex. Numerical predictions are presented in the form of a fitting formula as function of $M_Z, M_W, M_H, m_t$ and $\Delta{\alpha}$, ${\alpha_{\rm s}}$. [...] OpenAccess: PDF PDF (PDFA); 2017-08-0111:08 [PUBDB-2017-08782] Report/Journal Article et al Parton distribution functions, $\alpha_s$, and heavy-quark masses for LHC Run II [DESY-16-179, DO-TH-16-13, arXiv:1701.05838] Physical review / D 96(1), 014011 (2017) [10.1103/PhysRevD.96.014011]   We determine a new set of parton distribution functions (ABMP16), the strong coupling constant $\alpha_s$ and the quark masses $m_c$, $m_b$ and $m_t$ in a global fit to next-to-next-to-leading order (NNLO) in QCD. The analysis uses the $\overline{MS}$ scheme for $\alpha_s$ and all quark masses and is performed in the fixed-flavor number scheme for $n_f = 3, 4, 5$. [...] Restricted: PDF PDF (PDFA); 2017-07-1710:46 [PUBDB-2017-07732] Journal Article et al The three-loop splitting functions P q g ( 2 ) and P g g ( 2 , N F ) Nuclear physics / B 00, S0550321317301992 (2017) [10.1016/j.nuclphysb.2017.06.004]   Restricted: PDF PDF (PDFA); 2017-07-0314:52 [PUBDB-2017-06699] Report/Journal Article Kołodziej, K. Photon radiation in $e^+e^-\to$ hadrons at low energies with carlomat_3.1 [DESY-17-001; HU-EP-17-01; arXiv:1701.01837]   We present a sample of results for the cross sections of several processes of low energetic $e^+e^-$ annihilation into final states containing pions accompanied by one or two photons, or a light lepton pair. The results, which have been obtained with a new version of a multipurpose Monte Carlo program CARLOMAT, labelled 3.1, demonstrate new capabilities of the program which, among others, include a possibility of taking into account either the initial or final state radiation separately, or both at a time, and a possibility of inclusion of the electromagnetic charged pion form factor for processes with charged pion pairs. [...] OpenAccess: PDF PDF (PDFA); 2017-06-1913:43 [PUBDB-2017-05452] Report/Journal Article Vogt, A. On ${\gamma }_{5}$ in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution [DESY-15-061; NIKHEF-15-018; LTH-1042; arXiv:1506.04517] Physics letters / B 748, 432 - 438 (2015) [10.1016/j.physletb.2015.07.027]   We discuss the prescription for the Dirac matrix ${\gamma }_{5}$ in dimensional regularization used in most second- and third-order QCD calculations of collider cross sections. We provide an alternative implementation of this approach that avoids the use of an explicit form of ${\gamma }_{5}$ and of its (anti-) commutation relations in the most important case of no more than one ${\gamma }_{5}$ in each fermion trace. [...] OpenAccess: PDF PDF (PDFA); 2017-06-1414:42 [PUBDB-2017-04944] Report/Journal Article et al Asymptotic 3-loop heavy flavor corrections to the charged current structure functions $F^{W^{+}-W^{-}}_{L}(x,Q^{2})$ and $F^{W^{+}-W^{-}}_{2}(x,Q^{2})$ [DESY-16-148; DO-TH-16-15; arXiv:1609.06255] Physical review / D 94(11), 114006 (2017) [10.1103/PhysRevD.94.114006]   We calculate the massive Wilson coefficients for the heavy flavor contributions to the non-singlet charged current deep-inelastic scattering structure functions $F_L^{W^+}(x,Q^2)-F_L^{W^-}(x,Q^2)$ and $F_2^{W^+}(x,Q^2)-F_2^{W^-}(x,Q^2)$ in the asymptotic region $Q^2 \gg m^2$ to 3-loop order in Quantum Chromodynamics (QCD) at general values of the Mellin variable $N$ and the momentum fraction $x$. Besides the heavy quark pair production, also the single heavy flavor excitation $s \rightarrow c$ contributes. [...] OpenAccess: PDF PDF (PDFA); 2017-06-1316:14 [PUBDB-2017-04838] Preprint/Report Schneider, C. Refined Holonomic Summation Algorithms in Particle Physics [DESY-17-087; DO-TH-17-09; arXiv:1706.03677]   An improved multi-summation approach is introduced and discussed that enables one to simultaneously handle indefinite nested sums and products in the setting of difference rings and holonomic sequences. Relevant mathematics is reviewed and the underlying advanced difference ring machinery is elaborated upon. [...] OpenAccess: PDF PDF (PDFA); 2017-06-0613:38 [PUBDB-2017-04322] Report/Journal Article Schneider, C. The method of arbitrarily large moments to calculate single scale processes in quantum field theory [DESY-17-009; DO-TH 17-01; arXiv:1701.04614] Physics letters / B 771, 31 - 36 (2017) [10.1016/j.physletb.2017.05.001]   We device a new method to calculate a large number of Mellin moments of single scale quantities using the systems of differential and/or difference equations obtained by integration-by-parts identities between the corresponding Feynman integrals of loop corrections to physical quantities. These scalar quantities have a much simpler mathematical structure than the complete quantity. [...] OpenAccess: PDF PDF (PDFA); 2017-06-0611:46 [PUBDB-2017-04277] Preprint/Report et al Three Loop Massive Operator Matrix Elements and Asymptotic Wilson Coefficients with Two Different Masses [DESY-14-019; DO-TH-15-08; arXiv:1705.07030]   Starting at 3-loop order, the massive Wilson coefficients for deep-inelastic scattering and the massive operator matrix elements describing the variable flavor number scheme receive contributions of Feynman diagrams carrying quark lines with two different masses. In the case of the charm and bottom quarks, the usual decoupling of one heavy mass at a time no longer holds, since the ratio of the respective masses, $\eta = m_c^2/m_b^2 \sim 1/10$, is not small enough. [...] OpenAccess: PDF PDF (PDFA); 2017-06-0611:38 [PUBDB-2017-04273] Preprint/Report et al Iterated Elliptic and Hypergeometric Integrals for Feynman Diagrams [DESY-16-147; DO-TH-16-14; arXiv:1706.01299]   We calculate 3-loop master integrals for heavy quark correlators and the 3-loop QCD corrections to the $\rho$-parameter. They obey non-factorizing differential equations of second order with more than three singularities, which cannot be factorized in Mellin-$N$ space either. [...] OpenAccess: PDF PDF (PDFA);