Related papers: Is it possible to check urgently the 5-loop analyt…
The RG functions of the 2D $n$-vector $\phi^4$ model are calculated in the five-loop approximation. Perturbative series for the $\beta$ function and critical exponents are resummed by the Pade-Borel and Pade-Borel-Leroy techniques,…
The recent calculation of the four-loop beta function in QCD provides further evidence that the Banks-Zaks expansion in 16half-n_f is sufficiently well behaved to be useful even for n_f=2 light flavours. This expansion inherently predicts…
We investigate the effects of possible new four-Fermi operators on $e^+$ $e^-$ annihilation experiments. They represent a class of new physics, which has the potential to change the parameters of the $Z$ boson and at the same time…
We calculate one-loop radiative QCD corrections to the three polarized and unpolarized structure functions that determine the beam-quark polar angle dependence of the alignment (or longitudinal) polarization of light and heavy quarks…
In this paper, we consider the $\beta$ function at one-loop approximation for noncommutative scalar QED. The renormalization of the full theory, including the basic vertices, and the renormalization group equation are fully established.…
Misprints in the C_F^2 part of the splitting function \Delta P_{gq}^(1) Eq. (3.29) are corrected. Due to a minus sign error between the C_F^2- 1/2 C_A C_F piece and the remaining part of Eq. (A.4), Eq. (3.46) is changed. Finally…
Perturbative QCD corrections to hadronic $\tau$ decays and $e^+e^-$ annihilation into hadrons below charm are obtained from the Adler function, which at present is known in the chiral limit to five-loop accuracy. Extractions of the strong…
The present calculations in perturbative QCD reach the order $\alpha_s^4$ for several correlators calculated to five loops, and the huge computational difficulties make unlikely the full six-loop calculation in the near future. This…
The zero to four loop contribution to the cross section $R_{e^{+}e^{-}}$ for $e^{+}e^{-} \longrightarrow$ hadrons, when combined with the renormalization group equation, allows for summation of all leading-log ($LL$), next-to-leading-log…
As is known from QED, a possible solution to the ghost-pole trouble can be obtained by imposing the $Q^2$-analyticity imperative. Here, the pole is compensated by the $\alpha$ non-analytic contribution that results in finite coupling…
In view of the forthcoming experiments at high energy $e^+ e^-$ colliders, LEP2 and beyond, the process $e^+ e^- \to W^+ W^- \to 4f$ has been investigated for {\it off-shell} $W$'s. After deriving the matrix element for the process within…
We present the results of an O(alpha_s) calculation of the transverse polarization of top quarks produced in e+e- annihilation. In a first step we determine the transverse polarization of the top with regard to the hadron plane spanned by…
We consider large-angle two photon production in $e^+ e^-$ annihilation as a possible process to monitor the luminosity of a future $e^+ e^-$ circular collider (FCC-ee). We review and assess the status of the theoretical accuracy by…
At order $\alpha_s^4$ in perturbative quantum chromodynamics, even-integer $\zeta$-function values are present in Euclidean physical correlation functions like the scalar quark correlation function or the scalar gluonium correlator. We…
In this work we provide all the missing ingredients for calculating parity-violating 3-jet observables in e^+e^- collisions at next-to-leading order (NLO) including the full quark mass dependence. In particular we give explicit results for…
We present the results of a new evaluation of the running fine structure constant $\alpha$ at the scale of the $Z$ mass in which the role of the $e^+e^-$ annihilation input data needed in this evaluation is minimized. This is achieved by…
We calculate the non-singlet, the pure singlet contribution, and their interference term, at $O(\alpha^2)$ due to electron-pair initial state radiation to $e^+ e^-$ annihilation into a neutral vector boson in a direct analytic computation…
The precision of fixed-order calculations on the dihadron production in electron-positron annihilation is paramount for probing QCD factorization and constraining non-perturbative inputs. This paper investigates the QCD corrections to the…
We present a thorough phenomenological analysis of the experimental data from Belle Collaboration for the transverse $\Lambda$ and $\bar\Lambda$ polarisation, measured in $e^+e^-$ annihilation processes, for the case of inclusive (plus a…
Dyson-Schwinger equations are used to evaluate the 4-loop anomalous dimensions of quenched QED in terms of finite, scheme-independent, 3-loop integrals. Three of the results serve as strong checks of terms from scheme-dependent 4-loop QCD…