Related papers: Renormalization Scheme Consistent Structure Functi…
The resummation for the event-shape variable jet broadening is extended to next-to-next-to-leading logarithmic accuracy by computing the relevant jet and soft functions at one-loop order and the collinear anomaly to two-loop accuracy. The…
We extract the small x asymptotic behaviour of the Altarelli-Parisi splitting functions from their expansion in leading logarithms of 1/x. We show in particular that the nominally next-to-leading correction extracted from the Fadin-Lipatov…
We investigate $\phi^{2n+1}$ deformations of the generalized free theory in the $\epsilon$ expansion, where the canonical kinetic term is generalized to a higher-derivative version. For $n=1$, we use the conformal multiplet recombination…
We discuss the phenomenological extraction of the leading $ j$-plane singularity from singlet structure functions $ F_s $ measured at small $ x. $ Using a saddle-point method we show that $ {\rm d ln} F_s /{\rm d ln}{1 \over x} $ is a…
We investigate the unpolarized virtual photon structure functions $F_2^gamma(x,Q^2,P^2)$ and $F_L^gamma(x,Q^2,P^2)$ in perturbative QCD for the kinematical region $Lambda^2 ll P^2 ll Q^2$, where $-Q^2(-P^2)$ is the mass squared of the probe…
In recent years, Fractal Inspired Models of quark and gluon densities at small x have been proposed. In this paper, we investigate longitudinal structure function F-L (x, Q2) within this approach. We make predictions using the QCD based…
We define a general scheme for the evolution of fragmentation functions which resums soft gluon logarithms in a manner consistent with fixed order evolution. We present an explicit example of our approach in which double logarithms are…
We review the large N method of calculating high order information on the renormalization group functions in a quantum field theory which is based on conformal integration methods. As an example these techniques are applied to a typical…
We apply the methods of modern analytic bootstrap to the critical $O(N)$ model in a $1/N$ expansion. At infinite $N$ the model possesses higher spin symmetry which is weakly broken as we turn on $1/N$. By studying consistency conditions for…
Based on the Cornwall-Jackiw-Tomboulis effective potential, we extensively study nonperturbative renormalization of the gauged Nambu-Jona-Lasinio model in the ladder approximation with standing gauge coupling. Although the pure…
We explore the possibilities of using the fermionic functional renormalization group to compute the phase diagram of systems with competing instabilities. In order to overcome the ubiquituous divergences encountered in RG flows, we propose…
The impact of the resummation of leading small-$x$ terms in the anomalous dimensions is briefly summarized for the evolution of non--singlet and singlet polarized structure functions.
We propose and analyze a regularization approach for structured prediction problems. We characterize a large class of loss functions that allows to naturally embed structured outputs in a linear space. We exploit this fact to design…
We present a general formalism that allows for the computation of large-order renormalized expansions in the spacetime representation, effectively doubling the numerically attainable perturbation order of renormalized Feynman diagrams. We…
We calculate structure functions at small $x$ both under the assumption of a hard singularity (a power behaviour $x^{-\lambda}, \lambda$ positive, for $x\rightarrow 0$) or that of a soft-Pomeron dominated behaviour, also called double…
We start from the two existing QCD evolution equations for structure functions, the BFKL and DGLAP equations, and discuss the theoretical hints for a unifying picture of the evolution in $x$ and $Q^2.$ The main difficulty is due to the…
I review the k-factorization method to combine the high-energy behaviour in QCD with the renormalization group. Resummation formulas for coefficient functions and anomalous dimensions are derived, and their applications to small-x scaling…
We study systematically, through two loops, the divergence structure of the supersymmetric WZ model defined on the N=1/2 nonanticommutative superspace. By introducing a spurion field to represent the supersymmetry breaking term F^3 we are…
We analyze power corrections to flavour singlet deep inelastic scattering structure functions in the framework of the infrared renormalon model. Our calculations, together with previous results for the non-singlet contribution, allow to…
In this work, we investigate the effects of logarithms on the asymptotic behavior of power expansion/OPE in supper-renormalizable QFTs. We performed a careful investigation of the large $p^2$ expansion of a scalar-scalar two-point function…