We present a detailed comparison of predictions at NNLO accuray computed by four publicly available computer codes for Drell-Yan processes at the LHC and Tevatron colliders. We point out that while there is agreement among the predictions at the next-to-leading order accuracy, the predictions at the next-to-next-to-leading order (NNLO) differ, whose extent depends on the observable. The sizes...

The mass of the discovered Higgs boson is one of its most precisely measured properties with an experimental accuracy at the sub-percent level. Its measured value can place strong constraints on extensions of the Standard Model, in particular on the Minimal Supersymmetric Standard Model. To fully exploit this experimental precision, very precise predictions of the mass of the...

We consider gauged U(1) extensions of the standard model of particle physics with three right-handed sterile neutrinos and a singlet scalar. The neutrinos obtain mass via the type I seesaw mechanism. We compute the one loop corrections to the elements of the tree level mass matrix of the light neutrinos and show explicitly the cancellation of the gauge dependent terms. We present a general...

The accurate description of the internal structure of hadrons is a very challenging task. In order to compare the predictions with the highly-accurate experimental data, it is necessary to control any possible source of theoretical uncertainties. Thus, we can use the information extracted from final state measurement to constraint our knowledge about the internal structure of hadrons. In this...

Abstract

We use the Schwinger-DeWitt approach to address the four-fermion composite Higgs effective model proposed by Miransky, Tanabashi and Yamawaki (MTY). The surprising

benefit of such an approach is that it is possible to ascribe to a SM type Higgs a quark-antiquark structure of predominantly bottom flavor with a small top admixture, which in turn yields a Higgs mass compatible with...

In my talk I try to summarize the various activities in WG1 happened in the past year. I also try to summarize the efforts led to a special issue in the Symmetry journal and give a brief overview of the contributions appearing in it.

I will discuss recent development of the amplitude level evolution formalism at higher orders in QCD. I will highlight applications of the formalism towards improved parton branching algorithms as well as the resummation of non-global observables.

A crucial challenge in perturbative Quantum Field Theory is the description of quantum fluctuations at high-energy scattering processes by the calculation of multi-loop scattering amplitudes. Aiming for improving the efficiency of these computations, we delve into a new technique based on the Loop-Tree Duality (LTD). We analyse the multiloop topologies that appear for the first time at four...

Hard exclusive processes play a prominent role in exploring the strong interaction dynamics of hadronic reactions in the framework of QCD. In this context, the pion-photon transition form factor $\gamma \gamma^\ast \to \pi^0$ at large momentum transfer serves as one of the simplest exclusive processes for testing the theoretical predictions based upon perturbative QCD factorization.

Whereas...

Hadronic tau dacays are one of the important classic means to measure the value of the strong coupling. Since may years there is a discrepancy between two difference ways to treat the QCD perturbation series, called FOPT and CIPT, which is larger than the scale uncertainties of both individual series, and which add an additional annoying uncertainty in the extracted strong coupling value....

We calculate non-singlet quark operator matrix elements of deep-inelastic

scattering in the chiral limit including operators with total derivatives.

This extends previous calculations with zero-momentum transfer through the

operator vertex which provides the well-known anomalous dimensions for the

evolution of parton distributions, as well as calculations in off-forward kinematics...

Quantum Field Theory, as the keystone of particle physics, has offered great insights into deciphering the core of Nature. Despite its striking success, by adhering to local interactions, Quantum Field Theory suffers from the appearance of divergent quantities in intermediary steps of the calculation, which encompasses the need for some regularization/renormalization prescription. As an...

Dimensional regularization and renormalization in the Breitenlohner-Maison/’t Hooft-Veltman scheme, proved to be consistent at all loop orders, is a scheme that is widely used in phenomenological applications of (non-supersymmetric) QFTs. When being employed for theories with chiral fermions, however, the chiral and the BRST symmetries become broken, due to the specific γ5 treatment.

In...

Starting from collider energies of a few TeV, electroweak vector boson fusion/scattering becomes the dominant production mode at lepton colliders for Standard Model and new physics processes that are relevant to studying the EW sector. In this regime, a muon collider would effectively act as a ``high-luminosity weak boson collider,'' offering a wide range of opportunities to precisely measure...

The study of the Z-boson decay was crucial for the success of the LEP experiment. In $e^{+}e^{-}$ collisions, with the centre of mass energy matched to its mass, i.e. $\sim 91$ GeV, around 17 million Z-bosons were produced. Significant statistics allowed for precise measurements of its decay products along with the Standard Model (SM) parameters. The precision of LEP was so high that quantum...