This article describes a search for low-mass axionlike particles (ALPs) at the Large Hadron Collider (LHC). If ALPs were produced LHC via gluon-gluon fusion and decayed to bosons, energy dependence of measured diboson cross-sections would differ from Standard Model expectation. Measurements $WW$ $Z\ensuremath{\gamma}$ differential cross sections by ATLAS collaboration are interpreted constrain ...

The infrared behaviour of Landau gauge QCD vertex functions is investigated employing a skeleton expansion of the Dyson-Schwinger and Renormalization Group equations. Results for the ghost-gluon, three-gluon, four-gluon and quark-gluon vertex functions are presented. Positivity violation of the gluon propagator, and thus gluon confinement, is demonstrated. Results of the Dyson-Schwinger equatio...

The flow-equation method of continuous unitary transformations is used to eliminate the minimal quark-gluon interaction in the light-front quantized QCD Hamiltonian. The coupled differential equations in the two lowest Fock sectors correspond to the renormalization of the light-front gluon mass and the generation of an effective quark-antiquark (as well as gluon-gluon) interaction. The original...

Nonlocal gluon condensates are vacuum expectations of the product field strength tensors. Short-distance expansions two-, three-, and four-gluon presented up to dimension-eight local operators. We propose a method for calculating Wilson coefficients based on Feynman diagram technique in background approach. The is demonstrated using glueball current correlators as examples. Methodological aspec...

One of the primary goals of the RHIC spin program is to determine the gluon polarization distribution within the proton. At leading order, pp collisions at RHIC involve a mixture of quark-quark (qq), quark-gluon (qg), and gluon-gluon (gg) scattering processes, with qg and gg contributions dominating. This makes RHIC an ideal place to study gluon polarization. For the past several years, the STA...

We apply the solution to the recursion relation for the double-off-shell quark current to the problem of computing one loop amplitudes with an arbitrary number of gluons. We are able to compute amplitudes for photon-gluon scattering, electron-positron annihilation to gluons, and gluon-gluon scattering via a quark loop in the case of like-helicity gluons. In addition, we present the result for t...

Abstract The infrared behaviour of gluon and ghost propagators, ghost-gluon vertex and three-gluon vertex is investigated for both the covariant Landau and the non-covariant Coulomb gauge. Assuming infrared ghost dominance, we find a unique infrared exponent in the d = 4 Landau gauge, while in the d = 3 + 1 Coulomb gauge we find two different infrared exponents. We also show that a finite dress...

We calculate the contribution arising from nonperturbative quark-gluon chromomagnetic interaction to the high energy total quark-quark cross section and to gluon distributions in nucleon. The estimation obtained within the instanton model of QCD vacuum leads to the conclusion that this type of interaction gives the dominating contribution to the pomeron coupling with the light quarks and to glu...