Electroweak Effects in Neutral Current Drell-Yan Processes within SANC System

The complete one-loop electroweak radiative corrections to the neutral current Drell-Yan process $pp \to \ell^+\ell^- X$ are presented for the case of longitudinal polarization of initial particles. The calculations are based on the SANC computer system. The paper contains a brief description of the SANC approach and a discussion of the sources of theoretical uncertainties in electroweak effects

EW one-loop corrections to the longitudinally polarized Drell--Yan scattering. (I). The Neutral current case

Complete one-loop electroweak corrections to neutral current Drell-Yan process $p p \to \ell^+\ell^- X$ are presented for the case of longitudinal polarization of initial particles. Cross sections for longitudinally polarized protons allow us to estimate different combinations of polarized quark distributions from single- and double-spin asymmetries. Numerical impact of electroweak next-order corrections to asymmetries as function of the vector boson rapidity and lepton pseudorapidities in the hadron-hadron centre-of-mass frame using the MC generator ReneSANCe is thoroughly studied.Comment: 7 pages, 9 figure

Computer package DIZET v. 6.45

The new version of the DIZET electroweak library is described. Changes and additional code features concerning the previous version are explained. The software allows one to make state-of-the-art theoretical predictions for pseudo-observable quantities, including higher-order radiative corrections. The current version of the DIZET library v. 6.45 incorporates advanced recent results of theoretical calculations. Numerical comparisons with the results of the previous version are performed. Estimates of theoretical uncertainties are discussed.Comment: 14 pages, 3 figures, 8 table

One-loop radiative corrections to photon-pair production in polarized positron-electron annihilation

A theoretical description of photon-pair production in polarized positron-electron annihilation is presented. Complete one-loop electroweak radiative corrections are calculated taking into account the exact dependence on the electron mass. Analytical results are derived with the help of the SANC~system. The relevant contributions to the cross section are calculated analytically using the helicity amplitude approach. The cases of unpolarized and longitudinally polarized fermions in the initial state are investigated. Calculations are realized in the Monte Carlo integrator MCSANCee and generator ReneSANCe which allow one the implementation of any experimental cuts used in the analysis of $e^+e^-$ annihilation data of both low and high energies.Comment: 17 pages, 6 tables, 3 figure

Theory for the FCC-ee : Report on the 11th FCC-ee Workshop

The Future Circular Collider (FCC) at CERN, a proposed 100-km circular facility with several colliders in succession, culminates with a 100 TeV proton-proton collider. It offers a vast new domain of exploration in particle physics, with orders of magnitude advances in terms of Precision, Sensitivity and Energy. The implementation plan foresees, as a first step, an Electroweak Factory electron-positron collider. This high luminosity facility, operating between 90 and 365 GeV centre-of-mass energy, will study the heavy particles of the Standard Model, Z, W, Higgs, and top with unprecedented accuracy. The Electroweak Factory $e^+e^-$ collider constitutes a real challenge to the theory and to precision calculations, triggering the need for the development of new mathematical methods and software tools. A first workshop in 2018 had focused on the first FCC-ee stage, the Tera-Z, and confronted the theoretical status of precision Standard Model calculations on the Z-boson resonance to the experimental demands. The second workshop in January 2019, which is reported here, extended the scope to the next stages, with the production of W-bosons (FCC-ee-W), the Higgs boson (FCC-ee-H) and top quarks (FCC-ee-tt). In particular, the theoretical precision in the determination of the crucial input parameters, alpha_QED, alpha_QCD, M_W, m_t at the level of FCC-ee requirements is thoroughly discussed. The requirements on Standard Model theory calculations were spelled out, so as to meet the demanding accuracy of the FCC-ee experimental potential. The discussion of innovative methods and tools for multi-loop calculations was deepened. Furthermore, phenomenological analyses beyond the Standard Model were discussed, in particular the effective theory approaches. The reports of 2018 and 2019 serve as white papers of the workshop results and subsequent developments

Electroweak radiative corrections to polarized top quark pair production

Electroweak effects in the $e^+e^- \to t \bar{t}$ annihilation process are described with taking into account polarization of the initial and final particles. We investigate the effects of complete one-loop electroweak radiative corrections and higher-order radiative effects to the total cross section and analyze different types of asymmetries for polarized initial and final states for typical energies and degrees of polarization of the ILC and CLIC projects. Numerical results are obtained with the help of Monte Carlo tools: the ReneSANCe event generator and the MCSANC integrator.Comment: 16 pages, 5 tables, 7 figure

Investigations of the Drell–Yan process at the LHC: Results and prospects

Experimental results on the Drell–Yan process obtained with the CMS detector in the first run of the Large Hadron Collider are briefly reviewed. Some original results on this process are presented, and the prospects for its further investigations in the second LHC run are analyzed