SABSPV - A Monte Carlo Integrator for Small-Angle Bhabha Scattering

SABSPV is a code designed to perform a theoretical evaluation of small-angle Bhabha scattering cross sections by suitably matching fixed-order perturbative calculations and structure-function techniques. The implementation of realistic experimental triggering conditions is achieved by using Monte Carlo integration.Comment: 12 pages, LaTeX, no figures, no macro

On Large-Angle Bhabha Scattering at LEP

The theoretical accuracy of the program TOPAZ0 in the large-angle Bhabha channel is estimated. The physical error associated with the full Bhabha cross section and its forward and backward components separately is given for some event selections and several energy points of interest for LEP1 physics, both for the $s$ and non-$s$ contributions to the cross section.Comment: 8 pages, LaTeX, six tables, no figure

ISR corrections to associated HZHZ production at future Higgs factories

We evaluate the QED corrections due to initial state radiation (ISR) to associated Higgs boson production in electron-positron ($e^+ e^-$) annihilation at typical energies of interest for the measurement of the Higgs properties at future $e^+ e^-$ colliders, such as CEPC and FCC-ee. We apply the QED Structure Function approach to the four-fermion production process $e^+ e^- \to \mu^+ \mu^- b \bar b$, including both signal and background contributions. We emphasize the relevance of the ISR corrections particularly near threshold and show that finite third order collinear contributions are mandatory to meet the expected experimental accuracy. We analyze in turn the r\^ole played by a full four-fermion calculation and beam energy spread in precision calculations for Higgs physics at future $e^+ e^-$ colliders.Comment: 11 pages, 3 figure

On the QED Radiator at Order α3\alpha^3

The ${\cal O} (\alpha^3)$ leading logarithmic contribution to the QED radiator in the additive form is considered. The effect of the correction on two-fermion physics at LEP1 and LEP2 is evaluated and critically compared with the one of next-to-leading ${\cal O} (\alpha^2)$ corrections. A critical comparison with existing estimates for the LEP1 energy range is also performed. The ${\cal O} (\alpha^3)$ leading logarithmic corrections turn out to be relevant in view of the experimental precision already reached at LEP1 and foreseen at LEP2.Comment: 10 pages, LaTeX, 3 .eps figures; added references, Comments and a comparison, basic results unchanged; final version to appear in Phys. Lett.

Dimensional reduction of solvency contagion dynamics on financial networks

Study of the application of dimensional reduction methods to the propagation of credit shocks within an interbank network, modeled according to the DebtRank dynamics

Neutral current Drell-Yan with combined QCD and electroweak corrections in the POWHEG BOX

Following recent work on the combination of electroweak and strong radiative corrections to single W-boson hadroproduction in the POWHEG BOX framework, we generalize the above treatment to cover the neutral current Drell-Yan process. According to the POWHEG method, we combine both the next-to-leading order (NLO) electroweak and QED multiple photon corrections with the native NLO and Parton Shower QCD contributions. We show comparisons with the predictions of the electroweak generator HORACE, to validate the reliability and accuracy of the approach. We also present phenomenological results obtained with the new tool for physics studies at the LHC.Comment: 10 pages, 14 figures, 1 table. One new figure, some plots with updated results, added text. Final version to appear in EPJ

The Top Quark and the Higgs Boson Mass from LEP SLC and CDF Data

The impact of the new experimental data from LEP, SLC and CDF on the top quark mass and the Higgs boson mass is investigated. The determinations of m_{top} and of an upper bound on m_{Higgs} are given, taking into account the experimental error on the QED coupling constant \alpha_{em} and on the b-quark mass m_b. The relevance of higher order theoretical uncertainties is pointed out. briefly reviewed.Comment: Latex (6 Figures upon request, [email protected]

Higgs boson decay into four leptons at NLOPS electroweak accuracy

In view of precision studies of the Higgs sector at the Run II of the LHC, the improvement of the accuracy of the theoretical prediction is becoming a pressing issue. In this framework, we detail a calculation of the full Next-to-Leading Order (NLO) electroweak corrections to Higgs boson decay into four charged leptons, by considering the gold-plated channel H -> Z(*) Z(*) -> 2l 2l', l,l' = e, mu. We match the NLO corrections with a QED Parton Shower (PS), in order to simulate exclusive multiple photon emission and provide novel results at NLOPS electroweak accuracy. We compare our NLO predictions to those of the program Prophecy4f and present NLOPS phenomenological results relevant for Higgs physics studies, with particular attention to precision measurements of the Higgs boson mass, spin-parity assignment and tests of the Standard Model. Our calculation is implemented in a new code, Hto4l, which can be easily interfaced to any generator describing Higgs boson production. As an example, we provide illustrative results for Higgs production and decay in the process gg -> H -> 4l using POWHEG with NLOPS accuracy in the production mode.Comment: 27 pages, 2 tables, 9 figures. New numerical results and plots for dressed leptons. Conclusions unchanged. Version to appear in JHE

FCC-ee: The Lepton Collider: Future Circular Collider Conceptual Design Report Volume 2

Overview of the research program of a future lepton collider

HE-LHC: The High-Energy Large Hadron Collider: Future Circular Collider Conceptual Design Report Volume 4

Overview of the research program of LHC at high energies