Combining our results for various O({alpha}{sub s}{sup 2}) corrections to the weak radiative B-meson decay, we are able to present the first estimate of the branching ratio at the ...next-to-next-to-leading order in QCD. We find B(B{yields}X{sub s}{gamma})=(3.15{+-}0.23)x10{sup -4} for E{sub {gamma}}>1.6 GeV in the B-meson rest frame. The four types of uncertainties: nonperturbative (5%), parametric (3%), higher-order (3%), and m{sub c}-interpolation ambiguity (3%) have been added in quadrature to obtain the total error.
This document summarises the current theoretical and experimental status of the di-Higgs boson production searches, and of the direct and indirect constraints on the Higgs boson self-coupling, with ...the wish to serve as a useful guide for the next years. The document discusses the theoretical status, including state-of-the-art predictions for di-Higgs cross sections, developments on the effective field theory approach, and studies on specific new physics scenarios that can show up in the di-Higgs final state. The status of di-Higgs searches and the direct and indirect constraints on the Higgs self-coupling at the LHC are presented, with an overview of the relevant experimental techniques, and covering all the variety of relevant signatures. Finally, the capabilities of future colliders in determining the Higgs self-coupling are addressed, comparing the projected precision that can be obtained in such facilities. The work has started as the proceedings of the Di-Higgs workshop at Colliders, held at Fermilab from the 4th to the 9th of September 2018, but it went beyond the topics discussed at that workshop and included further developments. FERMILAB-CONF-19-468-E-T, LHCHXSWG-2019-005
We explore the sensitivity of future hadron colliders to constrain the fermionic Higgs portal, with a focus on scenarios where the new fermions cannot be directly observed in exotic Higgs decays. ...This portal emerges in various models including twin-Higgs scenarios and dark matter models, posing significant challenges for collider tests. Working in an effective field theory (EFT), we determine the reach of the high-luminosity option of the Large Hadron Collider (HL-LHC), the high-energy upgrade of the LHC (HE-LHC) and a proposed Future Circular Collider (FCC) in probing the fermionic Higgs portal through off-shell and double-Higgs production. Notably, we find that quantum-enhanced indirect probes offer a better sensitivity than other direct Higgs measurements. We argue that this finding is valid in a wide class of ultraviolet realisations of the EFT. Our study presents a roadmap of a multifaceted search strategy for exploring the fermionic Higgs portal at forthcoming hadron machines.
We present the Flavour Les Houches Accord (FLHA) which specifies a unique set of conventions for flavour-related parameters and observables. The FLHA uses the generic SUSY Les Houches Accord (SLHA) ...file structure. It defines the relevant Standard Model masses, Wilson coefficients, decay constants, bag parameters, flavour observables, etc. The accord provides a universal and model-independent interface between codes evaluating and/or using flavour-related observables.