Intro

• Local organisers
• Pietro Slavich (LPTHE Paris)

Room: Physics high-rise (30.23), seminar room 6/1

Two-Loop Renormalization in the 2HDM and Applications

• Felix Egle (DESY)

Room: Physics high-rise (30.23), seminar room 6/1

Precision predictions of partial decay widths in the general Two-Higgs-Doublet Model

• Jose Angel Hernandez Cuevas (Universität Freiburg)

Room: Physics high-rise (30.23), seminar room 6/1 The Standard Model (SM) of particle physics has achieved remarkable success in describing a broad spectrum of experimentally observed phenomena in particle physics with high precision. However, there are still some phenomena that lie beyond its description, such as the existence of dark matter, the matter-antimatter asymmetry of the universe, and the origin of neutrino masses. Several extensions to the SM have been proposed to account for these phenomena. Among them, the general Two-Higgs-Doublet Model (THDM) provides a framework with a rich phenomenology. It comprises the symmetry-constrained THDM scenarios as special limits, and enables the study of new sources of CP violation, Higgs-mediated flavor violation, generalized Yukawa structures, and the impact of complex parameters in both the potential and the Yukawa sector. In this talk, I will present next-to-leading-order (NLO) predictions of partial decay widths of the Higgs boson within the general THDM. I will focus on Higgs-boson decays into fermions and on exploring renormalization conditions, including on-shell and MS renormalization conditions, together with different tadpole treatments, in order to establish criteria that can point to a good choice of renormalization schemes for some extensions of the SM.

Revisiting the Higgs-mass calculation in the scale-invariant THDM

• Pietro Slavich (LPTHE Paris)

Room: Physics high-rise (30.23), seminar room 6/1 2602.17643

Two-Loop Pole-Mass Matching in the CP-Violating NMSSM

• Martin Gabelmann (U. Freiburg)
• Martin Gabelmann (DESY)

Room: Physics high-rise (30.23), seminar room 6/1

On-shell Renormalisation of Vector-like Lepton Models

• Kilian Möhling (IKTP TU Dresden)

Room: Physics high-rise (30.23), seminar room 6/1 Vector-like leptons are a special class of SM extensions with strong impact on the tree-level mass generation, the lepton--Higgs interaction as well as precision observables like g-2 or CLFV decays, and therefore nicely complement studies of EW BSM scenarios with extended Higgs sectors. The strong LO correlations motivate the inclusion of higher order corrections which, however, come with several complications related to the structure of the enlarged lepton mass matrix and the resulting mixing. I present a renormalisation scheme with on-shell conditions for the lepton masses that addresses these issues and discuss subtleties regarding the RGEs and redundancies in the Lagrangian parameters. Phenomenological results on Higgs physics and low-energy lepton physics can also be presented.

Sensitivity to New Physics in Higgs Observables

• Kateryna Radchenko Serdula (IFT)

Room: Physics high-rise (30.23), seminar room 6/1 Precision measurements of Higgs interactions provide one of the most powerful avenues to probe physics beyond the Standard Model (SM). In this talk, I will present automated one-loop calculations of the Higgs trilinear self-coupling and the $hZZ$ coupling within the Two Higgs Doublet Model (THDM) framework. This analysis is particularly relevant in view of future experimental facilities, where percent-level precision will make loop effects indispensable. It clarifies the interplay between different Higgs observables and identifies which measurements offer the strongest sensitivity to new physics effects.

Renormalisation of Chiral Gauge Theories with Non-Anticommuting $\gamma_5$ at the Multi-Loop Level

• Matthias Weisswange (DESY)

Room: Physics high-rise (30.23), seminar room 6/1 The computation of high-precision electroweak observables is of growing importance to meet the stringent requirements of current and future experiments and to probe physics beyond the Standard Model (SM). Such computations inevitably encounter the $\gamma_5$-problem. The Breitenlohner-Maison/'t~Hooft-Veltman (BMHV) scheme provides the only known framework for treating $\gamma_5$ in dimensional regularisation (DReg) that is rigorously established to all orders. In this talk, I review the BMHV scheme along with the complications arising from the regularisation-induced breaking of BRST invariance and report on recent progress in the systematic renormalisation of chiral gauge theories within this framework. First, the multi-loop application of the BMHV scheme to an Abelian chiral gauge theory is presented up to the 4-loop level. Second, I discuss the BMHV renormalisation of the SM, including a complete 1-loop analysis, the implications of evanescent gauge interactions, and initial steps towards the 2-loop renormalisation.

Infrared divergences and the choice of regularization

• Wojciech Kotlarski (National Centre for Nuclear Research)

Room: Physics high-rise (30.23), seminar room 6/1 We discuss the treatment of infrared divergences when computing observables in the MSbar scheme, using the decay of Higgs to qqbar as an example.

NLO Calculation of the Process $h \to f \bar{f}$ in the Decoupling Renormalization Scheme

• Johannes Wünsche (TU Dresden, IKTP)
• Jonas Lang (National Center for Nuclear Research Poland)

Room: Physics high-rise (30.23), seminar room 6/1 We propose a decoupling renormalization scheme for use in the calculation of Higgs decays in BSM models, including models with extended Higgs sector, at NLO order. The calculation is implemented withing the FlexibleSUSY spectrum-generator generator. The current status of the work will be presented including a discussion of the decoupling limit, various subtleties of the scheme’s definition like the mixing angle renormalization and first numerical results.

EWPOs, effective potential and vacuum stability

• Georg Ralf Weiglein (Deutsches Elektronen-Synchrotron (DE))

Room: Physics high-rise (30.23), seminar room 6/1

Discussion and Closing Room: Physics high-rise (30.23), seminar room 6/1