HiggsBounds-5: testing Higgs sectors in the LHC 13 TeV Era

We present the first explicit calculation of leading two-loop corrections to the Higgs trilinear coupling λhhh in models with classical scale invariance (CSI), using the effective-potential approximation. Furthermore, we also study — for the first time at two loops — the relation that appears between the masses of all states in CSI theories, due to the requirement of reproducing correctly the 125-GeV Higgs-boson mass. In addition to obtaining analytic results for general CSI models, we consider two particular examples of Beyond-the-Standard-Model theories with extended Higgs sectors, namely an N-scalar model (endowed with a global O(N) symmetry) and a CSI version of the Two-Higgs-Doublet Model, and we perform detailed numerical studies of these scenarios. While at one loop the value of the Higgs trilinear coupling is identical in all CSI models, and deviates by approximately 82% from the (one-loop) SM prediction, we find that the inclusion of two- loop corrections lifts this universality and allows distinguishing different BSM scenarios with CSI. Taking into account constraints from perturbative unitarity and the relation among masses, we find for both types of scenarios we consider that at two loops λhhh deviates from its SM prediction by 100 ± 10% — i.e. a quite significant further deviation with respect to the one-loop result of ∼ 82%.

Section: Jhep03(2021)297mentioning

confidence: 70%

Two-loop analysis of classically scale-invariant models with extended Higgs sectors

Braathen

Kanemura

Shimoda

2021

“…One of them is B → X s γ [96][97][98][99][100], which forces m H ± > 580 GeV (for the Type II model); the constraints from R b are also included [96,101]; concerning the different signals for the SM-like Higgs boson, we required compatibility with the fits presented in ref. [102], whereas exclusion bounds from additional Higgs searches are taken into account via HiggsBounds5 [103]. We also considered experiments that restrict the amount of CP violation of the C2HDM; we used the most stringent limit on the electron EDM, |d e | < 1.1 × 10 −29 e cm at 90% confidence level, provided by the ACME collaboration [104].…”

Section: Computational Tools and Simulation Proceduresmentioning

confidence: 99%

Renormalization of the C2HDM with FeynMaster 2

Fontes

Romão

2021

We present the one-loop electroweak renormalization of the CP-violating 2-Higgs-Doublet Model with softly broken ℤ2 symmetry (C2HDM). The existence of CP violation in the scalar sector of the model leads to a quite unique process of renormalization, since it requires the introduction of several non-physical parameters. The C2HDM will thus have more independent counterterms than independent renormalized parameters. As a consequence, different combinations of counterterms can be taken as independent for the same set of independent renormalized parameters. We compare the behaviour of selected combinations in specific NLO processes, which are assured to be gauge independent via a simple prescription. FeynMaster 2 is used to derive the Feynman rules, counterterms and one-loop processes in a simultaneously automatic and flexible way. This illustrates its use as an ideal tool to renormalize models such as the C2HDM and investigate them at NLO.

“…The constraints include the theoretical ones like the requirements of non-tachyonic particle spectrum, absence of an unphysical global minimum and that of Landau poles in various Yukawa-type couplings like 'λ', 'κ', y t and y b and the experimental ones from the flavor sector and those coming from collider experiments like the LEP, Tevatron and the LHC. In addition, up-to-date constraints pertaining to the observed Higgs sector are checked via dedicated packages like HiggsBounds-v5.4.0 [121][122][123] and HiggsSignals-v2.3.0 [124,125] and the mass of the SM-like Higgs boson is considered within the range 122 GeV < m h SM < 128 GeV to account for the uncertainties in its theoretical estimates. However, with the mass of the smuons (and, in general, of all the sfermions) set to be in the multi-TeV domain, we do not attempt to reproduce the purported discrepancy between the theoretically predicted and the experimentally measured values of muon anomalous magnetic moment JHEP04(2021)122…”

Section: Resultsmentioning

confidence: 99%

A relatively light, highly bino-like dark matter in the Z3-symmetric NMSSM and recent LHC searches

Abdallah

Datta

Roy

2021

A highly bino-like Dark Matter (DM), which is the Lightest Supersymmetric Particle (LSP), could be motivated by the stringent upper bounds on the DM direct detection rates. This is especially so when its mass is around or below 100 GeV for which such a bound tends to get most severe. Requiring not so large a higgsino mass parameter, that would render the scenario reasonably ‘natural’, prompts such a bino-like state to be relatively light. In the Minimal Supersymmetric Standard Model (MSSM), in the absence of comparably light scalars, such an excitation, if it has to be a thermal relic, is unable to meet the stringent experimental upper bound on its abundance unless its self-annihilation hits a funnel involving either the Z-boson or the Standard Model (SM)-like Higgs boson. We demonstrate that, in such a realistic situation, a highly bino-like DM of the popular Z3-symmetric Next-to-Minimal Supersymmetric Standard Model (NMSSM) is viable over an extended range of its mass, from our targeted maximum in the vicinity of the mass of the top quark down to about 30 GeV. This is facilitated by the presence of comparably light singlet-like states that could serve as funnel (scalars) and/or coannihilating (singlino) states even as the bino-like LSP receives a minimal (but optimal) tempering triggered by suitably light higgsino states that, in the first place, evade stringent lower bounds on their masses that can be derived from the Large Hadron Collider (LHC) experiments only in the presence of a lighter singlino-like state. An involved set of blind spot conditions is derived for the DM direct detection rates by considering for the very first time the augmented system of neutralinos comprising of the bino, the higgsinos and the singlino which highlights the important roles played by the NMSSM parameters ‘λ’ and tan β in delivering a richer phenomenology.