Multi-lepton signatures of additional scalar bosons beyond the Standard Model at the LHC

Self Cite

The simplified modelWithout appealing to any ultraviolet complete theory, 2 the anomaly-free simplified model considered in this article is constructed from a few simple assumptions. Most importantly, 1 Early discrepancies from Run 1 data sets not considered in Ref.[2] include opposite sign di-leptons and missing transverse energy with a full hadronic jet veto (see Ref.[1]) or di-leptons in association with at least one b-jet [3,4], among others (see also Section 4.1 and Section 4.2).2 It can be shown, however, that the assumptions used to construct the model can be mapped consistently onto the parameter space of a 2HDM with an additional singlet scalar [7].

Section: Introductionmentioning

confidence: 60%

Section: Introductionmentioning

confidence: 61%

Section: Introductionmentioning

confidence: 99%

“…Other multi-lepton final states considered in Ref. [1] and here were not included in the significance reported in Ref. [2].…”

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

The emergence of multi-lepton anomalies at the LHC and their compatibility with new physics at the EW scale

Buddenbrock

Cornell

Fang

et al. 2019

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Neutral exotica at FASERν and SND@LHC

Ansarifard

Farzan

2022

The (g − 2)μ anomaly indicates that the second generation of leptons should have new interactions beyond the standard model. The high flux of νμ and $$ \overline{\nu} $$ ν ¯ μ at the forward experiments such as FASERν and SND@LHC makes them suitable setups to search for new interactions of the second generation leptons. In this paper, we build a model in which the second generation left-handed leptons couple to a new right-handed neutrino, N and a new Higgs doublet which also couples to the quarks. The scattering of high energy νμ off nuclei can produce N. We investigate how forward experiments can test this model by looking for the N production vertex followed by the displaced vertex of the N decay. Discovering even a single such event can be a harbinger to look for the spectacular signals of the new Higgs doublet production at the LHC. We discuss the possibility of explaining the (g − 2)μ anomaly by adding more generations of N which will lead to chain decays of N and multiple leptons with distinct signals both at forward experiments and at the CMS and ATLAS detectors. Finally, we show that by adding a new light singlet scalar mixed with the neutral component of the new Higgs doublet (i.e., 2HDM+S model), the statistics of the data sample can be dramatically increased.

Robustness of ARS leptogenesis in scalar extensions

Fischer

Lindner

Woude

2022

Extensions of the Standard Model (SM) with sterile neutrinos are well motivated from the observed oscillations of the light neutrinos and they have shown to successfully explain the Baryon Asymmetry of the Universe (BAU) through, for instance, the so-called ARS leptogenesis. Sterile neutrinos can be added in minimal ways to the SM, but many theories exist where sterile neutrinos are not the only new fields. Such theories often include scalar bosons, which brings about the possibility of further interactions between the sterile neutrinos and the SM. In this paper we consider an extension of the SM with two sterile neutrinos and one scalar singlet particle and investigate the effect that an additional, thermalised, scalar has on the ARS leptogenesis mechanism. We show that in general the created asymmetry is reduced due to additional sterile neutrino production from scalar decays. When sterile neutrinos and scalars are discovered in the laboratory, our results will provide information on the applicability of the ARS leptogenesis mechanism.