In this work, we investigate the possibility to address the excess observed around 95 GeV in the <math><mi>γ</mi><mi>γ</mi></math>, <math><mi>τ</mi><mi>τ</mi></math>, and <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math> channels as a scalar resonance(s) within the Georgi-Machacek model. In our analysis, we find that the excess can be easily accommodated in the channels (<math><mi>γ</mi><mi>γ</mi></math> and <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math>) simultaneously, where the 95 GeV candidate is a single peak resonance (SPR) due to a light <math><mi>C</mi><mi>P</mi></math>-even scalar. We found that the excess in the <math><mi>τ</mi><mi>τ</mi></math> channel can be addressed simultaneously with <math><mi>γ</mi><mi>γ</mi></math> and <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math> only if the 95 GeV candidate is a twin peak resonance (TPR), i.e., another <math><mi>C</mi><mi>P</mi></math>-odd scalar in addition to the <math><mi>C</mi><mi>P</mi></math>-even scalar. We demonstrate that the nature of the 95 GeV scalar resonance candidate (SPR or TPR) can be probed via the properties of its di-<math><mi>τ</mi></math> decay.

United Arab Emirates

Amine Ahriche

95 GeV excess in the Georgi-Machacek model: Single or twin peak resonance

The anomalies observed in the <math><mi>W</mi></math> mass measurements at the CDF-II experiments and the excesses seen around 95 GeV at the Large Hadron Collider (LHC) motivate this work, in which we investigate and constrain the parameter space of the Scale Invariant Scotogenic Model with a Majorana dark matter candidate. The scanned parameters are chosen to be consistent with the dark matter relic density and the observed excesses at <math><mo>∼</mo><mn>95</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> signal strength rates in different channels. We found that significant part of the viable space addresses the excess in the channel <math><mi>γ</mi><mi>γ</mi></math>, while a tight part can address the excess in both <math><mi>γ</mi><mi>γ</mi></math> and <math><mi>b</mi><mover><mi>b</mi><mo>¯</mo></mover></math> channels. Furthermore, the model’s viable parameters can be probed in both the LHC and future <math><msup><mi>e</mi><mo>+</mo></msup><msup><mi>e</mi><mo>−</mo></msup></math> colliders for di-Higgs production.

Algeria

Mohamed Lamine Bellilet

South Africa

Sudan

Mohammed Omer Khojali

Mukesh Kumar

Anza-Tshildzi Mulaudzi

Scale invariant scotogenic model: CDF-II <math><mi>W</mi></math>-boson mass and the 95 GeV excesses

We investigate the properties of the gravitational waves (GW) generated during a strongly first order electroweak phase transition (EWPT) in models with the classical scale invariance (CSI). Here, we distinguish two parameter space regions that correspond to the cases of (1) light dilaton and (2) purely radiative Higgs mass (PRHM). In the CSI models, the dilaton mass, or the Higgs mass in the PRHM case, in addition to some triple scalar couplings are fully triggered by the radiative corrections (RCs). In order to probe the RC effects on the EWPT strength and on the GW spectrum, we extend the standard model by a real singlet to assist the electroweak symmetry breaking and an additional scalar field Q with multiplicity N  Q  and mass m  Q . After imposing all theoretical and experimental constraints, we show that a strongly first order EWPT with detectable GW spectra can be realized for the two cases of light dilaton and PRHM. We also show the corresponding values of the relative enhancement of the cross section for the di-Higgs production process, which is related to the triple Higgs boson coupling. We obtain the region in which the GW spectrum can be observed by different future experiments such as LISA and DECIGO. We also show that the scenarios (1) and (2) can be discriminated by future GW observations and measurements of the di-Higgs productions at future colliders.

Japan

Shinya Kanemura

Masanori Tanaka

Gravitational waves from phase transitions in scale invariant models

In this work, we investigate the parameter space of the Georgi-Machacek (GM) model, where we consider many theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs diphoton decay, the Higgs total decay width, and the LHC measurements of the signal strengths of the SM-like Higgs boson <math><mi>h</mi></math> in addition to the constraints from doubly charged Higgs bosons and Drell-Yan di-photon production and the indirect constraint from the <math><mi>b</mi><mo>→</mo><mi>s</mi></math> transition processes. We investigate also the possibility that the electroweak vacuum could be destabilized by unwanted wrong minima that may violate the <math><mrow><mi>C</mi><mi>P</mi></mrow></math> and/or the electric charge symmetries. We found that about 40% of the parameter space that fulfills the above mentioned constraints are excluded by these unwanted minima. In addition, we found that the negative searches for a heavy resonance could exclude a significant part of the viable parameter space, and future searches could exclude more regions in the parameter space.

Zahra Bairi

Italy

More constraints on the Georgi-Machacek model

In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop diagrams. The standard model (SM) is extended by three singlet Majorana fermions and two inert scalar doublets instead of one doublet as in the minimal scotogenic model. The model scalar sector includes two CP-even, two CP-odd and two charged scalars in addition to the Higgs. The dark matter (DM) candidate could be either the light Majorana fermion (Majorana DM), or the lightest among the CP-even and the CP-odd scalars (scalar DM). We show that the model accommodates both Majorana and scalar DM within a significant viable parameter space, while considering all the relevant theoretical and experimental constraints such as perturbativity, vacuum stability, unitarity, the di-photon Higgs decay, electroweak precision tests and lepton flavor violating constraints. In addition to the collider signatures predicted by the minimal scotogenic model, our model predicts some novel signatures that can be probed through some final states such as   .

A scotogenic model with two inert doublets

In this work, we investigate the viability of a light Higgs (<math><mrow><mi>η</mi></mrow></math>) scenario in the Georgi-Machacek (GM) model, where we consider all theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs diphoton and undetermined decays and the Higgs total decay width. In addition, we consider more recent experimental bounds from the searches for doubly charged Higgs bosons in the vector boson fusion channel <math><msubsup><mi>H</mi><mn>5</mn><mrow><mo>+</mo><mo>+</mo></mrow></msubsup><mo>→</mo><msup><mi>W</mi><mo>+</mo></msup><msup><mi>W</mi><mo>+</mo></msup></math>, Drell-Yan production of a neutral Higgs boson <math><mi>p</mi><mi>p</mi><mo>→</mo><msubsup><mi>H</mi><mn>5</mn><mn>0</mn></msubsup><mo>(</mo><mi>γ</mi><mi>γ</mi><mo>)</mo><msubsup><mi>H</mi><mn>5</mn><mo>+</mo></msubsup></math>, and for the light scalars at LEP <math><msup><mi>e</mi><mo>−</mo></msup><msup><mi>e</mi><mo>+</mo></msup><mo>→</mo><mi>Z</mi><mi>η</mi></math>, and at ATLAS and CMS in different final states such as <math><mi>p</mi><mi>p</mi><mo>→</mo><mi>η</mi><mo>→</mo><mn>2</mn><mi>γ</mi></math> and <math><mi>p</mi><mi>p</mi><mo>→</mo><mi>h</mi><mo>→</mo><mi>η</mi><mi>η</mi><mo>→</mo><mn>4</mn><mi>γ</mi><mo>,</mo><mn>2</mn><mi>μ</mi><mn>2</mn><mi>τ</mi><mo>,</mo><mn>2</mn><mi>μ</mi><mn>2</mn><mi>b</mi><mo>,</mo><mn>2</mn><mi>τ</mi><mn>2</mn><mi>b</mi></math>. By combining these bounds together, we found a parameter space region that is significant as the case of the SM-like Higgs to be the light <math><mi>C</mi><mi>P</mi></math>-even eigenstate, and this part of the parameter space would be tightened by the coming analyses.

Constraining the Georgi-Machacek model with a light Higgs boson

In this work, we consider an extension of the Standard Model with an inert Higgs doublet and a real scalar singlet, in order to address problems around the origin of dark matter (DM). In this model, the lightest among the <math><mi>C</mi><mi>P</mi></math>-odd and <math><mi>C</mi><mi>P</mi></math>-even neutral inert components plays the role of a DM candidate, where the model parameters are subject to many theoretical and experimental constraints. These constraints include vacuum stability, perturbativity, LEP negative searches, electroweak precision tests, Higgs diphoton, Higgs invisible and Higgs undetermined decays, DM relic density, and DM direct detection bounds. Using these constraints, we find that the allowed parameter space for these models is quite sizable and could be explored in upcoming collider and astrophysical searches.

Saudi Arabia

Ammar Abdalgabar

Alan S. Cornell

Dark matter in a singlet-extended inert Higgs-doublet model

In this work, we investigate the possibility of having scale invariant (SI) standard model (SM) extensions, where the light CP-even scalar matches the SM-like Higgs instead of being a light dilaton. After deriving the required conditions for this scenario, we show that the radiative corrections that give rise to the Higgs mass can trigger the scalar mixing to the experimentally allowed values. In addition, we discuss the constraints on the parameters space that makes the CP-even scalars properties in a good agreement with all the recent ATLAS and CMS measurements. We illustrate this scenario by considering the SI-scotogenic model as an example, while imposing all the theoretical and experimental constraints. We show that the model is viable and leads to possible modifications of the di-Higgs signatures at current/future with respect to the SM.

Purely radiative Higgs mass in scale invariant models

In this paper, we investigate the mutual impact between the dark matter (DM) requirements and the scalar sector in the scale invariant (SI) scotogenic model [A. Ahriche et al., J. High Energy Phys. 06 (2016) 182], that is motivated by the neutrino mass and DM within a classically SI framework. We show that the existence of annihilation channels that are mediated by the Higgs/dilaton may relax the DM relic density constraints on the contributions of <math><msub><mi>N</mi><mn>1</mn></msub><msub><mi>N</mi><mn>1</mn></msub><mo>→</mo><msub><mo>ℓ</mo><mi>α</mi></msub><msub><mo>ℓ</mo><mi>β</mi></msub><mo>,</mo><msub><mi>ν</mi><mi>α</mi></msub><msub><mover><mi>ν</mi><mo>¯</mo></mover><mi>β</mi></msub></math>. This allows the new Yukawa interactions (responsible for neutrino mass generation) to take small values and therefore avoid the mass degeneracy between the <math><mrow><mi>C</mi><mi>P</mi></mrow></math>-even and <math><mrow><mi>C</mi><mi>P</mi></mrow></math>-odd inert scalars, unlike the case of the minimal scotogenic model. In contrast to many Majorana DM models, the DM in the SI-scotogenic model couples to the quarks at tree level, and hence the constraint from the direct detection experiments is very important on the space parameter.

Rachik Soualah

Scale invariant scotogenic model: Dark matter and the scalar sector

We investigate the phenomenology of an extension of the Standard Model (SM) by a non-Abelian gauge group <math><mi>SU</mi><mo>(</mo><mn>2</mn><msub><mo>)</mo><mrow><mi>HS</mi></mrow></msub></math> where all SM particles are singlets under this gauge group, and a new scalar representation <math><mi>ϕ</mi></math> that is singlet under SM gauge group and doublet under <math><mi>SU</mi><mo>(</mo><mn>2</mn><msub><mo>)</mo><mrow><mi>HS</mi></mrow></msub></math>. In this model, the dark matter (DM) candidates are the three mass-degenerate dark photons <math><msub><mi>A</mi><mi>i</mi></msub></math> (<math><mrow><mi>i</mi><mo>=</mo><mn>1</mn></mrow></math>, 2, 3) of <math><mi>SU</mi><mo>(</mo><mn>2</mn><msub><mo>)</mo><mrow><mi>HS</mi></mrow></msub></math>, and the hidden sector interacts with the (SM) particles through the Higgs portal interactions. Consequently, there will be a new <math><mi>C</mi><mi>P</mi></math>-even scalar <math><mi>η</mi></math> that could be either heavier or lighter than the SM-like Higgs. By taking into account all theoretical and experimental constraints such as perturbativity, unitarity, vacuum stability, non-SM Higgs decays, DM direct detection, and <math><mrow><mi>M</mi></mrow></math> relic density, we found viable DM is possible in the range from GeV to TeV. Within the viable parameters space, both of the triple Higgs coupling and the di-Higgs production at LHC14 could be enhanced or reduced depending on the scalar mixing and the mass of the scalar particle <math><mi>η</mi></math>.