Phenomenology of dark matter and mirror fermions from a left-right mirror model with singlet scalar

Author(s):  
Idham Syah Alam

Abstract We investigate a left-right mirror model with SU(3)c×SU(2)L×SU(2)R×U(1)Y and a discrete Z2 symmetry, which introduces mirror fields that are copies of the standard model fields. The mirror fields have the opposite chirality to their standard model counterpart fields. We also introduce singlet scalars as dark matter. The new interaction between dark matter, standard model fermions, and mirror fermions can account for dark matter abundance, charged lepton flavor violation, lepton anomalous magnetic moment, and flavor changing neutral current. We demonstrated that if we choose dark matter annihilation into muon as the dominant annihilation channel for leptophilic dark matter, both the observed dark matter abundance and the observed discrepancy between theory and experiment in the muon anomalous magnetic moment can be explained without contradicting the bound derived from charged lepton flavor violating processes. We briefly discuss how mirror fermions will be produced at the future linear collider, as mirror fermions can interact with neutral gauge bosons in this model. Finally, we discuss the lightest mirror neutrino decay mechanism, which will be highly abundant if stable.

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Stefan Antusch ◽  
A. Hammad ◽  
Ahmed Rashed

Abstract We investigate the sensitivity of electron-proton (ep) colliders for charged lepton flavor violation (cLFV) in an effective theory approach, considering a general effective Lagrangian for the conversion of an electron into a muon or a tau via the effective coupling to a neutral gauge boson or a neutral scalar field. For the photon, the Z boson and the Higgs particle of the Standard Model, we present the sensitivities of the LHeC for the coefficients of the effective operators, calculated from an analysis at the reconstructed level. As an example model where such flavor changing neutral current (FCNC) operators are generated at loop level, we consider the extension of the Standard Model by sterile neutrinos. We show that the LHeC could already probe the LFV conversion of an electron into a muon beyond the current experimental bounds, and could reach more than an order of magnitude higher sensitivity than the present limits for LFV conversion of an electron into a tau. We discuss that the high sensitivities are possible because the converted charged lepton is dominantly emitted in the backward direction, enabling an efficient separation of the signal from the background.


2003 ◽  
Vol 18 (16) ◽  
pp. 2769-2778
Author(s):  
Graham D. Kribs

I explain the theoretical connection between lepton flavor violation and muon g - 2 in supersymmetry1. Given any central value deviation of muon g - 2 from the standard model that is assumed to be due to weak scale supersymmetry, I show that stringent bounds on lepton flavor violating scalar masses can be extracted. These bounds are essentially independent of supersymmetric parameter space. I then briefly compare this indirect handle on supersymmetric lepton flavor violation with direct observation at a future lepton collider operating in the e- e- mode. This is a summary of a talk given at e- e-01: 4th International Workshop on Electron-Electron Interactions at TeV Energies.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Andreas Crivellin ◽  
Christoph Greub ◽  
Dario Müller ◽  
Francesco Saturnino

Abstract Leptoquarks are hypothetical new particles, which couple quarks directly to leptons. They experienced a renaissance in recent years as they are prime candidates to explain the so-called flavor anomalies, i.e. the deviations between the Standard Model predictions and measurements in b → sℓ+ℓ− and b → cτν processes and in the anomalous magnetic moment of the muon. At the one-loop level these particles unavoidably generate effects in the purely leptonic processes like Z → ℓ+ℓ−, Z →$$ v\overline{v} $$ v v ¯ , W → ℓν and h → ℓ+ℓ− and can even generate non-zero rates for lepton flavor violating processes such as ℓ → ℓ′γ, Z → ℓ+ℓ′−, h → ℓ+ℓ′− and ℓ → 3ℓ′. In this article we calculate these processes for all five representations of scalar Leptoquarks. We include their most general interaction terms with the Standard Model Higgs boson, which leads to Leptoquark mixing after the former acquires a vacuum expectation value. In our phenomenological analysis we investigate the effects in modified lepton couplings to electroweak gauge bosons, we study the correlations of the anomalous magnetic moment of the muon with h → μ+μ− and Z → μ+μ− as well as the interplay between different lepton flavor violating decays.


2021 ◽  
Vol 2021 (9) ◽  
Author(s):  
Junjie Cao ◽  
Jingwei Lian ◽  
Yusi Pan ◽  
Di Zhang ◽  
Pengxuan Zhu

Abstract Very recently, a Fermilab report of muon g− 2 showed a 4.2σ discrepancy between it and the standard model (SM) prediction. Motivated by this inspiring result and the increasing tension in supersymmetric interpretation of the anomalous magnetic moment, it is argued that in the general next-to-minimal supersymmetric standard model (GNMSSM), a singlino-dominated neutralino can act as a feasible dark matter (DM) candidate in explaining the discrepancy naturally. In this case, the singlino-dominated DM and singlet-dominated Higgs bosons can form a secluded DM sector with $$ {\overset{\sim }{\chi}}_1^0{\overset{\sim }{\chi}}_1^0 $$ χ ~ 1 0 χ ~ 1 0 → hsAs responsible for the measured DM relic abundance when $$ {m}_{{\overset{\sim }{\chi}}_1^0} $$ m χ ~ 1 0 ≳ 150 GeV and the Yukawa coupling κ is around 0.2. This sector communicates with the SM sector by weak singlet-doublet Higgs mixing, so the scatterings of the singlino-dominated DM with nucleons are suppressed. Furthermore, due to the singlet nature of the DM and the complex mass hierarchy, sparticle decay chains in the GNMSSM are lengthened in comparison with the prediction of the minimal supersymmetric standard model. These characteristics lead to sparticle detection at the Large Hadron Collider (LHC) being rather tricky. This study surveys a specific scenario of the GNMSSM, which extends the ℤ3-NMSSM by adding an explicit μ-term, to reveal the features. It indicates that the theory can readily explain the discrepancy of the muon anomalous magnetic moment without conflicting with the experimental results in DM and Higgs physics, and the LHC searches for sparticles.


2002 ◽  
Vol 17 (23) ◽  
pp. 3284-3299 ◽  
Author(s):  
JOHN ELLIS

Motivations for physics beyond the Standard Model are reviewed, with particular emphasis on supersymmetry at the TeV scale. Constraints on the minimal supersymmetric extension of the Standard Model with universal soft supersymmetry-breaking terms (CMSSM) are discussed. These are also combined with the supersymmetric interpretation of the anomalous magnetic moment of the muon. The prospects for observing supersymmetry at accelerators are reviewed using benchmark scenarios to focus the discussion. Prospects for other experiments including the detection of cold dark matter, μ → e γ and related processes, as well as proton decay are also discussed.


2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Debajyoti Choudhury ◽  
Suvam Maharana ◽  
Vandana Sahdev ◽  
Divya Sachdeva

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