Basis independent study of supersymmetry without R parity and the tau neutrino mass

A minimal lepton number violation (LNV) is proposed which could naturally appear in SUSY theories, if Yukawa and LNV couplings had a common origin. According to this idea properly implemented into MSSM with an additional abelian flavor symmetry the prototype LNV appears due to a mixing of leptons with superheavy Higgs doublet mediating Yukawa couplings. As a result, all significant physical manifestations of LNV reduce to those of the effective trilinear couplings LLE and LQD aligned, by size and orientation in a flavor space, with the down fermion (charged lepton and down quark ) effective Yukawa couplings, while the effective bilinear terms appear generically suppressed relative to an ordinary µ-term of MSSM. Detailed phenomenology of the model related to the flavor-changing processes both in quark and lepton sectors, radiatively induced neutrino masses and decays of the LSP is presented. Remarkably, the model can straightforwardly be extended to a Grand Unified framework and an explicit example with SU (7) GUT is thoroughly discussed.

Section: Hhlm Versus Hlmmentioning

confidence: 76%

Supersymmetry inspired minimal lepton number violation

Chkareuli¹,

Gogoladze

Green

et al. 2000

“…7 Since b 3 0, the hZZ coupling is smaller than its value in the RPC case, leading to a smaller e ϩ e Ϫ →Zh production rate. The limits on m h given in Ref.…”

Section: ͑15͒mentioning

confidence: 98%

New scalar resonances from sneutrino-Higgs-boson mixing in supersymmetry with small lepton number (R-parity) violation

Bar‐Shalom¹,

Eilam²,

Mele³

2001

We consider new s-channel scalar exchanges in top quark and massive gauge-boson pair production in e ϩ e Ϫ collisions, in supersymmetry with a small lepton number violation. We show that a soft bilinear lepton number violating term in the scalar potential which mixes the Higgs and the slepton fields can give rise to a significant scalar resonance enhancement in e ϩ e Ϫ →ZZ, W ϩ W Ϫ and in e ϩ e Ϫ →t t. The sneutrino-Higgs-boson mixed state couples to the incoming light leptons through its sneutrino component and to either the top quark or the massive gauge bosons through its Higgs component. Such a scalar resonance in these specific production channels cannot result from trilinear Yukawa-like R-parity violation alone, and may, therefore, stand as strong evidence for the existence of R-parity violating bilinears in the supersymmetric scalar potential. We use the CERN LEP2 measurements of the WW and ZZ cross sections to place useful constrains on this scenario, and investigate the expectations for the sensitivity of a future linear collider to these signals. We find that signals of these scalar resonances, in particular in top-pair production, are well within the reach of linear colliders in the small lepton number violation scenario.

“…The bilinear soft term (B ) 3 leads in general to a non-vanishing VEV of the tau-sneutrino, ν τ = vν τ . However, since lepton number is not a conserved quantum number in this scenario,theĤ d andL 3 superfields lose their identity and can be rotated to a particular basis (Ĥ d ,L 3 ) in which either 3 or v 3 = vν τ are set to zero [26,[80][81][82][83]. In what follows, we choose for convenience to work in the "no VEV" basis, vν τ = 0, which simplifies our analysis below.…”

Section: The Rpv Susy Frameworkmentioning

confidence: 99%

R -parity violating supersymmetry and the 125 GeV Higgs boson signals

Cohen¹,

Bar‐Shalom²,

Eilam³

et al. 2019

We study the impact of R-parity violating Supersymmetry (RPV SUSY) on the 125 GeV Higgs production and decay modes at the LHC. We assume a heavy SUSY spectrum with multi-TeV squarks and SU(2) scalar singlets as well as the decoupling limit in the SUSY Higgs sector. In this case the lightest CP-even Higgs is SM-like when R-parity is conserved. In contrast, we show that when R-parity violating interactions are added to the SUSY framework, significant deviations may occur in some production and decay channels of the 125 GeV Higgs-like state. Indeed, we assume a single-flavor (mostly third generation) Bilinear RPV (BRPV) interactions, which generate Higgs-sneutrino mixing, lepton-chargino mixing and neutrino-neutralino mixing, and find that notable deviations of O(20−30%) may be expected in the Higgs signal strength observables in some channels, e.g., in pp → h → µ + µ − , τ + τ − . Moreover, we find that new and detectable signals associated with BRPV Higgs decays to gauginos, h → ν τχ 0 2 and h → τ ± χ ∓ 2 , may also arise in this scenario. These decays yield a typical signature of h → τ ± ∓ + E T ( = e, µ, τ ) that can be much larger than in the SM, and may also be accompanied by an O(20 − 30%) enhancement in the di-photon signal pp → h → γγ. We also examine potential interesting signals of Trilinear R-parity violation (TRPV) interactions in the production and decays of the Higgs-sneutrino BRPV mixed state (assuming it is the 125 GeV scalar) and show that, in this case also, large deviations up to O(100%) are expected in e.g., pp → h → µ + µ − , τ + τ − , which are sensitive to the BRPV×TRPV coupling product.1 The CP-odd scalar mass matrix, m 2 O , has a massless state which corresponds to the Goldstone boson. 2 We note that too large values of δB may drive (depending on the other free-parameters in the Higgs sector) the lightest mass-squared eigenstates of both the CP-even and CP-odd mass matrices to non-physical negative values. We will thus demand non-negative mass-squared physical eigenvalues for the CP-even and CP-odd physical states by bounding δB accordingly.