Probing charged lepton number violation via ℓ±ℓ′±W∓W∓

Mayumi Aoki,Shinya Kanemura,Kazuki Enomoto

doi:10.1103/physrevd.101.115019

Mayumi Aoki, Shinya Kanemura + Show 1 more

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https://doi.org/10.1103/physrevd.101.115019

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Abstract

We study impacts of dimension-five lepton-number violating operators associated with two same-sign weak bosons, $\ell^\pm \ell^{\prime \pm} W^\mp W^\mp$, on current and future experiments for neutrino oscillation, lepton-number violating rare processes and high-energy collider experiments. These operators can contain important information on the origin of tiny neutrino masses, which is independent of that from the so-called Weinberg operator. We examine constraints on the coefficients of the operators by the neutrino oscillation data. Upper bounds on the coefficients are also investigated by using the data for processes of lepton number violation such as neutrinoless double beta decays and $\mu^-$-$e^+$ conversion. These operators can also be directly tested by searching for lepton-number violating dilepton production via the same-sign W boson fusion process at high-energy hadron colliders like the Large Hadron Collider. We find that these operators can be considerably probed by these current and future experiments.

Highlights

In 2012, the Higgs boson was discovered at the Large Hadron Collider (LHC) [1], and the existence of all particles predicted in the Standard Model (SM) was confirmed empirically
We study impacts of dimension-five lepton number violation (LNV) operators associated with two same-sign weak bosons, lÆl0ÆW∓W∓, on current and future experiments for neutrino oscillation, LNV rare processes and high energy collider experiments
We have investigated phenomenological consequences of the lÆl0ÆW∓W∓ operators

Summary

INTRODUCTION

In 2012, the Higgs boson was discovered at the Large Hadron Collider (LHC) [1], and the existence of all particles predicted in the Standard Model (SM) was confirmed empirically. We study impacts of dimension-five LNV operators associated with two same-sign weak bosons, lÆl0ÆW∓W∓, on current and future experiments for neutrino oscillation, LNV rare processes and high energy collider experiments. These operators can contain important information on the origin of tiny neutrino masses, which is independent of that from the Weinberg operator. Upper bounds on the coefficients are investigated using the data for LNV processes such as neutrinoless double beta decays and μ−-eþ conversion These operators can be directly tested by the lepton number violating processes via the same-sign W boson fusion process at high energy hadron colliders, like the LHC. In Refs. [16,17,23,24], the models where the dimension-nine operators in Eq (7) are yielded at tree or one-loop level are investigated

NEUTRINO MASSES

CONSTRAINTS FROM LOW ENERGY EXPERIMENTS

CONSTRAINT FROM HIGH-ENERGY COLLIDER EXPERIMENTS

CONCLUSION