Charged lepton flavor violation (CLFV) is forbidden in the Standard Model (SM) due to massless neutrinos and absence of right-handed neutrinos. The discovery of neutrino oscillations established that the neutrinos are massive and the lepton flavor is not an exact symmetry of nature. A minimal extension of the SM that incorporates right-handed neutrinos gives rise to CLFV through loop-level diagrams involving neutrinos. However, such processes are extremely rare, for instance, the branching fraction of $\mu \to e\gamma$ is expected to be at the level of $10^{-54}$, far beyond the sensitivity of current collider experiments. In contrast, several new physics models predict CLFV decay rates within the sensitivity of current experiments, such as the Belle and Belle II experiments, which have collected the world's largest asymmetric $e^+e^-$ collision data near the $\Upsilon(4S)$ resonance. The large data sample has utilized to explore the possibility of CLFV decays of $\tau$ leptons, $B$ mesons, and bottomonium states. The report reviews some latest results on these CLFV decays at Belle and Belle II.
The existence of right-handed (RH) neutrinos is strongly motivated by the observation of small neutrino masses and as a means to shed light on the origin of parity violation in the Standard Model (SM). Experimental searches for the corresponding mass eigenstates, referred to as heavy neutral leptons (HNLs), have been c...
P. Bolton, Fabian Esser, Lukáš Gráf et al.· 1 citation
The mono-photon process $e^+e^- \to \gamma+\mathrm{invisible}$ at Belle II probes both invisible new states and the electroweak couplings of neutrinos. In this work, we study the process $e^+e^- \to \gamma\nu\bar{\nu}$, finding that Belle II with the full expected dataset can determine the neutrino-sensitive effective...
C. H. D. de Lima, D. McKeen, Afif Omar et al.· 0 citations
The vanilla scotogenic model (VSM) featuring three right-handed neutrinos and an inert scalar doublet, offers a unified explanation of neutrino masses, dark matter (DM), and the baryon asymmetry of the Universe through leptogenesis. The typical mass scale of such a scenario lies in the vicinity of $\sim$ 10 TeV and abo...
Niloy Mondal, Dipankar Pradhan, Abhik Sarkar et al.· 1 citation
Upcoming experiments are set to dramatically improve the search for charged lepton flavor violation, with the sensitivity to the rates of $\mu\to eee$ decay and $\mu N\to eN$ conversion expected to improve by four orders of magnitude in the near future. We study how these measurements reshape our understanding of funda...
A. Di Lecce, Majid Ekhterachian, Marko Pesut et al.· 0 citations
An inverse seesaw model for neutrino masses and mixing is proposed, based on the spontaneous breaking of a $D_4$ flavor symmetry. The model simultaneously accounts for the neutrino oscillation parameters, the baryon asymmetry of the Universe through TeV-scale leptogenesis, and makes predictions for charged-lepton flavo...
Qiu Yan, Y. Reyimuaji, Xian-Shuo Zhang· 0 citations
We investigate thermal leptogenesis in an extension of the Type-I seesaw in which a real singlet scalar couples non-diagonally to the right-handed neutrinos. The interactions $-y_{ij}\phi N_iN_j$, with $i\neq j$, introduce new sources of CP violation in heavy-neutrino decays with a negligible enhancement of the standar...
Angus Spalding· 0 citations
We use cookies to run the site and, with your consent, for analytics and to show ads.
See our Cookie Policy.
