# Seattle Snowmass Summer Meeting 2022

Jul 16 – 26, 2022
US/Pacific timezone

## Probing heavy Majorana neutrino pair production at ILC in a $U(1)_{\rm B-L}$ extension of the Standard Model

Jul 18, 2022, 7:00 PM
2h 20m
211 South Ballroom (HUB)

### Speaker

Jurina Nakajima (SOKENDAI/KEK)

### Description

We consider a gauged B$-$L (Baryon number minus Lepton number) extension of the Standard Model (SM), which is anomaly free in the presence of three SM singlet Right Handed Neutrinos (RHNs). Associated with the $U(1)_{\rm B-L}$ gauge symmetry breaking, the RHNs acquire Majorana masses and then with the electroweak symmetry breaking, tiny Majorana masses for the SM(-like) neutrinos are naturally generated by the seesaw mechanism. As a result of the seesaw mechanism, the heavy mass eigenstates which are mainly composed of the SM-singlet RHNs obtain suppressed electroweak interactions through small mixings with the SM neutrinos. To investigate the seesaw mechanism, we study the pair production of heavy Majorana neutrinos through the $U(1)_{\rm B-L}$ gauge boson $Z^\prime$ at the 250 GeV and 500 GeV International Linear Collider (ILC). Considering the current and prospective future bounds on the B$-$L model parameters from the search for a resonant $Z^\prime$ boson production at the Large Hadron Collider (LHC), we focus on a smoking-gun'' signature of the Majorana nature of the heavy neutrinos: a final state with a pair of same-sign, same-flavor leptons, small missing momentum, and four hadronic jets. We estimate the projected significance of the signature at the ILC.

In-person or Virtual? In-person

### Primary author

Jurina Nakajima (SOKENDAI/KEK)

### Co-authors

Daniel Jeans (KEK) Arindam Das (Hokkaido University) Nobuchika Okada (University of Alabama) Prof. Keisuke Fujii (KEK) Dr Satomi Okada (University of Alabama) Dr Ryo Yonamine (KEK)