Search for Excited Neutrinos at HERA

TL;DR

This paper reports a search for excited neutrinos at HERA, setting new limits on their properties by analyzing e^-p collision data, with no evidence of their existence found.

Contribution

It provides the first mass-dependent exclusion limits on excited neutrinos at HERA, extending previous collider search boundaries.

Findings

No evidence for excited neutrino production.

Extended exclusion limits to higher masses.

Limits on the coupling to the compositeness scale.

Abstract

We present a search for excited neutrinos using e^-p data taken by the H1 experiment at HERA at a center-of-mass energy of 318 GeV with an integrated luminosity of 15 pb-1. No evidence for excited neutrino production is found. Mass dependent exclusion limits are determined for the ratio of the coupling to the compositeness scale, f/Lambda, independently of the relative couplings to the SU(2) and U(1) gauge bosons. These limits extend the excluded region to higher masses than has been possible in previous searches at other colliders.