LHC Searches for Non-Chiral Weakly Charged Multiplets

TL;DR

This paper explores the potential for detecting non-chiral, weakly charged fermion multiplets at the LHC, which are overlooked by standard searches due to their small mass splittings.

Contribution

It identifies a class of fermion multiplets with neutral lightest states that evade current detection strategies, highlighting the need for new search approaches.

Findings

Standard searches miss these multiplets due to small mass splittings.

Such multiplets could be relevant for dark matter.

Current LHC strategies need adaptation to detect these states.

Abstract

Because the TeV-scale to be probed at the Large Hadron Collider should shed light on the naturalness, hierarchy, and dark matter problems, most searches to date have focused on new physics signatures motivated by possible solutions to these puzzles. In this paper, we consider some candidates for new states that although not well-motivated from this standpoint are obvious possibilities that current search strategies would miss. In particular we consider vector representations of fermions in multiplets of $SU(2)_L$ with a lightest neutral state. Standard search strategies would fail to find such particles because of the expected small one-loop-level splitting between charged and neutral states.