Testing the Neutrino Content of the Muon at Muon Colliders

Abstract

Collinear emission of $W$ bosons off a high-energy muon induces a large muon-neutrino component among the Parton Distribution Functions (PDFs) of a muon. In this paper we study the phenomenology related to the $\hat{I}{½}_{\hat{I}}¼$ PDF at future high-energy muon colliders. We examine total rates and differential distributions of the $e\bar{\hat{I}}{½}_e$ and $W{\hat{I}}^3$ production processes, which receive a large, and often dominant, contribution from this PDF, allowing for a detailed experimental study. As a demonstration of the impact the $\hat{I}{½}_{\hat{I}}¼$ PDF could have for searches of new physics, we study the charged-current pair production of a couple of heavy states, components of a $\mathrm{SU}(2{)}_L$ doublet. In both $e\bar{\hat{I}}{½}_e$ production and charged-current pair production of heavy states, we compare results obtained using PDFs with those of a fixed-order simulation.

22 pages, 12 figures. v2: added analysis of charged-current production of heavy scalars, removed discussion of single-Higgs production