The future prospects of muon colliders and neutrino factories

TL;DR

This paper reviews the potential and challenges of muon beams for high energy physics, comparing proton and positron driver approaches, and discusses recent designs for muon colliders and neutrino factories.

Contribution

It provides a comprehensive comparison of proton and positron driver methods for muon beam production and discusses recent design studies for high-energy muon colliders.

Findings

Proton driver concepts are based on Muon Accelerator Program studies.

The LEMMA positron-driven source offers an attractive path to high-energy colliders.

A 14 TeV muon collider in the LHC tunnel could match the physics reach of a 100 TeV collider.

Abstract

The potential of muon beams for high energy physics applications is described along with the challenges of producing high quality muon beams. Two proposed approaches for delivering high intensity muon beams, a proton driver source and a positron driver source, are described and compared. The proton driver concepts are based on the studies from the Muon Accelerator Program (MAP). The MAP effort focused on a path to deliver muon-based facilities, ranging from neutrino factories to muon colliders, that could span research needs at both the intensity and energy frontiers. The Low EMittance Muon Accelerator (LEMMA) concept, which uses a positron-driven source, provides an attractive path to very high energy lepton colliders with improved particle backgrounds. The recent study of a 14 TeV muon collider in the LHC tunnel, which could leverage the existing CERN injectors and infrastructure and provide physics reach comparable to the 100 TeV FCC-hh, at lower cost and with cleaner physics conditions, is also discussed. The present status of the design and R&D efforts towards each of these sources is described. A summary of important R&D required to establish a facility path for each concept is also presented.