Status and prospects for long baseline experiments

Abstract

We will start with a brief overview of neutrino oscillation physics with emphasis on the remaining unanswered questions. Next we will discuss results and status of long baseline accelerator neutrino oscillation experiments that are in a mature data taking mode, have just started or are about to start data taking. Then, we will present the next generation of long baseline experiments with a primary goal to search for the yet to be measured third neutrino mixing angle. Finally we will introduce the plans for future long baseline accelerator neutrino oscillation experiments of which the primary goals are the search for CP violation in the neutrino sector, and the determination of the neutrino mass hierarchy. We will focus on experiments utilizing powerful (0.7 -4.0 MW) neutrino beams, either existing or in the design phase.

Beyond 3 neutrino oscillations

“…If, on the other hand, M µ, the seesaw mechanism [19] is realized. 3 In this case, the six neutrino mass eigenstates split into two triplets, one mostly made up of the active neutrinos (ν e,µ,τ ), the other mostly made up of the sterile neutrinos (ν s 1 ,s 2 ,s 3 ). The Majorana mass matrix of the mostly active states is m αβ = ∑ i µ α i M −1 i µ β i , while the mostly sterile states have masses M i (plus µM −1 corrections).…”

“…After several decades of confusion, neutrino oscillation data over the past ten years have revealed, beyond reasonable doubt, that neutrinos have mass and that leptons mix [1,2,3,4,5]. Almost all data from atmospheric, rector and accelerator neutrino experiments are consistent with the hypothesis that there are three neutrinos and that the standard model electroweak interactions properly describe all neutrino-associated processes.…”

“…Current and next-generation neutrino experiments [3,4,5,6] aim at definitively testing the three massive active neutrino hypothesis and, in the process, determining the "left-over" neutrino oscillation parameters (θ 13 , the CP-odd phase δ and the neutrino mass hierarchy). While almost all detailed discussions surrounding next-generation neutrino experiments concentrate on how well neutrino oscillation parameters can be measured or constrained, there is the possibility that "more" new physics, beyond massive neutrinos, can manifest itself in neutrino oscillations.…”