Recent Results from the MINOS experiment

TL;DR

The MINOS experiment at Fermilab has provided precise measurements of neutrino oscillation parameters, analyzed sterile neutrino components, and searched for electron neutrino appearance, with recent results setting limits on key mixing angles.

Contribution

This paper reports recent experimental results from MINOS, including precise measurements of neutrino oscillation parameters and limits on sterile neutrino components, based on extensive data analysis.

Findings

Measured $| riangle m^2_{32}|$ with high precision

Set a 90% C.L. limit of $ ext{sin}^2 2 heta_{13} < 0.29$

Analyzed neutral current data to constrain sterile neutrinos

Abstract

MINOS is an accelerator neutrino oscillation experiment at Fermilab. An intense high energy neutrino beam is produced at Fermilab and sent to a near detector on the Fermilab site and also to a 5 kTon far detector 735 km away in the Soudan mine in northern Minnesota. The experiment has now had several years of running with millions of events in the near detector and hundreds of events recorded in the far detector. I will report on the recent results from this experiment which include precise measurement of $|\Delta m^2_{32}|$, ~analysis of neutral current data to limit the component of sterile neutrinos, and the search for $\nu_\mu \to \nu_e$ conversion. The focus will be on the analysis of data for $\nu_\mu \to \nu_e$ conversion. Using data from an exposure of $3.14\times 10^{20}$ protons on target, we have selected electron type events in both the near and the far detector. The near detector is used to measure the background which is extrapolated to the far detector. We have found 35 events in the signal region with a background expectation of $27\pm 5(stat)\pm 2(syst)$. Using this observation we set a 90% C.L. limit of $\sin^2 2 \theta_{13} < 0.29$ for $\delta_{cp} = 0$ and normal mass hierarchy. Further analysis is under way to reduce backgrounds and improve sensitivity.