Measurement of the calorimetric energy scale in MINOS

Abstract

MINOS is a long-baseline neutrino oscillation experiment. A neutrino beam is created at the Fermi National Accelerator Laboratory in Illinois and fired down through the Earth. Measurements of the energy spectra and composition of the neutrino beam are made both at the source using the Near detector and 735 km away at the Soudan Underground Laboratory in Minnesota using the Far detector. By comparing the spectrum and flavour composition of the neutrino beam between the two detectors neutrino oscillations can be observed. Such a comparison depends on the accuracy of the relative calorimetric energy scale.This thesis details a precise measurement of the calorimetric energy scale of the MINOS Far detector and Calibration detector using stopping muons with a new "track window" technique. These measurements are used to perform the relative calibration between the two detectors. This calibration has been accomplished to 1.7% in data and to significantly better than 2% in the Monte Carlo simulation, thus achieving the MINOS relative calibration target of 2%.A number of cross-checks have been performed to ensure the robustness of the calorimetric energy scale measurements. At the Calibration detector the test-beam energy between run periods is found to be consistent with the detector response to better than 2% after the relative calibration is applied. The muon energy loss in the MINOS detectors determined from Bethe-Bloch predictions, data and Monte Carlo are compared and understood.To estimate the systematic error on the measurement of the neutrino oscillation parameters caused by a relative miscalibration a study is performed. A 2% relative miscalibration is shown to cause a 0.6% bias in the values of ∆m 2 and sin 2 (2θ).To my parents.i

Sterile neutrino oscillations in MINOS and hadron production in pC collisions

“…This technique is referred to as the "track window" technique, as the window to calculate the energy deposited is meant to select the hits which are close to the minimum ionising stage [103]. The final conversion of the detector pulse height into particle energy is achieved through the MINOS calibration detector [88] which was exposed to test beams of different particles at CERN.…”

An atmospheric muon neutrino disappearance measurement with the MINOS far detector

“…Thus one final calibration must be done, to translate this almost-fullycalibrated pulse height into a specific amount of energy deposition, known as the Muon Energy Unit, or M EU . The M EU is, ignoring small strip-to-strip variation, the detector response to a 1 GeV muon traversing 1 plane of scintillator at normal incidence [46].…”

“…A large ensemble of these averages is acquired, and the median of that ensemble is taken to be one M EU [46].…”

Preliminary Measurement of Neutrino Oscillation Parameters By NuMI/MINOS and Calibration Studies for Improving this Measurement

“…This value is also known as the muon energy unit (MEU) and is a value in ADC counts. The relative value of the MEU in the NearDet and FarDet compared to CalDet is used as the relative calibration [66].…”

“…The single cosmic muon ux is 0.42 &' which gives about 400 hits per strip per month [2]. Through-going muons are used since there is only a 10% difference in energy deposition between 1-10 [66]. Each muon produces 12 p.e.…”