The Status of MINOS

Mike KordoskyUniversity College London

for the collaboration

Outline

● NuMI / MINOS introduction and physics goals

● MINOS Detector description● Cosmic Rays and atmospheric at the Far

Detector● Experience with beam running in the Near

Detector● Near term goals and Conclusion

What is MINOS?

● Main Injector Neutrino Oscillation Search

● Long (735 km) Baseline

● Intense Neutrino Beam (NuMI)

● Near detector @ Fermilab

● Far detector @ Soudan, MN

Neutrino beam

Near detector

Far detector

● Muon neutrino disappearance

● Electron neutrino appearance

● Sterile neutrino component

● Atmospheric neutrinos

MINOS will study:

MINOS is the :

MINOS Collaboration The collaboration on the Fermilab site

with Near Detector surface building in background

Argonne – Athens – Benedictine – Brookhaven – Caltech – Cambridge – Campinas – Fermilab – College de France – Harvard – IIT – Indiana – ITEP Moscow – Lebedev – Livermore – Minnesota, Twin Cities – Minnesota, Duluth – Oxford – Pittsburgh – Protvino – Rutherford Appleton – Sao Paulo – South Carolina – Stanford – Sussex – Texas A&M – Texas-Austin – Tufts – Univ. College London – Western Washington – William & Mary - Wisconsin

175 physicists

32 institutions

6 nations

Disappearance

Survival Probability

● “atmospheric” oscillations from a beam source

● strong test of alternative hypotheses

● Large improvement in m2 measurement

● primary limitation: protons on target

nominal 3yr run

Electron Neutrino Appearance

● Much interest in e appearance and value of

13

● Measurement very challenging with MINOS detector & NuMI beam!

● But, if 13

is close to CHOOZ limit, we will see a ~3 signal in about 3yrs of

running

● Otherwise, will improve current limit by factor of 2-3

NuMI Beam

120 GeV/c p on graphite target

Magnetic Hornsfocus K

677 m decay pipe p,K stopped

Near detector

Control neutrino spectrum-- Move horns-- Move target

Neutrinos at the Main Injector

Near Detector

● Steel + Scint.

● 1km from Target

● 0.98 kton

● 282 steel planes

● B=1.2 T

● 64-anode PMTs

● High Rates

● QIE electronics

– no deadtime!

Near detector during construction

Coil Hole

Sci. Plane

PMTs, QIE electronics

PurposeMeasure beam before oscillations

Predict Far detector spectrum

To Far detector

Beam

Far Detector

● Soudan, MN

● 735 km from source

● 5.4 kton

● 486 steel planes

● B=1.3 T

● 16-anode PMTs

● 8x multiplexed

● VA electronics

Far detector: completed July 2003

Field Coil

PurposeMeasure -CC, NCenergy spectra, rates

Search for e appearance

PMTs & Electronics

To Fermilab

Veto shield

Optical Readout

8m wide

CalDet in T7

1 m

Optical Cables

PMTs

Beam

● Ran @ CERN PS

– T11: 0.5-3.6 GeV/c

– T7: 0.5-10.0 GeV/c

– mixed p,e,pi,mu beams

● Sixty 1-m2 planes

● Light level ~ Near and Far

● No B-field

● Ran w/ Far & Near readout

● External PID: CER & TOF

The CalDet

Purpose:

- Measure Response & Resolution- Characterize Event Topology- Confront & optimze MC- Develop Calibration Procedure- Study Near vs. Far readout

Detector Technology

Special Thanks M. Proga

2.54cm Steel absorber (2.50cm in CalDet)

Scint. 1cm thick, 4.1 cm wide WLS Fibers

Multi-anode PMT

Fiber ''cookie''

Scint. Plane

Readout Cable

PMT DarkBox

● Tracking-sampling calorimeter

● Segmentation:

– 5.94cm longitudinal

– 4.1cm transverse

● Planes rotated +/- 90 deg

● WLS collects/routes light to PMTs

Atmospheric Neutrinos

48events Cosmic Rays

Ex: Upward going muons

● First underground detector with B-field

● Can distinguish vs.-bar oscillations

● First publication (FC and PC analysis) to be submitted this summer

Moon Shadow

● Have collected 1e7 cosmic-ray muons in the Far Detector

● Can be used to observe the moon's shadow

● Used to determine angular resolution: < 1degree

HE primary cosmic rays

Far Detector

Near Detector: Single Spills

LE beam ~3-4 events/1e13 ppp spill HE beam ~8 events/1e13 ppp spill

spectrometer multiplexedTwo views: “U vs. Z” and “V vs. Z”

Near Detector: Isolating Single Events

● continuous read-out for 18 s

● 18.9 ns timing resolution

● Single events isolated via timing and position: “Slicing” hit-time in spill (s)

hit-time in spill (s)

5 “batches”

Near Detector: Contained CC Event

hit-time in spill (s) ~1.5 GeV/c , ~1.1 GeV shower

Near Detector: Rock Muon

hit-time in spill (s) ~6.3 GeV/c

Near Detector: Event Vertices

● Neutrino event vertex for data collected in May

● Already enough events to observe detector structure

fiducial volume

Partially instrumented plane (m)

horizontal position (m)

vertical position (m)

Fully instrumented plane (m)

Near Detector: Muon Track Direction

● Figures show zenith and azimuthal angles of -CC muon

tracks

● Beam pointing towards Far Detector:

– Zenith: Downward ~3.3 degrees, cos()=0.06

– Azimuth: Slightly west of true north: =156 degrees

● Good agreement with expectations!

Near Detector: Energy Spectra

● Data collected for 3 target positions

● More than 1.3e5 -CC

events recorded in May!

Near Detector -CC

events

reconstructed neutrino energy (GeV)

Far Detector: First Event

● First Event observed in the Far Detector: March 20, 2005.

● Event consists of a muon emanating from the rock in front of the detector.

● Muon points back to Fermilab and was in time with a beam spill.

Next Step: Choice of Beam Energy

● Run with low energy beam for first few months (~1e20 POT)

● Conduct initial oscillation analysis to check beam energy

Summary

● MINOS is taking beam data!

● Both detectors and NuMI beam operating rather smoothly.

● More than 140k nm-CC events recorded in Near Detector during May!

● Beam neutrinos observed in Far Detector!

● Initial oscillation analysis after ~1e20 POT, used to check beam configuration.

● Forthcoming atmospheric neutrino analysis.