STATUS of the MINOS Experiment

1. STATUS of the MINOS Experiment Argonne • Athens • Brookhaven • Caltech • Cambridge • Campinas • Dubna • Fermilab College de France • Harvard • Illinois Inst. of Technology • Indiana • ITEP-Moscow • Lebedev Livermore • Macalester • Minnesota-Twin Cities • Minnesota-Duluth • Oxford • Pittsburgh Protvino • Rutherford • Sao Paulo • South Carolina • Stanford • Sussex • Texas A&MTexas-Austin • Tufts • University College London • Western Washington • Wisconsin P. Shanahan MINOS Collaboration

2. MINOS • Main Injector Neutrino Oscillation Search • Precision Dm2 and sin2(2q) measurement in nmdisappearance • Beam from Fermilab Main Injector: Mostly nm, tuneable energy • 2 detectors separated by 735km baseline • Near Detector: 1kt detector at Fermilab • Far Detector: 5.4kt detector at Soudan • Improved nmne limits • At 735 km, SK Dm21-4 GeV oscillation maximum 735 km P. Shanahan MINOS Collaboration

3. NuMI Beam 1270 events/kt-yr • Neutrinos at the Main Injector • 120 GeV Protons from Fermilab Main Injector • 10ms pulse, every 1.9s • Proton Intensity: • 4x1013 protons/pulse design • 2.5x1013 p/p expected at startup • Hadrons focused with 2 horns • Horn and target positionstune beam energy spectrum 2740 events/kt-yr 470 events/kt-yr 1040 m n Main Injector Rock: 240m,muon monitors 103 m Target, Horns Not to scale Decay pipe: 678m x 1m radius Hadron Absorber: 4.7 m Al/Fe Near Detector P. Shanahan MINOS Collaboration

4. NuMI Beam Status • Excavation of underground complex complete • Decay Pipe installed • Tunnel/Hall Outfitting in progress • Target has been fabricated • Horns have been assembled • Project will be complete/ commissioning starts Dec. 2004 MINOS Near Detector Hall (100m underground) Some of the NuMI Shielding - Much more than mass of Near and Far Detectors combined! P. Shanahan MINOS Collaboration

5. NuMI Beam Status Decay Pipe Horn 2 Assembly Decay Pipe encased in concrete to protect groundwater P. Shanahan MINOS Collaboration

6. Far Detector • 5.4kt total • 484 planes in two ~14.5m long “super modules” • Each plane 8m octagon • 2.54cm Fe, 1cm Scintillator • ~1.5T Magnetic field • Readout • 2 ended readout • 8x optical multiplexing into M16 multi-anode PMTs • ~92k strips, 23k channels • Overburden • 710 m (2090 mwe) 8m Magnet Coil 1 supermodule P. Shanahan MINOS Collaboration

7. Far Detector Status • Far Detector construction completed! • 1st supermodule operational since 7/02 • Veto Shield • Build from same scintillator used in detector • Help ID Atmospheric neutrino interactions A person Completed MINOS Far Detector P. Shanahan MINOS Collaboration

8. Y X Z Far Detector Data Example: 5.4 GeV/c up going m • Up Going Muons: n interactions below detector • Use timing to select up going muons • Magnetic Field • Distinguish m-, m+ Time vs. Y Up Going m log10(p) distributions Other sign m One sign m MINOS PRELIMINARY UPGOING MUON DATA P. Shanahan MINOS Collaboration

9. Atmospheric Neutrinos • MINOS is 1st Large, Underground detector with Magnetic Field • Distinguish m- from m+ • nmvs. nm • CPT test: P(nmnm)= P(nmnm)? Expected number of events: Number of events in Neutrino Antineutrino 24 kT years Reconstructed contained 440 260 vertex with muon Reconstructed upgoing muon 280 120 For Dm2=0.003 eV2, sin2 2q = 1.0 c2 Probability for nominal neutrino oscillation parameters compared to different values of Dm2 for antineutrinos. P. Shanahan MINOS Collaboration

10. Near Detector • Same sampling/structure as far detector • 980 t • High rate (10ms spill) • HE beam: 20 interactions/m/spill • LE beam: 3.2 interactions/m/spill • High speed electronics • 4x multiplexing in spectrometer only • All Planes have been assembled P. Shanahan MINOS Collaboration

11. MINOS n Event Topologies • nm identified by m in Charged Current interactions Interaction length6 planes MIP energy loss = 30MeV/plane nm CC n NC 1.2m ~1.0m 4.7m 1.7m Example Monte Carlo events Pulse height vs. Strip & plane 4-5 GeV neutrinos 1 plane  1.4 X0 ne CC P. Shanahan MINOS Collaboration 0.7m

12. CC events Oscillation Measurement • nm Charged Current events • Far detector observed/expectation for no oscillations • Energy dependence yields oscillation parameters • The Details… • Hadron production • Unlike Far, Near Detector sees non-point source of neutrinos • MIPP - hadron production experiment at Fermilab • Neutrino Cross sections • Detector response & Calibration • 2% relative, 5% absolute • CALDET calibration detector at CERN • See C. Smith’s talk in detector session Example No osc. Dm2=2x10-3 eV2 sin2(2q)=0.9 P. Shanahan MINOS Collaboration

13. 5 Year Plan • MINOS Collaboration has submitted a 5 year plan to Fermilab Physics Advisory Committee • Physics with beam starts 2005 • Expect 2.5x1020 protons 1st year • Request 25x1020 p.o.t total MC with Dm2 = 0.0025 eV2, sin2 2q = 1.0 P. Shanahan MINOS Collaboration

14. Electron Neutrino Appearance For Dm2 = 0.0025 eV2, sin2 2q13= 0.067 For Dm2 = 0.0025 eV2 3 s discovery potential for three different levels of protons on target and versus systematic uncertainty on the background. Observed number of ne CC candidates with and without oscillations. 25x1020 protons on target. P. Shanahan MINOS Collaboration

15. Summary • MINOS – Main Injector Neutrino Oscillation Search • 1kt Near Detector at Fermilab, 5.4kt Far Detector at Soudan, MN • nm disappearance • Demonstrate oscillatory energy dependence of effect • Precision measurements of Dm2, sin2(2q) (10%) • ne appearance • Improved bounds on |Ue3|2 • Status • Far Detector construction complete • Beam tunnel and Near Detector hall complete • Installation to start early 2004 • Physics starting April 2005 P. Shanahan MINOS Collaboration