Physics with a detector at Homestake Milind Diwan

Physics with a detector at Homestake Milind Diwan (BNL) 2/21/2008 SLAC P 5 meeting Total event rate with 300 k. T and 2 MW is ~200000 cc evts/yr (no oscillations, raw events) The Study: http: //nwg. phy. bnl. gov/fnalbnl yr~2 x 10⁷ sec

• Proposal for an Experimental Program in Neutrino Physics and Proton Decay in the Homestake Laboratory Developing Collaboration This is the author list of hep-ex/0608023 August 2006 2

Outline • Scientific/Technical issues for a new long baseline experiment regarding CP violation. • Ultimate reach with a detector at DUSEL and a conventional beam from FNAL. • Implementation with the first 100 k. T detector. 3

Scientific strategy • The Study: A very large detector is needed for the next steps for θ 13, mass ordering, and CP violation coming from the standard 3 -generation scenario. • The Study: Program should have broad physics capability: nucleon decay, supernova detection, astrophysical neutrinos. • Conventional wisdom: Experimental set up with a large matter effect, such as for 1300 km, is more sensitive to possible new physics. • For neutrino mixing the experiment must have internal redundancy to check 3 -gen CP violation and get hints of new physics if they are there. 4

Technical issues • Program should lead to measurement of 3 -generation parameters without ambiguities. (recall: CP measurement is approximately independent of θ 13). Need large detector independent of θ 13 value. • An offaxis program cannot overcome ambiguities easily. 300 k. T water Cherenkov detector @DUSEL Measurement of CP phase and Sin² 2θ 13 at several points. All ambiguities and mass hierarchy are resolved. 5

sin² 2θ₁₃= 0. 04, 300 k. T, 1300 km, ~2 MW @ 60 Ge. V 3 yrs neutrinos and 3 yrs antineutrinos Normal Reversed Spectra with 300 k. T detector and 2 MW beam from FNAL sig~1214 sig~564 • Background issues examined by FNAL/BNL study. sig~394 sig~627 Mark Dierckxsens(UChicago), Mary Bishai(BNL) 6 si

Ultimate Reach 60 Ge. V, 2 MW, 3+3 yrs, 300 k. T Mass ordering CP Violation θ₁₃ 0. 007 50% coverage at 3 sigma 0. 003 stat+ 5%syst Mark Dierckxsens(UChicago), Mary Bishai(BNL) 7

Intermediate proposal • ~100 k. T fiducial detector at Homestake with rock mechanics studies starting in fall of 2008. (Homestake Interim Lab. now exists, Super. K and SNO experience and success gives confidence in feasibility and performance. ) • New wide band beam from FNAL (pre-Project x) • Focus on θ 13, and mass hierarchy. • Get started on CP violation, p-decay, Supernovae. 8

sin² 2θ₁₃= 0. 04, 100 k. T, 1300 km, ~1 MW 60 Ge. V 3 yrs neutrinos and 3 yrs antineutrinos Normal Reversed Spectra with 100 k. T detector and 1 MW beam from FNAL s~210 s ~ s~100 400 evt Total rate of events ~30 k/yr noosc/raw evts s~60 9 s~100

Reach with 100 k. T water Cherenkov 60 Ge. V, 1 MW, 3+3 yrs, 100 k. T θ₁₃ Mass ordering 0. 025 0. 008 50% coverage at 3 sigma stat+5% syst 10

Same plots detail 3 yrs θ 13 3 yrs Mass ordering @ 2 sigma Same exposure in MW*10⁷ sec as previous plot 11

(Former Homestake Chief engineer)

muon rate/cavern~1/10 Hz 180 ft dia Rock removal at 5000 L (new) Parallel Access tunnel at 4850 L (new)

Technically limited schedule for a single 100 k. T fiducial detector Turn-on • Tube production is slowed to match excavation. Tube production is NOT the limiting factor. • For simplicity, water system, PMT testing, electronics, etc. are not shown. • For 300 k. T the time need not be tripled. 14

One time costs over next 3 yrs does not include R&D • 100 k. T estimate on next page and one time costs that are needed to establish the entire facility for the megaton-class detector. Item Cost Source Chamber design and coring $0. 76 M Laurenti Access tunnels $4. 5 M Laurenti Contingency $2. 6 M 50% of above Mining + other equip. $10. 0 M Laurenti PMT+Elec. R&D $4. 0 M Prel. Eng. +Subcontracts Water/materials R&D $2. 0 M Preliminary Contingency (non-civil) $3. 2 M Equip. has quotes Total $27. 1 M FY 2007 15

Summary cost for 100 k. T(do not triple for 300 k. T) Item Cost Source Single Cavity construction $28. 1 M* Laurenti contingency 30% $8. 4 M Preliminary Reviews PMT(50000 chan) $46. 7 M Auger, NNN 05, etc. Electronics, cables $10. 65 M UPenn+SNO Installation $8. 75 M Conceptual Water, DAQ, testing, etc. $11. 4 M Quote, made for 300 k. T Contingency(non-civil) $25. 0 M >30% for some items Total $139 M FY 2007 * Cost and schedule reviewed by RESPEC, does not have rock disposal 16

Conclusion • 100 k. T detector could be ready for physics by mid decade (~2015). • Unique physics capability in the world. Excellent sensitivity for θ₁₃ and mass ordering. • Get started on much larger program for CP violation, Nucleon decay, and Supernova physics. • Subsequent caverns could house different technology: better PMTs, Liquid Scintillator, Liquid Argon. . . 17

From Mark Laurenti Excavation costs do not include • General operations: mine, shaft, pumps, ventilation • Overhead functions: office, property maintenance, water consumption, power. • Mobilization/demobilization • Waste handling • EDIA • Do not triple for 3 caverns. 18

Collaboration requesting funds from DUSEL R&D One time costs From Mark Laurenti 19

Capital Investment From Mark Laurenti 20

100 k. T water Cherenkov CP reach

• • Nucleon decay and Supernova Large body of work by Hyper. K, and UNO. background levels for the positron+Pion mode • • 3. 6/MTon-yr (normal) 0. 15/MTon-yr (tight) Expected Sensitivity on K-nu mode is about ~8 x 10³³ yr Galactic Supernova in 300 k. T: 100000 evts/10 sec Ref: Shiozawa (NNN 05) 22 300 k. TX 10 yrs => 7 X 10³⁴ yrs