The US Long Baseline Neutrino Experiment Study - 1 Plenary Meeting of the International Design Study for the Neutrino Factory, CERN, Mar 29-31, 2007 Mary Bishai (BNL) mbishai@bnl.gov Mary Bishai, BNL 1 – p.1/37
U.S. Long Baseline ν Study The Chairs: Sally Dawson (BNL) and Hugh Montgomery (FNAL). Advisory Committee: Franco Cervelli (INFN) Milind Diwan (BNL); co-leader, Maury Goodman (ANL), Bonnie Fleming (Yale), Karsten Heeger (LBL), Takaaki Kajita (Tokyo), Josh Klein (Texas), Steve Parke (FNAL), Gina Rameika (FNAL); co-leader The Charge: Compare the neutrino oscillation physics potential of (report to NuSAG): 1) A broad-band proposal using either an upgraded beam of around 1 MW from the current Fermilab accelerator complex or a future Fermilab Proton Driver (PD) neutrino beam aimed at a DUSEL-based detector (Water Cerenkov and/or Liquid Argon). [this talk] 2) Off-Axis next generation options using a 1-2 MW neutrino beam from Fermilab and a liquid argon detector as a second detector for the NOVA experiment. [Niki Saoulidou’s talk] Status: Documents at http://nwg.phy.bnl.gov/fnal-bnl/ Mary Bishai, BNL 2 – p.2/37
BEAM SPECIFICATIONS AND DESIGNS ”Fermilab Proton Projections for Long-Baseline Neutrino Beams,” Robert Zwaska for the SNuMI planning group, July 17, 2006. FNAL-Beams-DOC-2393 ”Target System for a Long Baseline Neutrino Beam,” N. Simos, H. Kirk, J. Gallardo, S. Kahn, N. Mokhov. June 26, 2006. “Simulation of a Wide-band Low-Energy Neutrino Beam for Very Long Baseline Neutrino Oscillation Experiments,” M. Bishai, J. Heim, C. Lewis, A. D. Marino, B. Viren, F. Yumiceva, July 20, 2006 Mary Bishai, BNL 3 – p.3/37
Beam Options/Baselines NOVA II (NuMI off−axis) 810km HomeStake Mine,SD 1300km 2540km 1500km FNAL−MI BNL−AGS 2700km Henderson Mine, CO The following beam options and baselines are considered: Off axis beams using the 120 GeV NuMI beamline at FNAL to sites at 810km. A 28 GeV on-axis Wide-Band Beam (WBB) beam from the BNL AGS to DUSEL sites at 2540 and 2700 km. A newly designed on-axis ≤ 120 GeV Wide Band Low Energy (WBLE) beam and beamline from the FNAL MI to DUSEL sites at 1300km and 1500km. For the current study we will concentrate on beam options from FNAL Mary Bishai, BNL 4 – p.4/37
FNAL Beam Specs: E & Power Incremental upgrades possible (no proton driver): Use the existing recycler and anti- proton accumulator to store protons from the 8 GeV 15 Hz Booster during the MI cycle then inject to MI bringing intensity up to 6 × 10 13 p/ spill. Mary Bishai, BNL 5 – p.5/37
WBLE Beam Design Requirements The design specifications of a new WBLE beam based at the Fermilab MI are driven by the physics of ν µ → ν e oscillations: WBLE 120 GeV, CC rate, sin2theta13=0.02, at 1300km, 12km off-axis 0.1 24 Appearance Probability numu CC events (evt/GeV/(MW.1E7s)/kTon) cp=270 deg Requirements: 22 cp=180 deg 20 cp=90 deg 0.08 -Maximal possible neutrino fluxes 18 cp=0 deg 16 to encompass the 1st and 2nd 0.06 14 12 oscillation nodes, with maxima 10 0.04 8 at 2.4 and 0.8 GeV. 6 0.02 4 -High purity ν µ beam with negligible 2 0 0 -1 -0.5 0 0.5 1 1.5 2 ν e log(Energy/GeV) L = 1300 km -Minimize the neutral-current feed-down contamination at lower energy, therefore minimizing the flux of neutrinos with energies greater than 5 GeV where there is no sensitivity to the oscillation parameters is highly desirable. Mary Bishai, BNL 6 – p.6/37
WBLE Beam Spectra for VLBNO Decay pipe radius chosen to be 2m = the maximum that can be accomodated in FNAL rock with concrete shielding for a MW class beam. Siting restrictions at FNAL ⇒ decay pipe is ≤ 400 m in length WBLE beam, different energies, decay tunnels WBLE beam, different energies, decay tunnels WBLE 120 GeV beam, different off-axis angles, decay tunnels 10 -4 -4 /POT at 1Km 10 AGS 28 GeV (x4.3) WBLE, 120 GeV, 250 kA, Z=380m, R=2m WBLE, 60 GeV, 250 kA, Z=380m, R=2m WBLE 120 GeV, 380m long, 0.5 deg* ν µ, S/GEV/M 2 /POT AT 1KM WBLE, 40 GeV, 250 kA, Z=380m, R=2m WBLE 120 GeV, 180m long, 0.5 deg WBLE, 28 GeV, 250 kA, Z=380m, R=2m WBLE 120 GeV, 180m long, 0.25 deg -5 10 WBLE, 28 GeV, 250 kA, Z=180m, R=2m, 2 10 -5 WBLE 120 GeV, 180m long, 0.0 deg /GeV/m ν -6 10 10 -6 -7 10 10 -7 -8 10 0 5 10 15 20 25 0 5 10 15 20 ν E( ) GeV Neutrino Energy in GeV GEANT 3.21 simulation of wide-band horns+decay pipe, with FLUKA ’05 for target hadro-production. Based on NuMI simulation which matches observed MINOS event rate to 10% in 0 - 7 GeV range Mary Bishai, BNL 7 – p.7/37
ν e Appearance Rates 21 , 31 = 8 . 6 × 10 − 5 , 2 . 5 × 10 − 3 eV 2 , sin 2 2 θ 12 , 23 = 0 . 86 , 1 . 0 ∆ m 2 ν µ → ν e rate ν µ → ¯ ¯ ν e rates sin 2 2 θ 13 (sign of ∆ m 2 δ CP deg. 31 ) 0 ◦ -90 ◦ 180 ◦ +90 ◦ 0 ◦ -90 ◦ 180 ◦ +90 ◦ NuMI LE beam tune at 810km, per 100kT. MW. 10 7 s Beam ν e = 43 ∗ Beam ¯ ν e = 17 ∗ 15 mRad off-axis (NO ν A) (+) 0.02 76 108 69 36 20 7.7 17 30 (-) 0.02 46 77 52 21 28 14 28 42 Beam ν e = 11 ∗ Beam ¯ ν e = 3.4 ∗ 50 mRad off-axis (+) 0.02 5.7 8.8 5.1 2.2 2.5 1.6 0.7 3.3 (-) 0.02 4.2 8.0 5.7 2.0 2.3 2.2 0.8 3.6 WBLE 120 GeV beam at 1300km, per 100kT. MW. 10 7 s Beam ν e = 47 ∗∗ Beam ¯ ν e = 17 ∗∗ 9 mRad off-axis (+/-) 0.0 14 N/A N/A N/A 5.0 N/A N/A N/A (+) 0.02 87 134 95 48 20 7.2 15 27 (-) 0.02 39 72 51 19 38 19 33 52 ∗ = 0-3 GeV ∗∗ = 0-5 GeV, 1 MW. 10 7 s = 5 . 2 × 10 20 POT at 120 GeV, 1yr = 1 . 7 × 10 7 s Mary Bishai, BNL 8 – p.8/37
ν e Appearance Spectra —- sin 2 2 θ 13 = 0 . 02 , δ cp = 0 , normal hierarchy —- sin 2 2 θ 13 = 0 . 02 , δ cp = π , normal hierarchy —- sin 2 2 θ 13 = 0 . 02 , δ cp = − π/ 2 , reverse hierarchy NuMI LE at NO ν A WBLE 60 GeV at 1300km Spectral information = resolves degeneracies Mary Bishai, BNL 9 – p.9/37
FAR DETECTOR DESIGN/SIMULATIONS ”Background Rejection Study in a water Cherenkov detector.” C. Yanagisawa, C. K. Jung, P.T. Le, B. Viren, July 18, 2006 “T2KK Project & Likelihood study”. Fanny Dufour, FNAL-BNL VLB workshop, September 16, 2006 ”Monte Carlo study of a liquid Ar time projection chamber for long baseline neutrino experiments.” A. Curioni, August 10, 2006. www-larptc.fnal.gov/LBStudy LAr/2006LB.html Mary Bishai, BNL 10 – p.10/37
Water Cerenkov Simulation The ν atm GEANT simulation of SuperKamiokande is used. An π 0 reconstruction algorithim called “Pattern Of Light Fit” is used as input to a likelihood (DLH) analysis to reconstruct π 0 → γγ by looking for the 2nd ring. Independent studies by Chiaki Yanagisawa for FNAL-DUSEL WBB and Fanny Dufour for T2KK produce similar efficiency for signal and background. Super-K pre-selection DLH selection 1.00 0.50 ν e CC signal ν e CC signal NC NC 0.40 0.75 Selection Efficiency Selection Efficiency 0.30 0.50 0.20 0.25 0.10 0.00 0.00 0 1 2 3 4 5 0 1 2 3 4 5 E ν (GeV) E reco (GeV) Standard Super-K pre-selection efficiencies DLH selection efficiencies (Chiaki Y.) WCe. energy dependent efficiencies and smearing implemented in GLoBeS. Mary Bishai, BNL 11 – p.11/37
GLoBeS ν e Appearance Spectra sin 2 2 θ 13 = 0 . 04 , 300kT WCe. , WBLE 120 GeV, 1300km, 30E20 POT. Normal hierarchy ( — δ cp = − 45 ◦ , — δ cp = +45 ◦ ) Reversed hierarchy Events/0.25 GeV Events/0.25 GeV 20 20 ν signal + background: ν signal + background: running, 1300km, 30 10 PoT running, 1300km, 30 10 PoT 90 70 2 -5 -3 2 o 2 -5 -3 2 o ∆ δ ∆ δ m = 8.6 10 , +2.7 10 eV =+45 (702.5 evts) m = 8.6 10 , -2.7 10 eV =+45 (538.0 evts) CP CP 21,31 21,31 2 θ 2 θ δ o δ o sin 2 = 0.86, 1.00, 0.04 = +0 (807.3 evts) sin 2 = 0.86, 1.00, 0.04 = +0 (607.0 evts) 80 (12,23,13) CP (12,23,13) CP δ o 60 δ o =-45 (933.5 evts) =-45 (687.6 evts) CP CP 70 background: background: 50 all (414.7 evts) all (418.5 evts) 60 ν ν beam (196.4 evts) beam (199.3 evts) e e 40 50 40 Neutrino Neutrino 30 30 20 20 10 10 0 0 1 10 1 10 neutrino energy [GeV] neutrino energy [GeV] 40 Events/0.25 GeV Events/0.25 GeV ν 20 ν 20 signal + background: signal + background: running, 1300km, 30 10 PoT running, 1300km, 30 10 PoT 2 -5 -3 2 δ o 2 -5 -3 2 δ o ∆ ∆ m = 8.6 10 , +2.7 10 eV =+45 (366.2 evts) m = 8.6 10 , -2.7 10 eV =+45 (492.8 evts) 50 CP CP 21,31 21,31 35 2 2 θ o θ o sin 2 = 0.86, 1.00, 0.04 δ sin 2 = 0.86, 1.00, 0.04 δ = +0 (341.8 evts) = +0 (449.0 evts) CP CP (12,23,13) (12,23,13) δ o δ o =-45 (311.2 evts) =-45 (394.9 evts) CP CP 30 background: 40 background: all (201.1 evts) all (200.2 evts) 25 ν ν beam (120.6 evts) beam (119.3 evts) e e 30 20 Anti-Neutrino Anti-Neutrino 15 20 10 10 5 0 0 1 10 1 10 neutrino energy [GeV] neutrino energy [GeV] Mary Bishai, BNL 12 – p.12/37
Recommend
More recommend
