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A VLBL experiment to Measure CP, sin 2 2 q 13 and D m 2 23 sign. Yifang Wang. Content. Why LBL Optimum baseline ? Physics potential A detector design. We Know Now | D m 2 32 |, sin 2 2 q 32 ---- SuperK D m 2 21 , sin 2 2 q 21 ---- KamLAND,SNO
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A VLBL experiment to Measure CP, sin22q13 and Dm223 sign Yifang Wang
Content • Why LBL • Optimum baseline ? • Physics potential • A detector design
We Know Now |D m232|, sin22q32 ---- SuperK D m221, sin22q21 ---- KamLAND,SNO • We Want to Know in future • sin22q13, ±Dm232,d • Daya Bay n factory/beam
What is the optimum baseline ? Y.F. Wang et. al, PRD Phys. Rev. D65 (2002) 073006
A. Malensek, Fermilab note FN-341; M. Bonesini et al., EPJC20(2000)13
T2B and T2K: complimentaryY-F. Wang et al., Phys. Rev. D65 (2002) 073021
T2B and T2K: complimentary Aoki, K. Hagiwara et al, PRD 67(2003)093004
Study of density effects: Lian-You Shan et al., Phys. Rev. D 68 (2003) 013002
Detector Requirements • Particle ID: e, m, t • Pattern recognition: NC vs CC,nm vs ne • Energy resolution: P(En), Eff./Bkg • Charge ID(only fornF): wrong-sign muon • LARGE MASS
Currently(Proposed) Detectors for n Factory/Beam A 0.1-1.0 MT magnetized detector at 0.2-0.4M/kt ?
Water Cerenkov Calorimeter Dimensions: 4020125 m3 Each cell: 1 1 10 m3 10,000 tanks => 100Kt Segmentation to be optimized depending on the n beam, experimental hall, price, ... Y.F. Wang , NIM. A503(2003)141
PVC Water tanks with Reflective lining, viewed by two 8” PMT/tank Cerenkov light yield: 20,000 photons/meter For 20 m attenuation length, 90% reflection eff. Light collection eff. 20% Cone collection eff. 10% PMT Quantum eff. 20% Total 0.4% For through-going muons, 80 PE/Tank 1 m water = 2.77 X0 = 1.5 l0
Typical numbers • 3010300 m3 • 10,000 water tanks • 20,000 8” PMT/readout channels • 100,000 m2 RPC • 50,000 chambers
Excellent energy resolution from a homogeneous calorimeter Bias is intrinsic to Cerenkov detector, can be corrected
RPC • X-Y planes for each layer • 4 cm strip size • A total of 4105 m2 • identify cosmic-ray events • use cosmic-muons for calibration • pattern recognition • event shape, direction • tracking for charge ID
Toroid Magnet IF Pmmin= 5 GeV, we need 40 cm thick steel plate as magnet for every 20 m, a total of 6 magnet segments Total magnet weight: 16 kT
Large detector with excellent energy resolution and pattern recognition capabilities • Detector for n factory/beam • cosmic-ray composition • Supernova • Search for WIMPs, verify DAMA's results • Search for monopoles • Search for proton decays • Search for point and diffused sources • Search for large scale anisotropies • Search for fractionally charged particles • Lots of other cosmic-ray physics
A Simple Exercise: D m232 = D m231 = 3 10-3 eV2 D m221 = 5 10-5 eV2 sin22q32 = sin22q21 = 1 sin22q31 = 0.059 d = 0 A = 1 10-4 eV2 /GeV
Two Scenarios considered for the near future: A) JHF(HIPA) to Beijing L=2100 km 1300 events/100kt-Yr
B) Fermilab to Minos L=735 km 45K evts/100kt-Yr
Well reconstructed jet for e, m and good energy resolution for En
M.J. Chen et al., NIM accepted 1m*1m*13m尺寸的水箱模型
Total Volume: 250K m3
Summary • LBL experiments for CP and matter effects are needed • 2000-3000 km is an optimum baseline • Degeneracy of parameters can be solved by experiments at different baselines; earth density is a factor to be considered seriously • Water cherenkov detector is a good choice for such an experiment