Tau Neutrino Appearance via Neutrino Oscillations in Atmospheric ...

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31350030002000 Radon monitor readings at SuperKMine Air (at sink)Control Room Air2500radon level [Bq/m^3]200015001000500001/01/00 03/01/00 05/01/00 07/01/00 09/01/00 11/01/00 01/01/01Figure 2.12: The upper histogram (solid curve) shows the measured radonconcentration levels in the mine air [58]. The lower histogram (dashed curve)shows the corresponding radon levels in the SK dome. Strong seasonal variationsin the flow of mine air affect the radon level in the detector.air from inside the mine. During summer, air flows out the tunnel and duringwinter, cold fresh air flows into the mine.Fresh air from outside the mine is continuously pumped into the SK domearea at the rate of 10 m 3 /minute through an air duct along the 1.8 km Atotsuaccess tunnel to the SK experimental area.A “Radon Hut” houses the air blowers, air filters and cooler, and is locatedat the Atotsu tunnel entrance to take the air from approximately 25meters above the entrance, where the radon level was found to remain at 10∼ 30 Bq/m 3 all year long. The fresh air is delivered into the Super-K experimentalarea at a rate of 10 m 3 /minute (in 2002, the flow rate was increasedto 50 m 3 /min to improve the air quality in the water purification system andto distribute fresh air to newly installed experimental rooms around the SKdetector area). As a result, the typical radon concentration in the SK domeair is 20 ∼ 30 mBq/m 3 .Furthermore, to keep the radon level inside the detector absolute minimum,radon-free air is produced by the air purification system in the mine and iscontinuously pumped into the space above the water surface inside the Super-Ktank at a positive pressure to prevent radon air from entering the detector anddissolving into the purified water [60]. A schematic view of the air purification
32system is shown in Figure 2.13. The radon concentration of the radon-free airis less than 3 mBq/m 3 . The air purification system consists of compressors, abuffer tank, driers, and the filters. The air flow rate is about 18 m 3 /hour. Theprocess of the air purification system is described as follows:• Compressor:Compresses air to 7 ∼ 8.5 atm pressure.• Air Filter:Removes dusts in sizes of ∼ 0.3 µm.• Buffer Tank:Stores the air.• Air Drier:Dries the air and removes CO 2 gas to improve the radon removal capabilityin Carbon Columns.• Carbon Columns:Removes radon gas as carbon absorbs radon.• Air Filter:Further Removes small dust and particles of 0.01 µm ∼ 0.01 µm.• Charcoal Columns:Further removes the remaining radon gas with the charcoal cooled downto –40 ◦ C.2.6 Electronics and Data Acquisition System(DAQ)The analog signals from each ID PMT and OD PMT are sent to the dataaquisition system in one of four quadrant electronics huts in the SK dome areaAll the data are collected from four electronics hut and sent to the central hut,where the global even trigger is generated. The self-triggering DAQ systemcollects the analog signals of the time and charge information from each PMTand digitizes them to store as an “event”, which is then sent out to the onlinecomputer. In this section, the ID and the OD data acquisition systems andthe trigger system are described.
Page 1 and 2: Tau Neutrino Appearance via Neutrin
Page 3 and 4: Abstract of the DissertationTau Neu
Page 5 and 6: ContentsList of FiguresList of Tabl
Page 7 and 8: 6 Event Reconstruction 966.1 Vertex
Page 9 and 10: List of Figures1.1 Feynman diagrams
Page 11 and 12: 6.7 PID likelihood distributions fo
Page 13 and 14: AcknowledgementsAfter spending six
Page 15 and 16: I would like to thank administrativ
Page 17 and 18: 2and obey the exclusion principle a
Page 19 and 20: 4Table 1.1: Table of elementary par
Page 21 and 22: 6then, |ν α (t)〉 can be express
Page 23 and 24: 8As described in the next section,
Page 25 and 26: 10Table 1.2: List of the flavor rat
Page 27 and 28: 12much smaller than the unity with
Page 29 and 30: 14Data/Prediction (null oscillation
Page 31 and 32: Figure 2.1: The location of Super-K
Page 33 and 34: Figure 2.2: An overview of the Supe
Page 35 and 36: 202.1.1 Cherenkov RadiationThe prim
Page 37 and 38: 22Figure 2.5: The layout of the PMT
Page 39 and 40: 24< φ 520photosensitive area > φ
Page 41 and 42: 26Quantum efficiency0.20.10300 400
Page 43 and 44: 282.3.2 Outer Detector PMTThe OD ph
Page 45: 30CARTRIDGEPOLISHERUVSTERILIZERVACU
Page 49 and 50: 34A block diagram of the ATM board
Page 51 and 52: 3620-inch PMTSCHATMx 24020-inch PMT
Page 53 and 54: 38Super−Kamiokande Outer Detector
Page 55 and 56: 402.6.4 Flash ADCAs a part of the S
Page 57 and 58: 42UV filter ND filterXe Flash LampO
Page 59 and 60: 44Number of PMTs in Each Bin1400120
Page 61 and 62: 46ND filterTriggerPMTDyeN2 LaserDif
Page 63 and 64: 485432Timing Resolution (nsec)10543
Page 65 and 66: 50Optical FiberLASER337nmTop371nm40
Page 67 and 68: 52Light scattering measurementatten
Page 69 and 70: 54neutrino analyses, such an estima
Page 71 and 72: 56Number of events14012010080604020
Page 73 and 74: 58momentum/range (MeV/cm)432DATAM.C
Page 75 and 76: 60µ momentum/trackelectron momentu
Page 77 and 78: theoretical groups such as Honda fl
Page 79 and 80: 640Zenith angle of arrival directio
Page 81 and 82: 66Flux×E ν2(m -2 sec -1 sr -1 GeV
Page 83 and 84: 684% [105]. The flux of atmospheric
Page 85 and 86: 70where G E and G M are the electri
Page 87 and 88: 72resonance), M j is the mass of th
Page 89 and 90: 74σ (10 -38 cm 2 )0.25 (a) νp →
Page 91 and 92: 761.5(a) ν µN → µ - XIHEP-JINR
Page 93 and 94: 7821.751.5ν 16 O → l ± 16 O π
Page 95 and 96: 80ing experiments [158, 159, 160].
Page 97 and 98:
82shown in Figure 3.5. The timing o
Page 99 and 100:
8410.8ν τν µν eν - τν - µ
Page 101 and 102:
86Chapter 5Data ReductionThe Super-
Page 103 and 104:
88and exit the ID. The neutrino ene
Page 105 and 106:
90• NHITA 800 ≤ 50The number of
Page 107 and 108:
92• The distance between the cabl
Page 109 and 110:
94Coincidence muonsThe remaining co
Page 111 and 112:
96Chapter 6Event ReconstructionThe
Page 113 and 114:
9842 deg. ring(possible center)hit
Page 115 and 116:
100Number of events450400350Single-
Page 117 and 118:
102by muons or charged pions and ha
Page 119 and 120:
104Number of eventsNumber of events
Page 121 and 122:
106the changes in the vertex positi
Page 123 and 124:
108flux. This is because most of ν
Page 125 and 126:
110NUM 14RUN 999999SUBRUN 99EVENT 2
Page 127 and 128:
112expected to be upward-going.Base
Page 129 and 130:
114150100500(a)10 2 (b)1013.5 4 4.5
Page 131 and 132:
116SK-I Multi-GeV MCSK-II Multi-GeV
Page 133 and 134:
118Number of Events9080706050403020
Page 135 and 136:
120Table 7.5: Fraction of neutrino
Page 137 and 138:
122Number of Events604020TAU+BKGBKG
Page 139 and 140:
124100SK-ITAU+BKGBKGDATA6050SK-IITA
Page 141 and 142:
126• Up/down ratio : (For the obs
Page 143 and 144:
128• Charge-current ν τ interac
Page 145 and 146:
130• Tau likelihood selection eff
Page 147 and 148:
132Table 7.8: (For only SK-I) Summa
Page 149 and 150:
134Table 7.10: (Common to SK-I and
Page 151 and 152:
136because for non-zero θ 13 , Mul
Page 153 and 154:
138Bay [184] reactor experiments, a
Page 155 and 156:
140Table A.2: Summary of the damage
Page 157 and 158:
142Appendix BEnergy Flow AnalysisIn
Page 159 and 160:
Figure B.2: Example of subdivision
Page 161 and 162:
146be handled by setting any negati
Page 163 and 164:
148[16] K. Assamagan et al., Phys.
Page 165 and 166:
150[48] H. Seo, A Measurement of ν
Page 167 and 168:
152[84] T. H. Johnson et al., Phys.
Page 169 and 170:
154[125] G. Radecky et al., Phys. R
Page 171 and 172:
156[171] K. Hagiwara et al., Nucl.
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