Tau Neutrino Appearance via Neutrino Oscillations in Atmospheric ...

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33COMPRESSORAIR FILTER(0.3 m)BUFFERTANKAIR DRIERCARBONCOLUMNHEATEXCHANGERCARBONCOLUMNAIR FILTER(0.1 m)AIR FILTER(0.01 m)COOLEDCHARCOAL(-40 o C)SUPER-KAMIOKANDE AIR PURIFICATION SYSTEMFigure 2.13: A schematic view of the radon-reducing air system.2.6.1 Inner Detector DAQThe ID PMT signals are processed by the electronics modules called Analog-Timing-Modules (ATMs), a custom built front-end electronics module of TRIS-TAN KEK Online (TKO) standard optimized to handle a large number ofchannels by KEK [62, 63, 64]. The ATM is developped by Super-K collaboratorsand Toshiba. The ATM has a combined function of Analog to DigitalConverter (ADC) and Time to Digital Converter (TDC) and records the integratedcharge and the arrival timing information of each PMT signal. OneATM has 12 input channels for 12 PMTs. Each channel of the ATMs has acharge dynamic range of 550 pC with a resolution of 0.2 pC (∼ 0.1 p.e.), anda timing dynamic range of 1.2 µsec with a resolution of 0.3 nsec. To minimizethe electronics dead time in the data taking for two successive events, suchas a muon followed by its decay electron and supernova neutrino bursts, eachinput channel of the ATMs is designed to have two Charge to Analog Converters(QAC) and Time to Analog Converter (TAC) [65]. Each ATM boardhas the following ports on the front panel for:• HITSUM: the analog sum of signals from “hit” PMTs to be sent to aglobal trigger module• TRIGGER: the input port for a trigger signal• PMTSUM: a sum of analog signals from 12 PMTs, which was not usedin SK-I but is fed to Flash ADC in SK-II (See 2.6.4)• EVENT-COUNTER: takes 8 bit event count signals.
34A block diagram of the ATM board is shown in Figure 2.14.Each PMT signal sent to ATM is first amplified with a gain of 100 andthen split into four signals. One is sent out as PMTSUM output signal. One issent to the discriminator, with a threshold level of 0.25 p.e. for each channel.When a PMT signal exceeds the threshold, a HITSUM signal (200 ns width and15 mV pulse height) is sent out to the global trigger system. The pulse height ofa HITSUM signal is proportional to the number of hit PMTs. Simultaneously,a “gate” signal (400 ns width) for QAC and a “start” signal for TAC aregenerated to start storing the charge and time information for 1.2 µs. The restof two splitted signals are fed to QACs. If a global trigger (see section 2.6.3 isissued, a “stop” signal is sent to TAC and then the charge and time informationin QAC and TAC is digitized by ADC, which is stored in the internal memoryFIFO (First In First Out) in ATM. If no global trigger is not issued within1.2,µs, all the information in QAC and TAC is discarded. This analog inputblock of the ATM is shown in Figure 2.15.As shown in a schematic diagram of the ID DAQ system of Figure 2.16,each ATM board accepts signals from 12 PMTs. Total of 948 ATM boards arehoused in 48 TKO crates (i.e. each TKO crate houses 20 ATM boards). 12TKO crates are built in each of four quadrant electronics hut. A GO/NoGo(GONG) trigger module and a Super Control Header (SCH) also resides ineach TKO crate. The GONG module distribute the global trigger signalsand the event number to each ATM. The SCH module transfer the digitizeddata in the ATM FIFO memory to the Super Memory Partner (SMP) inVersa Module Europe (VME) crate. Two VME crates are installed in eachelectronics hut, and each VME is connected to 6 SMPs. The SMP modulesare designed to have two memory buffers, which can switch from one to theother when successive event occurs, to further reduce the electronics deadtime. The data is transfered from the SMP modules to server computers, SunUltraSPARC workstation, (2 workstations per electronics hut) via Bit-3 Sbus-VME interface card. Then finally the data is sent to a online host computervia FDDI (Fiber Distributed Data Interface) optical network. This online hostcomputer assembles the data into “events”. Once events are built, the dataare sent out to the offline system. More details of the ID DAQ can be foundin [58, 65, 66].2.6.2 Outer Detector DAQThe OD DAQ are rather simple compared to the ID DAQ. A schematicdiagram of the OD DAQ is shown in Figure 2.18. The paddle cards distributehigh voltage from each of HV main frame channels to 12 OD PMTs via coaxial
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 and 46: 30CARTRIDGEPOLISHERUVSTERILIZERVACU
Page 47: 32system is shown in Figure 2.13. T
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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