Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery...
-
Upload
derick-manning -
Category
Documents
-
view
224 -
download
0
Transcript of Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery...
![Page 1: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/1.jpg)
Takaaki Kajita (ICRR, U.of Tokyo)
• Production of atmospheric neutrinos• Some early history (Discovery of atmospheric
neutrinos, Atmospheric neutrino anomaly)• Discovery of neutrino oscillations• Studies of atmospheric neutrino oscillations• Sub-dominant oscillations –present and future-
III International Pontecorvo Neutrino Physics SchoolAlushta, Ukraine, Sep. 2007
![Page 2: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/2.jpg)
Atmosphere
![Page 3: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/3.jpg)
(Sign of the particles are neglected in this figure.)
![Page 4: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/4.jpg)
Calculating the atmospheric Calculating the atmospheric neutrino beamneutrino beam
Flu
x ×
E2
E(GeV)
Measured cosmic ray proton flux
Total flux+ geomagnetic field
+ (p+Nucleon) int.
+ decay of or K
+ ……
![Page 5: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/5.jpg)
Some features of the beam (1)Some features of the beam (1)
(+ )/(e+ e)(+ )/(e+ e)
/e ratio is calculated to an accuracy of better than 3% below ~ 5GeV.
/e ratio is calculated to an accuracy of better than 3% below ~ 5GeV.
![Page 6: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/6.jpg)
Some features of the beam (2)Some features of the beam (2)
Zenith angleZenith angle
Up-going Downcoszenith
Up/down ratio very close to 1.0 and accurately calculated (1% or better)
above a few GeV.
Up/down ratio very close to 1.0 and accurately calculated (1% or better)
above a few GeV.
@ Kamioka (Japan)
![Page 7: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/7.jpg)
Comment: Geomagnetic field and the Comment: Geomagnetic field and the fluxflux
Let’s assume a detector in Kamioka (Japan)
Calculate the minimum momentum of a cosmic ray proton directing to Kamioka arriving at the atmosphere.
Do
wn
-goi
ng
Up
-goi
ng
For this location, flux(up) > flux(down) in the low-energy rangeFor this location, flux(up) > flux(down) in the low-energy range
GeV/c
![Page 8: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/8.jpg)
Comment: Horizontal fluxComment: Horizontal fluxnow 10 years ago…
3D calculation 1D calculation
![Page 9: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/9.jpg)
Horizontal enhancementHorizontal enhancement
νC.R.(1D)
Target area(1D, 3D)
C.R.(3D)
3D1D
G. Battistoni et al., Astropart. Phys. 12, 315
(2000)
For simplicity, let’s assume that the direction of the secondary particles are isotropic (reasonable at low E.)
![Page 10: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/10.jpg)
Syst error better than 5%
Below 10GeV, the flux is predicted to better than 10%. Above 10GeV the flux calculation must be improved.
(This statement is for Honda04 flux.)
Below 10GeV, the flux is predicted to better than 10%. Above 10GeV the flux calculation must be improved.
(This statement is for Honda04 flux.)
How accurate is the absolute How accurate is the absolute normalization of the flux ?normalization of the flux ?
![Page 11: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/11.jpg)
Neutrino interactionsNeutrino interactions
Eν(GeV)
E/Quasi-elastic
1 productionDeep inelastic
CC total
lepton
N N’
Quasi-elastic
lepton
N N*
N’
1 production
lepton
N N’
Deep inelastic
![Page 12: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/12.jpg)
Event classificationEvent classification
Fully Contained (FC) (E ~1GeV)
Partially Contained (PC) (E ~10GeV)
Through-going (E~100GeV)
Stopping (E~10GeV)
![Page 13: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/13.jpg)
Comment: upward-going muons Comment: upward-going muons
∝E
Range∝∝
Enhanced sensitivity to high energy neutrinos
Wide energy range
![Page 14: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/14.jpg)
![Page 15: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/15.jpg)
Discovery of atmospheric neutrinos Discovery of atmospheric neutrinos
(NX)(NX)
At the depth of 3200 meters (8800 meters water equivalent) in South Africa First observed on Feb. 23, 1965By F.Reines et al.
At the depth of 2400 meters (7500 meters water equivalent) in India (Kolar Gold Field)First published on Aug. 15, 1965By C.V. Achar et al.
photo of the South Africa experiment
Detector for the KGF experiment
![Page 16: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/16.jpg)
Zenith angle distribution Zenith angle distribution (from the South Africa experiment 1978)(from the South Africa experiment 1978)
Vertical (going up or
down)
Horizontal going
Neutrino induced
muons
Neutrino induced
muons
Cosmic ray
muons
Cosmic ray
muons
PRD18, 2239 (1978)
![Page 17: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/17.jpg)
Idea to study oscillations with atmospheric neutrinos: Bilenky & Pontecorvo, Phys. Rep. 1978
![Page 18: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/18.jpg)
The first hint ? The first hint ? (South Africa experiment, 1978)(South Africa experiment, 1978)
Vertical Horizontal
Neutrino induced
muons
Neutrino induced
muons
Cosmic ray muons
Cosmic ray muons
4.06.1
Data
CarloMonte Deficit of muon dataDeficit of muon data
PRD18, 2239 (1978)
“We conclude that there is fair agreement between the total observed and expected neutrino induced muon flux …”
![Page 19: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/19.jpg)
Proton decay experimentsProton decay experimentsGrand Unified Theories (in the late 1970’s) p=1030±2 years
NUSEX (130ton)
Frejus (700ton)
Kamiokande (1000ton)
IMB (3300ton)
These experiments observed many contained
atmospheric neutrino events (background for
proton decay).
These experiments observed many contained
atmospheric neutrino events (background for
proton decay).
![Page 20: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/20.jpg)
Selection of atmospheric neutrinos Selection of atmospheric neutrinos Example: Kamiokande
At 1000m underground,
cosmic ray : 0.3/sec/detector
Atmospheric : 0.3/day/1000ton
Fiducial region
n
2.7m
3.5m
anti-counteranti-
counter
![Page 21: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/21.jpg)
ν
Charged particle
Photomultiplier tube (PMT)
50cm φ (Super-K)
20cm φ
n
1cos
n (refractive index)=1.34 in water
θ=42deg. for β=1
Number of Ch. photons with λ=300-600 nm emitted by a relativistic particle per cm = 340.
Need an efficient detection of the photons. Large PMTs
Detecting Cherenkov photonsDetecting Cherenkov photons
![Page 22: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/22.jpg)
Charged particle PMT
Detecting Cherenkov photons and event Detecting Cherenkov photons and event reconstructionreconstruction
Time: vertex position
direction
Pulse height (number of pe’s): energy
Color: timing
Size: pulse height
Super-K
![Page 23: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/23.jpg)
Too few muon decaysToo few muon decays
Kamiokande: J.Phys.Soc.Jpn 55, 711 (1986)
IMB: PRL57, 1986 (1986)
Proton decay background papers:Proton decay background papers:
vNX, =2.2sec)e
or
Nlepton+++X, ++, +e+
![Page 24: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/24.jpg)
/e ratio measurement in /e ratio measurement in KamiokandeKamiokande
1983 (Kamiokande construction)
electronics
Water system
![Page 25: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/25.jpg)
Electrons and muonsElectrons and muons
muon-like events
electron-like events
KamiokandeKamiokande
Super-KSuper-K
![Page 26: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/26.jpg)
Particle identificationParticle identificationelectron-like event
muon-like event
2
deg70 ..
2 )(..)'.(.
ep
ore expectedepdobsepParticle ID
e: electromagnetic shower, multiple Coulomb scattering
: propagate almost straightly, loose energy by ionization loss
Difference in the event patternDifference in the event pattern
![Page 27: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/27.jpg)
Particle ID performanceParticle ID performance
Cosmic ray μ e from μ decay
ε=99%@Super-K (98% @Kamiokande)
(figures from Super-K)
![Page 28: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/28.jpg)
First result on the First result on the /e ratio /e ratio (1988)(1988)
Kamiokande(3000ton Water Ch.
~ 1000ton fid. Vol.)
2.87 kton ・ year
Data MC prediction
e-like ( ~ CC e)
93 88.5
-like ( ~ CC )
85 144.0
“We are unable to explain the data as the result of systematic detector effects or uncertainties in the atmospheric neutrino fluxes. Some as-yet-unaccoundted-for physics such as neutrino oscillations might
explain the data.”
K. Hirata et al (Kamiokande ) Phys.Lett.B 205 (1988)
416.
![Page 29: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/29.jpg)
However, …However, …Let’s write the atmospheric deficit by (/e)data/(/e)MCLet’s write the atmospheric deficit by (/e)data/(/e)MC
![Page 30: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/30.jpg)
First supporting evidence for small First supporting evidence for small /e/e
IMB experiment also observed smaller (/e) (1991, 1992).
![Page 31: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/31.jpg)
Finally, …Finally, …Let’s write the atmospheric deficit by (/e)data/(/e)MCLet’s write the atmospheric deficit by (/e)data/(/e)MC
![Page 32: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/32.jpg)
Atmospheric Atmospheric neutrinos neutrinos
and neutrino and neutrino oscillations oscillations
Cosmic ray p, He, ……
Cosmic ray p, He, ……
Detector
oscillation
Detect down-going and up-going
Atmosphere
Down-going
Up-going
E
LmP
222 27.1
sinsin1)(
![Page 33: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/33.jpg)
Zenith angle distributionsZenith angle distributions
Consistent with no zenith angle dependence...
Kamiokande (Evis <1.3 GeV) IMB (<1.5GeV)
e-like -like
![Page 34: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/34.jpg)
Angular correlation Angular correlation
(CC e samples)
(CC sample)
Lepton momentum (MeV/c)
leptonNucleon(MN= 1GeV/c2)
![Page 35: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/35.jpg)
Next: zenith angleNext: zenith angle…(Kamiokande,1994)…(Kamiokande,1994)
multi-GeV -like
events
multi-GeV -like
events
Deficit of upward-going -like events
m2=1.6 ・ 10-2eV2
Up/Down=0.58 (2.9 σ)+0.13 -0.11
Up-going Down-going
No oscillation
Not high enough statistics to conclude …Not high enough statistics to conclude …
![Page 36: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/36.jpg)
![Page 37: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/37.jpg)
Super-Kamiokade detectorSuper-Kamiokade detector50,000 ton water Cherenkov detector(22,500 ton fiducial volume)
1000m underground
11200 PMT(Inner detector)
1900 PMT(Outer detector)
Exit
39m
42
m
![Page 38: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/38.jpg)
Around Super-K
Entrance to the mine
![Page 39: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/39.jpg)
Super-Kamiokande Super-Kamiokande (under construction, Dec. 1994)(under construction, Dec. 1994)
![Page 40: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/40.jpg)
Super-Kamiokande under constructionSuper-Kamiokande under construction
Early summer 1995
![Page 41: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/41.jpg)
Super-Kamiokande with pure waterSuper-Kamiokande with pure water
Jan. 1996
Kamiokande
![Page 42: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/42.jpg)
Event type and neutrino energyEvent type and neutrino energy
Fully Contained (FC)
Partially Contained (PC)
Through-going
Stopping
![Page 43: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/43.jpg)
Various types of atmospheric neutrino events (1)Various types of atmospheric neutrino events (1)
FC (fully contained)
・ Both CC e and (+NC)
・ Need particle identification to separate e and
Single Cherenkov ring electron-like event
Single Cherenkov ring muon-like event
Color: timing
Size: pulse height
Outer detector (no signal)
![Page 44: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/44.jpg)
Various types of atmospheric neutrino events (2)Various types of atmospheric neutrino events (2)
PC (partially contained)
・ 97% CC
Signal in the outer detector
![Page 45: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/45.jpg)
Various types of atmospheric neutrino events (3)Various types of atmospheric neutrino events (3)
Upward going muon
ν
・ almost pure CC
Upward stopping muon
Upward through-going muon
![Page 46: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/46.jpg)
Atmospheric Atmospheric neutrinos neutrinos
and neutrino and neutrino oscillations oscillations
Cosmic ray p, He, ……
Cosmic ray p, He, ……
Detector
oscillation
Detect down-going and up-going
Atmosphere
Down-going
Up-going
Up/down ratio measurement is essentially free from systematicsUp/down ratio measurement is essentially free from systematics
![Page 47: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/47.jpg)
Super-K Super-K @Neutrino98@Neutrino98
SK concluded that the observed zenith angle dependent deficit (and the other supporting data) gave evidence for neutrino oscillations.
Fully contained, 1-ring events
with Evis > 1.33GeV
plus partially contained events
![Page 48: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/48.jpg)
Super-Kamiokande data nowSuper-Kamiokande data now@Neutrino98
(535 day)@Neutrino98
(535 day)
Now (2290 day)
Now (2290 day)
No oscillation
oscillation
Up-going Down-going
![Page 49: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/49.jpg)
Results from the other atmospheric Results from the other atmospheric neutrino experimentsneutrino experiments
Soudan-2MACRO
MINOS(Atmospheric neutrinos only in this lecture)
![Page 50: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/50.jpg)
Soudan2Soudan2
CC quasi-elastic
e CC
CC deep inelastic
1 kton fine grain tracking calorimeter
![Page 51: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/51.jpg)
Soudan2Soudan2
Reconstructed Lν/ Eν dist.
No osc.
osc.
Phys.Rev. D68 (2003) 113004
• 5.9 kton ・ yr exposure• Partially contained events included.• L/E analysis with the “high resolution” sample• Upward stopping muons included. hep-ex/0507068
Zenith angle
e
μ
e μ
Up-going
Down-going
Upward stopping muons
![Page 52: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/52.jpg)
MACROMACRO
Upward through-going
Upward through-going
Upward-going PC
Upward-going PC
Upward stopping + down-
going PC
Upward stopping + down-
going PC
Down-going cosmic ray Upward
through-going
Upward through-going
77m
12m
10m
![Page 53: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/53.jpg)
or
MACROMACRO
Upward horizontal
PLB 566 (2003) 35 EPJ C36(2004)323
OscillationΔm2 =2.5×10-3
No osc.
Osc.
No osc.
![Page 54: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/54.jpg)
MINOS MINOS (atmospheric)(atmospheric)PRD73, 072002 (2006)
6.18 kton ・ yr (418days)
zenith-angle
L/E
Separation of and anti-
5.4 kton tracking detector with
magnetic field
hep-ex/0701045
![Page 55: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/55.jpg)
oscillation parametersoscillation parameters
Also, consistent results from long baseline experiments (K2K & MINOS) Lecture by K.Nishikawa
MINOS (Atmospheric)
Soudan-2
MACRO
Super-K
Kamiokande
, 90%C.L.
![Page 56: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/56.jpg)
Summary of Atmospheric Neutrino-1Summary of Atmospheric Neutrino-1
• Experimental studies of atmospheric neutrinos started in the mid. 1960’s.
• Different type of atmospheric neutrino experiments started in the 1980’s (proton decay experiments).
• Study of the background for proton decay found unexpected atmospheric deficit.
• In 1998, the deficit was concluded as evidence for neutrino oscillations.
• Various atmospheric neutrino experiments give consistent results.
![Page 57: Takaaki Kajita (ICRR, U.of Tokyo) Production of atmospheric neutrinos Some early history (Discovery of atmospheric neutrinos, Atmospheric neutrino anomaly)](https://reader030.fdocuments.us/reader030/viewer/2022033101/56649f435503460f94c63631/html5/thumbnails/57.jpg)
End