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Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Title
Neutrinos(and Electrons, Muons, and Pions)
Yoshi Uchida
UK Particle Physics Masterclass March 2007
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
up charm top
down strange bottom
electron muon tau
up charm top
down strange bottom
electron muon tau
u c td s be
u c td s be
electron muon tauneutrino neutrino neutrinoelectron muon tauneutrino neutrino neutrinoelectron muon tauneutrino neutrino neutrino
e
Matter Particles
Neutrinos:
Only feel the weak interaction⇒ the Earth is “transparent”
Massless by definition in the Standard Model
e creates electrons, creates muons, creates taus
through the Weak Interaction
The Standard Model
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
charm top
strange bottom
tau
tauneutrino
u c ts b
up
down
electron muon
electron muonneutrino neutrino
e
Matter Particles
ude
Particles inThis Talk
Dave Wark will talk aboutneutrinos too....
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
charm top
strange bottom
tau
tauneutrino
u c ts b
up
down
electron muon
electron muonneutrino neutrino
e
Matter Particles
ude
Particles inThis Talk
Pion
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Particle Interactions
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Electron Interactions in Matter
1m
electronwith 1 GeVof energy(about 2000 timesits mass)
Water
Electrons produces “showers” of positrons, electrons and photons, as they travel through matter
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
ComputerSimulations
Computer Simulations play a major role in particle physics.
The properties of particles and detectors are simulated using known properties of particle propagation in matter.
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
ComputerSimulations
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
More ParticleInteractions
1 Electron
10 Muons0.5 GeV 1.5 m H2O
0.5 Tesla Magnetic Field Can build detectors to take advantage of the different characteristics of particles
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
More ParticleInteractions
100000000000 Neutrinos
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The PionSimilar in mass to the muon, but feels the Strong Interaction
Image is of tracks captured in photographic emulsion, showingNuclear Disintegration
First seen by D. H. Perkins in 1946, when he was a PhD studentat the Imperial College High Energy Physics group
...
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Pion Decay and NeutrinosPion
Muon Electron
MuonAntineutrino
MuonNeutrino Electron
Antineutrino
– –
e–
Pions decay in fractions of a microsecond, eventuallyproducing 3 neutrinos
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
SuperKamiokande andAtmospheric Neutrinos
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Atmospheric NeutrinosZenith Angle
180º − Zenith Angle
Isotropic flux ofcosmic rays
km`
10000
Cosmic rays hit upper atmosphere and create pions, which in turn decay into of a few GeV
Look at neutrinos from different zenith (up/down)angles.Distance travelled since neutrino creation depends on this angle
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Neutrino Detection in WaterCharged particles (travelling faster than the speed of light in the medium) can emit light at specific angles to their direction of travel
chargedparticle
“Cerenkov” light
Detectors can identifythe “ring” formed bylight, to measure thedirection and speed ofthe particle
speed of light in water = 75%of speed in vacuum
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Electron and Muon Neutrinos
electron neutrino
muon neutrino
creates a single electron, which then creates a shower of electrons
creates a single muon
“fuzzy”cerenkovring
clearcerenkovring
(with energies of about 1 GeV)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Problem
For a 1 metre thickness of water, only about
1 in every 1,000,000,000,000 neutrinos
actually interacts this way
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Solution
Use a big detector
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
SuperKamiokande
40m by 40m tank1 km underground50,000 tonnes of waterLined with 11,000 photonsensors
8 atmospheric neutrinos / day!Kamioka Observatory,ICRR (Institute for Cosmic Ray Research),The University of Tokyo
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
SuperKamiokande (Winter 2005/06)
Rebuilding ofdetector after major accident in 2002 destroyed half of the photon sensors
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
SuperKamiokande (Winter 2005/06)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
“fuzzy” electronlike ring
SuperK Neutrino Events
“clear” muonlike ring
Patterns of light detected in the 20inch photon sensors
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Atmospheric NeutrinosZenith Angle
180º − Zenith Angle
Isotropic flux ofcosmic rays
km`
10000
Cosmic rays hit upper atmosphere and create pions, which in turn decay into of a few GeV
Look at neutrinos from different zenith (up/down)angles.Distance travelled since neutrino creation depends on this angle
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Atmospheric Neutrinos at SuperK
HorizontalUp Down
muonlikeelectronlike
1 0 1 1 0 1cos(zenith angle)
150
100
0
50
Even
ts
DataExpected
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Atmospheric Neutrinos at SuperK
HorizontalUp Down
muonlikeelectronlike
1 0 1 1 0 1cos(zenith angle)
150
100
0
50 DataExpected
Even
ts
Muon neutrinos “disappear” as they travel long distances
⇒ turning into tau neutrinos(invisible to SuperK)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Neutrino Oscillations
If neutrinos have different masses, Quantum Mechanicssays they can “turn into” each other as they travel
Oscillation probability
∝Interference of quantum matter waveswhich depends on mass differences
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Neutrino Oscillations
0 500 1000 Distance[km]/E[GeV]
muonneutrino
tauneutrino
STARTwith a puremuonneutrinobeam
The probability that the neutrino has become a tau neutrino swings back and forth with distance
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
KamLAND and Neutrino Oscillations
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The Kamioka Liquid Scintillator AntiNeutrino Detector
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
KamLAND
0 250 500 750 [km]
KamLAND ReactorBaseline Distribution
Reactor interactionsproduce antineutrinos:
1000 tonne detectorsees about 1 reactorantineutrino each day
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
KamLAND
(1879 PMTs)
(Water)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
KamLAND
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
KamLAND Result October 2004
258 candidates (365.2 if inversesquare propagation)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
“Distance / Energy” for KamLAND 2004
assuming 180km baseline (assuming
180km baseline)Distance / Energy [km / MeV]
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Other Hypotheses for Neutrino Disappearance
assuming 180km baseline
(alternative theories for neutrino disappearance)
(assuming 180km baseline)Distance / Energy [km / MeV]
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Evidence for Neutrino Oscillations
assuming 180km baseline (assuming
180km baseline)
To be improved in next results!
Distance / Energy [km / MeV]
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Present Status of Neutrino OscillationsWe have seen two types of verified neutrino oscillations
● “SuperK” atmospheric & accelerator
● Solar (Dave’s talk) & “KamLAND” reactor (ask me)
Oscillations ⇒ neutrinos must have mass
The only indication of Physics Beyond the Standard Model
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Present Status of Neutrino OscillationsOne mysterious oscillation result from the 1990s, currently being reexamined by the MiniBooNE experiment
⇒ the next big neutrino physics result, very soon?
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The Ice Cube Experiment
The South Pole
half a mile
1.5
mile
s
Instrumented todetect neutrinos
Uses the icesheet at theSouth Poleto act as a NeutrinoTelescope for neutrinosfrom the NorthernHemisphere
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
How to Help Build a New Neutrino Experiment
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The Concept
Oscillations seen in Atmospheric Neutrinos, can we make a better measurement?
Define Energy and Distance better
If our understanding is correct, a 3rd type of oscillation may exist, can we see this?
Use the most intense source of neutrinos possible
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The K2K Experiment (1999—2004)Muon neutrinos sent 250 km across Japan from KEK
Saw 112 neutrinos, confirmed “atmospheric” oscillations
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
JPARCMajor new particle / nuclear physics facility being built in Japan
Construction started in 2001
Can be used to create avery powerful neutrino beam
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The TokaitoKamioka (T2K) Experiment
Kamioka
JAPAN Tokai
T2K
SuperKamiokande
JPARC
JPARC
The most intense neutrino beamever
295 km baseline beam disappearance measuremente appearance discovery
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
A Neutrino Experiment at JPARC (formerly JHF)21 January 2003
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The T2K CollaborationMore than 300 members from
CanadaFrance
GermanyItalyJapanKoreaPolandRussiaSpain
SwitzerlandUnited Kingdom
United States
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Another Improvement
The most intense, optimised neutrino beam ever&
A 50,000 tonne neutrino detector
the need to understand the beam, and neutrino interactions, better than ever before
the performance of the experiment will depend on a much more sophisticated "Near Detector" than before
use a Magnetic Field, complex system of detectors
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The JPARC Neutrino Beam
NCarbon Target
JPARC 50 GeV Proton Ring and Neutrino Beam Complex
Same principle as atmospheric neutrino production(except you stop the muons before they decay)
IntenseProton Beam
Showerof Pions
Neutrino Beam
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The 280m Near Detector (ND280)
N
ND Hall
JPARC 50 GeV Proton Ring and Neutrino Beam Complex
280m
Distance is fixed from constraints due to surrounding structures(and untouchable forests)
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The “UA1” Magnet
Use of magnet enhances particle identification / measurement dramatically
An old magnet from CERN (which helped discover the W & Z particles), was available
for the Near Detector
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Conceptual Design Process 2004, 05
Design the “best” affordable Near Detector system which fits into the UA1 magnet
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Conceptual Design Process 2004, 05
Use of computer simulations (and backoftheenvelope estimations) to investigate many different detector concepts
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Conceptual Design Process 2004, 05
Vancouver Jul ’05
Rome Dec ’04
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Conceptual Design Process 2004, 05
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
T2K ND280 Conceptual Design ReportPublished August 2005: “This Conceptual Design Report details the physics requirements, motivations, and design considerations [of the ND280 detectors].”
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The T2KUK Proposal (January 2006)
UK Contributions on:● Neutrino Beam and Target Development● ND280 Electromagnetic Calorimeter Design and Construction● ND280 Electronics and Data Acquisition● ND280 Photosensor Development● T2K Software and Physics Analysis
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The Imperial College T2K Group
From left: Johnathan Anderson, Morgan Wascko, Mark Raymond, Marie Endamne, Matt Noy, Dave Wark, Joe Walding, Daniel Orme, Francois Van Schalkwyk, Antonin Vacheret, Peter Dornan, Masaki Shibasaki, Ian Taylor, Yoshi Uchida
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Imperial College T2K Group● Designing the detector
readout electronics for ND280
● Coordinates the photosensor study group in the UK
● Organises the Global T2K Offline Software group and UK Physics group
and
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Present Status
Approved by UK GovernmentNeutrino Beam to turn on April 2009ND280 to start running Autumn 2009
Oscillation measurements / discoveries a few years later....
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
The Future
DailyTelegraph
Undergoing vigorous R&Din UK and internationally
Yoshi.Uchida@imperial.ac.uk UK Particle Physics Masterclass 29 March 2006
Monitor our progress at
imperialhep.blogspot.com
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