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E1 Working Group Neutrino Factories and Muon Colliders. - PowerPoint PPT Presentation
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20 July 2001 Deborah Harris Fermilab 1
E1 Working GroupNeutrino Factories
and Muon Colliders
Ingredients: Todd Adams, Carl Albright, Mayumi Aoki, Valeri Balbekov, Richard Ball, Vernon Barger, Mike Berger, Mario Campanelli, Dave Casper, Weiren Chou, Dave Cline, Priscilla Cushman, Fritz DeJongh, Milind Diwan, Bonnie Fleming, Al Garren, Steve Geer, Gail Hanson, Debbie Harris, Atsuko Ichikawa, Carol Johnstone, Steve Kahn, Boris Kayser, Chiang Kee Jung, Bruce King, Yoshitaka Kuno, Manfred Lindner, Shinji Machida, Bill Marciano, Kirk McDonald, Kevin McFarland, Jorge Morfin, Nikolai Mokhov, Bill Molzon, Bill Morse, Ken Nagamine, Tsuyoshi Nakaya, David Neuffer, Yasuhiro Okada, Fred Olness, Robert Palmer, Zohreh Parsa, Bernard Pope, Stefano Rigolin, Lee Roberts, Andrea Romanino, Thomas Roser, Akira Sato, Heidi Schellman, Masato Shiozawa, Bob Shrock, Hank Sobel, Panagiotis Spentzouris, Ed Stoeffhaus, Larry Wai, Yi Fang Wang, Koji Yoshimura, Jae Yu, Mike Zeller … and many other enthusiastic folks
PHYSICS TO ADDRESS:PHYSICS TO ADDRESS: Neutrino Oscillations – Conventional BeamsIntense Muon Source PhysicsThe Rest of Neutrino Physics (non-oscillation)Neutrino Oscillations – Muon Storage Rings Muon Collider Physics
20 July 2001 Deborah Harris Fermilab 2
SNO Results
• After a long history of solar neutrino anomaly results, SNO is confirming that the discrepancy is due to neutrino physics and not the solar model
• e from the Sun become e and ( , )
K. Heeger, Les Houches ‘01
20 July 2001 Deborah Harris Fermilab 3
SuperKamiokande Results
• Again, after a long history of “anomalous” results, the atmospheric neutrino data are indicating oscillations
K. Nishikawa, NuFact’01
20 July 2001 Deborah Harris Fermilab 4
We are in the middle of a fundamental discovery!
• Neutrinos have mass, and m/mtop < 10-14
• Oscillations can:– Give insight into the theory of flavor – what
makes a generation a generation?
– Tell us about the origin of fermion masses
– Suggest a high mass scale of new physics
– Contribute to understanding the origin of baryon asymmetry in the universe
This is one of precious few windows onto Grand Unified Theories linking quark and lepton sectors.
20 July 2001 Deborah Harris Fermilab 5
What do we know today?
made in the atmosphere are disappearing – stronger and stronger indications that they are becoming , not s
matm2 3x10-3eV2
e made in the sun are disappearing – 3 indication from SNO that they are becoming active, not s
msolar2 1x10-4eV2 or even lower
e appearing in a beam made in Los Alamos mLSND
2 2 to 0.1eV2
20 July 2001 Deborah Harris Fermilab 6
What do we ultimately want to know from
oscillations?
• How many neutrinos are there? Are any sterile? Where?
• What is the precise scale of mass splittings?• What is the mass hierarchy?
• Mixing in atmospheric and solar sectors appears maximal: is it really maximal, or just close?
Is 13 = 0? Is it ,2, or 3? Need precision!
• Is there CP in the lepton sector?
2/12/12/1
2/12/12/1
2/12/1 13
1
1
1
23
2
3
20 July 2001 Deborah Harris Fermilab 7
Three Generation Neutrino Oscillations
• Probability of a to b
• Oscillation has contributions from every m2 • Other 3 generation bonus: CP Violation
3
2
1
eProduce & Detect Weak Eigenstate, Detect Mass Eigenstate
U
a
b
b
b
3
2
1
a
1
a
1
Add all 3 Amplitudes and Square…
20 July 2001 Deborah Harris Fermilab 8
Parameters of Neutrino Oscillation
• “Standard” Scenario: 12, |m12| from solar 23, |m23| from atmospheric – Still missing 13 and
• CP Violation:
132313231223121323122312
132313231223121323122312
1313121312
ccescsscesccss
csesssccessccs
escscc
ii
ii
i
(s13=sin13, c13=cos13)
• 3-generation mixing:
13,32,12,, just like CKM
sinsin
2sin
4)()(
)()(
13
12212
E
Lm
PP
PP
ee
ee
20 July 2001 Deborah Harris Fermilab 9
To fully understand the physics behind fermion
mass and mixing…
• New Facilities– Upgraded proton source (1-4MW)
– Very intense beams
– Ultimately, a factory
• New Detectors– Focus on e appearance and
disappearance
– If LSND signature is oscillations: appearance gets higher priority
• Of course, we’re not the only ones excited about addressing these issues…
20 July 2001 Deborah Harris Fermilab 10
Superbeam Proposals
• All three use water Cerenkov detectors
• One uses already existing detector
• All three require new beamlines to be built
• Few 10-3 background fractions required !
• All have near detectors
Name Start
Year
Proton Power
Proton Energy
Neutrino
Energy
Baseline (km)
JHF to SuperK
2008? 0.77MW 50GeV 0.7GeV 350km
JHF to
HyperK
2013? 4MW 50GeV 0.7GeV 350km
CERN to UNO
2011
4MW 2.2GeV 250MeV 130km
20 July 2001 Deborah Harris Fermilab 11
Superbeam Proposals, Continued
Name Years of running
K-ton sin2213
Sensitivity(3)
CP Phase Sensitivity
(3)
JHF to SuperK 5 yrs 50 0.016 none
JHF to
HyperK
2 yrs 6 yrs
1000 0.0025 15o
CERN to UNO 2 yrs ,
10 yrs 400 0.0025 40o
•Is there another way to measure these parameters?•What has not been measured here?
T. N
akay
a, J
HF
20 July 2001 Deborah Harris Fermilab 12
The Case for a High Energy Superbeam
• The to e measurement is extremely important for determining the mixing matrix structure– At any one baseline the error will be due
to a combination of systematic and statistical errors on background levels
– Two baselines and energies will ensure that oscillations are in fact occurring and not something completely different.
• The mass hierarchy may be different from what people naively expect!– If so the matter effects will enhance the
antineutrino , not the neutrino – You would want the longer baseline to
see it for the first time!• If JHF-Kamiokande sees CP violation,
many years from now, they will still have an 8o uncertainty due to matter effects
20 July 2001 Deborah Harris Fermilab 13
Capabilities of High Energy Superbeams
• Assumptions:– Narrow Band Beam tuned at oscillation peak
– 70kTon fiducial volume detector, 50% effic.
– 2 years , 6-8 years to get equal statistics)
– Background fraction of 0.4%
– 4 x (1/5 NUMI ME) Flux x (730km2/ L2)
– m232 =+3.5x10-3 eV2 m23
2 =10-4 eV2
Baseline
(km)
E
(GeV)
sin213 Reach(3)
Sign (m23
2)(3)
sin213=1
350 1 .0013 .0016 - 20
730 2.1 .0017 .0026 - 24
1290 3.7 .0020 .0052 .04 32
1770 5 .0022 .0092 .02 40
2900 8.2 .0025 .037 .01 76Calculated during SNOWMASS; Barger, Marfatia, Whisnant
20 July 2001 Deborah Harris Fermilab 14
Superbeam detector optionswith broad physics reach
Water Cerenkov:e appearance provenBelow 1GeV!Questions:What about higher energies?Can we get to 10-3 background?
Liquid Argon TPC:Superb imaging qualityQuestions:Can such a large volumeOf cryogenic materialbe put underground?Is 10-3 background achievable in data? (MC looks promising)
20 July 2001 Deborah Harris Fermilab 15
Electron Candidate in Liquid Argon TPC
• 300 tons operating now
• Need to see how large a single volume can be made
20 July 2001 Deborah Harris Fermilab 16
Neutrino Factory Capability
• Beam comes from
• Above 10 GeV muon storage rings, get much more out per proton power
• Backgrounds for e at the 10-4 level or better with old detector technology
• The ONLY way we know to get a e beam!
• Very well-known fluxes makes for very high precision on mixing angles and mass splittings
ee ee
20 July 2001 Deborah Harris Fermilab 17
From Superbeam to Neutrino Factory
Detector—Charge ID
• tt
In a granular detector
(x ≈ 100 m) B=1T,
One can start to imagine
discriminating e+ from e-
BUT…only those that shower late…Muons in this field should work well
Primary goal in neutrino factory: muon charge identification
M. C
ampa
nelli
, I
CA
RU
S d
etec
tor
MC
UN
O D
esig
n
20 July 2001 Deborah Harris Fermilab 18
Neutrino Factory Reach
Factor of 10 betterThan JHF upgrade!If LMA and 13 small,Might even see signs of solar mass scale!Larger parameter space accessible for CP studies(hep-ph/010352)
If LSND confirmed:Look for appearance at
shorterBaselines—CP studies galore!(hep-ph/010352)
20 July 2001 Deborah Harris Fermilab 19
13 = 0 ?
Path to a muon storage ring neutrino experiment
YOU ARE HERE
e seen in
superbeams!
LSND CONFIRMED
Solar solution is NOT LMA !
e not seen
in superbeams!
e seen in
superbeams!
e not seen
in superbeams!
Solar solution is LMA !
Want two beams:
e e
low intensity entry level 1019 /yr short baseline
CP and T precision tests
CP hint? matter effects precision
13
LSND NOT CONFIRMED
matter effects precision
13
20 July 2001 Deborah Harris Fermilab 20
There’s more to life than oscillations…
• We need diversity: If we look for new physics under only one lamppost we are sure to miss something!
• We need more lampposts!• In particular, we may be getting hints of new physics in
the muon sector:
• We cannot let this hint go untested!• Steps towards a neutrino factory can also provide
needed lampposts.
1010)16(462
2
theorymeasured aag
a
E821, B
rookh
aven,
3.2B e
+can’t b
e wron
g
20 July 2001 Deborah Harris Fermilab 21
New Lampposts
• On the way to a high energy muon collider, we will learn to build: 1. Neutrino “superbeam” from high
intensity (1- 4 MW) proton driver
2. Low-emittance, low energy spread muon beam at 200 MeV
3. 3 GeV muon beam
4. 20-50 GeV muon storage ring
5. Muon Collider operating as a Higgs Factory
20 July 2001 Deborah Harris Fermilab 22
Muons do more than decay: Charged Lepton Flavor Physics
Now
Proton driver
200 MeV
3GeV
20 -50GeV storage ring
to e conversion
SUSY predicts 10-
15 levelIn scenario where ’s oscillate
Two order of
magnitude improvements possible
(g-2)2.6discrepancy now – best
probe of tan
EDM:Violates P
and T reversal
invariance! A
measurement indicates new physics
Could improve by 4 orders of magnitude!
20 July 2001 Deborah Harris Fermilab 23
to e conversion at BNL-AGS
Looks like the front of a Neutrino factory: 5x1011 /spillStart 2006Goal: B( Al e Al) = 10-17
20 July 2001 Deborah Harris Fermilab 24
Neutrinos do more than oscillate I:
standard and exotic processes
Now
Proton driver
200 MeV
20 GeV storage ring
50 GeV storage ring
Muon collider
Structure functions:Scattering off protons
& deuterons yields
quark-by-quark
description of nucleonDetectors: low mass, good PID, tracking, energy, charge
measurements (liquid
TPCs?)
Polarized targets?
Heavy flavor
production:
Charm and
bottom via
CC/NC: c + b
content of
nucleon; get CKM matrix
elementsDetectors: need
high precision tracking
Neutrino magnetic moment:
(conventional)
High statistics at superbeams
enable order-of-
magnitude improveme
nts
(non-conventional) resonant cavities? phase
rotation?
20 July 2001 Deborah Harris Fermilab 25
Neutrinos do more than oscillate II:
lepton number violation•PROCESSES: +e- -+e (E > 10.7 GeV)
e+e- -+(E > 10.7 GeV)
+e++ +e (E < 10.7 GeV)
•Each violates lepton family number (L=2)
•Consequence of left-right theories and dileptons
•Signature of a wrong-sign (μ-) in a μ+ beam.
•Low energy stage will improve limits by 1-2 orders of magnitude.
•High energy limit limited only by detector efficiency. Improve limits by 2-3 orders of magnitude.
•Requires good charge and particle identification.
~3x10-7~5x10-6NEE=50GeV
~2x10-6~3x10-5Not effectiveE=20GeV
~2x10-5~3x10-410-4 ~10-5E=2.5GeV
NENot effective10-4 ~10-5E=200MeV
~2x10-5~3x10-4~3x10-5Super-B
Liquid CH4
(1800kg-yr)
Si-CCD
(126kg-yr)
Large TPC
(1kT-yr)
Detector 1km from source, 100% efficiency, μ/π decay rate taken into account
20 July 2001 Deborah Harris Fermilab 26
Physics at a Muon Collider / Higgs Factory
• Can measure Higgs boson mass to ~100 keV
• s-channel Higgs production – cross section much higher with
• Can measure Higgs width to 1 MeV
• Hints in current scenario:1. ~115 GeV Higgs with SM couplings?
2. (g-2) discrepancy of 2.6
3. bs
• For large values of tan , there is a range of heavy Higgs boson masses for which discovery is not possible at LHC or e+e- LC
• Higgs Factory muon collider is a step towards the high energy muon collider!
20 July 2001 Deborah Harris Fermilab 27
E1 working group position paper
• The recent evidence for neutrino oscillations is a profound discovery. The US should strengthen its lepton flavor research program by expediting construction of a high-intensity conventional neutrino beam ("superbeam") fed by a 1 - 4 MW proton source.
• A superbeam will probe the neutrino mixing angles and mass hierarchy, and may discover leptonic CP violation. The full program will require neutrino beams at a number of energies, and massive detectors at a number of baselines. These facilities will also support a rich program of other important physics, including proton decay, particle astrophysics, and charged lepton CP- and flavor- violating processes.
• The ultimate laboratory for neutrino oscillation measurements is a neutrino factory, for which the superbeam facility serves as a strong foundation. The development of the additional needed technology for neutrino factories and muon colliders requires a ongoing vigorous R&D effort in which the US should be a leading partner.
20 July 2001 Deborah Harris Fermilab 28
Conclusions
• We’re in the middle of a fundamental discovery – this IS the frontier!
• We need new beamlines and new detectors to explore this new world
– Proton drivers (1-4MW)
– Superbeam
– Large underground detector
• Neutrino Detectors can bring diverse physics:
– Proton decay
– Atmospheric & solar neutrino studies
• Neutrino Beamlines can also bring diverse physics:
– Precision muon physics (edm, g-2, etc)
– Neutrino non-oscillation physics
• The ultimate laboratory for oscillation measurements is a neutrino factory—we need to pursue R&D NOW to make it happen
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