e1 working group neutrino factories and muon colliders

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


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


SuperKamiokande Results

• Again, after a long history of “anomalous” results, the atmospheric neutrino data are indicating oscillations

K. Nishikawa, NuFact’01


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.


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


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


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…


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


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…


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


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


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


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


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)


Electron Candidate in Liquid Argon TPC

• 300 tons operating now

• Need to see how large a single volume can be made


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


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


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)


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


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


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


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!


to e conversion at BNL-AGS

Looks like the front of a Neutrino factory: 5x1011 /spillStart 2006Goal: B( Al e Al) = 10-17


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?


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


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!


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.


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

e1 working group neutrino factories and muon colliders

Documents

debbie harris

atmospheric neutrino

solar sectors

mass eigenstateuadd

mass hierarchy

solar model ne

muon collidersingredients

solar nq23