# Presentation: 035233

## E1 Working GroupNeutrino 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:**** **
**Neutrino Oscillations – Conventional Beams**
**Intense Muon Source Physics**
**The Rest of  Neutrino Physics (non-oscillation)**
**Neutrino Oscillations ****– ****Muon Storage Rings **
**Muon Collider Physics**

- Deborah Harris    Fermilab

- 20 July 2001

## 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

- Deborah Harris    Fermilab

- 20 July 2001

## SuperKamiokande Results

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

- K. Nishikawa, NuFact’01

- Deborah Harris    Fermilab

- 20 July 2001

## 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.

- Deborah Harris    Fermilab

- 20 July 2001

## 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
- mLSND2 2 to 0.1eV2

- Deborah Harris    Fermilab

- 20 July 2001

## 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?

- Deborah Harris    Fermilab

- 20 July 2001

## Three Generation Neutrino Oscillations

- Probability of a to b
- Oscillation has contributions from every m2
- Other  3 generation bonus:
-     CP Violation

- Produce & Detect Weak Eigenstate,
- Detect Mass Eigenstate

- U

- Add all 3
- Amplitudes and
- Square...

- Deborah Harris    Fermilab

- 20 July 2001

## Parameters of Neutrino Oscillation

**“****Standard” Scenario:  **
******12****, |********m****12****| from solar ******
******23****, |********m****23****| from atmospheric ******
**Still missing ********13  ****and ******
**CP Violation:****  **

- (**s****13****=sin********13****, c****13****=cos********13****)**
**3-generation mixing:  **
******13****,********32****,********12****,********, just like CKM**

- Deborah Harris    Fermilab

- 20 July 2001

## 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...

- Deborah Harris    Fermilab

- 20 July 2001

## 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 |

- Deborah Harris    Fermilab

- 20 July 2001

## Superbeam Proposals, Continued

- n

- m

| Name | Years of running | K-ton | sin2213
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. Nakaya, JHF

- Deborah Harris    Fermilab

- 20 July 2001

## 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 8****o ****uncertainty due to matter effects**

- Deborah Harris    Fermilab

- 20 July 2001

## 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 m232 =10-4 eV2

| Baseline
(km) | E 
(GeV) | sin213 Reach(3)
   |  | Sign (m232) | 
(3)
sin213=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 | 76 |

- Calculated during SNOWMASS; Barger, Marfatia, Whisnant

- Deborah Harris    Fermilab

- 20 July 2001

## Superbeam detector optionswith broad physics reach

**Water Cerenkov**:
- e appearance proven
- Below 1GeV!
- Questions:
- What about
- higher energies?
- Can we get to 10-3
- background?

**Liquid Argon TPC:**
- Superb imaging quality
- Questions:
- Can such a large volume
- Of cryogenic material
- be put underground?
- Is 10-3 background achievable in data?
- (MC looks promising)

- Deborah Harris    Fermilab

- 20 July 2001

## Electron Candidate in Liquid Argon TPC

- 300 tons operating now
- Need to see how large a single volume can be made

- Deborah Harris    Fermilab

- 20 July 2001

## 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

- Deborah Harris    Fermilab

- 20 July 2001

## 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. Campanelli,
-  ICARUS detector MC

-  UNO Design

- Deborah Harris    Fermilab

- 20 July 2001

## Neutrino Factory Reach

- Factor of 10 better
- Than 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 shorter
- Baselines—CP studies galore!
- (hep-ph/010352)

- Deborah Harris    Fermilab

- 20 July 2001

## Path to a muon storage ring neutrino experiment

**Path to a muon storage ring neutrino experiment**

- Deborah Harris    Fermilab

- 20 July 2001

## 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.**

**E821, Brookhaven,**
**3.2B e****+****can’t be wrong**

- Deborah Harris    Fermilab

- 20 July 2001

## New Lampposts

**On the way to a high energy muon collider, we will learn to build:**
- Neutrino “superbeam” from high intensity (1- 4 MW) proton driver
- Low-emittance, low energy spread muon beam at 200 MeV
- 3 GeV muon beam
- 20-50 GeV muon storage ring
- Muon Collider operating as a Higgs Factory

- Deborah Harris    Fermilab

- 20 July 2001

## 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**** level**
**In scenario where ********’s oscillate**
**Two order of magnitude improvements possible**

**(g-2)******
**2.6********discrepancy now ****– ****best probe of **
**tan ******

****** ****EDM****:**
**Violates P and T reversal invariance! A measurement indicates new physics**
**Could improve by 4 orders of magnitude!**

- Deborah Harris    Fermilab

- 20 July 2001

##  to e conversion at BNL-AGS

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

- Deborah Harris    Fermilab

- 20 July 2001

## 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 nucleon**
**Detectors: 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 elements**
**Detectors: need high precision tracking**

**Neutrino magnetic moment****:**
**(conventional)**
**High statistics at superbeams enable order-of-magnitude improvements**
**(non-conventional)**** resonant cavities?**
** ****phase rotation?**

- Deborah Harris    Fermilab

- 20 July 2001

## 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.

- Detector 1km from source, 100% efficiency,  μ/π decay rate taken into account

- Deborah Harris    Fermilab

- 20 July 2001

## 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:
**~115 GeV Higgs with SM couplings?**
**(g-2)******** discrepancy of 2.6******
**b********s******
- 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!**

- Deborah Harris    Fermilab

- 20 July 2001

## 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.**

- Deborah Harris    Fermilab

- 20 July 2001

## 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**

- Deborah Harris    Fermilab

- 20 July 2001