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E1 Working Group Neutrino Factories and Muon Colliders.
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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, ShinjiMachida, 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
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 • ne from the Sun become ne and (nm , nt) K. Heeger, Les Houches ‘01 Deborah Harris Fermilab
SuperKamiokande Results • Again, after a long history of “anomalous” results, the atmospheric neutrino data are indicating oscillations K. Nishikawa, NuFact’01 Deborah Harris Fermilab
We are in the middle of a fundamental discovery! • Neutrinos have mass, and mn/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
What do we know today? • nm made in the atmosphere are disappearing – stronger and stronger indications that they are becoming nt, not ns • Dmatm2 3x10-3eV2 • ne made in the sun are disappearing – 3s indication from SNO that they are becoming nactive, not ns • Dmsolar2 1x10-4eV2 or even lower • ne appearing in a nm beam made in Los Alamos • DmLSND2 2 to 0.1eV2 Deborah Harris Fermilab
What do we ultimately want to know from n 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 Q13 = 0? Is it l,l2, or l3? Need precision! • Is there CP in the lepton sector? Deborah Harris Fermilab
Three Generation Neutrino Oscillations Produce & Detect Weak Eigenstate, Detect Mass Eigenstate U • Probability of na to nb • Oscillation has contributions from every Dm2 • Other 3 generation bonus: CP Violation Add all 3 Amplitudes and Square… Deborah Harris Fermilab
Parameters of Neutrino Oscillation • (s13=sinQ13, c13=cosQ13) • 3-generation mixing: • Q13,Q32,Q12,d, just like CKM • “Standard” Scenario: • Q12, |Dm12| from solar n • Q23, |Dm23| from atmospheric n • Still missing Q13 and d • CP Violation: Deborah Harris Fermilab
To fully understand the physics behind fermion mass and mixing… • New Facilities • Upgraded proton source (1-4MW) • Very intense n beams • Ultimately, a n factory • New Detectors • Focus on ne appearance and nm disappearance • If LSND signature is oscillations: nt appearance gets higher priority • Of course, we’re not the only ones excited about addressing these issues… Deborah Harris Fermilab
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 Deborah Harris Fermilab
m Superbeam Proposals, Continued n • Is there another way to measure these parameters? • What has not been measured here? T. Nakaya, JHF Deborah Harris Fermilab
The Case for a High Energy Superbeam • The nm to ne 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 s, not the neutrino s • 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 Deborah Harris Fermilab
Capabilities of High Energy Superbeams • Assumptions: • Narrow Band Beam tuned at oscillation peak • 70kTon fiducial volume detector, 50% effic. • 2 years n, 6-8 years n (to get equal statistics) • Background fraction of 0.4% • 4 x (1/5 NUMI ME) Flux x (730km2/ L2) • Dm232 =+3.5x10-3 eV2 Dm232 =10-4 eV2 Calculated during SNOWMASS; Barger, Marfatia, Whisnant Deborah Harris Fermilab
Superbeam detector optionswith broad physics reach Water Cerenkov: ne 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
Electron Candidate in Liquid Argon TPC • 300 tons operating now • Need to see how large a single volume can be made Deborah Harris Fermilab
Neutrino Factory Capability • Beam comes from • Above 10 GeV muon storage rings, get much more nm out per proton power • Backgrounds for nenm at the 10-4 level or better with old detector technology • The ONLY way we know to get a ne beam! • Very well-known fluxes makes for very high precision on mixing angles and mass splittings Deborah Harris Fermilab
From Superbeam to Neutrino Factory Detector—Charge ID 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 • tt M. Campanelli, ICARUS detector MC UNO Design Primary goal in neutrino factory: muon charge identification Deborah Harris Fermilab
Neutrino Factory Reach Factor of 10 better Than JHF upgrade! If LMA and Q13 small, Might even see signs of solar mass scale! Larger parameter space accessible for CP studies (hep-ph/010352) If LSND confirmed: Look fornt appearance at shorter Baselines—CP studies galore! (hep-ph/010352) Deborah Harris Fermilab
Path to a muon storage ring neutrino experiment Deborah Harris Fermilab
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
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
Muons do more than decay: Charged Lepton Flavor Physics m to e conversion SUSY predicts 10-15 level In scenario where n’s oscillate Two order of magnitude improvements possible Now Proton driver 200 MeV 3GeV 20 -50GeV storage ring m EDM: Violates P and T reversal invariance! A measurement indicates new physics Could improve by 4 orders of magnitude! (g-2)m 2.6s discrepancy now – best probe of tan b Deborah Harris Fermilab
m to e conversion at BNL-AGS Looks like the front of a Neutrino factory: 5x1011 m/spill Start 2006 Goal: B(m Al e Al) = 10-17 Deborah Harris Fermilab
Neutrinos do more than oscillate I:standard and exotic processes 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? Now Proton driver 200 MeV 20 GeV storage ring 50 GeV storage ring Muon collider Neutrino magnetic moment: (conventional) High statistics at superbeams enable order-of-magnitude improvements (non-conventional) resonant cavities? phase rotation? Heavy flavor production: Charm and bottom via CC/NC: c + b content of nucleon; get CKM matrix elements Detectors: need high precision tracking Deborah Harris Fermilab
Large TPC (1kT-yr) Si-CCD (126kg-yr) Liquid CH4 (1800kg-yr) Super-B ~3x10-5 ~3x10-4 ~2x10-5 Em=200MeV 10-4 ~10-5 Not effective NE Em=2.5GeV 10-4 ~10-5 ~3x10-4 ~2x10-5 Em=20GeV Not effective ~3x10-5 ~2x10-6 Em=50GeV NE ~5x10-6 ~3x10-7 Neutrinos do more than oscillate II:lepton number violation • PROCESSES:nm+e-m-+`ne (Em > 10.7 GeV) • ne+e- m-+ nm (Em > 10.7 GeV) m+e++ nm+`ne (Em < 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
Physics at a Muon Collider / Higgs Factory • Can measure Higgs boson mass to ~100 keV • s-channel Higgs production – cross section much higher with m • Can measure Higgs width to 1 MeV • Hints in current scenario: • ~115 GeV Higgs with SM couplings? • (g-2)m discrepancy of 2.6s • bsg • For large values of tan b, 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
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
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