Physics Working Group report

1
Physics Working Group report
http//www.hep.ph.ic.ac.uk/iss/wg1-phys-phen/index
.html

• on behalf of Yori Nagashimaand the Physics
  Working Group

Acknowledgements all who contributed to the work
and life of the group a very functional team!
2
The Physics Working Group

• ISS charge to Physics Working Group
• Convener Yorikiyo Nagashima (Osaka)
• Council
• D.Harris (FNAL), P.Hernandez (Valencia), S.King
  (Southampton), M.Lindner (Heidelberg), K.Long
  (Imperial), W.Marciano (BNL), M.Mezzetto (Padua),
  H.Murayama (LBL), K.Nakamura (KEK), L.Roberts
  (Boston), O. Yasuda (Tokyo)
• Sub-groups and conveners
• Theoretical S. King
• Phenomenological O. Yasuda
• Experimental K. Long
• Muon Physics L. Roberts

Evaluate the physics case for a second-generation
super-beam, a beta-beam facility and the Neutrino
Factory and to present a critical comparison of
their performance
3
The Physics Working Group

• Members
• Organisation
• WWW page and mailing list
• http//www.hep.ph.ic.ac.uk/iss/wg1-phys-phen/index
  .html
• NF-SB-ISS-PHYSICS_at_JISCMAIL.AC.UK
• Physics workshops
• Workshops
• Imperial 14 21 November 2005
• Boston 6 10 March 2006
• Valencia 3 6 July 2006

S. Antusch, A. Blondel, J.  Bouchez, D. Casper,
P. Chimenti, E. Couce, A. Donini, M. Dracos,
E. Fernandez-Martinez, F. Filthaut, R. Gandhi,
A. de Gouvea, P. Hernandez, P. Huber, S. King,
K. Long, T. Matsushita, M. Mezzetto, N. Mondal,
Y. Nagashima, J. Nelson, S. Pascoli,
J. Peltoniemi, B.A. PopovS. Rigolin, L. Roberts,
C. Rogers, A. Romanino, T. Schwetz, Y. Uchida,
S. Umasankar, W. Winter, K. Zuber, M. Zisman
4
Contents

• Introduction
• Neutrino oscillations and theory
• Performance comparison
• Second-generation super beam
• Beta beam
• Neutrino Factory
• Conclusions

5
Standard neutrino Model (S?M)?

• Neutrino oscillations implies
• Neutrino mass ?? 0 and masses not equal
• ?L and ?R present
• and can interact (albeit very very weakly)
• Neutrino has no conserved q.n. except, perhaps,
  global lepton number
• Mass states mix to produce flavour states

6
Symmetries beyond the SM

• Super-symmetry
• Symmetry in spin space
• Generations/families
• The result of some family symmetry?
• SU(3)family?
• Pattern of properties within one generation
• B L symmetry?
• Grand Unified Theory (GUT), e.g. SO(10)?
• Horizontal relates properties across generations
• Vertical relates properties of quarks and leptons

Supersymmetric partner of the neutrino may be
inflaton
7
To understand the physics of flavour

• See-saw mechanism gives a natural explanation
  of both
• Small neutrino mass
• Large lepton mixing angles
• so neutrino probes physics at very high mass
  scales
• Create observed baryon asymmetry through heavy,
  Majorana, neutrinos?
• Detailed understanding of properties of neutrino
  is required to understand the physics of flavour

8
Quark-lepton relationship example
9
Quark-lepton relationship example

• Define
• Precision evaluated assuming

10
Charged/neutral lepton mixing relationship

• If physics of flavour is explained by family
  and/or GUT symmetries, then there must be
  relationships between quark and lepton mixing
  parameters
• Within a particular model, predictions for these
  relationships can be made
• Challenge to neutrino experimenters
• Measure neutrino mixing parameters with a
  precision similar to the precision with which the
  quark mixing parameters are known

11
Identifying the correct theory

• Precise knowledge of neutrino mixing parameters
  can discriminate

Chen et al., hep-ph/0608137
12
Beyond the Standard ? Model
The work of the Phenomenology and Muon Subgroups

• Two main issues
• Effect of new physics
• Tests of three-flavour unitarity
• Focus on new physics for next few slides
• Parameterise new physics by effective 4-fermion
  interaction
• For processes involvingcharged lepton,
  boundspresently

eaß
Yasuda et al, Roberts et al.
13
New physics in neutrino oscillations

• Example
• Silver channel at the Neutrino Factory

14
Muon physics

• Muon has been a key tool in the establishment of
  the Standard Model
• Two avenues to search for non-SM effects
• Measure precisely ?EDM and ?MDM
• Search for lepton-flavour violation
• Experiments require high fluxes
• Neutrino Factory front end offers 1014 µ/sec
• Example µ ? e conversion
• Present B.R. limit 6 10-16
• PRISM ? PRIME sensitivity at the level of 10-19
  to 10-18
• Neutrino Factory front end potential
  sensitivity 10-20

15
Super-beam performance

• Conventional p ? µ ?µ
• Super ? driven by multi MW proton beam
• Options considered
• SPL ? Frejus 10 year exposure, on-axis beam
• Proton beam energy 2.2/3.5 GeV
• Neutrino beam energy 0.3 GeV
• Baseline 130 km
• J-PARC ? HyperKamiokande 10 year
  exposureoff-axis beam
• Proton beam energy 50 GeV
• Neutrino beam energy 0.6 GeV
• Baseline 295 km
• T2KK one detector in Japan, second in Korea
  attractive option for degeneracy resolution

E. Fernandez J.E. Champagne T. Schwetz
16
Super-beam performance

• Options considered (continued)
• On-axis, wide-band beam two options (10 yr)
• BNL ? Henderson/Homestake
• Proton beam energy 24 GeV
• Neutrino beam energy 0 6 GeV
• Baseline 2500 km
• FNAL ? Henderson/Homestake
• Proton beam energy 120 GeV
• Neutrino beam energy 0 10 GeV
• Baseline 1250 km
• Advantages
• See 1st 2nd max., so good degeneracy resolution
• Challenge
• Needs good Eres for recons. bg suppression

17
Super-beam physics

• Principal channel ?µ ? ?e
• Search for/measure ?13, d
• Measure ?m312
• Disappearance ?µ ? ?µ
• Test ?23 maximality
• Atmospheric
• Measure atmospheric parameters precisely
• Combined with
• Atmospheric or WBB sign(?m312)
• Beta-beam greater sensitivity to d
• Neutrino Factory aids NF degeneracy
  resolution

18
Super-beam ?13 discovery

• T2HK (slightly) out-performs SPL
• T2HK closer to being systematically limited
  (effect of going from 2 systematic errors to 5)

19
Super-beam sensitivity to d

• T2HK offers (slightly) better sensitivity

20
Super-beam mass hierarchy (WBB)

• Short baselines of the SPL and T2HK options offer
  little sensitivity to the mass hierarchy
• The WBB, because of the much longer baseline, has
  sensitivity to the mass hierarchy down to 4
  10-3

L 1300 km
L 2500 km
21
Neutrino Factory performance
platinum
Golden

• Reference Neutrino Factory
• 1021 useful decays/yr exposure 5 plus 5 years
• 50kTonne magnetised iron detector (MID) with
  MINOS performance
• Backgrounds (for golden channel)
• Right-sign muons
• Charm decays
• Eres 0.15 E?
• variable E? bins, efficiency and migration
  matrices

P. Huber, M. Lindner M. Rolinec W. Winter, A.
Donini, et al.
22
NF Golden channel optimisation
sin22?135s sensitivity
One detectorGolden

• Magic baseline (7500 km) good degeneracy solver
• Stored muon energy gt 20 GeV

23
NF Golden channel optimisation
CP violation 3s sensitivity
One detectorGolden

• Baseline 3000 5000 km
• Stored-muon energy gt 30 GeV

24
NF Golden channel optimisation
Mass hierarchy 3s sensitivity
One detectorGolden

• Baseline 7500 km
• Stored muon energy 20 50 GeV

25
NF Summary for single MID
26
NF Multiple baselines

• Plot performance for two 25kT detectors relative
  to the performance for one 50 kT detector at the
  magic baseline

Second detector at3000 kmpreferred as it
hassensitivity to CPviolation
Stored muonenergy 50 GeV
27
NF additional channels

• Emulsion cloud chamber Silver
• OPERA-like performance 5 kTonne
• Emulsion cloud chamber Silver
• 10 kT 5 times efficiency
• Liquid argon detector Platinum
• 15 kTonne Eres 0.15 E? charge ID to 7.5
  GeV
• 0.2 signal efficiency, 0.01 charge confusion
• Baseline same as MID
• Golden with electron CID Platinum
• 50 kt charge ID up to 50 GeV

28
NF additional channels
One detector

• Improved performance due to degeneracy resolution

29
NF improved golden detector (MID)

• Lower energy threshold
• Efficiency reaches plateau at 50 by 1 GeV
• 50 by 3 GeV gives comparable performance
• Background 0.001/E2 of all NC and same fraction
  of right sign muons
• Better energy resolution
• Eres 0.15 ?E?0.5 0.085 GeV

Golden
One detectorGolden
One detectorGolden

• Stored muon energy 25 GeV
• Baselines 3000 km (CP) and 7500 km (hierarchy)

30
Neutrino Factory summary
Golden (Golden)MB Plat 50 kT, MID, L
4000 km Golden 50 kT, MID, L 7500 kmplus
Platinum Eµ 20 GeV
Golden (Golden)MB 50 kT, MID, L 4000 km 50
kT, MID, L 7500 km Eµ 20 GeV
Golden (Golden)MB 50 kT, MID, L 4000 km 50
kT, MID, L 7500 km Eµ 50 GeV
Golden 50 kT, MID, L 4000 km Eµ 50 GeV
31
Beta-beam

• Two beta-beam options considered
• Option 1
• Gamma 100
• Baseline 130 km
• Option 2
• Gamma 350
• Baseline 730 km
• Fluxes
• He 2.9 1018 decays per year
• Ne 1.1 1018 decays per year
• Interesting options to be considered
• Li, B

E. Couce P. Hernandez M. Mezzetto T. Schwetz
32
Comparison CP violation
SPL Systematics 2 5
T2HK Systematics 2 5
WBB Systematics from proposal
Beta beam ? 100 500 kT H2O Ç (130 km) ?
350 500 kT H2O Ç (730 km)
Neutrino Factory Golden, 4000, Eµ 50
GeV Golden (4000 km), Golden (7500 km) Eµ 20
GeV
33
Neutrino Factory detector

• Magnetised Iron detector
• Cervera
• Baseline?
• 40 kTon
• Hadronic energy resolution (MINOS like)
• Energy threshold (new analysis)
• Potential for improvement through RD?

34
Comparison CP violation
SPL Systematics 2 5
T2HK Systematics 2 5
WBB Systematics from proposal
Beta beam ? 100 500 kT H2O Ç (130 km) ?
350 500 kT H2O Ç (730 km)
Neutrino Factory Golden, 4000, Eµ 50
GeV Golden (4000 km), Golden (7500 km) Eµ 20
GeV
35
Comparison CP violation
SPL Systematics 2 5
T2HK Systematics 2 5
WBB Systematics from proposal
Beta beam ? 100 500 kT H2O Ç (130 km) ?
350 500 kT H2O Ç (730 km)
Neutrino Factory Golden, 4000, Eµ 50
GeV Golden (4000 km), Golden (7500 km) Eµ 20
GeV
36
Comparison mass hierarchy
SPL Systematics 2 5
T2HK Systematics 2 5
WBB Systematics from proposal
Beta beam ? 100 500 kT H2O Ç (130 km) ?
350 500 kT H2O Ç (730 km)
Neutrino Factory Golden, 4000, Eµ 50
GeV Golden (4000 km), Golden (7500 km) Eµ 20
GeV
37
Comparison ?13
SPL Systematics 2 5
T2HK Systematics 2 5
WBB Systematics from proposal
Beta beam ? 100 500 kT H2O Ç (130 km) ?
350 500 kT H2O Ç (730 km)
Neutrino Factory Golden, 4000, Eµ 50
GeV Golden (4000 km), Golden (7500 km) Eµ 20
GeV
38
Conclusions

• Compelling case for precision neutrino programme
• Develop and evaluate methods to discriminate
  between theories describing the Physics of
  Flavour
• Evaluate contribution a muon-physics programme
  can make
• Extensive performance evaluation of super-beam,
  beta-beam, and Neutrino Factory options
• Large ?13
• Comparable sensitivity
• ? need to include cost and schedule
  considerations in evaluating optimum
• Intermediate ?13
• Neutrino Factory better, beta beam competitive
• ? need to include cost and schedule
  considerations in evaluating optimum
• Low ?13
• With present assumptions Neutrino Factory
  out-performs other options
• ? need to include cost and schedule
  considerations in evaluating optimum
• Clear motivation to move from ISS phase to full
  Design Study phase