1. nuSTORM: Neutrinos from STORed Muons
NuPhys 2014
Queen Mary, University of London
Paul Soler, 16 December 2014

2. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Muon Storage Rings
Neutrinos from muon decay in storage rings
Decay rings for muons were proposed by Koshkarev (CERN-ISR-DI-74-62) in 1974 and Neuffer (Telemark Conference), 1980
The main motivation is a new type of neutrino beam with well-understood characteristics from decays of muons:
This led to developments of modern Neutrino Factories, first proposed by Geer: Phys. Rev D57, 6989 (1998)
Simple first step is nuSTORM, decay ring without need for muon cooling or any new technology
nuSTORM proposals at Fermilab and CERN:
Fermilab LoI (arXiv: ) and PAC proposal (arXiv: ) and EoI CERN (arXiv: )
NuPhys, Queen Mary, Univ. of London: 16 December 2014

3. nuSTORM: Neutrinos from STORed Muons
nuSTORM: storage ring for 3.8 GeV/c muons that can be realised now without any new technology
Pions of 5 Gev/c captured and injected into ring.
52% of pions decay to muons before first turn:
This creates a first flash of neutrinos from pion decays
Ring designed to store muons with p = 3.8 GeV ± 10%
Muons decay producing neutrinos:
Creates hybrid beam of neutrinos from pion & muon decay
3.8 GeV/c
NuPhys, Queen Mary, Univ. of London: 16 December 2014

4. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Physics motivation
Physics motivation of nuSTORM:
Definitive resolution of sterile neutrino problem and search for short-baseline neutrino oscillations
Creation of a neutrino beam with a flux accuracy of for neutrino scattering physics: “the neutrino light source”
Measurement of ne cross sections and nuclear effects in neutrino-nucleus collisions, essential for long baseline neutrino oscillation programme
Creation of a test bed for muon accelerator R&D for future high intensity neutrino factories and muon collider
A new way of doing neutrino physics
NuPhys, Queen Mary, Univ. of London: 16 December 2014

5. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Neutrino Factories
Neutrino Factories have demonstrated best potential sensitivity for CP violation of all future facilities:
However, these are very expensive facilities and very challenging technologically
562 m
NuPhys, Queen Mary, Univ. of London: 16 December 2014

6. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Long baseline physics
Precision requirement for CP violation:
For 75% of CP asymmetry coverage at 3s: ACP as low as 5%
Requires 1.5% measurement of (~1% syst. error), but we measure rate:
Huber, Palmer, Bross
arXiv:1411:0629
NuPhys, Queen Mary, Univ. of London: 16 December 2014

7. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Long baseline physics
Precision requirement for CP violation:
In disappearance experiment we can satisfy:
In an appearance experiment , so na beam cannot measure
Huber, Mezzetto, Schwetz
arXiv:
CP violation sensitivity
for 75% dCP coverage
at LBNE
Syst. error on ratio in T2HK
Difference in and can be large
Huber, Palmer, Bross
arXiv:1411:0629
NuPhys, Queen Mary, Univ. of London: 16 December 2014

8. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Long baseline physics
Influence of measurement of cross-sections with less than 1% precision as potentially provided by nuSTORM:
Huber, Palmer, Bross
arXiv:1411:0629
NuPhys, Queen Mary, Univ. of London: 16 December 2014

9. Short baseline physics
LSND and MiniBooNE hints of and appearance
and reactor anomaly (6% deficit)
LSND
Reactor anomaly
MiniBooNE
NuPhys, Queen Mary, Univ. of London: 16 December 2014

10. Short baseline physics
Precision requirement for CP violation:
nuSTORM could probe all possible sterile neutrino appearance and disappearance channels (if En>t threshold) to test paradigm
NuPhys, Queen Mary, Univ. of London: 16 December 2014

11. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM Parameters
nuSTORM flux parameters from end-to-end simulation
Pions are captured in horn, transported, and injected into ring.
52% of pions decay to muons before first turn:
For 1020 POT, flash of neutrinos from 8.6×1018 pion decays
Muon momentum acceptance: (3.8 GeV ± 10%) circulate in ring.
Muon lifetime is 27 orbits of decay
For 1020 POT, expect 2.6×1017 m+ that decay:
Hybrid beam from pion and muon decay for neutrino cross-section measurements and sterile neutrino search
3.8 GeV/c
NuPhys, Queen Mary, Univ. of London: 16 December 2014

12. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM Facility
nuSTORM facility:
120 GeV protons on carbon or inconel target (100 kW)
NuMI-style horn for pion collection: recently optimised
Injection pions (5 GeV/c ± 10%) into storage ring: 0.09 p/POT
Storage ring: large aperture FODO lattice (3.8 GeV/c ± 10%) muons: 8×10-3 m/POT
NuPhys, Queen Mary, Univ. of London: 16 December 2014

13. nuSTORM Flux and Spectrum
nuSTORM flux and energy spectrum
nm from pion decay flux: 6.3×1016 n/m2 at 50 m
ne from muon decay flux: 3.0×1014 n/m2 at 50 m
nm from kaon decay flux: 3.8×1014 n/m2 at 50 m
Can be used for cross-section measurements and short baseline experiments
Use muon decay
neutrinos to
calibrate hadron
decay neutrinos?
NuPhys, Queen Mary, Univ. of London: 16 December 2014

14. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM Event Rates
Flux uncertainties for nuSTORM from beam diagnostics: < 1%
Event rates per 1021 POT in 100 ton Liquid Argon at 50 m
Limited by detector systematics:
NuPhys, Queen Mary, Univ. of London: 16 December 2014

15. Neutrino interactions at nuSTORM
Very rich physics programme (just some examples):
Electron neutrino and cross-section measurements
p0 production in neutrino interactions
Charged p and K production
Neutrino-electron scattering
Neutrino-nucleon scattering: charged current and neutral current (NC/CC ratio and sin2qW)
Nuclear effects in neutrino interactions
Semi-exclusive and exclusive processes: measurement of
production
New physics and exclusive processes: test of universality, heavy neutrinos, eV-scale pseudo-scalar penetrating particles ….
Over 60 physics topics
already identified: PhD theses
NuPhys, Queen Mary, Univ. of London: 16 December 2014

16. Neutrino interactions at nuSTORM
Example of CCQE measurement:
Data for and cross-sections
NuPhys, Queen Mary, Univ. of London: 16 December 2014

17. Possible near detectors at nuSTORM
Example of near detectors:
HiResMuNu like in LBNF
High pressure Ar gas LBNO near detector
WA105: 300 ton LAr Demonstrator?
NuPhys, Queen Mary, Univ. of London: 16 December 2014

18. First attempt at generic reconstruction
Geant4 generic simulation for near detector:
Totally Active Scintillator with Magnetised Iron Detector
Reconstruction of
Particle identification:
R. Bayes
Very preliminary
NuPhys, Queen Mary, Univ. of London: 16 December 2014

19. Sterile neutrino search
Assume two detectors:
Super-saturated Magnetised Iron: SuperBIND
Magnetic field: T
240 kA from 8 Superconducting
Trasmission Lines
NuPhys, Queen Mary, Univ. of London: 16 December 2014

20. Sterile neutrino search
Appearance search:
Disappearance search:
Adey et al., PRD 89 (2014)
With full reconstruction
and efficiencies, 1021 POT
NuPhys, Queen Mary, Univ. of London: 16 December 2014

21. Sterile neutrino search
Short-baseline oscillation search with near detector at 50 m and far detector at 2 km, 1021 POT exposure
Appearance and disappearance multi-variate analyses
Adey et al., PRD 89 (2014)
Appearance efficiencies
Disappearance efficiencies
NuPhys, Queen Mary, Univ. of London: 16 December 2014

22. Sterile neutrino search
Short-baseline oscillation search with near detector at 50 m and far detector at 2 km, 1021 POT exposure
Appearance and disappearance multi-variate analyses
Adey et al., PRD 89 (2014)
Appearance sensitivity
Disappearance sensitivity
99%
Still need to show combined analysis appearance/disappearance
NuPhys, Queen Mary, Univ. of London: 16 December 2014

23. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Muon Accelerator R&D
Path towards Neutrino Factory and Muon Collider
NuPhys, Queen Mary, Univ. of London: 16 December 2014

24. nuSTORM for Muon Accelerator R&D
nuSTORM: testbed for 6D muon cooling experiment
At end of straight: 3.5 m iron pion absorber
After absorber: 1010 m/pulse between MeV/c
NuPhys, Queen Mary, Univ. of London: 16 December 2014

25. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at Fermilab
nuSTORM could be sited at Fermilab
Total cost: $330 M
Near Detector Hall
Far Detector Hall (D0)
Target building
Decay ring
NuPhys, Queen Mary, Univ. of London: 16 December 2014

26. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at CERN?
However, P5 report was not supportive at Fermilab (probably due to high cost and interference with LBNF)
Explore siting at CERN?
Make the most of Neutrino Platform at new facility in North Area
M. Nessi
NuPhys, Queen Mary, Univ. of London: 16 December 2014

27. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at CERN?
Target station in North Area
For two detector oscillation search: near detector in North Area and far detector in Point 1.8
NuPhys, Queen Mary, Univ. of London: 16 December 2014

28. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at CERN?
nSTORM serving the Neutrino Platform at CERN
M. Nessi et al.
NuPhys, Queen Mary, Univ. of London: 16 December 2014

29. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at CERN?
nSTORM serving the Neutrino Platform at CERN
M. Nessi et al.
NuPhys, Queen Mary, Univ. of London: 16 December 2014

30. NuPhys, Queen Mary, Univ. of London: 16 December 2014
nuSTORM at CERN?
nSTORM serving the Neutrino Platform at CERN
M. Nessi et al.
NuPhys, Queen Mary, Univ. of London: 16 December 2014

31. NuPhys, Queen Mary, Univ. of London: 16 December 2014
Conclusions
nuSTORM is entry level Neutrino Factory that can be built now, without need of new technology like cooling
It complements long baseline programme: it measures all cross-sections with high precision due to <1% knowledge of flux, and resolves systematic errors for long-baseline
It would be the ultimate neutrino scattering facility: “a neutrino light source”, or the “LEP for neutrinos”
Serves as test-bed for muon acceleration R&D for future of particle physics (energy and intensity frontier)
A scenario of LBNF in USA, Hyper-KamiokaNDE in Japan and nuSTORM at CERN would make a truly worldwide programme
The question shouldn’t be:
“Can we afford nuSTORM?”
but instead: “Can we afford not to have nuSTORM?”
NuPhys, Queen Mary, Univ. of London: 16 December 2014