Beyond DUNE and Hyper-Kamiokande:
neutrino facilities from muon decay
Seminar,	
  Kyoto	  University	
  29	
  November	
  2018	  	
  Paul Soler
University of Glasgow

University of Glasgow❏

Nijo Castle: 1626❏

University of Glasgow: 1451
4th oldest English-speaking university

2

Contents

1. Physics Motivation
2. Neutrino Factory
3. Neutrino Factory Staging
4. Muon Ionization Cooling Experiment (MICE)
5. nuSTORM

Seminar, Kyoto University: 29 November 20183

1. Physics Motivation

Seminar, Kyoto University: 29 November 20184

Neutrino mixing❏

Weak eigenstates and mass eigenstates different:
Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix

!
# νe
# ν
# µ
# ντ
"

$
! ν $
$ c12
1
&
#
&
&
& = U # ν 2 & ⇒ U = −s12
&
&
##
&&
&
&
0
ν
%
3 %
"
%

s12
c12
0

0' $ 1 0) &0)⋅ & 0 c 23
) &1( % 0 −s23$
0 ' & c13)s23 )⋅ & 0) &c 23 ( &% −s13eiδ

'0 s13e −iδ )
1
0 )
)
0
c13 )(

where c ij = cos θ ij , and sij = sin θ ij❏

Three mixing angles and one CP violating phase"c12 c13$€U PMNS = $ −s12 c23 − c12 s23s13eiδ
$$ s12 s23 − c12 c23s13eiδ
#s12 c13c12 c23 − s12 s23s13eiδ
−c12 s23 − s12 c23s13eiδ%s13e−iδ 's23c13 ''c23c13 '&ν α = ∑Uαi ν i where α = e, µ, τ and i = 1, 2, 3iSeminar, Kyoto University: 29 November 20185

Neutrino oscillations❏

Three rotations in weak and mass eigenstate spaceν α (t ) = e

!!
ip⋅r

− iE i te∑ Uα i ν iiPνα →να" (t) = ν α " ν α (t)

2

=

*
*
U
U
U
∑ α i α"i α jUα" j cos%&(Ei − E j )t − φαα"ij '(i, j" Δm132 % 2" 2 %2
2 Δm12Pν eν µ (ν eν µ ) (x) = s sin 2θ13 sin $x ' + c23 sin 2θ12 sin $x' +# 4E &# 4E &
2
2
2
"
%
)
,
"
%
Δm
Δm
Δm
13
12
13
!
+ J cos$±δ −x '+x . sin $x ' with J! ≡ c13 sin 2θ12 sin 2θ 23 sin 2θ13
4E &* 4E - # 4E &
#
2
23

2

2

Includes CP violation: neutrino/antineutrino oscillation difference if δ≠0
Seminar, Kyoto University: 29 November 20186

Neutrino oscillations in matter❏

Resonant neutrino oscillation in matter: MSW effect– Discriminates between normal and inverted mass hierarchyPν eν µ (ν eν µ ) ( x ) = P1 + P2 + P3 + P4
2

⎛ Δ13 ⎞⎤
22
2 ⎡ B∓⎜⎟
P1 = s23 sin 2θ13 ⎜sinx⎢ 2 ⎥⎟⎣⎦⎝ B∓ ⎠2

⎛ Δ ⎞⎡ A ⎤2
P2 = c 23
sin2 2θ12 ⎜ 12 ⎟ sin2 ⎢ x ⎥⎝ A ⎠⎣ 2 ⎦~⎡ Δ⎤⎛ Δ Δ ⎞ ⎡ A ⎤ ⎡ B ⎤P3 = J cos δ cos⎢ 13 x ⎥⎜⎜ 12 13 ⎟⎟ sin⎢ x ⎥ sin⎢ ∓ x ⎥⎣ 2 ⎦⎝ A B∓ ⎠ ⎣ 2 ⎦ ⎣ 2 ⎦~⎡ Δ⎤⎛ Δ Δ ⎞ ⎡ A ⎤ ⎡ B ⎤P4 = ±J sin δ sin⎢ 13 x ⎥⎜⎜ 12 13 ⎟⎟ sin⎢ x ⎥ sin⎢ ∓ x ⎥⎣ 2 ⎦⎝ A B∓ ⎠ ⎣ 2 ⎦ ⎣ 2 ⎦Δ ij ≡

Δmij2

2E
with B∓ ≡A ≡ 2GF ne~
J ≡ c13 sin 2θ12 sin 2θ 23 sin 2θ13

(Δ13 cos 2θ13 ∓ A)2 + Δ213 sin2 2θ13 ≈ Δ13 ∓ A
Seminar, Kyoto University: 29 November 2018

7

❏

❏

Next generation long-baseline experiments
Main physics goals of long-baseline neutrino
experiments are to observe CP violation in neutrinos
and to determine neutrino mass ordering
Both T2K and NOvA are exhibiting hints of CP
violation in the neutrino sector at ~2σ level

PRL, 121, 171802 (2018)

Neutrino 2018

Seminar, Kyoto University: 29 November 2018

8

❏
❏

Next generation long-baseline experiments
Require next generation experiments for 5σ results
Hyper-K Design Report: arXiv:1805.04163– CP-violation accuracy: ΔδCP~ 23o after 10 years for δCP= ±90o

Seminar, Kyoto University: 29 November 2018

9

❏
❏

Next generation long-baseline experiments
Require next generation experiments for 5σ results
DUNE Interim Design Report: arXiv:1807.10334– CP-violation accuracy: ΔδCP~ 15o after 10 years for δCP= ±90o

Seminar, Kyoto University: 29 November 201810

Is discovering CP violation sufficient?
❏❏❏

Is discovering CP violation and determining the massordering sufficient or do we need more precision?
We want to test the Standard Neutrino Model, thethree-neutrino paradigm and search for new physics
Compare PMNS mixing matrix to models:
"
−iδ %
c
c
s
c
s
e
12 13
12 13
13
$
'
U PMNS = $ −s12 c23 − c12 s23s13eiδ c12 c23 − s12 s23s13eiδ s23c13 '$'$ s12 s23 − c12 c23s13eiδ −c12 s23 − s12 c23s13eiδ c23c13 '#&where cij = cosθ ij and sij = sin θ ij"
2/3$
U PMNS = $ −1 / 6$$ 1/ 6#%'1oo' !12=sin (1/√3)~35.3 ,2!23=45 ,2!13=0,2"=0
1 / 3 1 / 2 ' Harrison,)Perkins,)Scott)PLB)530)(2002),)167'−1 / 3 1 / 2 ' Tri-bimaximal mixing: suggestive of a
&
1/ 3

0

broken flavour symmetry

Seminar, Kyoto University: 29 November 201811

Is discovering CP violation sufficient?
❏

What precision is required to search for mechanism
behind the generation of neutrino masses?
– In quark sector, precision around 5o– Flavour sum rules:
q12 =35°+q13 cosd

current best fit values and errors
for q12 , q13 and q23 taken from
Fogli et al. 2012

q12 =32°+q13 cosd

Accuracy required ~5o

q23 =45°+

2 q13 cosd

q23 =45°-1ê 2 q13 cosd
q12 =45°+q13 cosd

ie. deviation of mixing angles
from tri-bimaximal mixing:" 1 %θ12 − θ13 cos δ = sin $ '
# 3&
−1

15È

Comprehensive review:
King, Luhn, Rep. Prog.
Phys. 76 (2013) 056201

current errors

050

predicted value of dCP @ÈD
100

Seminar, Kyoto University: 29 November 2018

3% on sin2 2q13
0.7% on sin2 q12
1% on sin2 2q23

150

12

Precision of long-baseline experiments❏

Precision requirement for CP violation:– For 75% of CP asymmetry coverage at 3σ: ACP as low as 5%– Requires 1.5% measurement of(~1% syst. error),but we measure rate:

Huber, Palmer, BrossarXiv:1411:0629
Seminar, Kyoto University: 29 November 201813

Precision of long-baseline experiments❏

Precision requirement for CP violation:– In disappearance experiment we can satisfy:
Huber, Mezzetto, Schwetz
arXiv:0711.2950– In an appearance experimentso να beam cannot measure,

CP violation sensitivity
for 75% δCP coverage
at LBNE– Syst. error on ratio– Difference inandHuber, Palmer, BrossarXiv:1411:0629

Seminar, Kyoto University: 29 November 2018

in T2HK
may be large
14Precision of long-baseline experiments❏

Influence of measurement of neutrino cross-sections withless than 1% precision (nuSTORM has that capability):

Huber, Palmer, BrossarXiv:1411:0629

Seminar, Kyoto University: 29 November 201815

2. Neutrino Factory

Seminar, Kyoto University: 29 November 201816

Neutrino Factory Studies❏ A Neutrino Factory is a neutrino beam facility frommuon decay delivering 1021 muon decays per year
❏ Birth of modern Neutrino Factory:― S. Geer: Phys Rev D57, 6989 (1998)

q Neutrino Factory studies:― CERN study: CERN Yellow Report 99-02 (1999)― Feasibility Study I at Fermilab: Fermilab-Pub-00/108-E (2000)― Feasibility Study II at Brookhaven: BNL-52623 (2001)― Feasibility Study IIa at Brookhaven: BNL-72369 (2004)― International Design Study: Interim Design Report 2011

IDS-NF-020 arXiv:1102.2402― Muon Accelerator Staging Scenarios: launched by Muon
Accelerator Programme (MAP) in USA 2013 (arXiv:1308.0494)
Seminar, Kyoto University: 29 November 201817

Neutrino Factory Baseline❏

International Design Study for a Neutrino Factory (IDS-NF)µ + → e+ +ν µ +ν e

Baseline reviewed 2012:
from 25 GeV to 10 GeV muons(v4.0), one storage ring with
detector at 2000 km, after
discovery that θ13 is largeµ − → e− +ν µ +ν e

562 m

❏

Magnetised Iron Neutrino
Detector (MIND):– 100 kton at ~2000 km

Seminar, Kyoto University: 29 November 201818

Neutrino Factory Baseline❏

Proton driverµ + → e+ +ν µ +ν e

– Proton beam ~8 GeV on target❏µ − → e− +ν µ +ν e

Target, capture and decay– Create π, decay into µ (MERIT)

❏

562 m

Bunching and phase rotation– Reduce ΔE of bunch❏

Ionization Cooling– Reduce transverse emittance(MICE)❏

Acceleration– 120 MeVà 10 GeV with RLAs
– FFAG option now not favoured❏

Decay ring

Neutrino spectra
calculable to highaccuracy– Store for ~100 turns– Long straight sections– 1021 muons/yearSeminar, Kyoto University: 29 November 201819

Optimum energy proton driver❏

Optimum beam energy

Adopted 10 ± 5 GeV

Nµ/(proton.GeV)– Depends on choice of target– Optimum energy for high-Z targets around 8 GeV– Results validated by HARP hadron production experimentarXiv:1112.2853

0.012

MARS+FLUKA

0.01

0.008

0.006
POS MARS1507@BNL − ICOOL 3.16 − 0 ns − ST2
NEG MARS1507@BNL − ICOOL 3.16 − 0 ns − ST2
POS MARS1507@CERN − ICOOL 3.10 − 3 ns − ST2a

0.004

NEG MARS1507@CERN − ICOOL 3.10 − 3 ns − ST2a
POS FLUKA 2008.3c − ICOOL 3.10 − 3 ns − ST2a
NEG FLUKA 2008.3c − ICOOL 3.10 − 3 ns − ST2a

0.002

0

5

6

7

8

9

10

11

12

13
14
Ekin (GeV)

Seminar, Kyoto University: 29 November 201820

Proton Driver❏ Requirements:
arXiv:1112.2853❏ Choice of proton driver depends on site:• LINAC based (SPL) proton driver at CERN
• Synchrotron(s)/FFAG based proton driver (green field
solution) – studied at RAL.
• PIP-2 LINAC based solution at Fermilab.
Seminar, Kyoto University: 29 November 201821

TargetLiquid Hg target in 20 T solenoid❏ Increased radiation shielding insurrounding target solenoid❏

1 cm

Target station &decay channel

Seminar, Kyoto University: 29 November 2018

MERIT

22

Muon Front End
Adiabatic B-field taper from Hgtarget to longitudinal drift❏ Add chicane to remove protons❏ Drift in ~1.5 T, ~60 m solenoid❏ Adiabatically bring on RF voltage
to bunch beam
❏ Phase rotation: variable frequencies❏– High energy front sees negative E-field– Low energy tail sees positive E-field– End up with smaller energy spread❏

Ionization Cooling: MICE demonstrator– Reduce transverse emittance by 36%– Performance: 0.066 µ/proton– Cooling increases muon yield by ~2.2
Seminar, Kyoto University: 29 November 2018

~36%

23

Acceleration❏

Baseline acceleration scheme at 10 GeV– Two “dog-bone” Recirculating Linear Accelerators (RLA)– First RLA up to 2.8 GeV– Second RLA up to 10 GeV
Side view

Seminar, Kyoto University: 29 November 201824

Decay Ring Geometry❏ Racetrack geometry for decay ring with insertion− Straight: 562 m− Upper arc: 121 m− Lower arc: 113 m− Insertion: 46 m
− Matching: 105 m (total)

Three µ+ and three µ- bunchesèCircumference = 1556 m
562 m

Divergence < 0.1/γ
Seminar, Kyoto University: 29 November 201825

Far Detector
❏

❏

❏
❏

Magnetised Iron neutrino
Detector (MIND): 100 kton
Octagonal plates andtoroidal field (as in MINOS)
Engineering metal plates
Magnetic field delivered by
100 kA current
14mx14mx3cm plates

Bross, Wands (FNAL)

Seminar, Kyoto University: 29 November 2018

26

MIND magnetisation❏

Magnetisation can be achieved using
Superconducting Transmission Line
(STL) developed for VLHC:– Either one 100 kA turn or 8x15 kA– Only need ~10 cm diameter hole❏

Extruded scintillator:

STL– Kuraray wavelength shifting fibrewith double-ended SiPMT readout

Seminar, Kyoto University: 29 November 2018

27

MIND efficiencies and background
BDT efficiency, focussing µ+

BDT background (stored µ-, focussing µ+)
Tau signal

Fractional Efficiency

Courtesy
R. Bayes
UofG
BDT efficiency, focussing µ-

BDT background (stored µ+, focussing µ+)

0.8
0.7

Tau signal

0.6
0.5
0.4
0.3
!+ extracted from !CC

0.2!- extracted from !CC

0.1
0
0

1

2

3

4

5
6
7
8
9 10
Total Neutrino Energy (GeV)

Seminar, Kyoto University: 29 November 201828

Performance 10 GeV Neutrino Factory❏❏

Optimisation for 10 GeV Neutrino Factory, 1021 µ/year with100 kton MIND at 2000 km gives best sensitivity to CP violation
Best possible performance for a Neutrino Factory: ΔδCP ~ 5oMore than 85% 5σ coverage(ie. 85% probability of CPV discovery!)arXiv:1203.5651

Seminar, Kyoto University: 29 November 201829

3. Neutrino Factory Staging

Seminar, Kyoto University: 29 November 201830

Muon Accelerator Staging Programme❏

Staging Neutrino Factory allows to produce physics at eachstage and spreads out cost – first step towards muon collider
Neutrino Factory (NuMAX)
Cool- Acceleration
ing
0.2–1
GeV

Initial 6D Cooling

MW-Class Target
Capture Sol.
Decay Channel
Buncher
Phase Rotator

Buncher

Accumulator

Front Endµ Storage Ring
µ+

ν

5 GeV

1–5
GeV

µ−

Accelerators:
Single-Pass Linacs

n Factory Goal:
1021 µ+ & µ− per year
within the accelerator
acceptance

ν

281m

Long Baseline NF

Share same complexµ-Collider Goals:
126 GeV a~14,000 Higgs/yr
Multi-TeV a
Lumi > 1034cm-2s-1

Muon Collider
Proton Driver

Front End

Acceleration

Cooling

Final Cooling

6D Cooling

µ−
Bunch
Merge

6D CoolingCharge Separator

Collider Ring
ECoM:

Positron Linac Positron
Ring

Higgs Factoryto~10 TeV
Accelerators:
Linacs, RLA or FFAG, RCS

Accelerationµ+µ−Collider Ring
ECoM:

µ+

10s of TeV

Positron Linacµ−IsochronousRings

Low EMmittance Muon
Accelerator (LEMMA):
1011 µ pairs/sec from+−e e interactions. The small
production emittance allows lower
overall charge in the collider rings– hence, lower backgrounds in acollider detector and a higher
potential CoM energy due toneutrino radiation.

Initial 6D Cooling

MW-Class Target
Capture Sol.
Decay Channel
Buncher
Phase Rotator

Combiner

Buncher

Accumulatorµ+

100 KWtargetLEMMA: Low
Emmittance Muon
Accelerator

SC Linac

Staging study
at FNAL:
from 5 GeV
Neutrino Factory
to Muon Collider

SC LinacarXiv:1808.01858

Proton Driver

Accelerators:
Linacs, RLA or FFAG, RCS

µ+

−

31µ

Stage 1: NuMAX commissioning❏

Neutrinos from a Muon Accelerator CompleX (NuMAX)– Neutrino Factory with 1020 straight muons decays/year @ 5 GeV– Muon ring at 5 GeV pointing neutrino beam towards Sanford– A 10kT MIND or magnetized LAr detector upgraded from LBNE
PIPII

J.P. Delahaye:study at FNAL

NuMAX
commissioning
PIPIII Dual use
Linac
3.75GeV
650MHzµ Preinjector
1.0 GeV
325MHz

No cooling

255MeV/c
Muons
Front-end

Target6.75 GeV
Protons

Accumulator
Buncher

Main Injector

Seminar, Kyoto University: 29 November 201832

Stage 2: NuMAX❏

Neutrinos from a Muon Accelerator CompleX (NuMAX)– Add small amount of 6D cooling– Neutrino Factory with 5×1020 straight muon decays/year @ 5 GeV– Muon ring at 5 GeV pointing neutrino beam towards Sanford
PIPII

J.P. Delahaye:study at FNAL

NuMAX and NuMAx+
PIPIII Dual use
Linac
3.75GeV
650MHzµ Preinjector
1.0 GeV
325MHzAdd cooling

255MeV/c
Muons

Cooling
Front-end

Target6.75 GeV
Protons

Accumulator
Buncher

Main Injector

Seminar, Kyoto University: 29 November 201833

Stage 3: NuMAX+❏

Neutrinos from a Muon Accelerator CompleX (NuMAX+)– Neutrino Factory with 1021 straight muons decays/year @ 5 GeV– Muon ring at 5 GeV pointing neutrino beam towards Sanford– Increased proton power and/or larger detectors
PIPII

J.P. Delahaye:study at FNAL

NuMAX and NuMAx+
PIPIII Dual use
Linac
3.75GeV
650MHzµ Preinjector
1.0 GeV
325MHzAdd cooling

255MeV/c
Muons

Cooling
Front-end

Target6.75 GeV
Protons

Accumulator
Buncher

Main Injector

Seminar, Kyoto University: 29 November 201834

Stage 4: Higgs Factory❏

Higgs Factory: production of Higgs at 126 GeV CM– Collider capable of providing ~13,500 Higgs events per year withexquisite energy resolution: direct Higgs mass and width– Possible upgrade to a Top Factory with production of up to 60000 top
particles per year
Higgs factory
PIPII

J.P. Delahaye:study at FNAL
Add 6D cooling

PIPIII Dual use
Linacµ Preinjector
1.0 GeV
325MHz6D cooling
Bunch
merge
6D coolingCharge separator

255MeV/c
Muons

3.75GeV
650MHz6.75 GeV
Protons

125GeV
300 m

RLA

Compressor Accumulator
Initial Cooling
Buncher
Front-end Target
Main Injector
Seminar, Kyoto University: 29 November 201835

Stage 5: Muon Collider❏

Multi-TeV muon collider:– If warranted by LHC results a muon collider can reach up to 10 TeV– Likely offers the best performance, least cost and power consumption of
any lepton collider operating in the multi-TeV regime.

J.P. Delahaye:study at FNAL

PIPII

Muon collider
PIPIII Dual use

Post cooling
acceleration

Linac

0.25 GeV
Final cooling

1.0 GeV
325MHz6D cooling
Bunch
merge
6D coolingCharge separator

255MeV/c
Muons

3.75GeV
650MHz6.75 GeV
Protons

RLA

Compressor Accumulator
Initial Cooling
Buncher
Front-end Target
Seminar, Kyoto University: 29 November 2018

RCS

Muon
Collider1.5 to 6 (10)TeV
2.5 to 6km
36A Potential Muon Accelerator
Complex at Fermilab:
νSTORM è NuMAXè Higgs Factory

Fermilab site

LBNE
Superbeam
To
SURF

1 GeV Proton
Linac (PIPII)

Accum
ulator&Compr
FreRingsssor EnontdTarget IInniittial
ial 6cC
ooolionlg C D Final
ool Cool

1-3 GeV Proton 
Linac (PIPIII)

1 GeV Muon
Linac (325MHz)
3-6.75 GeV Proton &1.25-5 GeV Muon
Linac(s) (650MHz)

Muon Beam
R&D Facilityft
J.P.Delahaye

Staging scenario
fully compatible
with the PIP-IIstage option

To Near Detector(s) for
Short Baseline
Studies

Later upgradable
to a Muon Colliderftwith Tevatron size
37
MAP Meeting, FNAL: 29 May 2014
at
6
TeV
37
Seminar, Kyoto University: 29 November 2018

Staging summary❏

Summary of machine parameters as a function of staging
scenarios
NuMAX

NuMAX

NuMAX+

Higgs Fact
125 GeV

Muon Coll.
6 TeV ***

Commissioning

Beam energy (GeV/c)

5

5

5

62.5

3000

Cooling

No

Initial 6D

Initial 6D

6D no final

Full 6D

Proton beam power on target

1MW

1MW

2.75 MW4 MW

1.8 MW

Proton beam energy on target

6.75 GeV

6.75 GeV

6.75 GeV

6.75 GeV

6.75 GeV

Acceleration cycle rep rate(Hz)

60

60

60

15

6

1.36 1012

1.36 1012

3.75 1012

2.6 1013

2.9 1013

Transmission efficiency (%)

15.3

56.7

56.7

15.4

6.9

µ / bunch in ring

3.5 109

1.3 1010

3.5 1010

4 1012

2.0 1012

Bunches in ring

60

60

60

1

1

4.9 1019

1.8 1020

5.0 1020µ / cycle at front end

ν towards detector/year(107s)
Higgs per year (107 sec)

13500

Luminosity (1034 cm-2s-1)

12Seminar, Kyoto University: 29 November 201838

Physics performance of NuMAX
Physics performance in terms of fraction of CP phase δ withmeasurement accuracy at or below Δδ
P. Huber
CKM 2011

1.0

0.8⇤⌅ at 1⌃⇧23 ⇥40

LBNE10
LBNE

0.6

PIP ⇤2.3MW⌅

LBNE
T2HK

NuMAX ⇤commissioning⌅

0.4

NuMAX
NuMAX

0.2

0.0
0

10kt

GLoBES 2014

Fraction of ⌅

❏

34kt

10

20

30

⇤⌅ °⇥

magnetized LAr

40

Seminar, Kyoto University: 29 November 201850
39

4. Muon Ionization CoolingExperiment (MICE)

Seminar, Kyoto University: 29 November 201840

Muon Cooling❏ Muon Ionization Cooling:― Muon Ionization Cooling is the key technology required to be able

to build front-end of a Neutrino Factory and a Muon Collider(ie. stochastic cooling enabled proton-antiproton collider in 1980s)

Principle

Practice

Small β⊥ ⇒ strong focusingdεT
εT dEµβ⊥ (13.6 MeV )
≈−
+
2
dz
Eµ β dz 2mc 2 β 3
Eµ X 0
Ionization: cooling

2

Multiple scattering: heating

Seminar, Kyoto University: 29 November 201841

Muon Ionization Cooling Experiment❏ Muon Ionization Cooling Experiment:― Letter of Intent: November 2001
― Proposal at Rutherford Appleton Laboratory (RAL): January 2003
― International collaboration built muon ionization coolingexperiment at RAL
Time-of-flighthodoscope 1(ToF 0)

Variable thickness
high-Z diffuser

7th February 2015

Absorber/focus-coilmodule

Upstream
spectrometer module

Downstream
spectrometer module
Electron
Muon
Ranger
(EMR)

MICE
Muon
Beam
(MMB)

MICE

Cherenkov
counters(CKOV)

ToF 1

Liquid-hydrogen
absorber
Scintillating-fibre
trackers

Seminar, Kyoto University: 29 November 2018

Pre-shower
(KL)
ToF 2

42

MICE Beam
❏ Muon beam from ISIS (800 MeV proton synchrotron)
ISIS
ProtonSynchrotron

Target
0

5

10

15 m

Q1
Q2

Pion channel
Diffuser

Q3

Pion momentum
Dipole 1(D1)

Muon cooling channel

Pion to muon decay
Muon momentum

SciFi Tracker

SciFi Tracker(a)Decay Solenoid(DS)
Dipole 2 Q4 Q5 Q6(D2)

Q7 Q8 Q9

TOF0 Ckov

MICE Experiment

TOF1

TOF2

KL EMR(b)

Muon optics
MICE Muon Beam line (MMB)

Spectrometer
Solenoid

Seminar, Kyoto University: 29 November 2018

Focus
Coil

Spectrometer
Solenoid43

Muon Ionization Cooling Experiment❏ Cooling Channel with Partial Return Yoke

Seminar, Kyoto University: 29 November 201844

MICE Data❏

MICE data set (2015-2017): 350x106 triggers

Seminar, Kyoto University: 29 November 201845

Multiple Coulomb Scattering❏First measurement of muon Multiple Coulomb Scattering in
R. Bayes, J. Nugent
lithium hydride at 140-240 MeV/c― Validation of Molière scattering model and Geant4❏

Validation of energy loss model

Seminar, Kyoto University: 29 November 201846

Measurement of beam emittanceSingle particle reconstruction: creates virtual beams byperforming ensemble of all particles❏ 4D-phase space of particles: (x, px , y, py )4 Σ
4 D 4D covariance❏ Normalised RMS transverse emittance: εT =matrix: Σ❏Ellipsoid containing
4D phase-space
RMS volume

mc

4D

Reconstructed phase spaceshows coupling of different
variables for emittancecalculation❏

Ionization cooling implies reduction oftransverse emittance after absorber
Seminar, Kyoto University: 29 November 201847

Transverse single-particle amplitude❏

Transverse single-particle amplitude:― Phase-space distance of muon from beam core
T −1
⊥
T
x
y

A = ε u Σ u with v = (x, p , y, p ) and u = v − v

Mean amplitude is proportional to RMS emittance❏ Ionization cooling reduces amplitude in the core of the beam(higher amplitude density at low amplitudes)❏

Seminar, Kyoto University: 29 November 201848

Change in amplitude across absorber
No absorber: decrease in number of core muons❏ Absorber: increase in number of core muons (cooling signal)❏

Seminar, Kyoto University: 29 November 201849

Ratio of cumulative core densities
Cumulative core density increase for LH2 and LiH absorbers
N
down❏ More cooling (RAmp>1) at higher input emittances
A
∑ n
❏

N
RAmp
≡ n=1N

up
A
∑ n
n=1

First demonstration and characterisation of ionization cooling!
Seminar, Kyoto University: 29 November 201850

Fractional emittance evolution❏

Fractional emittance is phase-space volume occupied byfraction α of beam (α=9% is 1σ of 4D phase space)1
Δεα 2ΔεT2εα = (π mcεT ) ⇒
≈
2
εα
εT

❏

Fractional (9%) emittance evolution 6 mm, 140 MeV/c, LiH, flip

Also shows
ionization
cooling!

Seminar, Kyoto University: 29 November 201851

Reverse emittance exchange
Emittance exchange: muon
collider 6D cooling and g-2❏ Reverse emittance exchange
lengthens bunch andincreases luminosity in MC❏ Polyethylene wedge absorber❏

Simulation

Simulation

Reverse emittance exchange: transverse cooling and longitudinal heating
Seminar, Kyoto University: 29 November 201852

5. nuSTORM

Seminar, Kyoto University: 29 November 2018

53

❏

nuSTORM: Neutrinos from STORed Muons
nuSTORM: storage ring for 3.8 GeV/c muons

3.8 GeV/c– Pions of 5 Gev/c captured 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: p = 3.8 GeV ± 10%– Muon decays (1 lifetime=27 orbits):– For 1020 POT, expect 2.6×1017 µ+ decays– Creates hybrid beam of neutrinos from pions & muons54
Seminar, Kyoto University: 29 November 2018

nuSTORM Facility❏

nuSTORM facility:––––

120 GeV protons on carbon or inconel target (100 kW)
NuMI-style horn for pion collection
Stochastic injection pions (5 GeV/c ± 10%) into storage ring: 0.09 π/POT
Storage ring: large aperture FODO lattice (3.8 GeV/c ± 10%) muons:
8×10-3 µ/POT

Seminar, Kyoto University: 29 November 2018

55

nuSTORM Flux❏

nuSTORM flux and energy spectrum

Use muon decay
neutrinos tocalibrate hadron
decay neutrinos?

–
–
–
–

+
+
νµ from pion decay π → µ + ν µ flux: 6.3×1016 ν/m2 at 50 m++
νe from muon decay µ → e + ν µ + ν e flux: 3.0×1014 ν/m2 at 50 m++
νµ from kaon decay K → µ + ν µ flux: 3.8×1014 ν/m2 at 50 m
Can be used for cross-section measurements and short baseline
experiments
56

Seminar, Kyoto University: 29 November 2018

nuSTORM event rates❏❏

Flux uncertainties for nuSTORM: < 1%
Event rates per 1021 POT in 100 tons of Liquid Argon at 50 m

– Limited by detector systematics:

Seminar, Kyoto University: 29 November 201857

Sterile neutrino search❏

Requires two magnetised detectors for neutrino oscillations:p

3.8 GeV [ ± 10% ]μπ
5 GeV [ ± 10% ]

❏

❏

18

10 decays/yr
226 m

μ

νe → νµND

FD~2000 mSuper-saturated Magnetised
Iron to remove wrong-sign muons:SuperBIND
Magnetic field: 1.5-2.6 T

240 kA from 8 Superconducting
Trasmission Lines
Seminar, Kyoto University: 29 November 201858

Sterile neutrino search❏Appearance search:2

Peµ (x) = 4 Ue4 Uµ 42

Adey et al., PRD 89 (2014) 071301

2
2
"
%
"
%
Δm
x
Δm
2
2
2
14
14 x
sin $
' ≡ sin ( 2θ eµ ) sin $'# 4E &# 4E &

With full reconstructionand efficiencies, 1021 POT❏

Disappearance search:
Pµµ (x) = 4 Uµ 4

2

(1− U )
2

µ4

2 &
2 &
#
#
Δm
x
Δm
x
sin 2 % 14 ( ≡ sin 2 ( 2θ µµ ) sin 2 % 14 ($ 4E '$ 4E '

Seminar, Kyoto University: 29 November 201859

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) 071301 (Ryan Bayes’ analysis)
Appearance efficiencies

Disappearance efficiencies

Seminar, Kyoto University: 29 November 201860

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) 071301 (Ryan Bayes’ analysis)
Appearance sensitivity

Disappearance sensitivity

99%
99%
99%

After FNAL SBL programme, sterile neutrinos might not be relevant
Seminar, Kyoto University: 29 November 201861

Neutrino interactions at nuSTORM❏

Example of CCQE measurement errors: ~2-3%– Data forand ν e cross-sections– Systematic errors completely dominated by detector

Seminar, Kyoto University: 29 November 2018

62

Neutrino interactions at nuSTORM
Influence of nuSTORM cross-section measurements
on DUNE and T2HK δCP measurements
CKM 2011

1.0
0.8

Dd atÈ 1s
q23 =40

0.6

NuMAX+ H3MW, 34ktL

LBNE + Project X H2.3MW, 34ktL
T2HK H0.7MW, 560ktL

0.4

T2HK + nuSTORM

0.2
0.0
0

LBNO H0.8MW, 100ktL
ESS H5MW, 500ktL

GLoBES 2014

Fraction of d❏

Daedalus H 1+2+
2.5+2.5 MWL + T2HKn

5

10

15

20

25

30

Dd@°D
Seminar, Kyoto University: 29 November 2018

63

nuSTORM as 6D cooling testbed❏

nuSTORM: testbed for 6D muon cooling experiment– At end of straight: 3.5 m iron pion absorber– After absorber: 1010 µ/pulse between 100-300 MeV/c

Seminar, Kyoto University: 29 November 2018

64

nuSTORM siting at CERN❏

nuSTORM at CERN (Physics Beyond Colliders study group)

Decay ringsupport building

Near
detectorPrimary Beam absorber❏Muon
decay ringComplementary physics
programme at CERN tolong-baseline experiments
in Japan and USA
K. Long

Targetcomplex

Preliminary draft target complex development

Seminar, Kyoto University: 29 November 201865

Conclusions❏❏

There is a physics case beyond Hyper-K and DUNE: test forthree-neutrino paradigm and beyond Standard Model physics
Design Study for a Neutrino Factory (IDS-NF)– Feasible Neutrino Factory has been designed– Staging of Neutrino Factory (ie. NuMAX) delivers physics at each stage– Provides a route to deliver high-energy muon collider❏❏

MICE has demonstrated muon ionization cooling for the
first time: it shows that Neutrino Factory is feasible
NuSTORM could be first neutrino beam from muon decay– To be used for neutrino cross-section measurements and sterile
neutrino search– Complementary to Hyper-K and DUNE – maximises physics impact oflong-baseline experiments

Seminar, Kyoto University: 29 November 201866