Swiss neutrino program - Callum Wilkinson (Declaring my possible bias) - CERN Indico
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Swiss neutrino program
Callum Wilkinson
(Declaring my possible bias)
Neutrino physics in Switzerland
Federico Sanchez
Teresa Montaruli
Antonio Ereditato
Michele Weber
Laura Baudis
Nicola Serra
André Rubbia
Stefan Antusch
2
Open neutrino questions
Neutrino oscillation now firmly established as physics beyond standard
model, but…
● Why are the masses and mixing so different
to quark sector?
● What is the absolute neutrino mass scale?
● Are neutrinos their own antiparticle?
● Are there more than three neutrino families?
● Matter-antimatter asymmetry→
leptogenesis?
● What are the mixing parameters?
3
Open neutrino questions
Neutrino oscillation now firmly established as physics beyond standard
model, but…
● Why are the masses and mixing so different
to quark sector?
● What is the absolute neutrino mass scale?
0νββ, see
Theory work ● Are neutrinos their own antiparticle? underground talk
required to
build a
● Are there more than three neutrino families?
consistent ● Matter-antimatter asymmetry→ leptogenesis?
picture
● What are the mixing parameters?
Neutrino
oscillation
experiments 4
Reminder: disappearance
● Oscillation probability has an amplitude and a phase:
● Neutrino energy, Eν, and distance, L, dependent effect
Infer parameters from
position and depth of the
oscillation “dip”
5
Reminder: appearance
Complex relationship between parameters: Dependence
on ±Δm231
Sign change
for νe and νe
T2K flux, L = 295 km
Energy dependent
matter effect acts as an
CP violation increase in Δm2
6
Oscillation status ~2019
Atmospheric Accelerator Reactor
Solar
Parameter |Δm2| θ23 δ θ13 Δm221 θ12 Two length scales
Uncertainty
2% 5% 18% 1.5% 2.3% 2% |Δm2| ~2 x 10-3
PDG 2018 Δm221 ~7 x 10-5
7
Neutrino oscillation questions
● What is the mass ordering (hierarchy)?
● Leptonic CP violation? δCP ≠ 0,π?
● Is θ23 = 45˚? If not, is θ23 < 45˚ or > 45˚?
● Is neutrino mixing fully described by a 3x3 matrix?
8
Eν = 600 MeV
20 ND samples
e-like FHC
μ-like FHC
e-like FHC
Event rate
Neutrino flux
Cross section
Detector smearing
Oscillation probability 9
T2K analysis
~50 institutions, ~350 collaborators
Cross section
28 at Swiss institutions measurements:
UniGe, UniBe, ETHZ
Technical support
and operations:
UniBe, UniGe, UniGe, UniBe,
ETHZ ETHZ
ETHZ, UniGe
10T2K analysis
Group leader: Prof. A. Rubbia
Joint CC0π-CC1π measurement
Postdocs: Dr. L. M. Bueno, Dr. S. constraining nuclear models
Murphy, Dr. B. Radics Joint on-/off-axis measurement
PhD students: C. Alt, K. Fusshoeller, measure Eν dependence
C.M. Schlosser
Participation in data
taking in Japan
Offline data quality
Validation of evaluation
neutrino-nucleon
models in Monte
Carlo simulation
MCMC oscillation fit: developing
additional systematics to better
11
constrain neutrino fluxT2K analysis
Convenership of XSEC group (CW)
CC inclusive in antineutrino mode
Unique NC1π+ measurement
Development of Participation in data
new models taking in Japan
Cross section Support UniGe with
parameters from magnet operations
global dataset
(NUISANCE)
Tests of new cross section
models with ND data
12T2K analysis
CC0π in water
CC1π Np in CH (coordination with ETHZ)
CC inclusive with Wagasci/BabyMind
ND280 magnet
coordination and
maintenance
BabyMind operation
and maintenance
Implemented state of
the art CC0π model in
T2K event generator
Collaboration with
theorists for model
development
Developing Bayesian
statistical analysis with 13
advanced Neural NetworkT2K analysis
~50 institutions, ~350 collaborators
Cross section
28 at Swiss institutions measurements:
UniGe, UniBe, ETHZ
Technical support
and operations:
UniBe, UniGe, UniGe, UniBe,
ETHZ ETHZ
Federico Sanchez
Elected as T2K
co-spokesperson
April 2019
ETHZ, UniGe
14Latest T2K results (2019)
Maximal
● ~30% of design exposure 2σ contours
● World leading θ23 measurement,
consistent with maximal mixing
● Increasingly strong exclusion of CP
conservation (δCP = 0,π)
● Expect results with ~50% more
antineutrino data in a few months 15IceCube
Complementary to accelerator
program:
● Natural atmospheric source
● Different energy region: ~5-50 GeV
Similar sensitivities to outstanding
questions with planned upgrades
Rich neutrino physics program:
● Cross section measurements
beyond energy reach of
accelerators
● Constraints on beyond 3x3 mixing
M.G. Aartsen et al., J. Phys. 16
G44 (2017) 5, 054006FNAL Short Baseline Neutrino (SBN) program
● Three detector program designed to
MiniBooNE resolve short baseline oscillation anomalies
● Three detector setup to sample the
neutrino flux at different points
● Liquid argon TPCs:
● Differentiate signal electrons from
background photons
● Improved energy reconstruction
e-
γ’s
νe CC
17
R. Acciarri et al, Phys. Rev. D95 (2017) 072005SBN overview
●
Ultimate goal is to confirm or disprove hints
for neutrino mixing at large Δm2 at 5σ
● Identify and characterise any backgrounds
responsible for previous excesses
● Both problematic for 3x3 neutrino mixing
measurements
18MicroBooNE status
νμ + Ar → μ- + X
Stage 1 of SBN: data since 2015
arXiv:1905.09694
●
● Physics co-ordinator (M. Weber)
and IB chair (A. Ereditato) at Bern
● Hardware and data analysis from
UniBe
Eur. Phys. J. C (2019) 79:248
● 3 physics papers, 13 detector
physics papers, more expected:
● Charged particle multiplicity: EPJC
(2019) 79:248
● CCπ0: PRD 99 (2019) 091102
● CC-INC: arXiv:1905.09694
● Vital inputs for future LAr
19
detectors (see later)SBN near and far detectors
● SBND hardware delivered by UniBe:
● Cosmic Ray Taggers (CRTs)
Instruments 1 (2017) 1, 2
● Laser calibration system
JINST 9 (2014) 11, T11007
● SBND detector construction ongoing
● Data taking with full SBN expected in
2021 (including ICARUS) – physics
results soon after
20Preparing for the future
21T2K-II
● Upgrade the T2K beamline.
20x1021 POT by 2026, x9
current statistics
● ND improvements help reduce
systematics
● Potential for δCP determination
NH (but unknown)
if true δCP is close to T2K
best fit
● Benefits from preparations for
Hyper-K...
K. Abe et al. (T2K), arXiv:1607.08004, 2016 22Hyper-K
187 kt (FV) tank close
to current Super-K Upgraded JPARC
location. High rate! beam and T2K-II
near detector
components
Uses existing
facilities and
established
technologies
Potential second tank
in Korea
Low rate, but 2nd
oscillation maximum
enhances sensitivity 23Hyper-K
● Adding a second detector gives
strong hierarchy sensitivity
● Powerful δCP measurement –
caveats if hierarchy unknown
● Also proton decay,
supernova/solar neutrinos
24
arXiv:1611.06118T2K upgrade and HK
SuperFGD, ToF and T2K upgrade Development of PMT readout
●
Electronics readout design/production for HK
●
Full construction of the Time of Flight
(ToF) detector (synergy with SHiP)
●
Coordination mechanics and
integration
●
Test beam analysis R&D optical readout of (HP)TPC
●
Future experiments & upgrades
CERN test
beam 2018 ●
Building setup, exploring readout
options
Collaboration with
IFAE (Spain) and
INFN
25
D. Sgalaberna et al., JINST 13 (2018) 2, P02006● High intensity neutrino beam at Fermilab
● 40 kt (FV) LArTPC far detector, 1300 km baseline
● Near detector system at Fermilab
● Primary purpose: neutrino oscillations (δCP, mass hierarchy)
● Also nucleon decay, solar/supernova neutrinos
26DUNE near detector
● Must control flux and cross-section systematics for
oscillation analysis by sampling unoscillated beam
● Centre is ArgonCube → culmination of a long LArTPC R&D
effort from UniBe
● Several improvements for high rate DUNE ND environment
27ArgonCube R&D
Modular, to reduce
high voltage Improved light
JINST 8 (2013) P07002 collection modules
JINST 11 (2016) no.03, P03017 Instruments 2 (2018) no.1, 3
Resistive field shaping to
minimize damage in
Pixel charge readout, event of breakdown
unambiguous reconstruction Instruments 3 (2019) no.2, 28
JINST 13 (2018) no.10, P10007
arXiv:1801.08884 28ArgonCube 2x2 demonstrator
● Medium-sized test of four
modules → supported by
FLARE grant
● Now testing cryogenics and
constructing modules
● To be moved to neutrino beam
in Fermilab ~Autumn 2020.
~1 million events/year!
● Vital R&D work for DUNE,
potential for exciting physics
results! 29ArgonCube collaboration
ArgonCube collaboration meeting March 2019
● Now 100 members, 23 institutes → broad
international commitment
● Spokesperson and leadership from UniBe
30ProtoDUNE
● Two large 800 t far detector
prototypes at CERN
● Single (SP) and dual-phase
(DP) readout
●
DP closed (13th June), final
instrument checks ongoing,
filling approved, starts 8th July
31ETHZ activities on DUNE
• Full Dual-Phase LAr detector simulation
• Nucleon-decay sensitivity study in DUNE
- sensitivity studies for new physics
• Proton-decay and atmospheric neutrino
background simulation using the NEUT
neutrino-nucleus event generator
Experimental and service work:
● Participation in WA105 DP LAr project
● LArSoft software development for event
reconstruction in Dual-Phase LAr
Group leader: Prof. A. Rubbia
Postdocs: Dr. L. M. Bueno, Dr. S. Murphy, Dr. B. Radics
PhD students: C. Alt, K. Fusshoeller, C.M. Schlosser
32DUNE oscillation analysis
e
nc
a
Ap
ar
pe
e
pp
ar
sa
an
Di
ce
(7 years)
33DUNE sensitivity
● Powerful probe of neutrino oscillation phenomena
● Complementary to Hyper-K program (longer baseline)
● DUNE Technical Design Report due in ~1 month with
sophisticated sensitivity projections 34DsTau: ντ production DsTau
● Spokesperson is A. Ariga at UniBe
● Ds→ντ rate largest uncertainty in ντ measurements
Experimental setup in North Area
● DsTau will study ντ production:
● CERN SPS protons
● Nuclear emulsions to observe D → τ → X
s
● Provide ν inputs for SHiP, FASER
τ
● 1/10 scale pilot run successful in 2018. Physics
run planned 2021-2022
● Approved by CERN June 2019 (SPSC-P-354)
SPS 400 GeV
35Summary
● Current experiments will guide answers to key questions:
● δCP / mass hierarchy → few sigma
● Are hints for beyond 3x3 mixing upheld?
● Leading roles for Swiss groups on T2K and SBN
● Future experiments will make precision measurements, and
probe oscillation phenomena in unprecendented detail:
● Key role for UniGe in T2K→Hyper-K transition
● Pivotal role of Swiss groups in DUNE
36Backup
37Basic layout
● Δm232 sets Pmax~500 L/Eν (km/GeV)
● Trade-off between L and E:
● R ~ 1/L2
● R ~ Eν
● 0.1 ≤ Eν ≤ 10 GeV
● Accelerator/mine location often limits L
38Accelerator neutrino beams
NuMI beamline
Advantages:
● Narrow and tunable energy range
● Narrow beam spill windows
● Relatively pure ν or ν beams
μ μ
● Can be turned on and off
Able to probe all outstanding questions
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