Precision measurement and new physics searches by neutrino ...
Transcript of Precision measurement and new physics searches by neutrino ...
物理学院SCHOOL OF PHYSICS
Precision measurement and new physics searches by neutrino oscillation experiments
Jian Tang
Seminar @ SJTU & TDLi Institute, Sept. 30
Collaborators:
Yong Du, Hao-Lin Li, Jiang-Hao Yu (CAS-ITP)
Zhuo-Jun Hu, Jia-Jie Ling,
Sampsa Vihonen, Tse-Chun Wang, Yi-Bing Zhang
Ref: JHEP01(2021)124, JHEP03(2021)019, arXiv: 2106.15800
2021/09/30 Jian Tang
Table of contents
• Motivations
• Non-unitarity(NU) v.s non-standard interactions(NSIs)
• Global fits of mixing parameters without unitarity
• Constraints of NSIs based on SMEFT
• Summary
2
2021/09/30 Jian Tang
Three-generation neutrino oscillations
3
• For 3 ν framework , we have 6+1 free parameters in neutrino oscillations:
P (θ12, θ13, θ23, δ, Δm212, Δm31
2) + ρ (in matter)√ √ √ √? √?
2021/09/30 Jian Tang
Where are neutrinos from?
4
Natural source
Artificial source
10-4 10-3 104103 105 106 107 1010109 1011108 1012
keV MeV GeV TeV
E [eV]
~Electron mass ~Proton mass ~LHC
???
???
??
??
2021/09/30 Jian Tang
Working principles of neutrino oscillation experiments
5
• Get the neutrino source as clean as possible. Muon decay v.s pion decay beams.
• Deploy the best detector to reconstruct the oscillated neutrino spectra: Gd-WC, LAr
TPC, scintillator detector with flavour&charge identifications…
• Data mining: precision measurement & discovery of new physics…
Neutrino source
Near detector(cancellation of
systematics in flux&X-section...)
Far detector
Baseline
L ~ E/m2
2021/09/30 Jian Tang
An example: T2K
6
K. McFarland, Neutrino InteractionUncertainties @ NNN2018
2021/09/30 Jian Tang
Simulations of neutrino oscillations w/o new physics
7
By GLoBES
2021/09/30 Jian Tang
Lots of neutrino experiments to get a new horizon
8
More are coming…
2021/09/30 Jian Tang
WC detectors: KamiokandeSKHyperK
• Bigger than bigger! PMT technology revolutionized!
9
3 kton WC 20% coverage
with 20’’ PMT
50 kton WC 40% coverage
with 20’’ PMT
260 kton WC 40% coverage
with 20’’+HQE PMT
• Construction started in 2020.
• Data taking from 2027.
• J-PARC neutrino beam will be upgraded from 0.7 to 1.3 MW
2021/09/30 Jian Tang
LAr TPC: DUNE
10
Courtesy: Guang Yang@NuFact2021
2021/09/30 Jian Tang
LSc: DYB (20 t*8) JUNO (20 kt)
11
• Daya Bay neutrino experiment: mission completed!
Credit: Miao He
Dec. 12, 2020
MCP-PMT
20’’+HQE
MH sensitivity:
∆χ2= 15.07
By GLoBES
2021/09/30 Jian Tang
NuFACT2021: WG1 proposed questions
• What is the neutrino mass ordering?
• Are there CP violations in the lepton sector?
• How much precision shall we reach to tell new physics?
• What are the current and future systematic limitations on precision measurement and how to address them?
• Is the neutrino mixing matrix unitary?
• Are there non-standard neutrino interactions?
• Are there more than three-flavor neutrinos?
• How to deal with the reactor flux deficit?
• How consistent are results from NOvA and T2K?
• How to examine neutrino mass models based on flavor symmetries (A4, S4, Modular…)?
• What’s next even after neutrino mass ordering and Dirac CP phase?
• …
12
2021/09/30 Jian Tang
Table of contents
• Motivations
• Non-unitarity(NU) v.s non-standard interactions(NSIs)
• Global fits of mixing parameters without unitarity
• Constraints of NSIs based on SMEFT
• Future prospects
13
2021/09/30 Jian Tang
Non-unitary neutrino mixings (NU)
14
2021/09/30 Jian Tang
Non-Standard Interactions (NSIs)
15
NSI happens to neutrino propagation in matter NSI at neutrino productions
• New physics beyond SM: new particles, new couplings,
new phenomenon...
2021/09/30 Jian Tang
Discovery of CPV affected by NU/NSIs
16Phys.Rev.D 95 (2017) 3, 033005JHEP 10 (2016) 138 by Dr. Shao-Feng Ge
2021/09/30 Jian Tang
Table of contents
• Motivations
• Non-unitarity(NU) v.s non-standard interactions(NSIs)
• Global fits of mixing parameters without unitarity
• Constraints of NSIs based on SMEFT
• Future prospects
17
2021/09/30 Jian Tang
• Reduced constraints without the unitary assumption in the quark mixing.
• Let’s keep the democratic way in quark and lepton mixing?18
What if there is non-unitary mixing?
?
Lepton mixing
www.nu-fit.org
No unitarity assumption here!
Quark mixing
2021/09/30 Jian Tang
Simple mathematics w/o unitarity assumption
19
Unitarity
Non-unitarity(NU)
• Only 4 real parameters with unitarity.
• Now we have 13 real parameters after rephrasing fields for NU!
18 real parameters in linear algebra
-5 by rephrasing fields in physics
2021/09/30 Jian Tang
What if there is non-unitary mixing?
20
• Correlations between 3nu mixing matrix
elements without unitarity assumption.
• Octant degeneracies get worse for NU.
2021/09/30 Jian Tang
What if there is non-unitary mixing?
21
• Nice precision in the first and second row/column.
• Tau neutrino physics are to be improved for better constraints on 3rd row/column!
ClosureNormalizations
2021/09/30 Jian Tang
Table of contents
• Motivations
• Non-unitarity(NU) v.s non-standard interactions(NSIs)
• Global fits of mixing parameters without unitarity
• Constraints of NSIs based on SMEFT
• Future prospects
22
2021/09/30 Jian Tang
Working principle of effective field theory (EFT)
23
2021/09/30 Jian Tang 24
EFT: connecting low-energy phenomenon to high-energy scale
Credit: Adam Falkowski
2021/09/30 Jian Tang
• Start from a UV theory
25
• Matching by covariant derivative expansion, EoM
• Solve for classical solution
An example for demonstration
2021/09/30 Jian Tang
An example for demonstration
• Put the classical solution back to Lagrangian density
26
• Fierz transformation to Warsaw basis
2021/09/30 Jian Tang
An example for demonstration
• Run down from scale M to electroweak scale v
27
• Probably generate non-zero Wilson coefficients other than Cle
• Matching at electroweak scale to LEFT
2021/09/30 Jian Tang
Matching between QM and QFT NSIs
28
• QM NSIs are fully independent without much info
about the underlying theory.
• QFT NSIs allow their correlations.
2021/09/30 Jian Tang
EFT: connecting low-energy phenomenon to high-energy scale
29
• Dimension-6 operators only
• Neutrino masses are generated by
dimension-5 Weinberg operators
Effective operators
Cut-off scale
Wilson coefficient
2021/09/30 Jian Tang
SMEFT-NSIs by T2K and NOvA
30
• T2K and NOvA are already sensitive to new physics around 20 TeV.
• Correlations among different dimension-6 operators play important roles.
2021/09/30 Jian Tang
SMEFT-NSIs by reactor neutrino experiments
31
• Reactor neutrino experiments are sensitive to new physics around 5 TeV.
• Complementarity between LBL and reactor expts due to different sets of operators
2021/09/30 Jian Tang
Table of contents
• Motivations
• Non-unitarity(NU) v.s non-standard interactions(NSIs)
• Global fits of mixing parameters without unitarity
• Constraints of NSIs based on SMEFT
• Future prospects on SMEFT-NSIs
32
2021/09/30 Jian Tang
Democratic treatment of CKM and PMNS mixing
33
Smelli
Quark mixing v.s neutrino mixing/scattering
2021/09/30 Jian Tang
SMEFT-NSIs by T2HK and DUNE
34
NC-NSIs
CC-NSIs
• Cover 1635 SMEFT operators in dimention-6. ND is important to constraint SMEFT-NSIs.
• DUNE has better sensitivity than T2HK due to the longer baseline.
2021/09/30 Jian Tang
SMEFT-NSIs by JUNO w/o TAO and COHERENT
35
CC-NSIs
NC-NSIs
2021/09/30 Jian Tang
Summary
• Neutrino oscillation is the first direct evidence BSM.
• Discovery of CPV & determination of MH is around the corner. Neutrino will be used for new physics searches.
• New physics might be hidden in the uncertainties.
• Unitary mixing should not be taken by default, as tau neutrino-related part is yet to be improved.
• We can have better knowledge of underlying theory by RGE running and matching in different scales to connect the low-energy neutrino oscillation experiments and the UV completion model in SMEFT.
• Let’s work together to discover new physics with neutrinos…
36
2021/09/30 Jian Tang
Precision measurement and tau-neutrino physics?
37
• Pushing precision to sub-percent level and probe new physics
arXiv:2108.11107
THANK YOU
38