Japan-based neutrino program Masato Shiozawa (UTokyo) Super-K talk by Y.Suzuki, K2K/T2K talk T.Nakaya, T2K talk by A.Izmaylov, Super-K talk by M.Shiozawa, Hyper-K talk by G.Catanesi, Kamland-Zen talk by J.Shirai, @this workshop
Japan-based neutrino programMasato Shiozawa (UTokyo)
Super-K talk by Y.Suzuki,K2K/T2K talk T.Nakaya, T2K talk by A.Izmaylov,
Super-K talk by M.Shiozawa, Hyper-K talk by G.Catanesi,
Kamland-Zen talk by J.Shirai, @this workshop
2
Super-K, 22kton Fid. mass
Hyper-Kamiokande2026~, 190kton mass, >1.3MW beam
J-PARC 470kW beam (T2K)
SK-Gd(201X~) J-PARC >750kW (T2K-II)
• Seamless program to get timely results • Rich physics, big chance of discoveries
0123456789
10
600 800 1000 1200
Num
ber o
f Eve
nts
0123456789
10
600 800 1000 1200Total invariant mass (MeV/c2)
Num
ber o
f Eve
nts 3
Proton decay (p→e+π0) search• Single event discovery is still possible in Super-K• Hyper-K is only realistic approach to proton lifetime beyond 1035 years
Hyper-K 10 years
0"<"ptot"<"100"MeV/c"�
p→e+π0 signal (τp=1.7 x 1034 years)
Invariant Proton Mass (MeV/c2)
~9σ discovery
Atmospheric ν background
• ~10MeV ν astronomy w/ essential information of (1)ν’s direction, (2)time, and (3)energy•w/ High mass (22kton→190kton)
4
Neutrino astrophysics/astronomy
• Unique solar νe to study ~2σ tension btw νe and reactor νe
• Supernova ν burst up to ~Mpc distance to study explosion mechanism and BH/NS formation. Capability to provide SN direction w/ ~1o accuracy for alerting other telescopes including γ/GW observatory.
• SN diffuse ν to investigate dim-SN's and BH formation. Chance of discovery at SK-Gd and measurements in Hyper-K.
Filter tanksGd loaded water tank
New water system under construction
~1o Pointing (Center of Galaxy)
Diffuse SN ν at HK
5
• T2K suggests |sinδCP|=1 and aims to discover w/ 3σ.• Big chance of CP violation discovery, and then measurement w/ precision of < 20 degree in HK.
year
Expected CPV significance
(Based on DUNE CDR, arxiv:1601.05471 Table 2.1, “optimized” beam design)
(2tank staging)
2022 2026 2030 2034 20380
2
4
6
8
10
CPV significance for δ=-90°, normal hierarchy
Sign
ifica
nce
[σ]
HK
DUNE
T2K
T2K-II
NOvA
2-Tanks
SK suggests normal hierarchy w/ ~2σ, further improvements are foreseen.Determination possible by 2~3 years (sin2θ23=0.5) at HK.
Mass hierarchy determination
BandforCPvalues
6
νµ
νe
•Japan-based neutrino program will have rich physics with world-leading science outputs•Hyper-Kamiokande is the flagship experiment in the program
• Ready-to-go design
• Budget request is being issued in Japan
•Open for international participants• Many places where international contributions
(intellectual/in-kind) are necessary
Final remark
7