Download - T2KK および T2KO 実験での質量階層性、CP位相測定の可能性
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T2KK および T2KO 実験での質量階層性、CP位相測定の可能性
Yoshitaro Takaesu U of Tokyo
In collabora0on with K. Hagiwara, N. Okamura, P. Ko (work in progress)
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t 2.06.29 AM
t 2.06.29 AM
Mass Hierarchy Dirac CP Phase
Several ways to determine them Long Base Line
LBNE
Nova
Fermi Lab
T2K
J-‐PARC
LBNO
CERN
Atmospheric
ICECUBE
SK
HK INO
Experiments for MH and CP phase
Reactor (MH) JUNO (CHINA) RENO-‐50 (KOREA)
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T2KK: 100 kton in Korea [hep-‐ph/0410229, 0504026, 0901.1517, 1001.5165] T2KO: 100 kton in Oki Island [0804.2111, 1209.2763] * SK (22.5kton) will be used as a near detector
3
SK
T2KO (650 km) T2KK
(1000 km)
T2K (250 km)
100 100
22
Oki
T2KK and T2KO proposals
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Analysis method �2analysis
• SystemaWcs • maXer density: 6% • Cross secWon, normalizaWon: 3% • fiducial volume: 3% • NC pi0 BG modeling (T2K result)
• Parameters �m2
12 = (7.5± 0.2)� 10�5eV2
�m213 = ±2.35� 10�3eV2
• Backgrounds • Secondary beam: • miss-‐ID neutrino • pi0 BG with improved rejecWon (POLFIT) SK
T2KO
T2KK
�e, �̄e, �̄µ(�µ)
�CP
sin2 2�12 = 0.857± 0.024sin2 2�13 = 0.095± 0.005sin2 �23 = 0.5± 0.1
・Signal: �µ � �e, �µ �̄µ � �̄e, �̄µ*Improvements from 0901.1517 1209.2763
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Expected energy distribu0ons
Total events CCQE signal CCRES signal NCpi0 BG (uncertainty) miss-‐ID neutrino BG
SK
T2KO
T2KK �
�̄
�
�
�̄
�̄
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0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
NH, sin2θ23 = 0.5
ν : ν− = 5 : 0
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
NH, sin2θ23 = 0.54 : 1
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
NH, sin2θ23 = 0.53 : 2
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
NH, sin2θ23 = 0.5
2.5 : 2.5
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
IH, sin2θ23 = 0.5
ν : ν− = 5 : 0
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
IH, sin2θ23 = 0.54 : 1
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
IH, sin2θ23 = 0.53 : 2
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (3.0°, 0.5°)
IH, sin2θ23 = 0.5
2.5 : 2.5
MH sensi0vity with and beam (T2KK) � �̄The sensiWvity is enhanced by including anW-‐neutrino focusing beam.
3:2 ~ 1:1 neutrino anW-‐neutrino beam raWo is best. MH can be determined with 3 – 5 sigma CL in 5 years.
T2KK NH T2KK IH
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MH sensi0vity with and beam (T2KO)
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Oki) = (2.5°, 0.9°)
NH, sin2θ23 = 0.5
ν : ν− = 5 : 0
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Oki) = (2.5°, 0.9°)
NH, sin2θ23 = 0.54 : 1
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Oki) = (2.5°, 0.9°)
NH, sin2θ23 = 0.53 : 2
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Oki) = (2.5°, 0.9°)
NH, sin2θ23 = 0.5
2.5 : 2.5
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (2.5°, 0.9°)
IH, sin2θ23 = 0.5
ν : ν− = 5 : 0
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (2.5°, 0.9°)
IH, sin2θ23 = 0.54 : 1
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (2.5°, 0.9°)
IH, sin2θ23 = 0.53 : 2
0
5
10
15
20
25
30
35
40
-180 -90 0 90 180
∆χ2
δCP
OAB(SK, Kr) = (2.5°, 0.9°)
IH, sin2θ23 = 0.5
2.5 : 2.5
� �̄The sensiWvity is enhanced by including anW-‐neutrino focusing beam.
3:2 ~ 1:1 neutrino anW-‐neutrino beam raWo is best. MH can be determined with 2 – 4 sigma CL in 5 years.
T2KO NH T2KO IH
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0
10
20
30
40
50
60
-180 -90 0 90 180
Unc
erta
inty
of δ
CP
true δCP
OAB(SK, Kr) = (3.0°, 0.5°), NH (true-MH fit)ν : ν− = 5 : 0
4 : 13 : 2
2.5 : 2.5
0
10
20
30
40
50
60
-180 -90 0 90 180
Unc
erta
inty
of δ
CP
true δCP
OAB(SK, Kr) = (3.0°, 0.5°), IH (true-MH fit)ν : ν− = 5 : 0
4 : 13 : 2
2.5 : 2.5
CP measurement with and beam � �̄UWlizing anW-‐nu beam also improves the CP phase measurements.
0
10
20
30
40
50
60
-180 -90 0 90 180
Unc
erta
inty
of δ
CP
true δCP
OAB(SK, Oki) = (2.5°, 0.9°), NH (true-MH fit)ν : ν− = 5 : 0
4 : 13 : 2
2.5 : 2.5
0
10
20
30
40
50
60
-180 -90 0 90 180
Unc
erta
inty
of δ
CP
true δCP
OAB(SK, Oki) = (2.5°, 0.9°), IH (true-MH fit)ν : ν− = 5 : 0
4 : 13 : 2
2.5 : 2.5
T2KK NH T2KK IH
T2KO NH T2KO IH
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Summary We revisited the sensiWvity of T2KK and T2KO proposals to neutrino mass hierarchy and Dirac CP phase with
realisWc pi0 background esWmaWon anW-‐nu beam opWon
Dirac CP phase The sensiWvity is slightly improved.
If MH is determined, T2KK measures with > +-‐ 20° accuracy. T2KO measures with > +-‐ 20° accuracy.
MH The sensiWvity is significantly improved by including
anW-‐nu beam opWon. Especially for CP phase ~ -‐90 deg. (NH) and ~90 deg. (IH).
T2KK has sensiWvity (3° OAB, ). T2KO has sensiWvity (2 ~ 3° OAB, ).
3 � 5� sin2 �23 = 0.5sin2 �23 = 0.52 � 4�
�CP
�CP