大 亚 湾 实 验 结 果 唯 象 学 后 果

大 亚 湾 实 验 结 果 的 唯 象 学 后 果
1
A: The Daya Bay result
( 春 天 的 故 事 )
邢 志 忠
B: The phenomenology
( 敢 问 路 在 何 方 )
C: Concluding remarks
( 传 奇 )
Disclaimer: 报 告 人 的 观 点 只 代 表 其 个 人 的 科 学 见 解
@ 山 东 大 学 物 理 学 院 , 二 零 一 二 年 三 月 十 六 日 下 午

Three Swordsmen
2
Groundbreaking: October 2007

Part A
March 8
3
News Release +
Special Seminar
2
sin 2 13
0.092 0.016(stat)
0.
005 (syst)
8.8 0.8
13

Part A
The Experiment
4
Near detector
55 days of data
Far detector
10416 events
Disappearance neutrino oscillations:
Near detector

The rate-only analysis
Input (MINOS 2011):
m
2.32 10 eV
2 0.12 3 2
31 0.08
Result (best-fit ±1):
8.8 0.8
13
arXiv:1203.1669 (submitted to PRL)

The dip
The preliminary shape analysis

Part A
A Milestone
7
France Korea China
The preliminary hints in 2011
T2K (Japan): 2.5
MINOS (USA): 1.7
~8
13
Double Chooz (France): 1.7
Signature in HEP
< 3 (hint)
3~5 (evidence)
> 5 (discovery)
5.2

Fritzsch-Xing Plot (28 fundamental parameters in Nature)
m d
M W
m u
m s
12
12
m c
m b
13
G N
s
13
m t
m e
23
w
23
m 1
m
q
l
m 2
m
M H
m 3
Z.Z. Xing

R. Davis 1968
A. McDonald
SNO 2001
M. Koshiba
1987
9
Reactor
anti-’s
F. Reines,
C. Cowan
1956
A. Suzuki
KamLAND
2002
Daya Bay
2012
KamLAND 2005
Borexino 2010
Y. Totsuka, T. Kajita SK 1998

Part A
Quarks (63 — 73):
Flavor Mixing
10
Experiments:
Leptons (1962):
θ 12
θ 23
θ 13
δ → new physics ?
~13° ~2° ~0.2° ~65° unitarity ?
turning point
(we assume three Majorana neutrinos + unitarity)
P
θ 23
θ 12
θ 13
δ/ρ/σ new physics ?
~45° ~34° ~9° ~? ? ? unitarity ?

Part B
Origin of Flavor Mixing
11
Weak interaction (flavor) state:
Mass state:
Weak charged-current interactions:
The MNSP matrix:
mass matrices

Part B
Two Strategies
12
Strategy (A): flavor mixing angles depend on mass ratios.
Strategy (B): constant leading term
+ perturbation matrix.
1996
Some linear
correlations
or equalities
1977
22 33
Texture zeros
1978
S. Weinberg H. Fritzsch
Flavor symmetries

Part B
Flavor Symmetries
Guiding Principle
13
The Flavor or Family Symmetry might be the promising way towards
deeper understanding of fermion mass generation and flavor mixing
(Harari et al 78; Froggatt, Nielsen 79; ……).
Flavor Symmetry
S 3
, S 4
, A 4
, Z 2
, U(1) F
, SU(2) F
, ……
Symmetry Breaking
李 政 道 -Friedberg
Observed patterns of fermion masses and flavor mixing

Part B
Texture Zeros
14
Example: 15 two-zero textures of the Majorana neutrino mass matrix.
Frampton, Glashow, Marfatia:
hep-ph/0201008
(02 Jan 2002)
Phys. Lett. B 536
(2002) 79
30 May 2002 180 citations
doing research is a fun
Xing:
hep-ph/0201151
(17 Jan 2002)
Phys. Lett. B 530
(2002) 159
28 March 2002
100 citations

Part B
Constant Patterns
15
Example (A): Democratic FlavorMixing Pattern (Fritzsch, Xing 1996).
Example (B): Tri-bimaximal Flavor Mixing Pattern (Harrison, Perkins,
Scott 2002; Xing 2002; He, Zee, 2003)

Part B
Perturbations
16
To illustrate, we typically take
Democratic
The nine matrix elements are all O(0.1) ---- natural?
Tri-bimaximal
The smallest (largest) angle receives the maximum
(minimum) correction ---- unnatural?

Part B
Quantum Corrections
17
A mechanism of neutrino mass generation most
likely works at a super-high energy scale. After
integrating out heavy degrees of freedom, one
is left with the unique Weinberg operator:
0 9
New Physics Scale
Impossible
unless ……
arXiv:1203.3118
RGEs = Cable Car
罗 舒
To compare a theory with experiments,
one must run the RGEs of the effective
-mass matrix down to low energies:
RGE = renormalization-group equation
Electroweak Scale

Part B
Initially 0 ?
13
18
Example (A): Tetra-maximal mixing (Xing, 2008)
Example (B): Correlative mixing (Xing, Jan 2011)
Comment (1): it is easier to get perturbations or quantum corrections
Comment (2): it is not easy to get such a pattern from group theories

Part B
How to Play?
19
What distinguishes different families of fermions?
----- they have the same gauge quantum numbers,
yet they are quite different from one another.
★ Radiative Mechanism (S. Weinberg 1972; A. Zee 1980)
★ Texture Zeros (S. Weinberg; H. Fritzsch 1977; H. Fritzsch 1978)
★ Family Symmetries (H. Harari et al 1978; C. Froggatt, H. Nielsen 1979)
★ Seesaw Mechanism (P. Minkowski 1977; T. Yanagida 1979; ……)
★ Extra Dimensions (K. Dienes et al; G. Dvali, A. Smirnov 1999)
Our Philosophy

Part B
The Structure
20
Off-diagonal asymmetries
of the CKM matrix:
Almost symmetric!
The MNSP matrix exhibits an approximate symmetry in modulus:
9
13
Conditions:
or
What to do
next ?

Part B
The 1 st Paper on CPV
21
Quarks:
The Cabibbo Texture: the tri-maximal mixing + maximal CP violation:
The Jarlskog invariant:

Part B
CP & T Violation
22
Under CPT invariance, CP- and T-violating asymmetries are identical:
Comments:
12
13
23
34
9
45
★ CP / T violation cannot show up in the disappearance
neutrino oscillation experiments ( = );
★ CP / T violation is a small three-family flavor effect;
★ CP / T violation in normal lepton-number-conserving
neutrino oscillations depends only upon the Dirac phase
of U ; hence such oscillation experiments cannot tell us
whether neutrinos are Dirac or Majorana particles.
J sin cos sin cos sin cos sin 3.6sin 10
2 2
12 12 23 23 13 13

Part B
Unitarity Triangles
12
13
23
23
34
9
90
45

Part B
Matter-Antimatter
24
1933
Dirac’s conjecture

Part B
Leptogenesis
25
◆ add 3 heavy right-handed Majorana neutrinos
into SM & keep its SU(2)×U(1) gauge symmetry:
Fukugita, Yanagida 86
◆ lepton-number-violating & CP-violating decays of heavy neutrinos:
◆ non-perturbative (B-L)-conserving weak sphaleron reactions work:
CP violation L-number asymmetry B-number asymmetry
◆ a link to low-energy CP violation? The phase counting: 9 phases at
high scales, 3 phases at low scales ----- related indirectly via SEESAW.

Part B
It’s a Dream!
26
Cosmological matter-antimatter asymmetry
Origin
of
-mass
Seesaw
+
Leptogenesis
Signatures
at colliders
Neutrino oscillations & lepton number violation
Cosmic messenger: neutrino astronomy and neutrino cosmology.
Surprise maker: history of neutrino physics was full of surprises.

Part B
Sterile Neutrinos?
27
Seesaw
active
flavor
sterile
flavor
mass
state
……

Part B
Parametrization
28
sterile part
interplay
active part
Full parametrization:
15 rotation angles
15 phase phases
Xing, arXiv:1110.0083

Part B
Unitarity Polygons
Deformed
unitarity
triangles
29
New effects
of
CP violation
≤ 1% level

Open Questions
2011 (440 pages)
the absolute mass scale?
the mass hierarchy problem?
the flavor desert problem?
how small is ? 13
leptonic CP violation?
answered
the Majorana nature?
how many species? …
cosmic background?
supernova & stellar ’s?
UHE cosmic ’s?
warm dark matter?
matter-antimatter asymmetry…

Part C
曾 经 沧 海 难 为 水
A very important role
in the evolution of
< 1%
the Universe

Cosmic Flavor Physics
CB
Hot DM
Baryogenesis
Leptogenesis
Supernova ’s
(relic background)
……
A New Road Ahead?

Part C
Reference
33
arXiv:1203.1672

I Wish You Another Fairy Tale
传 奇
只 是 因 为 在 人 群 中 多 看 了 你 一 眼
再 也 没 能 忘 掉 你 的 容 颜
梦 想 着 偶 然 能 有 一 天 再 相 见
从 此 我 开 始 孤 单 地 思 念
想 你 时 你 在 天 边
想 你 时 你 在 眼 前
想 你 时 你 在 脑 海
想 你 时 你 在 心 田
宁 愿 相 信 我 们 前 世 有 约
今 生 的 爱 情 故 事 不 会 再 改 变
宁 愿 用 这 一 生 等 你 发 现
我 一 直 在 你 身 旁
从 未 走 远 ……