past present future Heidi Schellman Frank Merritt Fest 2015 1 What we knew in 1971 2 Neutrinos exist Cowan Reines 1956 There are two kinds Lederman Schwartz Steinberger 1962 ID: 328524
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Slide1
NeutrinoS:past present future
Heidi Schellman @ Frank Merritt Fest 2015
1Slide2
What we knew in 1971
2
Neutrinos exist (Cowan, Reines 1956)There are two kinds (Lederman, Schwartz, Steinberger - 1962 )
They may interact through W and Z boson exchange (Glashow, Weinberg, Salaam - 1968)Slide3
3Slide4
FERMILAB NALCAL, July 1971
4
NAL, CALTECH JOIN IN NEUTRINO STUDIES (EXPERIMENT 21
)
The
Caltech-NAL researchers planned to carry their studies on neutrinos up to about 300
BeV
. In July 1971, data existed only up to about 10
BeV
.
Evidence suggests the W has a mass greater than that of two
protons…The Caltech-NAL experiment …, hoped to produce and detect the particle if its mass is less than about 20 proton masses. Slide5
Neutral currents observed 1973
5
Gargamelle
hadronic neutral current event
nSlide6
Weinberg angle measurement: 1997
6Slide7
What we know now
7
Neutrinos Oscillate!Solar – Davis 1960’sAtmospheric –
SuperK
– 1998
+ many others
Neutrinos have Mass (but what is it?)
The mixing angles are largish!
q
13
- Daya Bay, RENO,
Chooz, T2K, MINOS - 2012Slide8
8
23
13
12
Precision measurementsSlide9
9
Summary of experiments
D
m
2
23
D
m
2
12Slide10
10Slide11
What’s left
11Slide12
Unknown: Mass hierarchy and mass offset
12
Normal
Hierarchy
Inverted
Hierarchy
D
m
12
D
m
23
> 0
D
m
23
<
0
We know the absolute value of the mass differences but not the minimum mass or the sign of
D
m
2
23
?
?
Interactions with matter can tell the difference.
D
m
2
12
> 0 is known from solar,
sign of
D
m
2
23
is still unknownSlide13
By 2035: Mass Hierarchy and CP violating phase – DUNE + HyperK
+ reactor
13Slide14
Absolute mass scale may take longer!
14
D
m
2
13
= .0025 says at least 1 has m > 0.050 eV
Cosmology -
S
m
< 0.23 eV - PLANCK 2015Direct - me
< 0.200 eV –
Katrin
2018?
Neutrino-less 2
b
decay
If Majorana
And inverted hierarchy
Stolen from MR-M at NSAC WorkshopSlide15
Surprises
15
Is there CP violation in the Majorana phases? Are there more ‘sterile’ neutrino species?
Are there right handed ones?
Are they the dark matter?
Why don’t we know what 95% of the Universe is anyways?Slide16
Example: nMSM
16
3 “light” R-handed neutrinos, keV and GeV mass scales
N
1
is dark matter candidate
N
2
N
3
may be visible in
CCFR/NuTeVATLAS/CMSBeam dump experiments
Phys.Rev.Lett. 110 (2013) 6, 061801Slide17
Neutrinos tell no lies
17
Neutrinos are hard to makeThey are hard to findBut once you find them, every
one tells
you a lot