mass Stuart Freedman memorial symposium Berkeley Jan 11 2014 Hamish Robertson University of Washington a long wait for a little weight 2 Neutrinos oscillate have mass Super Kamiokande ID: 426729
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Slide1
neutrino mass
Stuart Freedman memorial symposiumBerkeley, Jan 11, 2014
Hamish Robertson, University of Washington
a long wait for a little weightSlide2
2
Neutrinos oscillate, have mass
Super-
Kamiokande
KamLAND
SNOSlide3
Particle Physics Cosmology
What
is the
neutrino mass
scale?Slide4
Neutrino mass from Beta Spectra
neutrino masses
mixing
With flavor mixing
:
from oscillations
mass scale
4Slide5
Mass limits from tritium
5Slide6
6
Hamish
Robertson, Stuart Freedman, Tom Bowles, Carol Bowles, Karl-Erik Bergkvist.
Erice
1980.
(from Tom)Slide7
7
Tom Bowles, Carol Bowles, Stuart Freedman, Hamish Robertson, Erice
1980. (from Tom)Slide8
8
Magnetic spectrometers showed no kink. But they had shape correction factors.
"
Contrary to intuition, a null
result is not inherently more reliable than a positive one
.”
J.J. SimpsonGrabowski spectrometerSlide9
Current
status:
Mainz
: solid T
2
, MAC-E filter
C. Kraus et al., Eur. Phys. J. C40, 447 (2005)
Troitsk
:
gaseous T
2
, MAC-E filter
V.
Aseev
et al.,
PRD 84 (2011) 112003
Together:…
m
v
<
1.8
eV
(95% CL)
9Slide10
Mass and mixing parameters
m
21
2
7.54
+
0.21
-0.21
x 10
-5
eV
2
m
32
2
|
2.42
+
0.12
-0.11
x 10
-3
eV
2
m
i
>
0.055
eV
(90% CL)
<
5.4
eV
(
95%
CL)*
12
34.1
+
0.9
-0.9
deg
23
39.2
+1.8
-1.8
deg
13
9
.1
+0.6
-0.7
deg
sin
2
13
0.025
+
.
003
-
.
003
Marginalized 1-D 1-
uncertainties.
*C. Kraus et al., Eur. Phys. J. C40, 447 (2005
); V.
Aseev
et al. PRD
84
(2011) 112003
.
Other refs, see
Fogli
et al. 1205.5254
10
Oscillation
KinematicSlide11
TLK
KATRIN
At
Karlsruhe Institute
of
Technology
unique
facility
for
closed
T
2
cycle
:
Tritium Laboratory Karlsruhe
11
A
direct, model-independent
, kinematic method, based on
β
decay of tritium.
~ 75 m
long
with
40
s.c
.
solenoidsSlide12
12
~0.4
eV
First measurement, U
IE
= 700V, electron gun source.
July 12, 2013.Slide13
13
Measuring something and getting it wrong?Slide14
A window to work in
Molecular
excitations
14
Energy lossSlide15
KATRIN
’s uncertainty budget
Statistical
Final-state spectrum
T
-
ions in T
2
gas
Unfolding energy loss
Column density
Background slope
HV variation
Potential variation in sourceB-field variation in sourceElastic scattering in T2 gas
σ
(m
v
2
)
0
0.01 eV
2
σ
(m
v
2
)
total
= 0.025 eV
2
15
m
v
<
0.2
eV
(90 % CL)Slide16
What is the branching ratio for T
2 → 3He
T+?
Source
Experiment
Theory
Snell
Wexler
TH
0.932
± 0.019
0.895
± 0.011
---
T
2
---
0.945 ± 0.006
0.36
Need a test of the final-state theory for KATRIN and Project 8
Tritium Recoil-Ion Mass Spectrometer (
TRIMS
)Slide17
Mass Range Accessible
Present
Lab Limit
1
.8
eV
starting
2016
KATRINSlide18
18
K.
Abazajian, CF5 SummarySlide19
e
μ
τ
c
s
u
d
t
b
ν
h
ν
m
ν
l
meV
eV
keV
MeV
GeV
TeV
LEPTONS
QUARKS
??Slide20
Mass Range Accessible
Present
Lab Limit
1
.8
eV
starting
2016
KATRINSlide21
The Last Order of Magnitude
If the mass is
below 0.2
eV
, how
can we measure it?
KATRIN may be the largest such experiment possible.
Size of experiment now:
Diameter 10 m.
Rovibrational
states of
THe
+
,
HHe
+
molecule
Source T
2
column density near max
Next diameter: 300 m!
σ
(m
v
)
2
~ 0.38 eV
2Slide22
(B.
Monreal and J. Formaggio, PRD 80:051301, 2009)
Radiated power ~ 1
fW
Cyclotron radiation from tritium beta decay
Working on the UW prototype
25.5-GHz waveguide cellSlide23
Signal is a rising “chirp” in frequencySlide24
Project 8: a phased approachSlide25
Project 8 sensitivity
25Slide26
Neutrino Mass Limits from Beta decaySlide27
2013
2014
2015
2016
2017
2018
2019
Analysis 2
Planck:
Construction
Running
KATRIN:
Phase I
Proof concept
Prototype
Project 8:
Neutrino mass: some milestones
27Slide28
28
Stuart Freedman, Steve Elliott, Hamish Robertson. Spanish coast 1992. Photo by John Wilkerson.Slide29
29Slide30
Capture of relic Neutrinos
PTOLEMY project
30Slide31
Capture of relic Neutrinos
PTOLEMY project
31Slide32
PTOLEMY Experimental Layout
32
Tritium Source Disk
(Surface Deposition)
High Field Solenoid
Long High Uniformity
Solenoid (~2T)
Accelerating
Potential
MAC-E filter
(De-accelerating
Potential)
Accelerating
Potential
RF Tracking
(38-46 GHz)
Time-of-Flight
(De-accelerating
Potential)
Cryogenic
Calorimeter
(~0.1eV)
Low Field
Region
e
-
E
0
-18.4keV
0-1keV
(~150eV)
E
0
E
0
+30kV
~50-150eV
below
EndpointSlide33
PTOlemy
summary100 g of tritium (1 MCi) on 12-m diameter disk.
Relic capture rate ~ 10/year without local clustering.Also presumably able to measure mass, active and sterile.Transition-edge sensor array to provide basic 0.1-eV resolution.Tagging with RF cyclotron radiation a la Project 8.
Necessary to understand quantum effects of binding of T
2
on surface.
33Slide34
Inputs
Present laboratory limit 1.8 eV (90% CL) from Mainz and
Troitsk experiments on tritiumKATRIN experiment under construction.
Project 8
in proof-of-concept phase.
Cosmological
inputs driven by Planck, SPT, ACT
, Sloan …34Slide35
Planck XVI
WP = WMAP Polarization data
A
L
= weak lensing parameter
τ
= optical depth at recombination
“…
Planck lensing likelihood
favours
larger
Σm than the temperature power spectrum.”
First Planck analysis (March 2013)Slide36
(B.
Monreal and J. Formaggio
, PRD 80:051301, 2009)
Cyclotron radiation from tritium beta decay
25.5-GHz waveguide cellSlide37
Neutrinoless
Double Beta Decay
1 sigma
W.
Rodejohann
, 1206.2560
Depends on m
v
but not a `direct’ measurementSlide38
Electron Capture Holmium
Expt (ECHO)
38
187
J.F. WilkersonSlide39
39
J.F. Wilkerson
187
Electron Capture Holmium Expt (ECHO)Slide40
Neutrino mass Physics Impact
40Slide41
summary
Direct mass measurements are largely model independent: Majorana or DiracNo nuclear matrix elementsNo complex phasesNo cosmological degrees of freedom
One experiment in construction (KATRIN); 2015 start.Three experiments in R&D (Project 8, ECHo, PTOLEMY)
41