decay correlations 2015-06-19 · september 4, 2014 testing cvc and ckm unitarity via saf-β-decay,...
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Decay Correlations
Fundamental Neutron Physics Summer School 2015
Gertrud KonradAtominstitut, TU Wien, Austria
Stefan‐Meyer‐Institut Wien, ÖAW, Austria
The University of Tennesse, Knoxville 14‐20 June 2015
Thanks for contributions from:H. Abele, S. Baeßler, F. Wietfeldt, A. Young
Energy generation within the Sun
Sun eruption, August 31, 2012, NASA‘s Solar Dynamics Observatory
Energy generation within the Sun
2e
222
11 30 0
A
V
0.42MeV
S 6 ln 2R
ppp
p p H e
f EEE m
ftgg
Rate for initial reaction in the pp chain
Sun eruption, August 31, 2012, NASA‘s Solar Dynamics Observatory
Current status of
Lattice QCD PDG 2014
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
T. Bhattacharya et al., Phys. Rev. D 85, 054512 (2012)
PDG 2011
Ag
K.A. Olive et al. (PDG), Chin. Phys. C 38, 090001 (2014)
A Vg g
Properties of the Neutron
June 19, 2015 G. Konrad, TU & SMI Wien, Austria
• Charge: < 10-21 e neutral
• Mass: 1838.683 me 939.565 MeV/c2
• Spin: ½ ħ• Lifetime: 880.3(1.1) s
( ) . 2n p e 782 334keVQ m m m m c
+n p e e Q
Decay Correlations, Summer School Knoxville
quark mixing
coupling strength
A Vg g decay
. .
2n
ud2
4908 7 1 9 s1
1 3V
V F udg G VA. Czarnecki et al., PR D 70, 093006 (2004)
Fermi transitions
Gamow-Teller transitions A F udg G V
Outline
• Motivation
• Neutron beta‐decay within the Standard Model
• Searches for new physics beyond the Standard Model
• Summary and Outlook
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
The Neutron Alphabet I
3
22F
22ud e e 0 e5
e e
d 1 1 3d d d 2 2
G V p E E EE
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
J.D. Jackson et al., PR 106, 517 (1957)
-1n
• 3 unknown parametersGF, Vud,
• 20 or more observables
n, a, b, A, B, C, D, …• yet unmeasured
b
A Vg g
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Determination of the decay correlations
Leptons
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
ProtonNeutron
Matrixelements
Clebsch‐Gordon
Fermi
Gamow‐Teller
, JJ m
based on J. Döhner, PhD thesis, Uni Heidelberg, 1990
Determination of neutrino‐electron correlation a
same opposite
same opposite
N NN N
a
Fermi
Gamow‐Teller
, JJ m
a=1
a=1
a=-1
2 222 2 2 2
V F A GT A GT V A A2 2 2 2 2
V AV F A GT
1 3 2 3 2 13 1 3
g M g M g M g g gg gg M g M
a
Current status of the decay correlations
2
2
cos2
1 3B
0.27484C A B
2
2
1
1 3a
2
2
cos2
1 3A
2
sin2 0
1 3D
180
Observable Standard Model Status PDG 2014
Lifetime τn/τn 0.1%
Ratio of weak coupling constants / 0.2%
Neutrino‐electron correlation a/a 3.9%
Fierz interference term b = 0 yet unmeasured
Beta asymmetry A/A 0.8%
Neutrino asymmetry B/B 0.3%
Proton asymmetry C/C 1.1%
Triple correlation D = (‐1 2) × 10‐4 = (180.02±0.03)°
u
n 2 2d
4908.7 1.9 s11 3V
A Vig g e
K.A. Olive et al. (Particle Data Group), Chin. Phys. C 38, 090001 (2014)
Weak magnetism
• 3 unknown parametersGF, Vud,
• 20 or more observables
n, a, b, A, B, C, D, …
• yet unmeasuredb, f2
2
2
11 3
a
2
2
Re2
1 3A
ee WM
e2%
21 ,A A Eam
fE c
A Vg g
3
22 22F ud e e 0 e5
e e
d 1 1 3d d d 2 2
p E E EE
G V
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
M. Gell‐Mann, Phys. Rev. 111(1), 362 (1958)
Beyond the Standard Model physics
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
• Study the structure of the weak interaction value of weak magnetism form‐factor f2 predicted (CVC hypothesis) value f2 = (κp-κn)/2 ≈ 1.8529 tested only to O(10%) in A=12 system large theoretical uncertainties
• Test the Standard Model of particle physics self‐consistency of the Standard Model unitarity of the Cabibbo‐Kobayashi‐Maskawa (CKM) quark‐mixing matrix
superallowed 0+→ 0+ decays
Present best test of the Standard Model
2 2 2 4us uu bd1 1 1 6 10V VV
Kaon decays B‐decays
September 4, 2014 Testing CVC and CKM unitarity via SAF-β-decay, Solvay Workshop Brussels 2014 Courtesy of J. Hardy
Determination of
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
A Vg g
K.A. Olive et al. (PDG), Chin. Phys. C 38, 090001 (2014)
A
A BA B
C
Measurement of beta asymmetry parameter A2
ene
e e
d 1 cosd d
vE c
A ne
Electron energy spectra
2same opposite
2same opposite
21 3
N NN N
A
The PERKEO II experiment @ ILL
• Cold neutron beam from H113 @ ILL• Neutron beam preparation (polarization, spin flip, collimation)• Neutron beam analysis• Electron spectroscopy with PERKEO II spectrometer• Beam stop
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
H. Abele et al., Phys. Lett. B 407,212 (1997)H. Abele et al., Phys. Rev. Lett. 88, 211801 (2002)
The spectrometer PERKEO II
Systematic uncertainties:• Background• Detector response: monoenergetic conversion electron sources• Edge effect• Electron backscattering: second scintillation detector• Magnetic mirror effect (adiabatic invariant )
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
e eexp,i e
e e
i i
i i
N E N EN
A EN E E
1T
e eexp e ne
1= cos2
v vE Pf PfA Ac
Ac
2p B
Latest PERKEO II resultsBackground subtraction
Energy calibration
Energy spectra
Asymmetry spectra
H. Abele, NIM A 611, 193 (2009)D. Mund et al., PRL 110, 172502 (2013)D. Mund, Ph.D. thesis, Uni Heidelberg, 2006
47530.11926A
Spin down
Spin up
Channel
Energy
Channe
l
Energy
Channel
Detector
Neutrons
Resulting electron signal
Background signalwith shutter up closed
The successor PERKEO III @ ILL
• Large decay volume: count rate increased by ca. one order of magnitude• Pulsed neutron beam: background suppression
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
B. Märkisch et al., NIM A 611, 216 (2009)
SM polarizer
casemate
150 mT
Preliminary ‛results‘ from PERKEO III
Energy spectra Asymmetry spectrum
31.9 10A A
fourfoldimprovementcompared to PDG
Result still blinded
H. Mest, Ph.D. thesis, Uni Heidelberg, 2011H. Saul, Ph.D. thesis, TU Wien, in progress
TOF spectra
A new approach to A: UCNA @ LANSCE
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Latest results from UCNA
Energy spectrum
Asymmetry spectrum
Corrections
0.11952 110A
J. Liu et al., PRL 105, 181803 (2010)B. Plaster et al., PR C 86, 055501 (2012)M.P. Mendenhall et al., PR C 87, 032501(R) (2013)
Future prospects: The new facility PERC @ FRM II
high flux ϕ=2×1010 cm-2s-1 and high decay rate =1×106 m-1s-1
improved by up to 2 orders of magnitude to sub‐10‐4‐level highest phase space dΩe , dΩp densities
• Statistics:• Sensitivity:
cold neutrons
velocityselector chopper
polarizer & spin flipper, 5m
neutron guide=0.5T
D. Dubbers et al., NIM A 596, 238 (2008) G. K. et al., J. Phys.: Conf. Ser. 340, 012048 (2012)
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Limitation of electron/proton divergenceCritical angleMagnetic mirror field Count rate
Beta asymmetry Figure of merit
D. Dubbers et al., NIM A 596, 238 (2008)
G. K. et al., J. Phys.: Conf. Ser. 340, 012048 (2012)
1 1
0 0
sinsin
BB
Future prospects: The new facility PERC @ FRM II
high flux ϕ=2×1010 cm-2s-1 and high decay rate =1×106 m-1s-1
improved by up to 2 orders of magnitude to sub‐10‐4‐level highest phase space dΩe , dΩp densities
precise cuts in dΩe , dΩp :
≤ 10‐4 (for e‐), especially ΔP/P=10-4
a, b, A, B, C, f2, …
manufacturing within 18, commissioning within 24 months beam site at FRM II/Garching (DE) under construction
1 1
0 0
sinsin
BB
• Statistics:• Sensitivity:
• Systematics:
• Versatility:• Status:
cold neutrons
velocityselector chopper
polarizer & spin flipper, 5m
neutron guide=0.5T
D. Dubbers et al., NIM A 596, 238 (2008) G. K. et al., J. Phys.: Conf. Ser. 340, 012048 (2012)
C. Klauser, PhD thesis, TU Wien, 2013C. Klauser et al., J. Phys.: Conf. Ser. 340, 012011 (2012)
Detection systems for PERC
Observable Correlations Measurement principle Examples
β and p momenta
a, b, A Magnetic spectrometerPLUS position sensitive detectors
β energy A, B, b, f2, g2radiativecorrections
β energy sensitive detectors such asscintillation OR silicon detectors
PERKEO I‐III UCNA
p energy a, C Retardation spectrometer PLUS p detector aSPECT
p velocity a, C Wien filter PLUS position sensitive detector
p TOF a p beam pulsed by electric gate voltagePLUS p detector
Sensitivity of decay correlations on
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
aAB
aAB
A Vg g
PDG 201
4
Determination of from a
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
A Vg g
Measurement of neutrino‐electron correlation a
e
a < 0
Tp small
n
νe
p+
e-a > 0
Tp large
n
νe
p+
e-
ecos 1 ecos 1 Recoil energy spectrum
2e
ee e
d 1 cosd d
vE c
a
The retardation spectrometer aSPECTProton transmission function
F. Glück et al., EPJ A 23, 135 (2005)S. Baeßler, G. K. et al., EPJ A 38, 17 (2008)G. Konrad et al., NP A 827, 529c (2009)
current goal: 1-2 %design goal: 0.3 %
2p B
The retardation spectrometer aSPECTIntegral proton spectrum
current goal: 1-2 %design goal: 0.3 %
Crucial prerequisite: background• stable over time • independent of analyzing plane voltage
F. Glück et al., EPJ A 23, 135 (2005)S. Baeßler, G. K. et al., EPJ A 38, 17 (2008)G. Konrad et al., NP A 827, 529c (2009)
aSPECT beam time 2013
R. Maisonobe, PhD thesis, UJF Grenoble, 2014A. Wunderle et al., in: Proc. of PANIC2014, submitted
p0
p1
10 1 exp tt pf p
Backgroundwithout neutron beam
Background time evolutionwith neutron beam
Ansatz:
no additional E×B
|Size| of correction:• no additional E×B: ≈ 1 %
Current goal: 1‐2 %
G. K., PhD thesis, JGU, 2011
aSPECT beam time 2013Backgroundwithout neutron beam
Background time evolutionwith neutron beam
R. Maisonobe, PhD thesis, UJF Grenoble, 2014A. Wunderle et al., in: Proc. of PANIC2014, submitted
10 1 exp tt pf p
|Size| of correction:• no additional E×B: ≈ 1 %• additional E×B: < 0.1%
Ansatz:
p0
p1
Current goal: 1‐2 %
additional E×B
G. K., PhD thesis, JGU, 2011
A new approach to a: aCORN @ NIST
INDIANAUNIVERSITY
current goal: < 5 %design goal: 0.5 %
F.E. Wietfeldt et al., NIM A 538, 574 (2005),NIM A 545, 181 (2005), NIM A 611, 207 (2009)
Measurement principleB. Yerozolimsky et al., arXiv:nucl‐ex/0401014, 2004
aCORN data (2013)
aCORN data
aCORN data5.0
4.5
4.0
3.5
3.0
2.5
2.0
prot
ontim
eof
fligh
t(s
)
10008006004002000beta energy (keV)
sample of aCORN data (2013)
5.0
4.5
4.0
3.5
3.0
2.5
2.0
prot
on ti
me
of fl
ight
(s)
1000800400 600beta energy (keV)
2000
aCORN Monte Carlo
current goal: < 5 %design goal: 0.5 %
Future prospects for a: Nab @ SNS / abBA
Ee [MeV]
p p2
[MeV
2 /c2 ]
cos θeν = 1
Proton phase space (Dalitz plot) Probability (arb. units)
0
0.25
0.5
0.75
1
1.25
1.5
0 0.2 0.4 0.6 0.8
cos θeν = 0cos θeν = -1
Ee =
236 keV
450 keV
700 keV
Kinematics in INM approximation
• energy conservation
• momentum conservation2 2 2
e ep 2 cos ep p p p p
e,max eEE E
2ep
e
1 cos epa pE
22p emin, max
p p p
Edges
Slope
D. Počanić et al., NIM A 611, 211 (2009)
2e
ee e
d 1 cosd d
vE c
a
The Nab spectrometer
design goal: 0.1 %
SegmentedSi detector
decay volume (field rB,DV·B0)
0 kV
0 kV
-30 kV
magnetic filterregion (field B0)
Neutronbeam
TOF region(field rB·B0)
Sim
ulat
ed c
ount
s [a.
u.]
0.002 0.004 0.0060
Ee = 300 keVEe = 500 keVEe = 700 keV
1/tp2 [µs-2]
D. Počanić et al., NIM A 611, 211 (2009)S. Baeßler et al., arXiv:1209.4663v1 [nucl-ex], 2012A. Salas-Bacci et al., NIM A 735, 408 (2014)
Proton 1/tp2 histograms:
pp
p pcosm dztp z
Outline
• Motivation
• Neutron beta‐decay within the Standard Model
• Searches for new physics beyond the Standard Model
• Summary and Outlook
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Decay parameters
• 10 unknown parametersGF, Vud, Cj, Cjꞌ, j=V, A, S, T
• 20 or more observables
n, a, b, A, B, C, D, …• Coupling constants Lj to left‐
handed and Rj to right‐handed neutrinos
F. Glück et al., NP A 593, 125 (1995)
F ud
2 j jj LG RVC F ud
2 jj jRG VC L
3
22 22F ud e e 0 e5
e e
d 1 1 3d d d 2 2
p E E EE
G V
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
Decay correlations
2 2 2 22 2 2 2V A S T V A S TL L L L R R Ra R
* * * *2 3 3S V A T S V A TL L L L R R R Rb
2 2 2 2* * * *2 A V A T S T A V A T S TL L L L L L R R R R RA R
F. Glück et al., NP A 593, 125 (1995)
• 10 unknown parameters: GF, Vud, Lj, Rj, j=V, A, S, T
• 20 or more observables: n, a, b, A, B, C, D, …
2 2 2 22 2 2 23 3 3 3V A S T V A S TL L L L R R R R
yet unmeasured
3
22 22F ud e e 0 e5
e e
d 1 1 3d d d 2 2
p E E EE
G V
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
Prospects for scalar and tensor interactions
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
b at 10‐3 level precision LHC limits
CMS search for → X
1
1 ∙
M. González‐Alonso, O. Naviliat‐Cuncic, NPAC‐13‐03; arXiv:1304.1759see also: G. Konrad et al., in: Proc. 5th BEYOND 2010, World Scientific, 660, 2011, arXiv: 1007.3027v2 (2010)
Prospects for scalar and tensor interactions
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
b at 10‐4 level precision
CMS search for → X
1
1 ∙
LHC limits
T. Bhattacharya et al., PR D85,054512 (2012)M. González‐Alonso, O. Naviliat‐Cuncic, NPAC‐13‐03; arXiv:1304.1759
Beyond the Standard Model physics• Study the structure of the weak interaction
value of weak magnetism form‐factor f2 predicted (CVC hypothesis) value f2 = (κp-κn)/2 ≈ 1.8529 tested only to O(10%) in A=12 system large theoretical uncertainties
• Test the Standard Model of particle physics self‐consistency of the Standard Model unitarity of the Cabibbo‐Kobayashi‐Maskawa (CKM) quark‐mixing matrix
• Search for ‘new physics beyond‘ and new symmetry concepts left‐right symmetry, leptoquarks, supersymmetry (SUSY), etc. right‐handed admixtures, exotic scalar and tensor admixtures can continue to probe for SUSY in regions where it is not accessible to LHC deviations from CKM unitarity ≥ 10‐4 fall in the LHC inaccessible region 10‐3 level b measurements complementary to improved LHC results
superallowed 0+→ 0+ decays
Present best test of the Standard Model
2 2 2 4us uu bd1 1 1 6 10V VV
Kaon decays B‐decays
Measurement of the Fierz interference term b
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Electron energy spectrum
‛Prototype‘ of a UCN calorimeter: UCNb @ LANSCE
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
PMTs
PMTs
b box
UCN ball valve
UCN guide
Calibrationinsert
K. Hickerson, Ph.D. thesis, Caltech, 2012
Electron energy spectrum
Future prospects for b: Nab @ SNS
design goal: 0.003
Systematic uncertainties• Electron energy determination:
• Background
2% of events in tail(deadlayer, external bremsstrahlung)
Yie
ld1
101
102
103
104
105
detected Ee [keV] 0 50 100 150 200 250 300
Detector response to decayelectron with Ee = 300 keV
Electron energy spectrum
D. Počanić et al., NIM A 611, 211 (2009)S. Baeßler et al., arXiv:1209.4663v1 [nucl-ex], 2012
Future prospects for b: PERC @ FRM II
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Electron energy spectrum Electron momentum spectrum
Magnetic spectrometer @ PERC
no low momentum measurements large corrections for θ non‐adiabatic transport of particles B2‐field coupled with B3‐field pitch angles easily distorted
+ large drift distances O(dm)
B2=0.5TB3=0.01T
3 3
, cosprB B
ppq q
Radius of gyration:
R×B drift momentum spectrometer: NoMoS
Last Coil of PERC
Tilted Coils
e‐/p+ beam
Detector
Aperturey
zx
B3=0.15T
B2=0.5T
α
DDR×Bvd qR²B²
y
xz
ElectronsProtons
X. Wang, G. K., H. Abele, NIM A 701, 254 (2013)
+ extremely versatile+ adiabatic transport of particles+ low momentum measurements+ small corrections for θ+ large acceptance of θ
RB
3
1, (cos )c
d 1os2dT B
v tDq
pp
R×B drift momentum spectrometer: NoMoS
Last Coil of PERC
Tilted Coils
e‐/p+ beam
Detector
Aperture
B3=0.15T
B2=0.5T
α
DDElectronsProtons
+ extremely versatile+ adiabatic transport of particles+ low momentum measurements+ small corrections for θ+ high resolution:
Δp/p=14.4 keVc-1mm-1
small drift distances O(cm)
1.2%mm‐1
X. Wang, G. K., H. Abele, NIM A 701, 254 (2013)
R×Bvd qR²B²
y
zx
y
xz
3
1, (cos )c
d 1os2dT B
v tDq
pp
RB
Decay correlations
* * * * * *2 2 2S A V T A T S A V T A TL L L L L L R R R R R Rb
2 2 2 2* * * *2 A V A T S T A V A T S TL L L L L L R R R R RA R
F. Glück et al., NP A 593, 125 (1995)
• 10 unknown parameters: GF, Vud, Lj, Rj, j=V, A, S, T
• 20 or more observables: n, a, b, A, B, C, D, …
2 2 2 22 2 2 23 3 3 3V A S T V A S TL L L L R R R R
yet unmeasured
3
22 22F ud e e 0 e5
e e
d 1 1 3d d d 2 2
p E E EE
G V
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
0e
e
B bB mE
2 2 2 2* * * *0 2 A V A T S T A V A T S TL L L L L L R R R R R RB
Signal for MSSM expected at 3~ 10B S. Profumo et al., PR D 75, 075017 (2007)
Measurement of neutrino asymmetry parameter B2
en
e
d 1 cosd d
vE c
B
n
2same opposite
2same opposite
21 3
N NN N
B
Electron energy spectra
Spin down, electron down, proton up
Spin up, electron down, proton up
Spin down, electron up, proton up
Spin up, electron up, proton up
The spectrometer PERKEO II
e eexp e
e e
N EB
N EE
N E N E
2e
2e
exp ee
e
2 3 31
8 4 24=3 2
14
A B
a
v r rc rvr rP cE
v rc rvr
c
BA B
a
e e e
max
v E mrc E E
Background B‐n‐displacement
0.9802 50B Limit on ‛right‐handed‘ W boson:
2R 296 GeV/cm W
M . Schumann et al., PRL 99, 191803 (2007)
A new approach to B0 and b: UCNB @ LANSCE
design goal: 0.1 %
A. Salas‐Bacci et al., NIM A 735, 408 (2014)
Measurement of proton asymmetry parameter C
2
p p npp p
d 1 , cosd d
C TE
np
Proton energy spectra
same opposite
same opposite
0.27484C A BN NN N
The spectrometer PERKEO II
exp e
Q Q Q QE
Q Q Q QC
M . Schumann et al., PRL 100, 151801 (2008)
0.2377 26C
The successor PERKEO III
goal: 0.2 %
accel. potential- 30 kV
0 V0 V 0 V
proton energy filter0V to +1 kV
magnetic field
photomultipliertubes
p e
scintillator withconductive coating
protonconversion foil
e
from neutrondecay volume
A similar approach: PANDA @ SNS
T. Chupp et al.
goal: 0.1 % p pdC T TC
The Neutron Alphabet I
3
22F
22ud e e 0 e5
e e
d 1 1 3d d d 2 2
G V p E E EE
ne e e
e n e
e
ee
1 p p p p p pE E E E E E
a A B DmE
b
J.D. Jackson et al., PR 106, 517 (1957)
-1n
• 3 unknown parametersGF, Vud,
• 20 or more observables
n, a, b, A, B, C, D, …
• yet unmeasuredb
A Vg g
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
221 3
D
Measurement of D coefficient: TRINE @ ILL
D = (–2.86.4stat3.0syst)·10-4
T. Soldner et al, Phys. Let. B 581, 49 (2004)
e p
3n e
e e n
n
e
p
n e
ed 1 1d d d p p p
p p DE E E
pD
E Ep
ep
ppp
00 01 10 11
004 D
DP
e ,p e ,p
e ,p e ,p
i j i jij
i j i j
N NN N
with
Measurement of D coefficient: emiT @ NIST
T Chupp et al, PR C 86, 035505 (2012)L.J. Lising et al., PR C 62, 055501 (2000)
D = (–0.941.89stat0.97syst)·10-4
e p
3n e
e e n
n
e
p
n e
ed 1 1d d d p p p
p p DE E E
pD
E Ep
The Neutron Alphabet II
2
22 22F ud e e 0 e4
e
d 1 1 3d d 2 2
G p E EV EE
n n ne e ee
e n e n n e
1 m p pb AE E E
N R
J.D. Jackson et al., PR 106, 517 (1957)
-1n
2 2 2 2* * * *e
e
2 A T V A S T A T V A S Tm L L L L L L R R R R R RE
N
* * * * * *2 2V T S A T A V T S A T AL L L L L L R R R R R R
F. Glück et al., NP A 593, 125 (1995)
2 2 2 22 2 2 23 3 3 3V A S T V A S TL L L L R R R R
2 2 2 2* * * *e
e
2 2 2 2A T V A S T A T V A S Tm L L L L L L R R R R Rp
R R
* * * * * *2 2 2V T S A T A V T S A T AL L L L L L R R R R R R
• 10 unknown parameters: GF, Vud, Lj, Rj, j=V, A, S, T
• 20 or more observables: n, a, b, A, B, C, D, N, R, …
The nTRV experiment @ PSI
e
pe
ppJn
p
2n n e
ee n n e
d 1d d
N pE E
R
Mott scattering
A. Kozela et al, PR C 85, 045501 (2012)A. Kozela et al., PRL 102, 172301 (2009)
Up‐down asymmetry
NSM = 0.066
Forward‐backward asymmetry
RSM = 0.00066
N = +0.0670.011stat0.004syst
R = +0.0040.012stat0.005syst
Rare decay modes• Radiative neutron β‐decay
electron innerBremsstrahlung (IB) proton IB weak‐vertex IB etc.
radiative corrections to continuum state β‐decay
• Bound state neutron β‐decay
hyperfine levels of metastable 2S state (for gS=gT=0)
signature for right‐handed currents
-3QEDBR =2.81 10en p e
6BR 4 10en H
d
u
W±
e-
νe
d
u
W±
e-
νe
d
u
W±
e-
νe
g gg
1 1 1 1 1 1, 0.6%, , 55.2%, , 44.2%,2 2 2 2 2 2
1 1and , 0; 02 2
Radiative neutron β‐decay: RDK @ NIST
en p e
R.L. Cooper et al., PR C81, 035503 (2010)
J. Nico et al., Nature 444, 1059 (2006)
stat syst -3expBR = 3.09 0.11 0.30 10
Bound state neutron β‐decay: BOB @ FRM II
J. McAndrew et al., Hyp. Int. 210, 13 (2012)W. Schott et al., Eur. Phys. J. A 30, 603 (2006)
Configuration gS = 0, gT = 0 gS = 0.1, gT = 0 gS = 0, gT = 0.1
44.14 % 46.44 % 43.40 %
55.24 % 53.32 % 55.82 %
0.622 % 0.238 % 0.780 %
0.0 % 0.0 % 0.0 %
1 1,2 2
1 1,2 2
1 1,2 2
1 1,2 2
September 12, 2013 Tests of Lorentz symmetry in neutron decay, PSI2013 Courtesy of J.S. Diaz
September 12, 2013 Tests of Lorentz symmetry in neutron decay, PSI2013 Courtesy of J.S. Diaz
September 12, 2013 Tests of Lorentz symmetry in neutron decay, PSI2013 Courtesy of J.S. Diaz
Summary & Outlook
• Neutron alphabet deciphers the Standard Model of particle physics observables in neutron β‐decay are abundant
• Precision measurements of neutron β‐decay address important open questions of particle physics and cosmology can continue to probe for SUSY in regions where it is not accessible to LHC 10‐3 level b measurements complementary to improved LHC results
• Rich experimenal program• New physics might be found. Maybe soon.
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria
Further reading
• H. Abele, Prog. Part. Nucl. Phys. 60, 1 (2008)• S Baeßler et al., J. Phys. G: Nucl. Part. Phys. 41, 114003 (2014)• V. Cirligiano, S. Gardner, B. Holstein, Prog. Part. Nucl. Phys. 71, 93 (2013)• D. Dubbers & M.G. Schmidt, Rev. Mod. Phys. 83, 11111171 (2011)• A.N. Ivanov, M. Pitschmann & N.I. Troitskaya, Phys. Rev. D 88, 073002
(2013)• J. Nico & M. Snow, Annu. Rev. Nucl. Part. Sci. 55, 27 (2005)• A.R. Young et al., J. Phys. G: Nucl. Part. Phys. 41, 114007 (2014)• etc.
June 19, 2015 Decay Correlations, Summer School Knoxville G.Konrad, TU & SMI Wien, Austria