Transcript Particle Physics with Neutrons

4. Correlation D and R measurements in decay
Neutron Spin
Electron
D
R
Neutron Spin
Electron
Neutrino
W dE e d e d   p e E e (E 0  E e )2dE e d e d 
p e p
p
p e  p
m
pe
e  pe
[1  a
b
  n (A
B
D
R
 N  e )]
Hartmut
Abele,
University
of
Heidelberg
E e E
Ee
Ee
Ee
E e E
e E e
1
4.1 Phase and Time Reversal Violation
sin f
|l|
Hartmut Abele, University of Heidelberg
2
D-Koefficient,
SM: D = 0, LR ≠ 0
Hartmut Abele, University of Heidelberg
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Measurement of D
D = 0 in SM

dW
1  a ppeepp  b mmee  σn  pe
p 
σ
p

p
n
e

 Ge ( Ee )   1  a
b
  A  dBW  1  D 

E
E
E
dEe de d
E
E
E

E
E

E
E
e

e
e 
e


n
e 
n 
e
 
P violation  Asymmetry with spin-flip
Principle Set-Up
Breaking of detector symmetry
Systematic effects
Hartmut Abele,
University
ofT.
Heidelberg
Diagram
from
Soldner
Nep00N
ep01   10   11
D 
 00
DPκD  APκ A  BPκB

N ep  N4epP D
4
Coefficient D
T. Soldner et al, Phys. Let. B 581 (2004) 49.
D = (–2.86.4stat3.0syst)·10-4
L.J. Lising et al, PRC 62 (2000) 055501.
D = (–612stat5syst)·10-4
T. Soldner et al, Phys. Let. B 581 (2004) 49.
Hartmut Abele, University of Heidelberg
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5. The Future
Hartmut Abele, University of Heidelberg
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Technical developments:
5.1 New sources
SNS, Oak Ridge,
Tennessee:
Hartmut Abele, University of Heidelberg
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ILL: new supermirror guide
Particle Physics: SM Tests
Hartmut Abele, University of Heidelberg
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FRM2 2005
Cold neutrons at the
FRM II
UCN source at the FRM
II
Hartmut Abele, University of Heidelberg
UCN Sources
UCN source PSI
UCN source at
Vienna
UCN Source at
Mainz
UCN Source
LANL
UCN Source NC
State
9
Future UCN Sources
Project
site
method
Production
Rate/cc (SD2)
Converter
volume
Useful
Density
PF4
ILL
60 MW Reactor,
LD2 (CW)
Not comparable
Not
comparabl
e
n ≤ 40
( n ≤ 20 now ?)
UCNA
prototype
LANL
Spallation
target, SD2
500 UCN/cc/μA
(up to 10 μA)
300 cc
n ≤ 150
UCNA
productio
n
LANL
Spallation
target, SD2
90 UCN/cc/μA
(up to 10 μA)
200 UCN/cc/μA
2000 cc
n ≤ 0.15/ μA
n < 4/μA
PULSTA
R
NCSU
1–2 MW
Reactor, SD2
(CW)
1.2×104
UCN/cc/MW
1000 cc
n ≤ (50 – 200)
Mainz/FR Technical
MII
University
Mainz
Pulsed Reactor,
SD2
~33 UCN/cc/MJ
(up to 6 MJ/600 s)
or ~2 UCN/cc/s
200–300 cc
n ≤ 3/pulse
n ≤ 350/pulse ?
Osaka
Osaka
University
Spallation
target, LHe
3.5 UCN/cc/μA
12000 cc
n ≤ 1.4
n < 280
SUNS
PSI
Spallation target 1.5×104/cc/μA
(8 mC in 4s/500s))
30000 cc
n < 2500
Hartmut
of Heidelberg
from A. Abele,
YoungUniversity
/ P. Huffman
10
Facilities
Nico, Snow, Annu Rev Nucl Part Sci 55 (2005) 55
Hartmut Abele, University of Heidelberg
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Facilities
Nico, Snow, Annu Rev Nucl Part Sci 55 (2005) 55
Hartmut Abele, University of Heidelberg
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Characteristics of experiments using
magnetic fields
Hartmut Abele, University of Heidelberg
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a Spect, Univ. MZ/TUM
Proton spectroscopy
Hartmut Abele, University of Heidelberg
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First impression
aSPECT is a retardation spectrometer for protons of free neutron decay
aSPECT
Hartmut Abele, University of Heidelberg
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Measurements at different UA values
Spectra for different values of UA, each background (UA = 800 V) subtracted
Hartmut Abele, University of Heidelberg
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Integral spectrum
obtained from ~ 1 h data taking
Hartmut Abele, University of Heidelberg
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aCORN
Surface barrier
detector
Hartmut Abele, University of Heidelberg
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Principle: momentum space diagram
Typical momentum vector
for pe
Solenoid and aperture
arrangement will allow
protons with momentum <
eBr/2
p lie in a second cylinder,
kinematically distinct
groups
a will cause an asymmetry
between coincidence
events between I and II.
Groups I and II can be
experimentally
distinguished by TOF.
Hartmut Abele, University of Heidelberg
19
Neutron beta-decay program of PNPI
Hartmut Abele, University of Heidelberg
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Hartmut Abele, University of Heidelberg
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Hartmut Abele, University of Heidelberg
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Nab
Electron and neutrino momenta from electron
energy
cose from proton momentum and electron energy
using
4T  1T
TOF between electron and proton
Hartmut Abele, University of Heidelberg
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UCNA Collaboration
California Institute of Technology
R. Carr, B. Filippone, J. Hsiao, R. McKeown, B. Plaster, B. Tipton, J. Yuan
Institute Lau-Langevin
P. Geltenbort
Idaho State University
R. Rios, E. Tatar
Los Alamos National Laboratory
J. Anaya, T. J. Bowles (co-spokesperson), T. Brun, M. Fowler, R. Hill, G. Hogan, T. Ito, K. Kirch, S.
Lamoreaux, M. Makela, C. L. Morris, A. Pichlmaier, A. Saunders, S. Seestrom, P. Walstrom
North Carolina State University/TUNL
H. O. Back, L. Broussard, A. T. Holley, R. K. Jain, R. W. Pattie, K. Sabourov, A. R. Young (cospokesperson), Y.-P. Xu
Petersburg Nuclear Physics Institute
A. Aldushenkov, A. Kharitonov, I. Krasnoshekova, M. Lasakov, A. P. Serebrov, A. Vasiliev
Tohoku University
S. Kitagaki
University of Kyoto
M. Hino, T. Kawai, M. Utsuro
University of Washington
A. Garcia, S. Hoedl, D. Melconian, A. Sallaska, S. Sjue
University of Winnipeg
J. Martin
Virginia Polytechnic Institute and State University
R. Mammei, M. Pitt, R. B. Vogelaar
Hartmut Abele, University of Heidelberg
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UCN residency time in bottle <
5s to limit depolarization…
Hartmut Abele, University of Heidelberg
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Systematic Uncertainty Budget
Original Goal: measure A to precision of 0.2% or better
for a decay rate of 116 Hz in our bottle
requires 45 days of beam time + 45 days to explore systematics
Dominant systematic corrections
Systematic Effect
Size of correction
Uncertainty
UCN Pol/spin-flip eff.
110-3
110-4
Wall depolarization
910-4
110-4
Backscattering
210-3
410-4
Field non-uniformity
710-4
710-5
Detector response
310-4
310-4
Detector linearity
610-5
610-5
Total background
.5 Hz
.1 Hz
2.510-3
1.010-3
Total
Hartmut
from A. Abele,
YoungUniversity of Heidelberg
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It’s built!
2,3 m
Hartmut Abele, University of Heidelberg
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The Proton Asymmetry in
Neutron Decay Experiment
“PANDA”
Alexander Komives - dePauw
Tim Chupp, Rob Cooper, Monisha Sharma -U.Michigan
Gordon Jones - Hamilton College
Fred Wietfeldt - Tulane
Scott Dewey, Jeff Nico, Alan Thompson, Tom Gentile,
Pieter Mumm - NIST
Hartmut Abele, University of Heidelberg
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Layout
By
For adiabatic neutron spin transport
Bx
M2
M1
polarizer
neutrons
Spin
Flipper
analyzer
N0(v)
P(v)
TP(v)
y
X
R
Detector
A(v)
TA(v)
z
L
Detector 1
Detector 2
Neutron beam
Into page
~
+30 kV
Detailed design work needed.
Hartmut Abele, University of Heidelberg
Uniform
field B
~
V0
Allows proton
spectroscopy
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The proton Asymmetry
p
e
p

N+
Asymmetry:
e

N-
N+ - N__________
N+ + N-
C = k(A+B) =
=
C Pn A F (1-f) + Afalse
background
spin flip efficacy
analyzing power
neutron polarization
|l|
4k ________
1+3| l
|2
l=
gA
____
gV
k=0.27484
Standard Model
dW
_____________
dEeded
= S(Ee) [1 + a
pe.pn
______
+
m
J
p
p
pexp
b ___e + ___.(A____e + B____ + D _______
)]
EeEn Ee J
Ee
E
EeE
Hartmut Abele, University of Heidelberg
JTW-57
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Motivation: C and l
|l|
C = k(A+B) = 4k ________
2
1+3| l |
PDG 2005
x
l ___
___
l
x
l
-1.2695±0.0029
a
-0.103±0.004
0.2688
A
-0.1173±0.0013
0.2403
B
+0.983 ±0.004
1.385
C
+0.238 ±0.011*
1.430
D
-0.0004±0.0006
general sys. error
f 180.06±0.0029
* Abele, 2005
dW
_____________
dEeded
= S(Ee) [1 + a
pe.pn
______
+
m
J
p
p
pexp
b ___e + ___.(A____e + B____ + D _______
)]
EeEn Ee J
Ee
E
EeE
Hartmut Abele, University of Heidelberg
JTW-57
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abBA
Collaboration
Hartmut Abele, University of Heidelberg
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PERKEO III
Virtually no systematic errors
- background
- edge effect
- mirror effect
B. Maerkisch, D. Dubbers, H.A.
Hartmut Abele, University of Heidelberg
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PERKEO III, Correlation A, University HD
neutron cloud
detector
velocity
neutron beam chopper
selector
proton or
electron detector
~2m, 150mT
decay volume
beam stop
Dubbers, Märkisch, H.A.
k  k
g  2
mw

Particles And Fields
g2
Tfi  Vud  u  (1   5 )d  2
 e  (1   5 )
2
8
k  mw
Weak magnetim
formfactor
matrix
for d-u transition:
Tfi 

hadron and
lepton currents:
vector- and
axial vector currents:
GF
Vud  u  (1   5 )d  e  (1   5 )
2
GF
Vud  J h J l
2
g M (k 2 )
V  i p [ gV (k )  
   k
2m p
2
A  i p [ g A (k )   5 
2
Lagrange function
for neutron decay:
J l  e  (1   5 )  v   a 
J h  d  (1  5 )u  V   A
 ig s (k 2 )k  ]n
gT (k 2 )
   k  5  ig P (k 2 )k   5 ]n
2m p
 p  n
1 GV
Lint 
 p (  (1  l 5 ) 
  k  )n  e   (1   5 )
2 2
2mp

1 GF
Vud  (V  lA )(v   a  ).
2 2
Hartmut Abele, University of Heidelberg
l
gA
gV
35
The future with the Perkeo III
neutron beam
observable
method
physics
pulsed
polarised
-asymmetry A
, scint. spectr.
CKM unitarity
weak
magnetism
pulsed
unpol.
p-spectrum 
e- correlation a
p, TOF
CKM unitarity
pulsed
polarised
p-asymmetry 
-asymmetry B
p, TOF
mass of right
handed Wboson
pulsed
unpol.
-spectrum
, magn. spectr. radiative
corrections
continous
unpol./pol.
-helicity
, Mott-scatt.
continous
p-helicity
p, Mott-scatt.
Hartmut Abele, University of Heidelberg
right-handed
currents
36
Find the Parameters…
Gw
H
Li pOi n eOi 1   5   Ri pOi n eOi 1   5  


2 i{S,V,T,A,P}

dW
pp
m σ  p
p
p p
 Ge ( Ee )  1  a e   b e  n  A e  B   D e 
dEeded
Ee E
Ee  n  Ee
E
Ee E

J.D. Jackson et al.: Phys. Rev. 106 (1957) 517
Surviving in the SM:
1 l2
a
1  3l 2
b0
A  2
D0
l
LA
LV
l  l  1
1  3l 2
 

 


1
2
2
2
2
2
2
2
2
LV  LS  LT  LA  RV  RS  RT  RA

2
b  Re  LS LV*  3LA LT*  RS RV*  3RA RT* 

2
2
2
2
2
A
Re LA  LV LA*  LT  LS LT*  RA  RV RA*  RT  RS RT*

2
D  Im  LS LT*  LV LA*  RS RT*  RV RA* 

a

  LV  LS  3 LT  3 LA
2
2
2
2

σe σn  pe 
dW  Ge ( Ee )  1   R 



E
e
n e 

Hartmut Abele, University of Heidelberg
 RV  RS  3 RT  3 RA
2
2
2

2
Slide from T. Soldner
37
Find the Parameters…
Gw
H
Li pOi n eOi 1   5   Ri pOi n eOi 1   5  


2 i{S,V,T,A,P}

dW
pp
m σ  p
p
p p
 Ge ( Ee )  1  a e   b e  n  A e  B   D e 
dEeded
Ee E
Ee  n  Ee
E
Ee E

 

 
or
gA
, Vud
gV
Test for right
handed currents
T violation beyond SM


σe σn  pe 
dW  Ge ( Ee )  1   R 



E
e
n e 

Hartmut Abele, University of Heidelberg
Slide from T. Soldner
38
Coffee maker
Hartmut Abele, University of Heidelberg
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