Hartmut Abele Knoxville, 8 June 2006 Neutron Decay Correlation Experiments.

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Hartmut AbeleKnoxville, 8 June 2006

Neutron DecayCorrelation Experiments

Hartmut Abele, University of Heidelberg 2

Neutron Beta Decay2 2 2 2 2

03 7 3

1( ) (1 3 ) ( )

2 F udW pdp p E E dpG Vc

Electron

Neutron Spin

ElectronNeutron SpinA

W()={1+v/cPAcos()}

Detector

Detector

Hartmut Abele, University of Heidelberg 3

Coefficient A

Coefficient A and lifetime determine Vud and

Electron

Neutron Spin

ElectronNeutron SpinA

W()={1+v/cPAcos()}

231

)1(2

A 231

)1(2

A

on flipper spin with spectrum electron

off flipper spin with spectrum electron

:N

:N

on flipper spin with spectrum electron

off flipper spin with spectrum electron

:N

:N

PfAAc

vexp PfAA

c

vexp

= gA/gV= gA/gV

No coincidences !

)31(

sec249082

2

udV)31(

sec249082

2

udV

2 2

0 0

(1 cos )sinv

N P dA dc

NN

NNAexp

NN

NNAexp A

N N

N Nexp

A

N N

N Nexp

Hartmut Abele, University of Heidelberg 4

For a correlation coefficient A measurements, we need …

Neutronsa Polarizera Spin Flipperan Analyzer

a Spectrometer

Hartmut Abele, University of Heidelberg 5

Correlation measurements in -decay

Electron

Proton

Neutrino

Neutron SpinA

B

C Observables in neutron decay:

Lifetime SpinMomenta of decay particles

Observables in neutron decay:

Lifetime SpinMomenta of decay particles

n n p e p e eeaa

DD

RRNN

Hartmut Abele, University of Heidelberg 6

Parameters and Observables

SM ParametersStrength: GF

Quark mixing: Vud

Ratio: = gA/gV

2 2 2 2 203 7 3

1( ) (1 3 ) ( )

2 F udW pdp p E E dpG Vc

5 41 2 2 2

3 7(1 3 )2

Re

ud F

f m cV G

h

2

( 1)2

1 3A

exp

N NA

N N

PfAAc

vexp

ObservablesLifetime Correlation ACorrelation BCorrelation CCorrelation aCorrelation DCorrelation RBeta SpectrumProton SpectrumPolarized SpectraBeta Helicity

Electron

Proton

Neutrino

Neutron Spin

A

B

C

5 41 2 2 2

3 7(1 3 )2ud

Re

F

fV

mG

ch

Hartmut Abele, University of Heidelberg 7

the Neutron

3-quark System: uddBeta-decay d u eFlux 1.2 x 1015 cm-2 s-1

cold neutronsultra cold neutrons

Hartmut Abele, University of Heidelberg 8

Hot topic questions beyond the SM

What do we learn from Vud and quark mixing?What is the origin of P-violation?

T-violation?

Additional forcesNumber of quark generationsNeutrino helicitySearch for RHC: W-mass and mixing

CP-violation

Hartmut Abele, University of Heidelberg 9

Neutrons at the SNS

Hartmut Abele, University of Heidelberg 10

Neutron Production at the ILL

Hartmut Abele, University of Heidelberg 11

Particle Physics: SM Tests

3D Neutron Tomography

Gravitation and Bound Quantum States

Hartmut Abele, University of Heidelberg 12

Neutron Production

Hartmut Abele, University of Heidelberg 13

1.1 A Measurement of Correlation A

• A new beam: decay rate 1 MHz/mThe ‘ballistic’ super-mirror cold-neutron guide H113H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002)

• New Polarizers (TU Munich, ILL, HD)

• New Geometry for Beam polarization

A perfectly polarized neutron beam

•Signal to Background > 1000 : 1

• A new beam: decay rate 1 MHz/mThe ‘ballistic’ super-mirror cold-neutron guide H113H. Haese et al., Nucl. Instr. Meth. A485, 453 (2002)

• New Polarizers (TU Munich, ILL, HD)

• New Geometry for Beam polarization

A perfectly polarized neutron beam

•Signal to Background > 1000 : 1

Hartmut Abele, University of Heidelberg 14

The Experimental Setup at PF1B

M. Schumann 2006M. Schumann 2006

Hartmut Abele, University of Heidelberg 15

1.2 Tools

Hartmut Abele, University of Heidelberg 16

Polarizer

Spin up: reflectedSpin down: absorbed

Coherent nuclear (strong) and electronic (magnetic) scattering

Scattering probability:

resulting polarization:

2

nucl magW a a

nucl maga a1W W

PW W

UUFF

xx

100 neV100 neV

Hartmut Abele, University of Heidelberg 17T. Soldner, A. Petoukhov, V. Nesvizhevsky, M. Kreuz

Hartmut Abele, University of Heidelberg 18

The new Polarizer

Munich, ILL, HDA new geometry for Beam polarization A perfectly polarized neutron beam

Status 2002

Status 2004

98 %98 %

100 %100 %

96 %96 %

100 %100 %

90 %90 %

95 %95 %

94 %94 %

96 %96 %

T. Soldner, A. Petoukhov, V. Nesvizhevsky, M. Kreuz

Hartmut Abele, University of Heidelberg 19

Tools

Fermipotential: - Matter 100 neV

Neutron guidesWavelength filterPolarizer/AnalyzerUCN- perfect mirror

- neutron bottlesSubstrat (Glas)

Nickel

NickelTitan

Titan

2d sin=n

d

UUFF

xx

100 neV100 neV

Hartmut Abele, University of Heidelberg 20

The new Polarizer

Munich, ILL, HDA new geometry for Beam polarization A perfectly polarized neutron beam

Status 2002

Status 2004

98 %98 %

100 %100 %

96 %96 %

100 %100 %

90 %90 %

95 %95 %

94 %94 %

96 %96 %

Hartmut Abele, University of Heidelberg 21

Rf Spin flipper

Lab frame

Rotating frame

Rotating frame

Hartmut Abele, University of Heidelberg 22

The Instrument

Hartmut Abele, University of Heidelberg 23

1.3 Coefficient A: Spectrometer Perkeo II

to beamstopto beamstop

precise electron spectroscopyprecise electron spectroscopy

Electron

Neutron Spin

ElectronNeutron SpinA

up: down:

NN

NNAexp

AN N

N Nexp

Hartmut Abele, University of Heidelberg 24

Principle:2x2- Detectiontwo hemispheresbackscattering suppressionlow backgroundstrong beam PF1:- count ratesystematic

Spectrometer Perkeo IIoben: unten:

NN

NNAexp

AN N

N Nexp

zum beamstopzum beamstop

precise electron spectroscopyprecise electron spectroscopy

2

( 1)2

1 3A

v

cexpA A Pf

= gA/gV

Hartmut Abele, University of Heidelberg 25

Results

Spectra Dissertation D. Mund, 2006

Hartmut Abele, University of Heidelberg 26

Result

Asymmetry A

Dissertation D. Mund, 2006

Hartmut Abele, University of Heidelberg 27

Beamrelated Background

Collimation system < 0.15 s-1

Det. 0

Det. 1

Fitregion

Electron-Spectrum

Beamline BG

Hartmut Abele, University of Heidelberg 28

2002 2002 2006 2006 correction uncertainty correction uncertainty polarization 1.1 % 0.3 % 0.3 % 0.1 % flipper efficiency 0.3 % 0.1 % 0.0 % 0.1 % Statistical error 0.45 % 0.26 % background 0.5 % 0.25 % 0.1 % 0.1 % detector function 0.26 % 0.1 % edge effect -0.24 % 0.1 % -0.22 % 0.05 % time resolution 0.25 % mirror effect 0.09 % 0.02 % 0.11 % 0.01 % backscattering 0.2 % 0.17% 0.003 % 0.001 % rad. corrections 0.09 % 0.05 % 0.09 % 0.05 % Sum 2.04 % 0.66 % 0.38 % 0.33 %

sum 2006 preliminary

2002 2002 2006 2006 correction uncertainty correction uncertainty polarization 1.1 % 0.3 % 0.3 % 0.1 % flipper efficiency 0.3 % 0.1 % 0.0 % 0.1 % Statistical error 0.45 % 0.26 % background 0.5 % 0.25 % 0.1 % 0.1 % detector function 0.26 % 0.1 % edge effect -0.24 % 0.1 % -0.22 % 0.05 % time resolution 0.25 % mirror effect 0.09 % 0.02 % 0.11 % 0.01 % backscattering 0.2 % 0.17% 0.003 % 0.001 % rad. corrections 0.09 % 0.05 % 0.09 % 0.05 % Sum 2.04 % 0.66 % 0.38 % 0.33 %

sum 2006 preliminary 2002: result: A = -0.1189(8) = -

1.2739(19)2006: result: A = -0.11948(40) = -1.2754(11)

Hartmut Abele, University of Heidelberg 29

Collaboration PERKEOII 1995 - 2006

ILL GrenobleJ. Last, U. Mayerhofer, O. Zimmer, V. Nesvizhevsky, T. Soldner, A. Petoukhov

Universität Heidelberg Stefan Baeßler, C. Raven, T. Müller, C. Metz, M. Astruc Hoffmann, Uta Peschke, Jürgen Reich, Bernhard Brand, Michael Kreuz, Ulrich Mayer Daniela Mund, Christian Plonka, Christian Vogel, Bastian Märkisch, Markus Brehm, Jochen Krempel, Marc Deissenroth, Marc Schumann, Alexander Kaplan, Daniel Wilkin, Dirk Dubbers, H.A.

U. MainzS. Baeßler

FZKF. Glück

Hartmut Abele, University of Heidelberg 30

Hartmut Abele, University of Heidelberg 31

Recommended value for lambda

= -1.27500.0009

Hartmut Abele, University of Heidelberg 32

1.4 A and

A as a function of gA and gV

Time reversal invariance, phase 180°ve = c, v = c,

see Lecture at Black Board

Hartmut Abele, University of Heidelberg 33

Hartmut Abele, University of Heidelberg 34

Thesis Doehner 1991

Hartmut Abele, University of Heidelberg 35

Hartmut Abele, University of Heidelberg 36

Hartmut Abele, University of Heidelberg 37

• Solar cycle p p D e+ e

p p e D e

• Neutron star formation p e n e

•Primordial element formation n e+ p e'

p e n e

n p e e'

•Neutrino detectors p e' n e+

•Neutrino forward-scattering e p e+ n etc.

•W, Z-production p p' W e e' etc.

• Solar cycle p p D e+ e

p p e D e

• Neutron star formation p e n e

•Primordial element formation n e+ p e'

p e n e

n p e e'

•Neutrino detectors p e' n e+

•Neutrino forward-scattering e p e+ n etc.

•W, Z-production p p' W e e' etc.

PROCESSES WITH SAME FEYNMAN DIAGRAM:

= gA/gV= gA/gV