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Hartmut Abele Knoxville, 8 June 2006 Neutron Decay Correlation Experiments
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Hartmut Abele, University of Heidelberg 2 Neutron Beta Decay Electron Neutron Spin Electron Neutron Spin A W( )={1+ v/c PA cos( )} Detector
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Hartmut Abele, University of Heidelberg 3 Coefficient A Coefficient A and lifetime determine V ud and Electron Neutron Spin Electron Neutron Spin A W( )={1+ v/c PA cos( )} = g A /g V No coincidences !
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Hartmut Abele, University of Heidelberg 4 For a correlation coefficient A measurements, we need … Neutrons a Polarizer a Spin Flipper an Analyzer a Spectrometer
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Hartmut Abele, University of Heidelberg 5 Correlation measurements in -decay Electron Proton Neutrino Neutron Spin A B C Observables in neutron decay: Lifetime Spin Momenta of decay particles Observables in neutron decay: Lifetime Spin Momenta of decay particles n p e e a D R N
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Hartmut Abele, University of Heidelberg 6 Parameters and Observables SM Parameters Strength: G F Quark mixing: V ud Ratio: = g A /g V Observables Lifetime Correlation A Correlation B Correlation C Correlation a Correlation D Correlation R Beta Spectrum Proton Spectrum Polarized Spectra Beta Helicity Electron Proton Neutrino Neutron Spin A B C
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Hartmut Abele, University of Heidelberg 7 the Neutron 3-quark System: udd Beta-decay d u e Flux 1.2 x 10 15 cm -2 s -1 cold neutrons ultra cold neutrons
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Hartmut Abele, University of Heidelberg 8 Hot topic questions beyond the SM What do we learn from V ud and quark mixing? What is the origin of P- violation? T-violation? Additional forces Number of quark generations Neutrino helicity Search for RHC: W- mass and mixing CP-violation
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Hartmut Abele, University of Heidelberg 9 Neutrons at the SNS
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Hartmut Abele, University of Heidelberg 10 Neutron Production at the ILL
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Hartmut Abele, University of Heidelberg 11 Particle Physics: SM Tests 3D Neutron Tomography Gravitation and Bound Quantum States
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Hartmut Abele, University of Heidelberg 12 Neutron Production
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Hartmut Abele, University of Heidelberg 13 1.1 A Measurement of Correlation A A new beam: decay rate 1 MHz/m The ‘ballistic’ super-mirror cold-neutron guide H113 H. 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/m The ‘ballistic’ super-mirror cold-neutron guide H113 H. 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
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Hartmut Abele, University of Heidelberg 14 The Experimental Setup at PF1B M. Schumann 2006
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Hartmut Abele, University of Heidelberg 15 1.2 Tools
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Hartmut Abele, University of Heidelberg 16 Polarizer Spin up: reflected Spin down: absorbed Coherent nuclear (strong) and electronic (magnetic) scattering Scattering probability: resulting polarization: UFUFUFUF x 100 neV
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Hartmut Abele, University of Heidelberg 17 T. Soldner, A. Petoukhov, V. Nesvizhevsky, M. Kreuz
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Hartmut Abele, University of Heidelberg 18 The new Polarizer Munich, ILL, HD A new geometry for Beam polarization A perfectly polarized neutron beam Status 2002 Status 2004 98 % 100 % 96 % 100 % 90 % 95 % 94 % 96 % T. Soldner, A. Petoukhov, V. Nesvizhevsky, M. Kreuz
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Hartmut Abele, University of Heidelberg 19 Tools Fermipotential: -Matter 100 neV Neutron guides Wavelength filter Polarizer/Analyzer UCN -perfect mirror -neutron bottles UFUFUFUF x 100 neV
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Hartmut Abele, University of Heidelberg 20 The new Polarizer Munich, ILL, HD A new geometry for Beam polarization A perfectly polarized neutron beam Status 2002 Status 2004 98 % 100 % 96 % 100 % 90 % 95 % 94 % 96 %
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Hartmut Abele, University of Heidelberg 21 Rf Spin flipper Lab frame Rotating frame
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Hartmut Abele, University of Heidelberg 22 The Instrument
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Hartmut Abele, University of Heidelberg 23 1.3 Coefficient A: Spectrometer Perkeo II to beamstop precise electron spectroscopy Electron Neutron Spin Electron Neutron Spin A
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Hartmut Abele, University of Heidelberg 24 Principle: 2x2 - Detection two hemispheres backscattering suppression low background strong beam PF1: -count rate systematic Spectrometer Perkeo II zum beamstop precise electron spectroscopy = g A /g V
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Hartmut Abele, University of Heidelberg 25 Results Spectra Dissertation D. Mund, 2006
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Hartmut Abele, University of Heidelberg 26 Result Asymmetry A Dissertation D. Mund, 2006
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Hartmut Abele, University of Heidelberg 27 Beamrelated Background Collimation system < 0.15 s -1 Det. 0 Det. 1 Fitregion Electron- Spectrum Beamline BG
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Hartmut Abele, University of Heidelberg 28 2002: result: A = -0.1189(8) = -1.2739(19) 2006: result: A = -0.11948(40) = -1.2754(11)
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Hartmut Abele, University of Heidelberg 29 Collaboration PERKEOII 1995 - 2006 ILL Grenoble J. 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. Mainz S. Baeßler FZK F. Glück
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Hartmut Abele, University of Heidelberg 30
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Hartmut Abele, University of Heidelberg 31 Recommended value for lambda = -1.2750 0.0009
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Hartmut Abele, University of Heidelberg 32 1.4 A and A as a function of g A and g V Time reversal invariance, phase 180° v e = c, v = c, see Lecture at Black Board
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Hartmut Abele, University of Heidelberg 33
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Hartmut Abele, University of Heidelberg 34 Thesis Doehner 1991
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Hartmut Abele, University of Heidelberg 35
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Hartmut Abele, University of Heidelberg 36
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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: = g A /g V
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