Journal Article

IMPULSE-2020-00149

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Measurement of the Weak Axial-Vector Coupling Constant in the Decay of Free Neutrons Using a Pulsed Cold Neutron Beam

Märkisch, B. (Corresponding author) ; Mest, H. ; Saul, H.MLZ* ; Wang, X.MLZ* ; Abele, H. ; Dubbers, D. ; Klopf, M. ; Petoukhov, A. ; Roick, C. ; Soldner, T. ; Werder, D.

2019
APS College Park, Md.

Please use a persistent id in citations: doi:10.1103/PhysRevLett.122.242501

Abstract: We present a precision measurement of the axial-vector coupling constantgAin the decay ofpolarized free neutrons. For the first time, a pulsed cold neutron beam was used for this purpose.By this method, leading sources of systematic uncertainty are suppressed. From the electron spectrawe obtainλ=gA/gV=−1.27641(45)stat(33)syswhich confirms recent measurements with improvedprecision. This corresponds to a value of the parity violating beta asymmetry parameter ofA0=−0.11985(17)stat(12)sys. We discuss implications on the CKM matrix elementVudand derive a limiton left-handed tensor interaction.

Keyword(s): Nuclei and Particles (1st) ; Particle Physics (2nd)

Note: This is NOT MEASURED at MEPHISTO!

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Contributing Institute(s):

1. Technische Universität München (TUM)

Experiment(s):

1. MEPHISTO: Facility for particle physics with cold neutrons (SR4b)

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; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; IF >= 5 ; JCR ; NCBI Molecular Biology Database ; Nationallizenz ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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