Reanalysis of the ß-ν[over ¯]_{e} Angular Correlation Measurement from the aSPECT Experiment with New Constraints on Fierz Interference.
Phys Rev Lett
; 132(10): 102501, 2024 Mar 08.
Article
em En
| MEDLINE
| ID: mdl-38518336
ABSTRACT
On the basis of revisions of some of the systematic errors, we reanalyzed the electron-antineutrino angular correlation (a coefficient) in free neutron decay inferred from the recoil energy spectrum of the protons which are detected in 4π by the aSPECT spectrometer. With a=-0.104 02(82) the new value differs only marginally from the one published in 2020. The experiment also has sensitivity to b, the Fierz interference term. From a correlated (b,a) fit to the proton recoil spectrum, we derive a limit of b=-0.0098(193) which translates into a somewhat improved 90% confidence interval region of -0.041≤b≤0.022 on this hypothetical term. Tighter constraints on b can be set from a combined [shown as superscript (c)] analysis of the PERKEO III (ß asymmetry) and aSPECT measurement which suggests a finite value of b with b^{(c)}=-0.0181±0.0065 deviating by 2.82σ from the standard model.
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01-internacional
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MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Ano de publicação:
2024
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Article