Reanalysis of the β - ν <overline> e Angular Correlation Measurement from the aSPECT Experiment with New Constraints on Fierz Interference

被引：4

作者：

Beck, M. ^{[1
]}

Heil, W. ^{[1
]}

Schmidt, Ch. ^{[1
]}

Baessler, S. ^{[2
,3
]}

Glueck, F. ^{[4
]}

Konrad, G. ^{[5
]}

Schmidt, U. ^{[6
]}

机构：

[1] Johannes Gutenberg Univ Mainz, Inst Phys, D-55128 Mainz, Germany

[2] Univ Virginia, Dept Phys, Charlottesville, VA 22904 USA

[3] Oak Ridge Natl Lab, Bethel Valley Rd, Oak Ridge, TN 37831 USA

[4] Karlsruhe Inst Technol KIT, Inst Astroteilchenphys IAP, D-76344 Eggenstein Leopoldshafen, Germany

[5] Tech Univ Wien, Atominstitut, A-1040 Vienna, Austria

[6] Ruprecht Karls Univ Heidelberg, Phys Inst, D-69120 Heidelberg, Germany

来源：

PHYSICAL REVIEW LETTERS | 2024年 / 132卷 / 10期

关键词：

HIGH-RESOLUTION; NEUTRON; SPECTROMETER; SIMULATION; ANGLES; IONS;

D O I：

10.1103/PhysRevLett.132.102501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

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 4 pi 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 (beta asymmetry) and aSPECT measurement which suggests a finite value of b with b((c)) = -0.0181 + 0.0065 deviating by 2.82 sigma from the standard model.

引用

页数：6