Nuclear Theory·nucl-th

Thursday·May 5, 2022

8 papers—6 primary·2 cross-listed

07
[Submitted on 4 May 2022] (cross-list from nucl-ex)
Improved Limit on Tensor Currents in the Weak Interaction from $^{8}$ Li $β$ Decay
M. T. Burkey · G. Savard · A. T. Gallant · N. D. Scielzo · T. Y. Hirsh · L. Varriano · G. H. Sargsyan · K. D. Launey · M. Brodeur · D. P. Burdette · E. Heckmaier · K. Joerres and 19 other authors
The electroweak interaction in the Standard Model (SM) is described by a pure vector-axial-vector structure, though any Lorentz-invariant component could contribute. In this work, we present the most precise measurement of tensor currents in the low-energy regime by examining the $β$ - $ν ˉ$ correlation of trapped $^{8}$ Li ions with the Beta-decay Paul Trap. We find $a_{β ν} = - 0.3325 \pm 0.001 3_{s t a t} \pm 0.001 9_{sy s t}$ at $1 σ$ for the case of coupling to right-handed neutrinos $(C_{T} = - C_{T}^{'})$ , which is consistent with the SM prediction.
Comments:
6 pages, 3 figures, 1 table
Subjects:
Nuclear Experiment (nucl-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2205.01865 [pdf]
PRL(2022)·38 citations
08
[Submitted on 4 May 2022] (cross-list from hep-ph)
Constraints on the dark photon from parity violation and the $W$ mass
A. W. Thomas🇦🇺 · X. G. Wang🇦🇺
We present an analysis of the experimental data for parity-violating electron scattering (PVES) and atomic parity-violation, including the effects of a dark photon. We derive the favored region of dark photon parameter space, which provides a good description of the experimental data from the Qweak Collaboration and the Jefferson Lab PVDIS Collaboration and simultaneously relieves the tension between the neutron skin thickness determined in the PREX-II experiment and nuclear-model predictions. In addition, we extract the parameter region required to explain the latest W-boson mass anomaly. Our results indicate that a heavy dark photon with mass above the Z boson mass is favored, while other sources of new physics beyond the Standard Model in addition to the dark photon would also be expected.
Comments:
6 pages, 1 table, 1 figure. The fit result is updated. More references are added
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2205.01911 [pdf]
PRD(2022)·28 citations

Affiliations

first authorsco-authorsvia INSPIRE

Improved Limit on Tensor Currents in the Weak Interaction from 8Li β Decay

Constraints on the dark photon from parity violation and the W mass

Affiliations

Improved Limit on Tensor Currents in the Weak Interaction from $^{8}$ Li $β$ Decay

Constraints on the dark photon from parity violation and the $W$ mass