Saved in:
Bibliographic Details
Main Authors: Anholm, Melissa, Behr, J. A., Melconian, D. G., Gwinner, G., Gorelov, A., McNeil, J. C., Fenker, B., Behling, S.
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2509.11502
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915704707481600
author Anholm, Melissa
Behr, J. A.
Melconian, D. G.
Gwinner, G.
Gorelov, A.
McNeil, J. C.
Fenker, B.
Behling, S.
author_facet Anholm, Melissa
Behr, J. A.
Melconian, D. G.
Gwinner, G.
Gorelov, A.
McNeil, J. C.
Fenker, B.
Behling, S.
contents By extending our analysis and simulations of our $^{37}$K $β$-decay data set to allow the $β$ asymmetry with respect to nuclear spin to vary with $β$ energy $E_β$, we have gained sensitivity to new physics that depends on a helicity factor for the $β$, $m_β/E_β$. In particular, we constrain Lorentz scalar and tensor quark-lepton interaction strengths at a sensitivity complementary to the similar Fierz interference term in neutron $β$ decay. Our result for that new physics is a Fierz interference term $b$ = 0.033 $\pm$ 0.084 (stat) $\pm$ 0.039 (syst), consistent with the standard model electroweak interaction value $b=0$. We consider presently achieved complementarity to $β$-decay and particle physics experiments, along with projectable technical improvements to our method.
format Preprint
id arxiv_https___arxiv_org_abs_2509_11502
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle $A_β[E_β]$ in $^{37}$K decay: new physics with opposite $β$ helicity
Anholm, Melissa
Behr, J. A.
Melconian, D. G.
Gwinner, G.
Gorelov, A.
McNeil, J. C.
Fenker, B.
Behling, S.
Nuclear Experiment
High Energy Physics - Phenomenology
Nuclear Theory
By extending our analysis and simulations of our $^{37}$K $β$-decay data set to allow the $β$ asymmetry with respect to nuclear spin to vary with $β$ energy $E_β$, we have gained sensitivity to new physics that depends on a helicity factor for the $β$, $m_β/E_β$. In particular, we constrain Lorentz scalar and tensor quark-lepton interaction strengths at a sensitivity complementary to the similar Fierz interference term in neutron $β$ decay. Our result for that new physics is a Fierz interference term $b$ = 0.033 $\pm$ 0.084 (stat) $\pm$ 0.039 (syst), consistent with the standard model electroweak interaction value $b=0$. We consider presently achieved complementarity to $β$-decay and particle physics experiments, along with projectable technical improvements to our method.
title $A_β[E_β]$ in $^{37}$K decay: new physics with opposite $β$ helicity
topic Nuclear Experiment
High Energy Physics - Phenomenology
Nuclear Theory
url https://arxiv.org/abs/2509.11502