Analysis of $^{115}$In $β$ decay through the spectral moment method
Fuente:
arXiv
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866917670857736192 |
|---|---|
| author | Kostensalo, Joel Lisi, Eligio Marrone, Antonio Suhonen, Jouni |
| author_facet | Kostensalo, Joel Lisi, Eligio Marrone, Antonio Suhonen, Jouni |
| contents | We analyze the $^{115}$In $β$-decay energy spectrum through the spectral moment method (SMM), previously introduced in the context of $^{113}$Cd $β$ decay. The spectral moments $μ_n$ are defined as averaged $n^{\rm th}$ powers of the $β$ particle energy, characterizing the spectrum normalization ($n=0$) and shape ($n\geq 1$) above a given threshold. For $^{115}$In, we consider three independent datasets characterized by different thresholds. We also consider three nuclear model calculations with two free parameters: the ratio of axial-vector to vector couplings, $r=g_{\rm A}/g_{\rm V}$, and the small vector-like relativistic nuclear matrix element (NME), $s=s$-NME. By using the most recent of the three datasets, we show that the first few spectral moments can determine $(r,\, s)$ values in good agreement with those obtained by full-fledged experimental fits. We then work out the SMM results for the other datasets. We find that, although $g_{\rm A}$ quenching is generally favored, the preferred quenching factors may differ considerably depending on the chosen experimental data and nuclear models. We discuss various issues affecting both the overall normalization and the low-energy behaviour of the measured and computed spectra, and their joint effects on the experimentally quoted half-life values. Further $^{115}$In $β$-decay data at the lowest possible energy threshold appear to be crucial to clarify these issues. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2405_11920 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Analysis of $^{115}$In $β$ decay through the spectral moment method Kostensalo, Joel Lisi, Eligio Marrone, Antonio Suhonen, Jouni Nuclear Theory High Energy Physics - Experiment High Energy Physics - Phenomenology Nuclear Experiment We analyze the $^{115}$In $β$-decay energy spectrum through the spectral moment method (SMM), previously introduced in the context of $^{113}$Cd $β$ decay. The spectral moments $μ_n$ are defined as averaged $n^{\rm th}$ powers of the $β$ particle energy, characterizing the spectrum normalization ($n=0$) and shape ($n\geq 1$) above a given threshold. For $^{115}$In, we consider three independent datasets characterized by different thresholds. We also consider three nuclear model calculations with two free parameters: the ratio of axial-vector to vector couplings, $r=g_{\rm A}/g_{\rm V}$, and the small vector-like relativistic nuclear matrix element (NME), $s=s$-NME. By using the most recent of the three datasets, we show that the first few spectral moments can determine $(r,\, s)$ values in good agreement with those obtained by full-fledged experimental fits. We then work out the SMM results for the other datasets. We find that, although $g_{\rm A}$ quenching is generally favored, the preferred quenching factors may differ considerably depending on the chosen experimental data and nuclear models. We discuss various issues affecting both the overall normalization and the low-energy behaviour of the measured and computed spectra, and their joint effects on the experimentally quoted half-life values. Further $^{115}$In $β$-decay data at the lowest possible energy threshold appear to be crucial to clarify these issues. |
| title | Analysis of $^{115}$In $β$ decay through the spectral moment method |
| topic | Nuclear Theory High Energy Physics - Experiment High Energy Physics - Phenomenology Nuclear Experiment |
| url | https://arxiv.org/abs/2405.11920 |