Saved in:
Bibliographic Details
Main Authors: Budner, Tamas, Friedman, Moshe, Sun, Lijie, Wrede, Christopher, Brown, B. Alex, Pérez-Loureiro, David, Surbrook, Jason, Adams, Alexander, Ayyad, Yassid, Bardayan, Daniel W., Chae, Kyungyuk, Chen, Alan A., Chipps, Kelly A., Cortesi, Marco, Glassman, Brent, Hall, Matthew R., Janasik, Molly, Liang, Johnson, O'Malley, Patrick, Pollacco, Emanuel, Psaltis, Athanasios, Stomps, Jordan, Wheeler, Tyler
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.04456
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913103345614848
author Budner, Tamas
Friedman, Moshe
Sun, Lijie
Wrede, Christopher
Brown, B. Alex
Pérez-Loureiro, David
Surbrook, Jason
Adams, Alexander
Ayyad, Yassid
Bardayan, Daniel W.
Chae, Kyungyuk
Chen, Alan A.
Chipps, Kelly A.
Cortesi, Marco
Glassman, Brent
Hall, Matthew R.
Janasik, Molly
Liang, Johnson
O'Malley, Patrick
Pollacco, Emanuel
Psaltis, Athanasios
Stomps, Jordan
Wheeler, Tyler
author_facet Budner, Tamas
Friedman, Moshe
Sun, Lijie
Wrede, Christopher
Brown, B. Alex
Pérez-Loureiro, David
Surbrook, Jason
Adams, Alexander
Ayyad, Yassid
Bardayan, Daniel W.
Chae, Kyungyuk
Chen, Alan A.
Chipps, Kelly A.
Cortesi, Marco
Glassman, Brent
Hall, Matthew R.
Janasik, Molly
Liang, Johnson
O'Malley, Patrick
Pollacco, Emanuel
Psaltis, Athanasios
Stomps, Jordan
Wheeler, Tyler
contents Positron decays of proton-rich nuclides exhibit large $Q$ values, producing complex cascades which often involve various radiations, including protons and $γ$ rays. Often, only one of the two are measured in a single experiment, limiting the accuracy and completeness of the decay scheme. An example is $^{31}$Cl, for which protons and $γ$ rays have been measured in detail individually but never with substantial sensitivity to proton-$γ$ coincidences. The purpose of this work is to provide detailed measurements of $^{31}$Cl $β$-delayed proton decay including $β$-$p$-$γ$ sequences, extract spectroscopic information on $^{31}$S excited states as well as their $β$ feeding, and compare to shell-model calculations. A fast, fragmented beam of $^{31}$Cl provided was deposited in the Gaseous Detector with Germanium Tagging (GADGET) system. GADGET's gas-filled Proton Detector was used to detect $β$-delayed protons, and the Segmented Germanium Array (SeGA) was used to detect $β$-delayed $γ$ rays. Up to 20 previously unobserved $β$-delayed proton transitions have been discovered, most of which populate excited states of $^{30}$P. Here present the first detailed $^{31}$Cl($βp γ$)$^{30}$P decay scheme and find improved agreement with theoretical calculations of the Gamow-Teller strength distribution for $^{31}$S excitation energies $7.5 < E_x < 9.5$ MeV. The present work demonstrates that the capability to detect $β$-delayed protons and $γ$ rays in coincidence is essential to construct accurate positron decay schemes for comparison to theoretical nuclear structure calculations. In some respects, this phenomenon for $β$-delayed protons resembles the pandemonium effect originally introduced for $β$-delayed $γ$ rays.
format Preprint
id arxiv_https___arxiv_org_abs_2510_04456
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle $β$-Delayed Proton Pandemonium: A first look at the $^{31}$Cl($βp γ$)$^{30}$P decay scheme
Budner, Tamas
Friedman, Moshe
Sun, Lijie
Wrede, Christopher
Brown, B. Alex
Pérez-Loureiro, David
Surbrook, Jason
Adams, Alexander
Ayyad, Yassid
Bardayan, Daniel W.
Chae, Kyungyuk
Chen, Alan A.
Chipps, Kelly A.
Cortesi, Marco
Glassman, Brent
Hall, Matthew R.
Janasik, Molly
Liang, Johnson
O'Malley, Patrick
Pollacco, Emanuel
Psaltis, Athanasios
Stomps, Jordan
Wheeler, Tyler
Nuclear Experiment
Nuclear Theory
Positron decays of proton-rich nuclides exhibit large $Q$ values, producing complex cascades which often involve various radiations, including protons and $γ$ rays. Often, only one of the two are measured in a single experiment, limiting the accuracy and completeness of the decay scheme. An example is $^{31}$Cl, for which protons and $γ$ rays have been measured in detail individually but never with substantial sensitivity to proton-$γ$ coincidences. The purpose of this work is to provide detailed measurements of $^{31}$Cl $β$-delayed proton decay including $β$-$p$-$γ$ sequences, extract spectroscopic information on $^{31}$S excited states as well as their $β$ feeding, and compare to shell-model calculations. A fast, fragmented beam of $^{31}$Cl provided was deposited in the Gaseous Detector with Germanium Tagging (GADGET) system. GADGET's gas-filled Proton Detector was used to detect $β$-delayed protons, and the Segmented Germanium Array (SeGA) was used to detect $β$-delayed $γ$ rays. Up to 20 previously unobserved $β$-delayed proton transitions have been discovered, most of which populate excited states of $^{30}$P. Here present the first detailed $^{31}$Cl($βp γ$)$^{30}$P decay scheme and find improved agreement with theoretical calculations of the Gamow-Teller strength distribution for $^{31}$S excitation energies $7.5 < E_x < 9.5$ MeV. The present work demonstrates that the capability to detect $β$-delayed protons and $γ$ rays in coincidence is essential to construct accurate positron decay schemes for comparison to theoretical nuclear structure calculations. In some respects, this phenomenon for $β$-delayed protons resembles the pandemonium effect originally introduced for $β$-delayed $γ$ rays.
title $β$-Delayed Proton Pandemonium: A first look at the $^{31}$Cl($βp γ$)$^{30}$P decay scheme
topic Nuclear Experiment
Nuclear Theory
url https://arxiv.org/abs/2510.04456