First strength measurements of low-energy resonances in the 45Sc(p,γ)46Ti reaction and its astrophysical implications
Abstract
The 45Sc(p,γ)46Ti reaction plays an important role in both hydrostatic and explosive nucleosynthesis. During hydrostatic oxygen and silicon burning in massive stars, including dynamic processes such as convective carbon-oxygen (C-O) shell mergers, it acts as a bottleneck that regulates the reaction flow in the Sc-Ti mass region. In oxygen-neon (ONe) novae, the ejecta indicate the production of elements up to the Fe group, as observed in V1974 Cygni, and the 45Sc(p,γ)46Ti reaction links nuclei above Ca to the Fe region. In core-collapse supernovae (CCSNe), it influences the production of the radioactive isotope 47Sc. At present, the thermonuclear reaction rate is based on statistical model calculations. In this work, we report on measurements of the 45Sc(p,γ)46Ti reaction performed using the 5~MV accelerator at the Nuclear Science Laboratory, University of Notre Dame, over a laboratory proton energy range of 526--1275~keV. We present the first direct measurements of the resonance strengths for six resonances at ElabR = 917.4, 1026.0, 1031.1, 1049.7, 1059.4 and 1257.5~keV, together with integrated resonance strengths at Elab = 555, 630, 700, 761 and 871~keV. For resonance energies below the lowest directly measured energy, available transfer-reaction data were used to estimate the resonance strengths. An updated thermonuclear reaction rate is derived, and its astrophysical implications are discussed.
Versions
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BibTeX
@misc{sidhu2026first,
title = {{First strength measurements of low-energy resonances in the $^45$Sc($p,γ$)$^46$Ti reaction and its astrophysical implications}},
author = {R. S. Sidhu and R. J. deBoer and J. Görres and M. Wiescher and W. N. Catford and C. Dembski and C. R. Jones and Ó. E. López-López and G. Lotay and K. Manukyan and M. Matney and J. O'Neill and J. Rufino and A. T. Sanchez and M. Williams and L. Zimmer},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.03284},
eprint = {2610.03284},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.03284},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - First strength measurements of low-energy resonances in the ^45Sc(p,γ)^46Ti reaction and its astrophysical implications
AU - R. S. Sidhu
AU - R. J. deBoer
AU - J. Görres
AU - M. Wiescher
AU - W. N. Catford
AU - C. Dembski
AU - C. R. Jones
AU - Ó. E. López-López
AU - G. Lotay
AU - K. Manukyan
AU - M. Matney
AU - J. O'Neill
AU - J. Rufino
AU - A. T. Sanchez
AU - M. Williams
AU - L. Zimmer
PY - 2026
DA - 2026/10/02
PB - arXiv
DO - 10.48550/arxiv.2610.03284
UR - https://arxiv.org/abs/2610.03284
AB - The ^45Sc(p,γ)^46Ti reaction plays an important role in both hydrostatic and explosive nucleosynthesis. During hydrostatic oxygen and silicon burning in massive stars, including dynamic processes such as convective carbon-oxygen (C-O) shell mergers, it acts as a bottleneck that regulates the reaction flow in the Sc-Ti mass region. In oxygen-neon (ONe) novae, the ejecta indicate the production of elements up to the Fe group, as observed in V1974 Cygni, and the ^45Sc(p,γ)^46Ti reaction links nuclei above Ca to the Fe region. In core-collapse supernovae (CCSNe), it influences the production of the radioactive isotope ^47Sc. At present, the thermonuclear reaction rate is based on statistical model calculations. In this work, we report on measurements of the ^45Sc(p,γ)^46Ti reaction performed using the 5~MV accelerator at the Nuclear Science Laboratory, University of Notre Dame, over a laboratory proton energy range of 526--1275~keV. We present the first direct measurements of the resonance strengths for six resonances at E^lab_R = 917.4, 1026.0, 1031.1, 1049.7, 1059.4 and 1257.5~keV, together with integrated resonance strengths at E^lab = 555, 630, 700, 761 and 871~keV. For resonance energies below the lowest directly measured energy, available transfer-reaction data were used to estimate the resonance strengths. An updated thermonuclear reaction rate is derived, and its astrophysical implications are discussed.
ER -