$^{57}$Zn $\beta$-delayed proton emission establishes the $^{56}$Ni $rp$-process waiting point bypass
Language
en
Article de revue
This item was published in
Phys.Lett.B. 2022, vol. 829, p. 137059
English Abstract
•In our letter, we address the dominant uncertainty regarding the extent of the rp-process flow bypass around <math altimg="si1.svg"><mmultiscripts><mrow><mi mathvariant="normal">Ni</mi></mrow><mprescripts/><none/><mrow> ...Read more >
•In our letter, we address the dominant uncertainty regarding the extent of the rp-process flow bypass around <math altimg="si1.svg"><mmultiscripts><mrow><mi mathvariant="normal">Ni</mi></mrow><mprescripts/><none/><mrow><mn>56</mn></mrow></mmultiscripts></math> waiting point for astrophysical conditions relevant to Type-1 X-ray bursts.•We removed the final significant uncertainty, the beta-delayed proton branching ratio for <math altimg="si13.svg"><mmultiscripts><mrow><mi mathvariant="normal">Zn</mi></mrow><mprescripts/><none/><mrow><mn>57</mn></mrow></mmultiscripts></math>, definitively determining that there is a <math altimg="si1.svg"><mmultiscripts><mrow><mi mathvariant="normal">Ni</mi></mrow><mprescripts/><none/><mrow><mn>56</mn></mrow></mmultiscripts></math> bypass.•In addition, we also identified the second case of the exotic <math altimg="si3.svg"><mi>β</mi><mo linebreak="goodbreak" linebreakstyle="after">−</mo><mi>γ</mi><mo linebreak="goodbreak" linebreakstyle="after">−</mo><mi>p</mi></math> decay mode in the fp-shell. We measured the <math altimg="si13.svg"><mmultiscripts><mrow><mi mathvariant="normal">Zn</mi></mrow><mprescripts/><none/><mrow><mn>57</mn></mrow></mmultiscripts></math>β-delayed proton (βp) and γ emission at the National Superconducting Cyclotron Laboratory. We find a <math altimg="si13.svg"><mmultiscripts><mrow><mi mathvariant="normal">Zn</mi></mrow><mprescripts/><none/><mrow><mn>57</mn></mrow></mmultiscripts></math> half-life of <math altimg="si4.svg"><mn>43.6</mn><mo>±</mo><mn>0.2</mn></math> ms, βp branching ratio of <math altimg="si5.svg"><mo stretchy="false">(</mo><mn>84.7</mn><mo>±</mo><mn>1.4</mn><mo stretchy="false">)</mo><mtext>%</mtext></math>, and identify four transitions corresponding to the exotic β-γ-p decay mode, the second such identification in the fp-shell. The p/γ ratio was used to correct for isospin mixing while determining the <math altimg="si13.svg"><mmultiscripts><mrow><mi mathvariant="normal">Zn</mi></mrow><mprescripts/><none/><mrow><mn>57</mn></mrow></mmultiscripts></math> mass via the isobaric multiplet mass equation. Previously, it was uncertain as to whether the rp-process flow could bypass the textbook waiting point <math altimg="si1.svg"><mmultiscripts><mrow><mi mathvariant="normal">Ni</mi></mrow><mprescripts/><none/><mrow><mn>56</mn></mrow></mmultiscripts></math> for astrophysical conditions relevant to Type-I X-ray bursts. Our results definitively establish the existence of the <math altimg="si1.svg"><mmultiscripts><mrow><mi mathvariant="normal">Ni</mi></mrow><mprescripts/><none/><mrow><mn>56</mn></mrow></mmultiscripts></math> bypass, with 14-17% of the rp-process flow taking this route.Read less <
English Keywords
Type-1 X-ray bursts
Waiting-point
-decay measurement of proton rich isotope
Type-1 X-ray bursts
Origin
Hal imported