Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction

Neutrino-induced reactions are a basic ingredient in astrophysical processes like star evolution. The existence of neutrino oscillations affects the rate of nuclear electroweak decays which participates in the chain of events that determines the fate of the star. Among the processes of interest, the...

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Detalles Bibliográficos
Autores principales: Saez, M. M., Civitarese, Enrique Osvaldo, Mosquera, Mercedes Elisa
Formato: Articulo Preprint
Lenguaje:Inglés
Publicado: 2018
Materias:
Astronomía
Física
Sterile neutrino
Supernova
R-process
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/98314
https://ri.conicet.gov.ar/11336/86308
https://www.worldscientific.com/doi/10.1142/S021827181850116X
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-98314
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Astronomía
Física
Sterile neutrino
Supernova
R-process
spellingShingle Astronomía
Física
Sterile neutrino
Supernova
R-process
Saez, M. M.
Civitarese, Enrique Osvaldo
Mosquera, Mercedes Elisa
Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
topic_facet Astronomía
Física
Sterile neutrino
Supernova
R-process
description Neutrino-induced reactions are a basic ingredient in astrophysical processes like star evolution. The existence of neutrino oscillations affects the rate of nuclear electroweak decays which participates in the chain of events that determines the fate of the star. Among the processes of interest, the production of heavy elements in core-collapse supernovae is strongly dependent upon neutrino properties, like the mixing between different species of neutrinos. In this work, we study the effects of neutrino oscillations upon the electron fraction as a function of the neutrino mixing parameters, for two schemes: the 1+1-scheme (one active neutrino and one sterile neutrino) and the 2+1-scheme (two active neutrinos and one sterile neutrino). We have performed this analysis considering a core-collapse supernovae and determined the physical conditions needed to activate the nuclear reaction chains involved in the r-process. We found that the interactions of the neutrinos with matter and among themselves and the initial amount of sterile neutrinos in the neutrino-sphere might change the electron fraction, therefore affecting the onset of the r-process. We have set constrains on the active-sterile neutrino mixing parameters. They are the square-mass-difference <math display="inline" overflow="scroll" altimg="eq-00003.gif"><mi mathvariant="normal">Δ</mi><msubsup><mrow><mi>m</mi></mrow><mrow><mn>1</mn><mn>4</mn></mrow><mrow><mn>2</mn></mrow></msubsup></math> , the mixing angle <math display="inline" overflow="scroll" altimg="eq-00004.gif"><msup><mrow><mo class="qopname">sin</mo></mrow><mrow><mn>2</mn></mrow></msup><mn>2</mn><msub><mrow><mi> </mi></mrow><mrow><mn>1</mn><mn>4</mn></mrow></msub></math>, and the hindrance factor <math display="inline" overflow="scroll" altimg="eq-00005.gif"><msub><mrow><mi>ξ</mi></mrow><mrow><mi>s</mi></mrow></msub></math> for the occupation of sterile neutrinos. The calculations have been performed for different values of <math display="inline" overflow="scroll" altimg="eq-00006.gif"><msub><mrow><mi>X</mi></mrow><mrow><mi>α</mi></mrow></msub></math>, which is the fraction of alpha particles. For <math display="inline" overflow="scroll" altimg="eq-00008.gif"><msub><mrow><mi>X</mi></mrow><mrow><mi>α</mi></mrow></msub><mo class="MathClass-rel">=</mo><mn>0</mn></math> the r-process is taking place if <math display="inline" overflow="scroll" altimg="eq-00009.gif"><mi mathvariant="normal">Δ</mi><msubsup><mrow><mi>m</mi></mrow><mrow><mn>1</mn><mn>4</mn></mrow><mrow><mn>2</mn></mrow></msubsup><mo class="MathClass-rel">≥</mo><mn>2</mn><mspace width=".17em" class="thinspace"></mspace><msup><mrow><mstyle><mtext class="textrm" mathvariant="normal">eV</mtext></mstyle></mrow><mrow><mn>2</mn></mrow></msup></math>, <math display="inline" overflow="scroll" altimg="eq-00010.gif"><msup><mrow><mo class="qopname">sin</mo></mrow><mrow><mn>2</mn></mrow></msup><mn>2</mn><msub><mrow><mi> </mi></mrow><mrow><mn>1</mn><mn>4</mn></mrow></msub><mo class="MathClass-rel"><</mo><mn>0</mn><mo class="MathClass-punc">.</mo><mn>8</mn></math> and <math display="inline" overflow="scroll" altimg="eq-00011.gif"><msub><mrow><mi>ξ</mi></mrow><mrow><mi>s</mi></mrow></msub><mo class="MathClass-rel"><</mo><mn>0</mn><mo class="MathClass-punc">.</mo><mn>5</mn></math>. For larger values of <math display="inline" overflow="scroll" altimg="eq-00012.gif"><msub><mrow><mi>X</mi></mrow><mrow><mi>α</mi></mrow></msub></math> the region of parameters is strongly reduced. The present results are compared to results available in the literature.
format Articulo
Preprint
author Saez, M. M.
Civitarese, Enrique Osvaldo
Mosquera, Mercedes Elisa
author_facet Saez, M. M.
Civitarese, Enrique Osvaldo
Mosquera, Mercedes Elisa
author_sort Saez, M. M.
title Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
title_short Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
title_full Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
title_fullStr Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
title_full_unstemmed Neutrino-induced reactions in core-collapse supernovae : Effects on the electron fraction
title_sort neutrino-induced reactions in core-collapse supernovae : effects on the electron fraction
publishDate 2018
url http://sedici.unlp.edu.ar/handle/10915/98314
https://ri.conicet.gov.ar/11336/86308
https://www.worldscientific.com/doi/10.1142/S021827181850116X
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AT civitareseenriqueosvaldo neutrinoinducedreactionsincorecollapsesupernovaeeffectsontheelectronfraction
AT mosqueramercedeselisa neutrinoinducedreactionsincorecollapsesupernovaeeffectsontheelectronfraction
bdutipo_str Repositorios
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