{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/32122"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/32122","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Weak interactions in nucleon matter","abstract":"Open","abstract_html":"Open","abstract_has_math":false,"creators":["Cowell, Shannon Tracy"],"institution":null,"degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Physics","degree_department":null,"school":null,"contributors":["Pandharipande, V.R."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2012,"date_issued":"2012-07-05T22:56:34Z","date_published":"2012-07-05T22:56:34Z","updated_at":"2026-07-22T22:25:30Z","subjects":["hot asymmetric nucleon matter","core-collapse supernovae","neutrino interactions","non- interacting Fermi gas"],"languages":["en"],"rights":["©2004 Cowell"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["Q. 539.75 Tc4c","FILM 2004 C8389"],"render_values":[{"text":"Q. 539.75 Tc4c","href":null,"code":true},{"text":"FILM 2004 C8389","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/32122","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Pandharipande, V.R."]},{"key":"dc:creator","label":"Author","values":["Cowell, Shannon Tracy"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2012-07-05T22:56:34Z","2004"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation / Thesis","text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Physics"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["hot asymmetric nucleon matter","core-collapse supernovae","neutrino interactions","non- interacting Fermi gas"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["©2004 Cowell"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["Q. 539.75 Tc4c","FILM 2004 C8389","http://hdl.handle.net/2142/32122"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Open","Neutrino interactions play a crucial role in many astrophysical environments such as core-collapse supernovae and neutron stars. In this work, reaction rates for neutrino emission, absorption and scattering are calculated in hot asymmetric nucleon matter at densities relevant to core-collapse supernovae. We derive a consistent set of effective interactions and effective operators starting from realistic forces using correlated basis theory. These effective interactions and operators are used to calculate weak interaction rates in matter in correlated Hartree-Fock and correlated Tamm-Dancoff approximations. In general, interactions increase the range of energy transfers and shift the strength of the response to larger energy transfers as compared to non-interacting Fermi gas. In addition, at small momentum transfers, the square of the nuclear matrix element of the charge changing weak operators are quenched 20 to 25% by short-range correlations in nucleon matter. These modifications to the nuclear response significantly alter the neutrino reaction rates as compared to a non-interacting Fermi gas. At the temperature and proton fraction considered, electron capture and neutrino scattering rates are ~ 2-4 times smaller than the rates obtained for a non-interacting Fermi gas. Neutrino absorption rates in matter are reduced by Pauli blocking. However, strong interactions enhance the reaction rate, particularly at small neutrino energies. The neutrino reaction rates at equilibrium density are also calculated in the Tamm-Dancoff approximation using zero-range effective interactions with parameters chosen to reproduce the equation of state and spin-isospin susceptibilities of matter. Many modern calculations of neutrino reaction rates use this kind of effective interaction and neglect the effects of short range correlations on the nuclear matrix elements of weak operators. This treatment is inconsistent and our results indicate that reaction rates calculated in this simple approximation may be considerably overestimated.","Submitted by Rachelle Ramer (rramer2@illinois.edu) on 2012-07-05T22:56:34Z No. of bitstreams: 1 Cowell.pdf: 1586811 bytes, checksum: f6db44da5eb671e6718cdfa0b2dc47c4 (MD5)","Made available in DSpace on 2012-07-05T22:56:34Z (GMT). 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In this work, reaction rates for neutrino emission, absorption and scattering are calculated in hot asymmetric nucleon matter at densities relevant to core-collapse supernovae. We derive a consistent set of effective interactions and effective operators starting from realistic forces using correlated basis theory. These effective interactions and operators are used to calculate weak interaction rates in matter in correlated Hartree-Fock and correlated Tamm-Dancoff approximations. In general, interactions increase the range of energy transfers and shift the strength of the response to larger energy transfers as compared to non-interacting Fermi gas. In addition, at small momentum transfers, the square of the nuclear matrix element of the charge changing weak operators are quenched 20 to 25% by short-range correlations in nucleon matter. These modifications to the nuclear response significantly alter the neutrino reaction rates as compared to a non-interacting Fermi gas. At the temperature and proton fraction considered, electron capture and neutrino scattering rates are ~ 2-4 times smaller than the rates obtained for a non-interacting Fermi gas. Neutrino absorption rates in matter are reduced by Pauli blocking. However, strong interactions enhance the reaction rate, particularly at small neutrino energies. The neutrino reaction rates at equilibrium density are also calculated in the Tamm-Dancoff approximation using zero-range effective interactions with parameters chosen to reproduce the equation of state and spin-isospin susceptibilities of matter. Many modern calculations of neutrino reaction rates use this kind of effective interaction and neglect the effects of short range correlations on the nuclear matrix elements of weak operators. This treatment is inconsistent and our results indicate that reaction rates calculated in this simple approximation may be considerably overestimated.","Submitted by Rachelle Ramer (rramer2@illinois.edu) on 2012-07-05T22:56:34Z No. of bitstreams: 1 Cowell.pdf: 1586811 bytes, checksum: f6db44da5eb671e6718cdfa0b2dc47c4 (MD5)","Made available in DSpace on 2012-07-05T22:56:34Z (GMT). No. of bitstreams: 1 Cowell.pdf: 1586811 bytes, checksum: f6db44da5eb671e6718cdfa0b2dc47c4 (MD5) Previous issue date: 2004","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Rachelle Ramer (rramer2@illinois.edu) on 2012-07-05T22:56:34Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:34:32-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: thesis/dissertation","Open Restriction set for Item 32392 on 2019-04-09T15:46:11Z with date null by fschaef2@illinois.edu.","Open Restriction set for Item 32392 on 2019-04-09T15:46:13Z with date null by fschaef2@illinois.edu.","Open Restriction set for Item 32392 on 2019-04-09T15:46:22Z with date null by fschaef2@illinois.edu.","Open Restriction set for Item 32392 on 2019-04-09T15:46:24Z with date null by fschaef2@illinois.edu.","Open Restriction set for Item 32392 on 2019-04-09T15:46:32Z with date null by fschaef2@illinois.edu.","Open Restriction set for Item 32392 on 2019-04-09T15:46:36Z with date null by fschaef2@illinois.edu."],"dc:identifier":["Q. 539.75 Tc4c","FILM 2004 C8389","http://hdl.handle.net/2142/32122"],"dc:language":["en"],"dc:rights":["©2004 Cowell"],"dc:subject":["hot asymmetric nucleon matter","core-collapse supernovae","neutrino interactions","non- interacting Fermi gas"],"dc:title":["Weak interactions in nucleon matter"],"dc:type":["Dissertation / Thesis","text"],"thesis:degree_discipline":["Physics"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."]},"updated_at":"2026-07-22T22:25:30Z"}