Nuclear Astrophysics of Worlds in the String Landscape Export

@misc{citeulike:873547, abstract = {Motivated by landscape models in string theory, cosmic nuclear evolution is analyzed allowing the Standard Model Higgs expectation value w to take values different from that in our world (w= 1), while holding the Yukawa couplings fixed. Major thresholds in w are estimated, and astrophysical consequences are described, associated with changes in nuclear stability and key reactions. The dependence of the neutron-proton mass difference on w is estimated based on recent calculations of strong isospin symmetry breaking, and is used to derive the threshold of neutron-stable worlds, w \~{} 0.6+/- 0.2. The effect of a stable neutron on nuclear evolution in the Big Bang and stars is shown to lead to radical differences from our world, such as a predominance of heavy r-process and s-process nuclei and a lack of normal galaxies, stars and planets. Rough estimates are reviewed of w thresholds for pp and pep reactions, and deuteron stability. A simple model of nuclear resonances is used to estimate the w dependence of overall carbon and oxygen production during stellar nucleosynthesis; carbon production is estimated to change by a fraction \~{}15(1-w). Radical changes in astrophysical behavior seem to require changes in w of more than a few percent, even for the most sensitive phenomena.}, archivePrefix = {arXiv}, author = {Hogan, Craig J.}, citeulike-article-id = {873547}, citeulike-linkout-0 = {http://arxiv.org/abs/astro-ph/0602104}, citeulike-linkout-1 = {http://arxiv.org/pdf/astro-ph/0602104}, day = {23}, eprint = {astro-ph/0602104}, keywords = {anthropic, astrophysics}, month = {Sep}, posted-at = {2006-09-26 13:41:01}, priority = {2}, title = {Nuclear Astrophysics of Worlds in the String Landscape}, url = {http://arxiv.org/abs/astro-ph/0602104}, year = {2006} }

TY - ELEC ID - citeulike:873547 L3 - citeulike-article-id:873547 N2 - Motivated by landscape models in string theory, cosmic nuclear evolution is analyzed allowing the Standard Model Higgs expectation value w to take values different from that in our world (w= 1), while holding the Yukawa couplings fixed. Major thresholds in w are estimated, and astrophysical consequences are described, associated with changes in nuclear stability and key reactions. The dependence of the neutron-proton mass difference on w is estimated based on recent calculations of strong isospin symmetry breaking, and is used to derive the threshold of neutron-stable worlds, w ~ 0.6+/- 0.2. The effect of a stable neutron on nuclear evolution in the Big Bang and stars is shown to lead to radical differences from our world, such as a predominance of heavy r-process and s-process nuclei and a lack of normal galaxies, stars and planets. Rough estimates are reviewed of w thresholds for pp and pep reactions, and deuteron stability. A simple model of nuclear resonances is used to estimate the w dependence of overall carbon and oxygen production during stellar nucleosynthesis; carbon production is estimated to change by a fraction ~15(1-w). Radical changes in astrophysical behavior seem to require changes in w of more than a few percent, even for the most sensitive phenomena. TI - Nuclear Astrophysics of Worlds in the String Landscape KW - anthropic KW - astrophysics AU - Hogan, Craig PY - 2006/Sep/23/ UR - http://arxiv.org/abs/astro-ph/0602104 ER -