Preon star: Difference between revisions
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#REDIRECT [[Exotic star#Preon stars]] |
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A '''preon star'''<ref name="Phys.Lett.B616,1(2005"> |
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{{R from merge}} |
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{{cite journal |
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|last1=Hansson |first1=J |
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|last2=Sandin |first2=F |
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|date=2005 |
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|title=Preon stars: a new class of cosmic compact objects |
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|journal=[[Physics Letters B]] |
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|volume=616 |issue= 1-2|pages=1-7 |
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|arxiv=astro-ph/0410417 |
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|doi=10.1016/j.physletb.2005.04.034 |
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}}</ref> is a theoretical type of [[compact star]] made of [[preon]]s, which are [[point particle|"point-like" particles]] conceived to be subcomponents of [[quark]]s and [[lepton]]s.<ref>{{cite book|last1=D'Souza |first1=I.A.|last2=Kalman|first2=C.S.|year=1992|title=Preons: Models of Leptons, Quarks and Gauge Bosons as Composite Objects|publisher=[[World Scientific]]|isbn=978-981-02-1019-9}}</ref> Their existence was first theorized in |
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2005 by [[Fredrik Sandin]] and [[Johan Hansson (theorist)|Johan Hansson]], both from the [[Luleå University of Technology]], [[Sweden]].<ref name="b">{{cite news|last1=Dorminey|first1=Bruce|title=Focus: Nuggets of New Physics|url=https://physics.aps.org/story/v20/st18|accessdate=19 January 2017|work=Physics|date=20 November 2007}}</ref> The theory behind them was that the sub-subatomic particles would have come before subatomic particles, which came before particles, and that the original stars were made of these sub-subatomic particles, with most gradually becoming made of sub-particles, and then particles. However, the theory postulates that it is possible for some stars made of the sub-subatomic particles to remain.<ref>{{cite web|last1=Ball|first1=Philip|title=Splitting the quark|url=http://www.nature.com/news/2007/071130/full/news.2007.292.html|website=Nature News|accessdate=20 January 2017|language=en|doi=10.1038/news.2007.292|date=30 November 2007}}</ref> It is believed that they may also form out of massive stars that collapse too unstably to become neutron stars, but not enough to become black holes.<ref name="PDF"/> |
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==Properties== |
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The equation for the mass of a preon star is predicted to be: <math>M \sim 2 \times 10^{24} kg \left ( \frac{Te V}{\land} \right )^\tfrac{3}{2}</math>.<ref name="PDF">{{cite thesis |last= Sandin|first=Fredrik |date=2007 |title=Exotic Phases of Matter in Compact Stars|type= |chapter=1 |publisher=Luleå University of Technology |docket= |oclc= 185216905 |url=http://epubl.ltu.se/1402-1544/2007/05/LTU-DT-0705-SE.pdf |access-date=20 January 2017}}</ref> Where: |
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: {{var|M}} is the mass of the star. |
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: {{math|<math>{\land}</math>}} is the top quark compositeness energy scale. |
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: {{var|TeV}} is the number of tera-[[Electronvolt|electron volt]]s. |
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The equation for the radius of a preon star is estimated to be: <math>R \sim 3 \times 10^{-3} m \left ( \frac{Te V}{\land} \right )^\tfrac{3}{2}</math>.<ref name="PDF"/> Where: |
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: {{var|R}} is the radius of the star. |
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: {{math|<math>{\land}</math>}} is the top quark compositeness energy scale. |
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: {{var|TeV}} is the number of tera-[[Electronvolt|electron volt]]s. |
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The maximum mass of a preon star is predicted to be: <math> \sim 10^{2} M_\oplus</math>.<ref name="PDF"/> Where: |
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: {{var|<math>M_\oplus</math>}} is the mass of the earth. |
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The maximum radius of a preon star is predicted to be: <math>R \sim 1 m</math>.<ref name="PDF"/> |
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The average density of a preon star is predicted to be: <math> \sim 10^{23} g/cm^{3}</math>; however, the density of the center is predicted to be greater.<ref name="PDF"/> |
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If they exist, the eigenmode frequency for radial oscillations of a preon star will be 10<sup>6</sup> greater than that of a neutron star. As the radius will be roughly 10<sup>5</sup> smaller than the radius of a neutron star, if sound travels through preons at the same speed it does neutrons, then the frequency will be increased by 10<sup>5</sup>, giving [[GHz]] frequencies. If sound travels faster in preons than it does neutrons, the frequency cannot exceed <math> \sim 10^{8} m s^{-1} / 0.1m \eqsim 1 GHz</math> even if the speed of light is approached.<ref name="PDF"/> |
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The existence of preons could explain [[ultra-high-energy cosmic ray]]s, as no known type of star or object can project cosmic rays with as much energy as they have, going up to 10<sup>21</sup> eV. The possibility of a massive star collapsing and, being too unstable to collapse only to a pulsar star, collapsing all the way to a pulsar preon star with a radius of a meter and a mass of 100 earths, would allow pulsar yields of up to <math> \sim 10^{34} V/m </math>, which would be more than enough for an ultra-high-energy cosmic ray. It is believed that any preon star under the maximum mass will be stable.<ref name="PDF"/> |
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If preons exist, they, and by extension preon stars, will not perform [[nucleosynthesis]]. Nor will such stars emit [[Hawking radiation]]. It is believed that a preon star will have a large magnetic field, and rapid rotation.<ref name="PDF"/> |
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==Theory and evidence== |
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One of the reasons that the theory of preon stars has so few backers, is that the existence of preons would contradict not only the theory of the [[Higgs boson]], but also the [[Standard Model|Standard Model of Physics]].<ref>{{cite news|last1=Wilkins|first1=Alasdair|title=Stars so weird that they make black holes look boring|url=http://io9.gizmodo.com/5710012/quark-stars-and-strange-matter-a-guide-to-the-weirdest-stars-in-the-universe|accessdate=19 January 2017|work=io9}}</ref> As the Higgs boson was tentatively confirmed by [[CERN]], the prevailing theory at present is that preons' existence is impossible.<ref>{{cite web|last=O'Luanaigh |first=C.|date=14 March 2013|title=New results indicate that new particle is a Higgs boson|url=http://home.web.cern.ch/about/updates/2013/03/new-results-indicate-new-particle-higgs-boson|publisher=[[CERN]]|accessdate=19 January 2017}}</ref> The two methods that are used to try to find preons – [[gravitational femtolensing]] and searching for [[gravitational waves]] – have so far yielded nothing.<ref name="b"/> |
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Preons, if they exist, will be impossible to create even with the [[Large Hadron Collider]], as it would require conditions similar to those of the [[Big Bang]].<ref>{{cite web|title=The Odd Case of Preon Stars|url=http://www.dailygalaxy.com/my_weblog/2009/08/preons-splitting-the-quark-because-subatomic-physics-wasnt-complicated-enough.html|website=The Daily Galaxy --Great Discoveries Channel|accessdate=20 January 2017}}</ref> |
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==References== |
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{{reflist}} |
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{{Star}} |
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[[Category:Star types]] |
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[[Category:Hypothetical stars]] |
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