View source for Physics:Photino

{{short description|Hypothetical superpartner of the photon}}
{{Infobox Particle
| bgcolour        =
| name            = Photino
| image           =
| caption         =
| num_types       =
| composition     = [[Physics:Elementary particle|Elementary particle]]
| statistics      = [[Physics:Fermion|Fermion]]ic
| group           = [[Physics:Fermion|Fermion]]
| generation      =
| interaction     = [[Physics:Electromagnetism|Electromagnetic]]
| particle        =
| antiparticle    =
| status          = Hypothetical
| theorized       =
| discovered      =
| symbol          = {{SubatomicParticle|Photino}}
| mass            =
| mean_lifetime   =
| decay_particle  =
| electric_charge = 0&nbsp;[[Physics:Elementary charge|''e'']]
| color_charge    =
| spin            = 1/2
}}

A '''photino''' is a hypothetical [[Physics:Subatomic particle|subatomic particle]], the [[Physics:Fermion|fermion]] [[Physics:Weakly interacting massive particles|WIMP]] superpartner of the [[Physics:Photon|photon]] predicted by [[Physics:Supersymmetry|supersymmetry]].<ref>{{cite journal |title=Tracking down the missing mass |journal=New Scientist |date=9 January 1986 |page=32 |url=https://books.google.com/books?id=Ri8kegHjaoYC&pg=PA32 |access-date=19 June 2020 |publisher=Reed Business Information |language=en}}</ref><ref>{{cite journal|title=Photinos from cosmic sources |first=V. J. |last=STENGER|volume=317|issue=6036|doi=10.1038/317411a0|journal=Nature|pages=411–413|bibcode=1985Natur.317..411S|year=1985|s2cid=4312378 }}</ref> It is an example of a [[Physics:Gaugino|gaugino]]. Even though no photino has ever been observed so far, it is one of the candidates for the lightest supersymmetric particle in the universe.<ref>{{cite journal |date=9 January 1986  |title=Tracking down the missing mass |url=https://books.google.com/books?id=Ri8kegHjaoYC&pg=PA32 | journal=New Scientist |issue=1490 |pages=32 |access-date=24 September 2015|last1= Information|first1= Reed Business}}</ref> It is proposed that photinos are produced by sources of ultra-high-energy cosmic rays.<ref>{{cite journal|last1=STENGER|first1=V. J.|title=Photinos from cosmic sources|journal=Nature|date=3 October 1985|volume=317|issue=6036|doi=10.1038/317411a0|pages=411–413|bibcode=1985Natur.317..411S|s2cid=4312378}}</ref>

==Photino numbers==
Photinos have a [[Physics:Lepton|lepton]] number 0, [[Physics:Baryon|baryon]] number 0, and [[Physics:Spin|spin]] 1/2. With an [[Physics:R-parity|R-parity]] of −1 it is a possible candidate for [[Astronomy:Dark matter|dark matter]].<ref>{{cite book |last1=Srednicki |first1=M. |title=Particle Physics and Cosmology: Dark Matter |date=2012 |publisher=Elsevier |isbn=978-0-444-59609-3 |page=283 |url=https://books.google.com/books?id=XI59041hwfMC&pg=PA283 |access-date=19 June 2020 |language=en}}</ref> It mixes with the superpartners of the [[Physics:Z boson|Z boson]] (zino) and the neutral higgs (higgsino) to form the [[Physics:Neutralino|neutralino]].

==See also==
{{div col|colwidth=35em}}
* {{annotated link|Physics:Supersymmetry}}
* {{annotated link|Physics:Photon}}
* {{annotated link|Physics:Dual photon}}
* {{annotated link|Physics:Electromagnetism}}
{{div col end}}

==References==
{{Reflist}}

{{Particles}}

[[Category:Hypothetical elementary particles]]



he:פוטינו

{{Sourceattribution|Photino}}