Editing Dark matter (section)

==== Undiscovered massive particles ====
{{main|Weakly Interacting Massive Particles}}
There exists no formal definition of a Weakly Interacting Massive Particle, but broadly, it is an [[elementary particle]] which interacts via [[gravity]] and any other force (or forces) which is as weak as or weaker than the [[weak nuclear force]], but also non-vanishing in strength. Many WIMP candidates are expected to have been produced thermally in the early Universe, similarly to the particles of the Standard Model<ref>{{cite journal | last = Garrett | first = Katherine | title = Dark matter: A primer | year = 2010 | journal = Advances in Astronomy | volume = 2011 | issue = 968283 | pages = 1–22 | doi = 10.1155/2011/968283| arxiv = 1006.2483 | bibcode = 2011AdAst2011E...8G | doi-access = free }}</ref> according to [[Big Bang]] cosmology, and usually will constitute [[cold dark matter]]. Obtaining the correct abundance of dark matter today via [[thermal production]] requires a self-[[annihilation]] [[Cross section (physics)|cross section]] of <math>\langle \sigma v \rangle</math> ≃ {{val|3|e=-26|u=cm<sup>3</sup>⋅s<sup>−1</sup>}}, which is roughly what is expected for a new particle in the 100&nbsp;[[GeV]]/''c''<sup>2</sup> mass range that interacts via the [[electroweak force]].

Because [[supersymmetry|supersymmetric]] extensions of the Standard Model of particle physics readily predict a new particle with these properties, this apparent coincidence is known as the "'''WIMP miracle'''", and a stable supersymmetric partner has long been a prime explanation for dark matter.<ref>{{cite journal |last1=Jungman |first1=Gerard |last2=Kamionkowski |first2=Marc |last3=Griest |first3=Kim |year=1996 |title=Supersymmetric dark matter |journal=Physics Reports |volume=267 |issue=5–6 |pages=195–373 |s2cid=119067698 |arxiv=hep-ph/9506380 |bibcode=1996PhR...267..195J |doi=10.1016/0370-1573(95)00058-5}}</ref> Experimental efforts to detect WIMPs include the search for products of WIMP annihilation, including [[gamma ray]]s, [[neutrino]]s and [[cosmic ray]]s in nearby galaxies and galaxy clusters; direct detection experiments designed to measure the collision of WIMPs with [[Atomic nucleus|nuclei]] in the laboratory, as well as attempts to directly produce WIMPs in colliders, such as the [[Large Hadron Collider]] at [[CERN]]. 

In the early 2010s, results from [[#Direct detection|direct-detection]] experiments along with the lack of evidence for supersymmetry at the [[Large Hadron Collider]] (LHC) experiment<ref>{{cite news |url=http://news.discovery.com/space/lhc-discovery-maims-supersymmetry-again-130724.htm |title=LHC discovery maims supersymmetry again |website=Discovery News}}</ref><ref>{{cite arXiv |last=Craig |first=Nathaniel |year=2013 |title=The State of Supersymmetry after Run I of the LHC |class=hep-ph  |eprint=1309.0528}}</ref> have cast doubt on the simplest WIMP hypothesis.<ref>{{cite journal |last1=Fox |first1=Patrick J. |last2=Jung |first2=Gabriel |last3=Sorensen |first3=Peter |last4=Weiner |first4=Neal |year=2014 |title=Dark matter in light of LUX |journal=Physical Review D |volume=89 |issue=10 |page=103526 |arxiv=1401.0216 |bibcode=2014PhRvD..89j3526F |doi=10.1103/PhysRevD.89.103526}}</ref>