Editing Weakly interacting massive particle (section)

== Theoretical framework and properties ==
WIMP-like particles are predicted by [[R-parity]]-conserving [[supersymmetry]], a type of extension to the [[Standard Model]] of particle physics, although none of the large number of new particles in supersymmetry have been observed.<ref>{{cite book |last1=Klapdor-Kleingrothaus |first1=H. V. |title=Beyond the Desert |publisher=IOP |year=1998 |editor1=Klapdor-Kleingrothaus |editor-first=V. |volume=1997 |page=485 |chapter=Double beta decay and dark matter search – window to new physics now, and in future (GENIUS) |bibcode=1998hep.ex....2007K |editor2=Paes |editor-first2=H. |arxiv=hep-ex/9802007}}</ref> WIMP-like particles are also predicted by [[universal extra dimension]] and [[little Higgs]] theories.
{| class="wikitable"
|-
! Model
! parity
! candidate
|-
| [[SUSY]]
| [[R-parity]]
| [[lightest supersymmetric particle]] (LSP)
|-
| [[universal extra dimension|UED]]
| KK-parity
| lightest Kaluza–Klein particle (LKP)
|-
| [[little Higgs]]
| [[T-parity]]
| lightest T-odd particle (LTP)
|}

The main theoretical characteristics of a WIMP are:
* Interactions only through the [[weak nuclear force]] and [[gravity]], or possibly other interactions with [[Cross section (physics)|cross-sections]] no higher than the weak scale;<ref name="Kamionkowski">{{cite journal |arxiv=hep-ph/9710467 |last1=Kamionkowski |first1=Marc |title=WIMP and Axion Dark Matter |journal=High Energy Physics and Cosmology |volume=14 |pages=394 |year=1997|bibcode=1998hepc.conf..394K }}</ref>
* Large mass compared to standard particles (WIMPs with sub-[[Electron volt|GeV]]/''c''<sup>2</sup> masses may be considered to be [[light dark matter]]).

Because of their lack of electromagnetic interaction with normal matter, WIMPs would be invisible through normal electromagnetic observations. Because of their large mass, they would be relatively slow moving and therefore "cold".<ref>{{cite journal |arxiv=0707.0472 |last1=Zacek |first1=Viktor |title=Dark Matter |year=2007 |doi=10.1142/9789812776105_0007 |journal=Fundamental Interactions|pages=170–206 |isbn=978-981-277-609-9 |s2cid=16734425 }}</ref> Their relatively low velocities would be insufficient to overcome the mutual gravitational attraction, and as a result, WIMPs would tend to clump together.<ref name="Griest">{{cite journal |arxiv=hep-ph/9303253 |last1=Griest |first1=Kim |title=The Search for the Dark Matter: WIMPs and MACHOs |journal=Annals of the New York Academy of Sciences |volume=688 |pages=390–407 |year=1993 |doi=10.1111/j.1749-6632.1993.tb43912.x|pmid=26469437 |bibcode=1993NYASA.688..390G |s2cid=8955141 }}</ref> WIMPs are considered one of the main candidates for [[cold dark matter]], the others being [[massive compact halo objects]] (MACHOs) and [[axions]]. These names were deliberately chosen for contrast, with MACHOs named later than WIMPs.<ref>{{cite journal |doi=10.1086/169575 |last=Griest |first=Kim |title=Galactic Microlensing as a Method of Detecting Massive Compact Halo Objects |journal=The Astrophysical Journal |date=1991 |volume=366 |pages=412–421 |bibcode=1991ApJ...366..412G}}</ref> In contrast to WIMPs, there are no known stable particles within the [[Standard Model]] of particle physics that have the properties of MACHOs. The particles that have little interaction with normal matter, such as [[neutrino]]s, are very light, and hence would be fast moving, or "hot".