Editing ATLAS experiment (section)

===Beyond the Standard model===
While the [[Standard Model]] predicts that [[quark]]s, [[lepton]]s and [[neutrino]]s should exist, it does not explain why the [[mass]]es of these particles are so different (they differ by [[order of magnitude|orders of magnitude]]). Furthermore, the mass of the [[neutrino]]s should be, according to the [[Standard Model]], exactly zero as that of the [[photon]]. Instead, neutrinos have [[mass]]. In 1998 research results at [[particle detector|detector]] [[Super-Kamiokande]] determined that neutrinos can oscillate from one [[Flavor (physics)|flavor]] to another, which dictates that they have a mass other than zero. For these and other reasons, many [[particle physics|particle physicists]] believe it is possible that the [[Standard Model]] will break down at energies at the [[electron volt#TeV|teraelectronvolt (TeV)]] scale or higher. Most alternative theories, the [[Grand Unified Theories]] (GUTs) including [[Supersymmetry]] (SUSY), predicts the existence of new particles with [[mass]]es greater than those of [[Standard Model]].

====Supersymmetry====
Most of the currently proposed theories predict new higher-mass particles, some of which may be light enough to be observed by ATLAS. Models of [[supersymmetry]] involve new, highly massive particles. In many cases these decay into high-energy [[quark]]s and stable heavy particles that are very unlikely to interact with ordinary matter. The stable particles would escape the detector, leaving as a signal one or more high-energy [[jet (particle physics)|quark jets]] and a large amount of [[missing energy|"missing"]] [[momentum]]. Other hypothetical massive particles, like those in the [[Kaluza–Klein theory]], might leave a similar signature. 
The data collected up to the end of LHC Run II do not show evidence of supersymmetric or unexpected particles, the research of which will continue in the data that will be collected from Run III onwards.

====CP violation====
The asymmetry between the behavior of matter and [[antimatter]], known as [[CP violation]], is also being investigated.<ref name="TPintro"/> Recent experiments dedicated to measurements of CP violation, such as [[BaBar]] and [[Belle experiment|Belle]], have not detected sufficient CP violation in the Standard Model to explain the lack of detectable antimatter in the universe. It is possible that new models of physics will introduce additional CP violation, shedding light on this problem. Evidence supporting these models might either be detected directly by the production of new particles, or indirectly by measurements of the properties of B- and D-[[meson]]s. [[LHCb]], an LHC experiment dedicated to B-mesons, is likely to be better suited to the latter.<ref name="PhysicsatLHC">{{cite journal |author1=N. V. Krasnikov |author2=V. A. Matveev |date=September 1997 |title = Physics at LHC |journal= Physics of Particles and Nuclei| volume= 28 |issue= 5 | pages= 441–470 |arxiv = hep-ph/9703204 |doi = 10.1134/1.953049 |bibcode = 1997PPN....28..441K |s2cid=118907038 }}</ref>

====Microscopic black holes====
Some hypotheses, based on the [[ADD model]], involve large extra dimensions and predict that [[micro black holes]] could be formed by the LHC.<ref>{{cite journal|title= Exploring higher dimensional black holes at the Large Hadron Collider |doi-access=free |first1=C.M. |last1=Harris |first2=M.J. |last2=Palmer |first3=M.A. |last3=Parker |first4=P. |last4=Richardson |first5=A. |last5=Sabetfakhri |first6=B.R. |last6=Webber |journal=Journal of High Energy Physics|volume=2005|year=2005|pages=053|doi= 10.1088/1126-6708/2005/05/053|arxiv = hep-ph/0411022 |bibcode = 2005JHEP...05..053H|issue= 5 |s2cid=15199183 }}</ref> These would decay immediately by means of [[Hawking radiation]], producing all particles in the Standard Model in equal numbers and leaving an unequivocal signature in the ATLAS detector.<ref>{{cite journal|title=Study of Black Holes with the ATLAS detector at the LHC |first1=J. |last1=Tanaka |first2=T. |last2=Yamamura |first3=S. |last3=Asai |first4=J. |last4=Kanzaki |journal=European Physical Journal C|volume=41|issue=s2|year=2005|pages=19–33|doi=10.1140/epjcd/s2005-02-008-x|arxiv = hep-ph/0411095 |bibcode = 2005EPJC...41...19T |s2cid=119444406 }}</ref>