Editing Interaction point

{{Short description|Place where particles collide in an accelerator}}
{{One source|date=May 2025}}
{{Expand Russian |date=December 2024}}

In [[particle physics]], an '''interaction point''' (IP)<ref>{{cite web |last1=Harris |first1=David |title=PEP-II interaction region {{!}} symmetry magazine |url=https://www.symmetrymagazine.org/article/april-2006/pep-ii-interaction-region?language_content_entity=und |website=symmetrymagazine.org |access-date=6 May 2025 |language=en |date=1 April 2006}}</ref> is the place where particles collide in an [[particle accelerator|accelerator]] experiment. The ''nominal'' interaction point is the design position, which may differ from the ''real'' or ''physics'' interaction point, where the particles actually collide. A related, but distinct, concept is the ''primary vertex'': the reconstructed location of an individual particle collision.

For [[Fixed-target experiment|fixed target experiments]], the interaction point is the point where beam and target interact. For [[collider]]s, it is the place where the beams interact.
Experiments ([[particle detector|detector]]s) at particle accelerators are built around the nominal interaction points of the accelerators. The whole region around the interaction point (the experimental hall) is called an interaction region.
Particle colliders such as [[LEP]], [[Hadron Elektron Ring Anlage|HERA]], [[Relativistic Heavy Ion Collider|RHIC]], [[Tevatron]] and [[Large Hadron Collider|LHC]] can host several interaction regions and therefore several experiments taking advantage of the same beam.

==References==
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[[Category:Accelerator physics]]
[[Category:Experimental particle physics]]
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