Physics:Quantum data analysis/Cross Sections: Difference between revisions
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A '''cross section''' is the standard quantity used to express the probability rate for a specified particle interaction. In particle physics it translates observed event counts into an effective interaction area after accounting for luminosity, selection efficiency, detector acceptance, backgrounds, and bin migration. Cross sections are central because they allow measurements from different experiments, energies, and final states to be compared with theory predictions.<ref name="pdg2024">{{cite journal |collaboration=Particle Data Group |title=Review of Particle Physics |journal=Physical Review D |volume=110 |issue=3 |pages=030001 |year=2024 |doi=10.1103/PhysRevD.110.030001}}</ref> | |||
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[[File:Quantum_data_analysis_cross_sections_yellow.png|thumb|280px|Cross | [[File:Quantum_data_analysis_cross_sections_yellow.png|thumb|280px|Cross sections represented as a compact particle-physics data analysis workflow.]] | ||
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== Inclusive and differential forms == | |||
An inclusive cross section counts all events satisfying a definition, while a differential cross section describes how the rate changes with variables such as transverse momentum, rapidity, invariant mass, or scattering angle.<ref name="pdg2024">{{cite journal |collaboration=Particle Data Group |title=Review of Particle Physics |journal=Physical Review D |volume=110 |issue=3 |pages=030001 |year=2024 |doi=10.1103/PhysRevD.110.030001}}</ref> | |||
== Experimental extraction == | |||
A measured cross section usually requires background subtraction, efficiency correction, luminosity normalization, and uncertainty propagation. When detector resolution moves events between bins, unfolding or forward-folded comparisons may be used.<ref name="cowan">{{cite book |last=Cowan |first=Glen |title=Statistical Data Analysis |publisher=Oxford University Press |year=1998 |isbn=978-0-19-850156-5}}</ref> | |||
== Theory comparison == | |||
Cross sections are compared with perturbative calculations, event-generator predictions, and effective models. Agreement or disagreement depends on the observable definition, phase-space cuts, order of calculation, and treatment of systematic uncertainties.<ref name="halzen">{{cite book |last1=Halzen |first1=Francis |last2=Martin |first2=Alan D. |title=Quarks and Leptons: An Introductory Course in Modern Particle Physics |publisher=Wiley |year=1984 |isbn=978-0-471-88741-6}}</ref> | |||
=See also= | =See also= | ||
Revision as of 20:57, 19 May 2026
A cross section is the standard quantity used to express the probability rate for a specified particle interaction. In particle physics it translates observed event counts into an effective interaction area after accounting for luminosity, selection efficiency, detector acceptance, backgrounds, and bin migration. Cross sections are central because they allow measurements from different experiments, energies, and final states to be compared with theory predictions.[1]
Inclusive and differential forms
An inclusive cross section counts all events satisfying a definition, while a differential cross section describes how the rate changes with variables such as transverse momentum, rapidity, invariant mass, or scattering angle.[1]
Experimental extraction
A measured cross section usually requires background subtraction, efficiency correction, luminosity normalization, and uncertainty propagation. When detector resolution moves events between bins, unfolding or forward-folded comparisons may be used.[2]
Theory comparison
Cross sections are compared with perturbative calculations, event-generator predictions, and effective models. Agreement or disagreement depends on the observable definition, phase-space cuts, order of calculation, and treatment of systematic uncertainties.[3]
See also
Table of contents (60 articles)
Index
Full contents
References
- ↑ 1.0 1.1 "Review of Particle Physics". Physical Review D 110 (3): 030001. 2024. doi:10.1103/PhysRevD.110.030001.
- ↑ Cowan, Glen (1998). Statistical Data Analysis. Oxford University Press. ISBN 978-0-19-850156-5.
- ↑ Halzen, Francis; Martin, Alan D. (1984). Quarks and Leptons: An Introductory Course in Modern Particle Physics. Wiley. ISBN 978-0-471-88741-6.
Source attribution: Physics:Quantum data analysis/Cross Sections
