Measurement of exclusive pion pair production in proton–proton collisions at √s=7TeV with the ATLAS detector

Creative Commons License

Aad G., Abbott B., Abbott D., Abeling K., Abidi S., Aboulhorma A., ...More

European Physical Journal C, vol.83, no.7, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 83 Issue: 7
  • Publication Date: 2023
  • Doi Number: 10.1140/epjc/s10052-023-11700-x
  • Journal Name: European Physical Journal C
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, zbMATH, Directory of Open Access Journals
  • Istanbul University Affiliated: Yes


The exclusive production of pion pairs in the process pp→ ppπ+π- has been measured at s=7TeV with the ATLAS detector at the LHC, using 80μb-1 of low-luminosity data. The pion pairs were detected in the ATLAS central detector while outgoing protons were measured in the forward ATLAS ALFA detector system. This represents the first use of proton tagging to measure an exclusive hadronic final state at the LHC. A cross-section measurement is performed in two kinematic regions defined by the proton momenta, the pion rapidities and transverse momenta, and the pion–pion invariant mass. Cross-section values of 4.8±1.0(stat)-0.2+0.3(syst)μb and 9±6(stat)-2+2(syst)μb are obtained in the two regions; they are compared with theoretical models and provide a demonstration of the feasibility of measurements of this type.