A search for an excited muon decaying to a muon and two jets in pp collisions at √ s = 8 TeV with the ATLAS detector


Aad G., Abbott B., Abdallah J., Abdinov O., Abeloos B., Aben R., ...More

New Journal of Physics, vol.18, no.7, 2016 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 7
  • Publication Date: 2016
  • Doi Number: 10.1088/1367-2630/18/7/073021
  • Journal Name: New Journal of Physics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Keywords: excited leptons, lepton compositeness, leptoquarks
  • Ankara University Affiliated: Yes

Abstract

Anew search signature for excited leptons is explored. Excited muons are sought in the channel pp → μμ∗→ μμ jet jet, assuming both the production and decay occur via a contact interaction. The analysis is based on 20.3 fb-1 of pp collision data at a centre-of-mass energy of s = 8 TeV taken with the ATLAS detector at the large hadron collider. No evidence of excited muons is found, and limits are set at the 95% confidence level on the cross section times branching ratio as a function of the excited-muonmass μμ∗. For μμ∗between 1.3 and 3.0 TeV, the upper limit on φB (μ∗→ μqq) is between 0.6 and 1 fb. Limits on sB are converted to lower bounds on the compositeness scale. In the limiting case L = μμ∗, excitedmuonswith amass below2.8 TeVare excluded.With the samemodel assumptions, these limits at larger μ∗masses improve upon previous limits fromtraditional searches based on the gauge-mediated decay μ∗→ μγ.