Measurements of Higgs boson production and couplings in the four-lepton channel in pp collisions at center-of-mass energies of 7 and 8 TeV with the ATLAS detector
Physical Review D - Particles, Fields, Gravitation and Cosmology 91:1 (2015)
Authors:
G Aad, B Abbott, J Abdallah, S Abdel Khalek, O Abdinov, R Aben, B Abi, M Abolins, OS AbouZeid, H Abramowicz, H Abreu, R Abreu, Y Abulaiti, BS Acharya, L Adamczyk, DL Adams, J Adelman, S Adomeit, T Adye, T Agatonovic-Jovin, JA Aguilar-Saavedra, M Agustoni, SP Ahlen, F Ahmadov, G Aielli, H Akerstedt, TPA Åkesson, G Akimoto, AV Akimov, GL Alberghi, J Albert, S Albrand, MJ Alconada Verzini, M Aleksa, IN Aleksandrov, C Alexa, G Alexander, G Alexandre, T Alexopoulos, M Alhroob, G Alimonti, L Alio, J Alison, BMM Allbrooke, LJ Allison, PP Allport, A Aloisio, A Alonso, F Alonso, C Alpigiani, A Altheimer, B Alvarez Gonzalez, MG Alviggi, K Amako, Y Amaral Coutinho, C Amelung, D Amidei, SP Amor Dos Santos, A Amorim, S Amoroso, N Amram, G Amundsen, C Anastopoulos, LS Ancu, N Andari, T Andeen, CF Anders, G Anders, KJ Anderson, A Andreazza, V Andrei, XS Anduaga, S Angelidakis, I Angelozzi, P Anger, A Angerami, F Anghinolfi, AV Anisenkov, N Anjos, A Annovi, A Antonaki, M Antonelli, A Antonov, J Antos, F Anulli, M Aoki, L Aperio Bella, R Apolle, G Arabidze, I Aracena, Y Arai, JP Araque, ATH Arce, JF Arguin, S Argyropoulos, M Arik, AJ Armbruster, O Arnaez, V Arnal, H Arnold
Abstract:
The final ATLAS Run 1 measurements of Higgs boson production and couplings in the decay channel H → ZZ∗ → l+l-l'+l'-, where l, l' = e or μ, are presented. These measurements were performed using pp collision data corresponding to integrated luminosities of 4.5 and 20.3 fb-1 at center-of-mass energies of 7 and 8 TeV, respectively, recorded with the ATLAS detector at the LHC. The H → ZZ∗ → 4l signal is observed with a significance of 8.1 standard deviations, with an expectation of 6.2 standard deviations, at mH = 125.36 GeV, the combined ATLAS measurement of the Higgs boson mass from the H → γγ and H → ZZ∗ → 4l channels. The production rate relative to the Standard Model expectation, the signal strength, is measured in four different production categories in the H → ZZ∗ → 4l channel. The measured signal strength, at this mass, and with all categories combined, is 1.44+0.40-0.33. The signal strength for Higgs boson production in gluon fusion or in association with tt or bb pairs is found to be 1.7+0.5-0.4, while the signal strength for vector-boson fusion combined with WH/ZH associated production is found to be 0.3+1.6-0.9.
