Evidence for the spin-0 nature of the Higgs boson using ATLAS data

G. Aad , S. Albrand (1) , J. Brown (1) , Q. Buat (1) , B. Clement (1) , J. Collot (1) , S. Crépé-Renaudin (1) , B. Dechenaux (1) , T. Delemontex (1) , P.A. Delsart (1) , C. Gabaldon (1) , M.H. Genest (1) , J.Y. Hostachy (1) , E. Laisne (1) , B.T. Le (1) , F. Ledroit-Guillon (1) , A. Lleres (1) , A. Lucotte (1) , F. Malek (1) , C. Monini (1) , J. Stark (1) , X. Sun (1) , B. Trocmé (1) , G. Rahal (2) , D. Boumediene (3) , Emmanuel Busato (3) , D. Calvet (3) , S. Calvet (3) , J. Donini (3) , E. Dubreuil (3) , N. Ghodbane (3) , Ph. Gris (3) , C. Guicheney (3) , H. Liao (3) , D. Pallin (3) , Daniela Paredes Hernández (3) , F. Podlyski (3) , C. Santoni (3) , Timothée Theveneaux-Pelzer (3) , Loïc Valery (3) , F. Vazeille (3) , L. Alio (4) , M. Barbero (4) , C. P. Bee (4) , C. Bertella (4) , N. Bousson (4) , J. C. Clémens (4) , Y. Coadou (4) , F. Djama (4) , F. Etienne (4) , L. Feligioni (4) , D. Hoffmann (4) , F. Hubaut (4) , E. B. F. G. Knoops (4) , E. Le Guirriec (4) , B. Li (5) , J. Maurer (4) , E. Monnier (4) , Y. Nagai (4) , J. Odier (4) , P. Pralavorio (4) , A. Rozanov (4) , T. Serre (4) , M. Talby (4) , N. Tannoury (4) , E. Tiouchichine (4) , S. Tisserant (4) , J. Toth (4) , F. Touchard (4) , M. Ughetto (4) , L. Vacavant (4) , N. Berger (6) , J. Colas (6) , M. Delmastro (6) , L. Di Ciaccio (6) , T.K.O. Doan (6) , S. Elles (6) , C. Goy (6) , T. Hryn'Ova (6) , S. Jézéquel (6) , H. Keoshkerian (6) , R. Lafaye (6) , J. Leveque (6) , V.P. Lombardo (6) , M. Maeno (6) , N. Massol (6) , P. Perrodo (6) , E. Petit (6) , H. Przysiezniak (6) , G. Sauvage (6) , E. Sauvan (6) , M. Schwoerer (6) , T. Todorov (6) , I. Wingerter-Seez (6) , R. Zitoun (6) , S. Abdel Khalek (7) , E. Augé (7) , S. Binet (7) , C. Bourdarios (7) , C. de La Taille (7) , J.B. de Vivie de Regie (7) , L. Duflot (7) , M. Escalier (7) , L. Fayard (7) , D. Fournier (7) , J.-F. Grivaz (7) , T. Guillemin (7) , S. Henrot-Versillé (7) , J. Hrivnac (7) , L. Iconomidou-Fayard (7) , J. Idarraga (7) , M. Kado (7) , N. Lorenzo Martinez (7) , A. Lounis (7) , N. Makovec (7) , F. Niedercorn (7) , L. Poggioli (7) , P. Puzo (7) , A. Renaud (7) , D. Rousseau (7) , G. Rybkin (7) , J.B. Sauvan (7) , J. Schaarschmidt (7) , A.C. Schaffer (7) , E. Scifo (7) , L. Serin (7) , S. Simion (7) , R. Tanaka (7) , M. Teinturier (7) , H.L. Tran (7) , D. Zerwas (7) , Zhiqing Zhang (7)

1 LPSC - Laboratoire de Physique Subatomique et de Cosmologie
2 CC-IN2P3 - Centre de Calcul de l'IN2P3
3 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
4 CPPM - Centre de Physique des Particules de Marseille
5 Purple Mountain Observatory
6 LAPP - Laboratoire d'Annecy de Physique des Particules
7 LAL - Laboratoire de l'Accélérateur Linéaire

Studies of the spin and parity quantum numbers of the Higgs boson are presented, based on proton-proton collision data collected by the ATLAS experiment at the LHC. The Standard Model spin-parity JP = 0+ hypothesis is compared with alternative hypotheses using the Higgs boson decays H->gamma gamma, H -> ZZ -> 4 leptons and H->WW -> l nu l nu, as well as the combination of these channels. The analysed dataset corresponds to an integrated luminosity of 20.7 fb-1 collected at a centre-of-mass energy of sqrt(s) = 8 TeV. For the H -> ZZ -> 4-lepton decay mode the dataset corresponding to an integrated luminosity of 4.6 fb-1 collected at sqrt(s) = 7 TeV is added. The data are compatible with the Standard Model JP = 0+ quantum numbers for the Higgs boson, whereas all alternative hypotheses studied in this letter, namely some specific JP = 0-; 1+; 1-; 2+ models, are excluded at confidence levels above 97.8%. This exclusion holds independently of the assumptions on the coupling strengths to the Standard Model particles and in the case of the JP = 2+ model, of the relative fractions of gluon-fusion and quark-antiquark production of the spin-2 particle. The data thus provide evidence for the spin-0 nature of the Higgs boson, with positive parity being strongly preferred.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

G. Aad, S. Albrand, J. Brown, Q. Buat, B. Clement, et al.. Evidence for the spin-0 nature of the Higgs boson using ATLAS data. Physics Letters B, 2013, 726, pp.120-144. ⟨10.1016/j.physletb.2013.08.026⟩. ⟨in2p3-00842149⟩