A search for excited neutrinos in [formula omitted] collisions at HERA

F D Aaron ,F Sefkow,J Katzy,A Belousov,S Schmitt,C Vallée,K Begzsuren,T Preda,A Kropivnitskaya,D Haidt,G Herrera,B Olivier,A Hovhannisyan,Y Soloviev,J Ferencei,B Stella,C Niebuhr,M Beckingham,R Kogler,C Grab,H Henschel,V Jemanov,R.N Shaw-West,J Meyer,G Eckerlin,K Daum,I Sheviakov,R Wolf,V Spaskov,W Bartel,V Lubimov,P Truöl,F Eisele,D Pitzl,A Petrukhin,N Berger,C Alexa,A Liptaj,M.-O Boenig,A Morozov,S Egli,S Aplin,H Zohrabyan,G Cozzika,J Cvach,R Felst,M Jacquet,A Asmone,K Urban,B Tseepeldorj,G Laštovička-Medin,C Kleinwort,M Rotaru,A Vargas Trevino,S Mikocki,F Moreau,P Smirnov,M Hildebrandt,D South,E Elsen,S Osman,Y Vazdik,A Lebedev,A Fedotov,A Raspiareza,K Nowak,S Ghazaryan,P Baranov,O Pejchal,I Milcewicz-Mika,R Roosen,D Traynor,S Essenov,L Lytkin,M Sauter,E Sauvan,A Zhokin,E Barrelet,M Steder,R Horisberger,A Valkárová,V Korbel,M Gouzevitch,K Krastev,Z Staykova,P Van Mechelen,A Specka,A Fomenko,A Nikiforov,A Makankine,I Tsurin,V Andreev,L Finke,A Zhelezov,A Astvatsatourov,G Buschhorn,J Turnau,T Frisson,P Marage,S Habib,Z Rurikova,R Plačakytė,P Robmann,T Hreus,J Žáček,M Wessels,T Zimmermann,H Peng,D Sunar,J Feltesse,C Schmitz,M Klein,P Kostka,L Favart,D Ozerov,U Straumann,A Cholewa,K Meier,E Tzamariudaki,F Tomasz,B List,C Helebrant,V Brisson,D Hoffmann,I Tsakov,M Goettlich,E Malinovski,S Levonian,E Rizvi,A Baghdasaryan,Y De Boer,C Kiesling,V Radescu,O Behnke,B Naroska,N Loktionova,V Dodonov,A Dubak,A Mehta,N Gogitidze,M Kraemer,L Goerlich,P Reimer,M Mudrinic,E Gabathuler,A Schöning,R Polifka,G Brandt,A Eliseev,V Efremenko,V Boudry,J.C Bizot,S Schmidt,I Glushkov,A Falkiewicz,G Nowak,V Yeganov,V Tchoulakov,I Panagoulias,C Pascaud,A.-I Lucaci-Timoce,G Leibenguth,J Delvax,H Jung,G Li,P Laycock,M Kapichine,F Cassol-Brunner,L Bystritskaya,T Toll,M Fleischer,A Dossanov,V Lendermann,J Kretzschmar,V Palichik,M.E Janssen,K Nankov,A Rostovtsev,C Risler,A Knutsson,B Delcourt,S Vinokurova,G Thompson,D Wegener,C Diaconu,A Bunyatyan,A De Roeck,G Franke,K Lipka,F Zomer,S Baudrand,V Chekelian,J Gayler,M Del Degan,X Janssen,E Wünsch,H Meyer,F Salvaire,L Schoeffel,T Klimkovich,D Bruncko,W Lange,G Grindhammer,K Müller,T Greenshaw,B Roland,I Božović-Jelisavc̆ić ,S V Rusakov ,Bogdan Povh ,K B Cantun Avila ,E A De Wolf ,J Zálešâk ,V Volchinskial ,K Kroger ,P D Thompson ,Peter Faulkner ,K H Hiller ,L N Shtarkov ,I R Kenyon ,C Wissing ,A Campbell ,K Černý ,Martin Brinkmann ,D Johnson ,J Braciník ,B R Grell ,T N Trinh ,I Sýkora ,Andreas Bernhard Meyer ,G D Patel ,J E Olsson ,M P J Landon ,Krzysztof Kutak ,T Naumann ,Jenny List ,N Raičević ,D P C Sankey ,H.‐C Schultz‐Coulon ,R C W Henderson ,Zhiqing Philippe Zhang ,I Ravdandorj ,П Мурін ,P R Newman ,Volker Michels ,J B Dainton ,A J Rahmat ,A W Jung ,D Šálek ,V Černý ,J V Morris ,S M Piec ,S Backović ,Magnus Hansson ,E Pérez ,B Antunović ,J G Contreras ,M Nožička ,J A Coughlan ,Michal Deák ,I Smijanic ,I Pićurić ,I Kluge ,M U Mozer ,J E Ruiz Tabasco ,S J Maxfield ,Y Zhu ,L Jönson ,Ian H Sloan ,Th D Papadopoulou ,M Pandurović ,A Giazov ,T H Tran ,H U Martyn ,L Marti ,R López-Fernández

doi:10.1016/j.physletb.2008.04.020

Abstract

A search for first generation excited neutrinos is performed using the full e−p data sample collected by the H1 experiment at HERA at a centre-of-mass energy of 319 GeV, corresponding to a total luminosity of 184 pb−1. The electroweak decays of excited neutrinos ν∗→νγ, ν∗→νZ and ν∗→eW with subsequent hadronic or leptonic decays of the W and Z bosons are considered. No evidence for excited neutrino production is found. Mass dependent exclusion limits on ν∗ production cross sections and on the ratio of the coupling to the compositeness scale f/Λ are derived within gauge mediated models. A limit on f/Λ, independent of the relative couplings to the SU(2) and U(1) gauge bosons, is also determined. These limits extend the excluded region to higher masses than has been possible in previous excited neutrino searches.

Highlights

CollaborationThese limits extend the excluded region to higher masses than has been possible in previous excited neutrino searches
The three-family structure and mass hierarchy of the known fermions is one of the most puzzling characteristics of the Standard Model (SM) of particle physics
Using the full e− p data sample collected by the H1 experiment at HERA with an integrated luminosity of 184 pb−1 a search for the production of first generation excited neutrinos is performed