Author/Authors :
ZEUS Collaboration، نويسنده , , S Chekanov، نويسنده , , M Derrick، نويسنده , , D Krakauer، نويسنده , , S Magill، نويسنده , , B Musgrave، نويسنده , , A Pellegrino، نويسنده , , J. Repond، نويسنده , , R Yoshida، نويسنده , , M.C.K. Mattingly، نويسنده , , P Antonioli، نويسنده , , G Bari، نويسنده , , M Basile، نويسنده , , L Bellagamba، نويسنده , , D Boscherini، نويسنده , , A Bruni، نويسنده , , G Bruni، نويسنده , , G. Cara Romeo، نويسنده , , L Cifarelli، نويسنده , , F. Cindolo، نويسنده , , et al.، نويسنده ,
Abstract :
Searches in ep collisions for heavy excited fermions have been performed with the ZEUS detector at HERA. Excited states of electrons and quarks have been searched for in e+p collisions at a centre-of-mass energy of 300 GeV using an integrated luminosity of 47.7 pb−1. Excited electrons have been sought via the decays e∗→eγ, e∗→eZ and e∗→νW. Excited quarks have been sought via the decays q∗→qγ and q∗→qW. A search for excited neutrinos decaying via ν∗→νγ, ν∗→νZ and ν∗→eW is presented using e−p collisions at 318 GeV centre-of-mass energy, corresponding to an integrated luminosity of 16.7 pb−1. No evidence for any excited fermion is found, and limits on the characteristic couplings are derived for masses ≲250 GeV.
