Search for lepton-flavor violation in e+p collisions at DESY HERA
Physical Review D Particles Fields Gravitation and Cosmology 65:9 (2002) 920041-9200416
Authors:
S Chekanov, M Derrick, D Krakauer, S Magill, B Musgrave, A Pellegrino, J Repond, R Yoshida, MCK Mattingly, P Antonioli, G Bari, M Basile, L Bellagamba, D Boscherini, A Bruni, G Bruni, G Cara Romeo, L Cifarelli, F Cindolo, A Contin, M Corradi, S de Pasquale, P Giusti, G Iacobucci, G Levi, A Margotti, T Massam, R Nania, F Palmonari, A Pesci, G Sartorelli, A Zichichi, G Aghuzumtsyan, D Bartsch, I Brock, J Crittenden, S Goers, H Hartmann, E Hilger, P Irrgang, HP Jakob, A Kappes, UF Katz, R Kerger, O Kind, E Paul, J Rautenberg, R Renner, H Schnurbusch, A Stifutkin, J Tandler, KC Voss, A Weber, H Wessoleck, DS Bailey, NH Brook, JE Cole, B Foster, GP Heath, HF Heath, S Robins, E Rodrigues, J Scott, RJ Tapper, M Wing, M Capua, A Mastroberardino, M Schioppa, G Susinno, HY Jeoung, JY Kim, JH Lee, IT Lim, KJ Ma, MY Pac, A Caldwell, M Helbich, X Liu, B Mellado, S Paganis, WB Schmidke, F Sciulli, J Chwastowski, A Eskreys, J Figiel, K Olkiewicz, MB Przybycie艅, P Stopa, L Zawiejski, B Bednarek, I Grabowska-Bold, K Jele艅, D Kisielewska, AM Kowal, M Kowal, T Kowalski, B Mindur, E Rulikowska-Zarebska, L Suszycki, D Szuba
Abstract:
A search has been made for lepton-flavor-violating interactions of the type e+p鈫抣X, where l denotes a 渭 or 蟿 with high transverse momentum, at a center-of-mass energy 鈭歴 of 300 GeV with an integrated luminosity of 47.7 pb-1 using the ZEUS detector at HERA. No evidence was found for lepton-flavor violation and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below 鈭歴, limits are set on 位eq1尾lq, where 位eq1 is the coupling of the LQ to an electron and a first-generation quark q1 and 尾lq is the branching ration of the LQ to l and a quark. For LQ masses exceeding 鈭歴, limits are set on the four-fermion contact-interaction term 位别辩伪 位濒辩尾/M2 LQ for leptoquarks that couple to an electron and a quark q伪 and also to l and a quark q尾. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in R-parity-violating supersymmetric models. In some cases involving heavy quarks and especially for l=蟿, the ZEUS limits are the most stringent published to date.
