A Search for resonance decays to lepton + jet at HERA and limits on leptoquarks

• Main Authors: Derrick, M., Basile, M., Bellagamba, L., Bruni, G., Contin, A., Corradi, M., Pesci, A., Goers, S., Hilger, E., Jakob, H. P., Katz, U. F., Meyer, U., Rautenberg, J., Renner, R., Voss, K. C., Cole, J. E., Foster, B., Heath, G. P., Rodrigues, E., Wing, M., Mastroberardino, A., Pac, M. Y., Mellado, B., Grabowska-Bold, I., Suszycki, L., Slominski, W., Adler, Volker, Chiochia, V., Fourletova, J., Goebel, F., Hain, W., Hartner, G. F., Hillert, S., Kahle, B., Mankel, R., Nguyen, C. N., Notz, D., Schneekloth, U., Wolf, G., Youngman, C., Genta, C., Coppola, N., Doyle, A. T., Hanlon, S., Lee, S. W., Holm, U., Wick, K., Long, K. R., Tapper, A. D., Nagano, K., Lim, H., Barreiro, F., Gonzalez, O., Terron, J., Barbi, M., Gliga, S., Lainesse, J., Stairs, D. G., Tsurugai, T., Dolgoshein, B. A., Dementiev, R. K., Katkov, I. I., Korzhavina, I. A., Proskuryakov, A. S., Koffeman, E., Kooijman, P., Pellegrino, A., Schagen, S., Brummer, N., Cottrell, A., Devenish, R. C. E., Patel, S., Carlin, R., Dusini, S., Parenti, A., Heaphy, E. A., Whitmore, J. J., Hart, J. C., Park, I. H., Pavel, N., Levy, A., Abe, T., Kagawa, S., Hirose, T., Nishimura, T., Arneodo, M., Ferrero, M. I., Sacchi, R., Solano, A., Koop, T., Butterworth, J. M., Lightwood, M. S., West, B. J., Ukleja, A., Plucinski, P., Eisenberg, Y., Gladilin, L. K., Hochman, D., Deshpande, A., Hughes, V. W.
• Format: Report
• Language: English
• Subjects: 318 GeV-cms; coupling: Yukawa; DESY HERA Stor; electron p > > jet electron anything; electron p > > jet neutrino anything; electron p: colliding beams; experimental results; final state: (jet lepton); leptoquark: mass; lower limit; narrow resonance: search for; positron p: colliding beams; R parity: violation; squark; supersymmetry; ZEUS
• ISSN: 1550-7998; 2470-0029; 0556-2821; 2470-0010; 1089-4918; 1550-2368
• DOI: 10.3204/pubdb-2017-11173

A search for narrow-width resonances that decay into electron+jet or neutrino+jet has been performed with the ZEUS detector at HERA operating at center-of-mass energies of 300 and 318 GeV. An integrated e+p luminosity of 114.8 pb-1 and e-p luminosity of 16.7 pb-1 were used. No evidence for any resonance was found. Limits were derived on the Yukawa coupling as a function of the mass of a hypothetical resonance that has arbitrary decay branching ratios into electron+quark or neutrino+quark. These limits also apply to squarks predicted by R-parity-violating supersymmetry. Limits for the production of leptoquarks described by the Buchmuller-Ruckl-Wyler model were also derived for masses up to 400 GeV. For Yukawa coupling of 0.1, leptoquark masses up to 290 GeV are excluded.