li-multileptons-2009.pdf (310.57 kB)
Multi-leptons with high transverse momentum at HERA
journal contribution
posted on 2009-01-01, 00:00 authored by F D Aaron, H Abramowicz, I Abt, L Adamczyk, M Adamus, M Aldaya Martin, C Alexa, K Alimujiang, V Andreev, S Antonelli, P Antonioli, A Antonov, B Antunovic, M Arneodo, A Asmone, V Aushev, O Bachynska, S Backovic, A Baghdasaryan, A Bamberger, A N Barakbaev, G Barbagli, G Bari, F Barreiro, E Barrelet, W Bartel, D Bartsch, M Basile, K Begzsuren, O Behnke, J Behr, U Behrens, L Bellagamba, A Belousov, A Bertolin, S Bhadra, M Bindi, J C Bizot, C Blohm, T Bold, E G Boos, M Borodin, K Borras, D Boscherini, D Bot, V Boudry, S K Boutle, I Bozovic-Jelisavcic, J Bracinik, G Brandt, M Brinkmann, V Brisson, I Brock, E Brownson, R Brugnera, N Brümmer, D Bruncko, A Bruni, G Bruni, B Brzozowska, A Bunyatyan, G Buschhorn, P J Bussey, J M Butterworth, B Bylsma, L Bystritskaya, A Caldwell, A J Campbell, K B Cantun Avila, M Capua, R Carlin, F Cassol-Brunner, C D Catterall, K Cerny, V Cerny, S Chekanov, V Chekelian, A Cholewa, J Chwastowski, J Ciborowski, R Ciesielski, L Cifarelli, F Cindolo, A Contin, J G Contreras, A M Cooper-Sarkar, N Coppola, M Corradi, F Corriveau, M Costa, J A Coughlan, G Cozzika, J Cvach, G D'Agostini, J B Dainton, F Dal Corso, K Daum, M Deák, Y De Boer, J De FavereauEvents with at least two high transverse momentum leptons (electrons or muons) are studied using the H1 and ZEUS detectors at HERA with an integrated luminosity of 0.94 fb-1. The observed numbers of events are in general agreement with the Standard Model predictions. Seven di- and tri-lepton events are observed in e+p collision data with a scalar sum of the lepton transverse momenta above 100GeV while 1.94 ± 0.17 events are expected. Such events are not observed in e-p collisions for which 1.19 ± 0.12 are predicted. Total visible and differential di-electron and di-muon photoproduction cross sections are extracted in a restricted phase space dominated by photon-photon collisions. © SISSA 2009.
