Search for new physics in the μμ+e/μ+E T channel with a low-pT lepton threshold at the Collider Detector at Fermilab

Authors

T. Aaltonen, University of Glasgow
J. Adelman, Carnegie Mellon University
T. Akimoto, University of Pennsylvania
M. G. Albrow, Joint Institute for Nuclear Research, Dubna
B. Álvarez González, University of California, Santa Barbara
S. Amerio, University of Michigan, Ann Arbor
D. Amidei, Lawrence Berkeley National Laboratory
A. Anastassov, Massachusetts Institute of Technology
A. Annovi, Fermi National Accelerator Laboratory
J. Antos, The Enrico Fermi Institute
G. Apollinari, Joint Institute for Nuclear Research, Dubna
A. Apresyan, The Ohio State University
T. Arisawa, Università di Pisa
A. Artikov, Univerzita Komenského v Bratislave
W. Ashmanskas, Joint Institute for Nuclear Research, Dubna
A. Attal, Universitat Autònoma de Barcelona
A. Aurisano, Università degli Studi di Padova
F. Azfar, TRIUMF
P. Azzurri, The University of New Mexico
W. Badgett, Joint Institute for Nuclear Research, Dubna
A. Barbaro-Galtieri, Karlsruher Institut für Technologie, Campus Süd
V. E. Barnes, The Ohio State University
B. A. Barnett, Helsingin Yliopisto
V. Bartsch, Seoul National University
G. Bauer, Chonnam National University
P. H. Beauchemin, The University of New Mexico
F. Bedeschi, Seoul National University
D. Beecher, Helsingin Yliopisto

Document Type

Article

Publication Date

3-2-2009

Abstract

A search for new physics using three-lepton (trilepton) data collected with the CDF II detector and corresponding to an integrated luminosity of 976 pb-1 is presented. The standard model predicts a low rate of trilepton events, which makes some supersymmetric processes, such as chargino-neutralino production, measurable in this channel. The μμ+ signature is investigated, where ℓ is an electron or a muon, with the additional requirement of large missing transverse energy. In this analysis, the lepton transverse momenta with respect to the beam direction (pT) are as low as 5GeV/c, a selection that improves the sensitivity to particles that are light as well as to ones that result in leptonically decaying tau leptons. At the same time, this low-pT selection presents additional challenges due to the non-negligible heavy-quark background at low lepton momenta. This background is measured with an innovative technique using experimental data. Several dimuon and trilepton control regions are investigated, and good agreement between experimental results and standard-model predictions is observed. In the signal region, we observe one three-muon event and expect 0.4±0.1μμ+ events from standard-model processes. © 2009 The American Physical Society.

Publication Source (Journal or Book title)

Physical Review D - Particles, Fields, Gravitation and Cosmology

Recommended Citation

Aaltonen, T., Adelman, J., Akimoto, T., Albrow, M., González, B., Amerio, S., Amidei, D., Anastassov, A., Annovi, A., Antos, J., Apollinari, G., Apresyan, A., Arisawa, T., Artikov, A., Ashmanskas, W., Attal, A., Aurisano, A., Azfar, F., Azzurri, P., Badgett, W., Barbaro-Galtieri, A., Barnes, V., Barnett, B., Bartsch, V., Bauer, G., Beauchemin, P., Bedeschi, F., & Beecher, D. (2009). Search for new physics in the μμ+e/μ+E T channel with a low-pT lepton threshold at the Collider Detector at Fermilab. Physical Review D - Particles, Fields, Gravitation and Cosmology, 79 (5) https://doi.org/10.1103/PhysRevD.79.052004