Top jets in the peak region: Factorization analysis with next-to-leading-log resummation
- Department of Physics, University of Arizona, Tucson, Arizona 85721 (United States)
- Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Foehringer Ring 6, 80805 Muenchen (Germany)
- California Institute of Technology, Pasadena, CA 91125 (United States)
- Department of Physics, Massachusetts Institute of Technology, Boston, MA 02139 (United States)
We consider top quarks produced at large energy in e{sup +}e{sup -} collisions, and address the question of what top mass can be measured from reconstruction. The production process is characterized by well-separated scales: the center-of-mass energy Q, the top mass m, the top decay width {gamma}{sub t}, and also {lambda}{sub QCD}; scales which can be disentangled with effective theory methods. In particular we show how the mass measurement depends on the way in which soft radiation is treated, and that this can shift the mass peak by an amount of order Q{lambda}{sub QCD}/m. We sum large logs for Q>>m>>{gamma}{sub t}>{lambda}{sub QCD} and demonstrate that the renormalization group ties together the jet and soft interactions below the scale m. Necessary conditions for the invariant mass spectrum to be protected from large logs are formulated. Results for the cross section are presented at next-to-leading order with next-to-leading-log (NLL) resummation, for invariant masses in the peak region and the tail region. Using our results we also predict the thrust distribution for massive quark jets at NLL order for large thrust. We demonstrate that soft radiation can be precisely controlled using data on massless jet production, and that in principle, a short-distance mass parameter can be measured using jets with precision better than {lambda}{sub QCD}.
- OSTI ID:
- 21205066
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 77, Issue 11; Other Information: DOI: 10.1103/PhysRevD.77.114003; (c) 2008 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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