# Measurement of the Top-Quark Mass with Dilepton Events Selected Using Neuroevolution at CDF

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http://hdl.handle.net/10138/24482

#### Citation

Aaltonen , T , Mehtälä , P , Orava , R , Mäki , T , Saarikko , H , Österberg , K & CDF Collaboration 2009 , ' Measurement of the Top-Quark Mass with Dilepton Events Selected Using Neuroevolution at CDF ' , Physical Review Letters , vol. 102 , no. 15 , pp. 152001 . https://doi.org/10.1103/PhysRevLett.102.152001

 Title: Measurement of the Top-Quark Mass with Dilepton Events Selected Using Neuroevolution at CDF Author: Aaltonen, T.; Mehtälä, Petteri; Orava, Risto; Mäki, Tuula; Saarikko, Heimo; Österberg, Kenneth; CDF Collaboration Contributor: University of Helsinki, Helsinki Institute of PhysicsUniversity of Helsinki, Helsinki Institute of PhysicsUniversity of Helsinki, Helsinki Institute of PhysicsUniversity of Helsinki, Helsinki Institute of PhysicsUniversity of Helsinki, Department of PhysicsUniversity of Helsinki, Department of Physics Date: 2009 Language: eng Number of pages: 8 Belongs to series: Physical Review Letters ISSN: 0031-9007 URI: http://hdl.handle.net/10138/24482 Abstract: We report a measurement of the top quark mass $M_t$ in the dilepton decay channel $t\bar{t}\to b\ell'^{+}\nu'_\ell\bar{b}\ell^{-}\bar{\nu}_{\ell}$. Events are selected with a neural network which has been directly optimized for statistical precision in top quark mass using neuroevolution, a technique modeled on biological evolution. The top quark mass is extracted from per-event probability densities that are formed by the convolution of leading order matrix elements and detector resolution functions. The joint probability is the product of the probability densities from 344 candidate events in 2.0 fb$^{-1}$ of $p\bar{p}$ collisions collected with the CDF II detector, yielding a measurement of $M_t= 171.2\pm 2.7(\textrm{stat.})\pm 2.9(\textrm{syst.})\mathrm{GeV}/c^2$. Subject: 114 Physical sciences hep-ex Rights:
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