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The subjet multiplicity in quark and gluon jets

We calculate the mean number of subjets in quark and gluon jets in the final state of e^+e^- annihilation. Since `quark' and `gluon' jets are scheme-dependent objects, we stress the importance of using the same definition as in experimental analyses. We define the jets using the k_perp alg...

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Detalles Bibliográficos
Autor principal: Seymour, Michael H
Lenguaje:eng
Publicado: 1996
Materias:
Acceso en línea:https://dx.doi.org/10.1016/0370-2693(96)00399-1
http://cds.cern.ch/record/298777
Descripción
Sumario:We calculate the mean number of subjets in quark and gluon jets in the final state of e^+e^- annihilation. Since `quark' and `gluon' jets are scheme-dependent objects, we stress the importance of using the same definition as in experimental analyses. We define the jets using the k_perp algorithm at a coarse scale y_1, and the subjets using a finer scale y_0, in the same algorithm. Gluon jets are anti-tagged by the presence of heavy quarks in both other jets. Our result is exact to leading order in alpha_s, and resums leading and next-to-leading logarithmic terms in the ratio y_1/y_0 to all orders in alpha_s.