We resum the invariant mass distribution of jets initiated by massive quarks in next-to-leading logarithmic approximation and beyond in heuristic way. We find that the inclusion of mass terms, in the N-moment space, results in the universal factor delta_N(Q^2;m^2), taking into account dead-cone effects and soft radiation characteristic of massive charges. This factor multiplies the massless jet distribution function J_N(Q^2). The variable N is rescaled by the mass correction parameter r = m^2/Q^2 << 1 with respect to the standard massless case, being m the quark mass and Q the hard scale. The functions A(alpha_S) and B(alpha_S), appear with a minus sign suppressing collinear effects at large N, as expected. In the same region, soft radiation not collinearly enhanced, characteristic of massive charges, makes its appearance with the function D(alpha_S). Phenomenological applications, such as the resummation of b --> c l nu decay spectra or the inclusion of beauty mass effects in t --> b W decays, are briefly sketched.

Resummed mass distribution for jets initiated by massive quarks / U. Aglietti, L. Di Giustino, G. Ferrera, L. Trentadue. - In: PHYSICS LETTERS. SECTION B. - ISSN 0370-2693. - 651:4(2007), pp. 275-292.

Resummed mass distribution for jets initiated by massive quarks

G. Ferrera
Penultimo
;
2007

Abstract

We resum the invariant mass distribution of jets initiated by massive quarks in next-to-leading logarithmic approximation and beyond in heuristic way. We find that the inclusion of mass terms, in the N-moment space, results in the universal factor delta_N(Q^2;m^2), taking into account dead-cone effects and soft radiation characteristic of massive charges. This factor multiplies the massless jet distribution function J_N(Q^2). The variable N is rescaled by the mass correction parameter r = m^2/Q^2 << 1 with respect to the standard massless case, being m the quark mass and Q the hard scale. The functions A(alpha_S) and B(alpha_S), appear with a minus sign suppressing collinear effects at large N, as expected. In the same region, soft radiation not collinearly enhanced, characteristic of massive charges, makes its appearance with the function D(alpha_S). Phenomenological applications, such as the resummation of b --> c l nu decay spectra or the inclusion of beauty mass effects in t --> b W decays, are briefly sketched.
Settore FIS/02 - Fisica Teorica, Modelli e Metodi Matematici
2007
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/172152
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