NLO massive event-shape differential and cumulative distributions

Autor(en)

Christopher Lepenik, Vicent Mateu

Abstrakt

We provide a general method to effectively compute differential and cumulative event-shape distributions to $\mathcal{O}(\alpha_s)$ precision for massive quarks produced primarily at an $e^+e^-$ collider. In particular, we show that at this order, due to the screening of collinear singularities by the quark mass, for all event shapes linearly sensitive to soft dynamics, there appear only two distributions at threshold: a Dirac delta function and a plus distribution. Furthermore, we show that the coefficient of the latter is universal for any infra-red and collinear safe event shape, and provide an analytic expression for it. Likewise, we compute a general formula for the coefficient of the Dirac delta function, which depends only on the event-shape measurement function in the soft limit. Finally, we present an efficient algorithm to compute the differential and cumulative distributions, which does not rely on Monte Carlo methods, therefore achieving a priory arbitrary precision even in the extreme dijet region. We implement this algorithm in a numeric code and show that it agrees with analytic results on the distribution for 2-jettiness, heavy jet mass and a massive generalization of C-parameter.

Organisation(en)

Teilchenphysik

Externe Organisation(en)

Universidad de Salamanca, Universidad Autónoma de Madrid

Journal

Journal of High Energy Physics

Band

2020

Anzahl der Seiten

53

ISSN

1029-8479

DOI

https://doi.org/10.1007/JHEP03(2020)024

Publikationsdatum

12-2019

Peer-reviewed

Ja

ÖFOS 2012

103034 Teilchenphysik

Schlagwörter

ASJC Scopus Sachgebiete

Nuclear and High Energy Physics

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/nlo-massive-eventshape-differential-and-cumulative-distributions(8daa68cb-c793-4b8b-8d46-f430c89c0b42).html