| Article | |
| Report number | arXiv:1807.11487 |
| Title | The Sudakov radiator for jet observables and the soft physical coupling |
| Author(s) | Banfi, Andrea (Sussex U.) ; El-Menoufi, Basem Kamal (Sussex U.) ; Monni, Pier Francesco (CERN) |
| Publication | 2019-01-09 |
| Imprint | 2018-07-30 |
| Number of pages | 33 |
| Note | 32 pages, 6 figures |
| In: | JHEP 1901 (2019) 083 |
| DOI | 10.1007/JHEP01(2019)083 |
| Subject category | hep-ph ; Particle Physics - Phenomenology |
| Abstract | We present a procedure to calculate the Sudakov radiator for a generic recursive infrared and collinear (rIRC) safe observable in two-scale problems. We give closed formulae for the radiator at next-to-next-to-leading-logarithmic (NNLL) accuracy, which completes the general NNLL resummation for this class of observables in the {\tt ARES} method for processes with two emitters at the Born level. As a byproduct, we define a physical coupling in the soft limit, and we provide an explicit expression for its relation to the $\overline{\rm MS}$ coupling up to ${\cal O}(\alpha_s^3)$. This physical coupling constitutes one of the ingredients for a NNLL accurate parton shower algorithm. As an application we obtain analytic NNLL results, of which several are new, for all angularities $\tau_x$ defined with respect to both the thrust axis and the winner-take-all axis, and for the moments of energy-energy correlation $FC_x$ in $e^+e^-$ annihilation. For the latter observables we find that, for some values of $x$, an accurate prediction of the peak of the differential distribution requires a simultaneous resummation of the logarithmic terms originating from the two-jet limit and at the Sudakov shoulder. |
| Copyright/License | publication: (License: CC-BY-4.0) preprint: (License: arXiv nonexclusive-distrib 1.0) |
Corresponding record in: Inspire
Record created 2018-08-16, last modified 2021-11-12
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