| Article | |
| Report number | arXiv:2409.08316 ; CERN-TH-2024-125 ; Nikhef 2024-013 ; OUTP-24-05P |
| Title | A collinear shower algorithm for NSL non-singlet fragmentation |
| Author(s) | van Beekveld, Melissa (NIKHEF, Amsterdam) ; Dasgupta, Mrinal (Manchester U.) ; El-Menoufi, Basem Kamal (Monash U.) ; Helliwell, Jack (Oxford U., Theor. Phys.) ; Monni, Pier Francesco (CERN) ; Salam, Gavin P. (Oxford U., Theor. Phys. ; U. Oxford (main)) |
| Publication | 2025-03-28 |
| Imprint | 2024-09-12 |
| Number of pages | 36 |
| Note | 22 pages (excluding appendices and references), 1 ancillary file |
| In: | JHEP 2503 (2025) 209 |
| DOI | 10.1007/JHEP03(2025)209 |
| Subject category | hep-ph ; Particle Physics - Phenomenology |
| Abstract | We formulate a collinear partonic shower algorithm that achieves next-to-single-logarithmic (NSL, $\alpha_s^n L^{n-1}$) accuracy for collinear-sensitive non-singlet fragmentation observables. This entails the development of an algorithm for nesting triple-collinear splitting functions. It also involves the inclusion of the one-loop double-collinear corrections, through a $z$-dependent NLO-accurate effective $1\to 2$ branching probability, using a formula that can be applied more generally also to future full showers with $1\to3$ splitting kernels. The specific NLO branching probability is calculated in two ways, one based on slicing, the other using a subtraction approach based on recent analytical calculations. We close with demonstrations of the shower's accuracy for non-singlet partonic fragmentation functions and the energy spectrum of small-$R$ quark jets. This work represents an important conceptual step towards general NNLL accuracy in parton showers. |
| Copyright/License | publication: © 2025 The Authors (License: CC BY 4.0), sponsored by SCOAP³ preprint: (License: CC BY 4.0) |
Corresponding record in: Inspire
Record created 2024-09-17, last modified 2025-04-28
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