Lund and Cambridge multiplicities for precision physics

Autor: Medves, Rok, Soto-Ontoso, Alba, Soyez, Gregory
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1007/JHEP10(2022)156
Popis: We revisit the calculation of the average jet multiplicity in high-energy collisions. First, we introduce a new definition of (sub)jet multiplicity based on Lund declusterings obtained using the Cambridge jet algorithm. We develop a new systematic resummation approach. This allows us to compute both the Lund and the Cambridge average multiplicities to next-to-next-to-double (NNDL) logarithmic accuracy in electron-positron annihilation, an order higher in accuracy than previous works in the literature. We match our resummed calculation to the exact NLO ($\mathcal{O}(\alpha_s^2)$) result, showing predictions for the Lund multiplicity at LEP energies with theoretical uncertainties up to $50\%$ smaller than the previous state-of-the-art. Adding hadronisation corrections obtained by Monte Carlo simulations, we also show a good agreement with existing Cambridge multiplicity data. Finally, to highlight the flexibility of our method, we extend the Lund multiplicity calculation to hadronic collisions where we reach next-to-double logarithmic accuracy for colour singlet production.
Comment: 64 pages, 11 figures, minor clarifications, version to appear in JHEP
Databáze: arXiv