Measurement of the angle between jet axes in pp collisions at √s=5.02 TeV

作者:Acharya, S.; Adamova, D.; Adler, A.; Rinella, G. Aglieri; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmad, S.; Ahn, S. U.; Ahuja, I.; Akindinov, A.; Al-Turany, M.; Aleksandrov, D.; Alessandro, B.; Alfanda, H. M.; Alfaro Molina, R.; Ali, B.; Alici, A.; Alizadehvandchali, N.; Alkin, A.; Alme, J.; Alocco, G.; Alt, T.; Altsybeev, I.; Anaam, M. N.; Andrei, C.; Andronic, A.; Anguelov, V.; Antinori, F.; Antonioli, P.; Apadula, N.; Aphecetche, L.; Appelshaeuser, H.; Arata, C.; Arcelli, S.; Aresti, M.
来源:JOURNAL OF HIGH ENERGY PHYSICS, 2023, (7): 201.
DOI:10.1007/JHEP07(2023)201

摘要

This article reports measurements of the angle between differently defined jet axes in pp collisions at root s = 5.02TeV carried out by the ALICE Collaboration. Charged particles at midrapidity are clustered into jets with resolution parameters R = 0.2 and 0.4. The jet axis, before and after Soft Drop grooming, is compared to the jet axis from the Winner-Takes-All (WTA) recombination scheme. The angle between these axes, Delta R-axis, probes a wide phase space of the jet formation and evolution, ranging from the initial high-momentum-transfer scattering to the hadronization process. The Delta R-axis observable is presented for 20 < p(T)(ch jet) < 100 GeV/c, and compared to predictions from the PYTHIA 8 and Herwig 7 event generators. The distributions can also be calculated analytically with a leading hadronization correction related to the non-perturbative component of the Collins Soper-Sterman (CSS) evolution kernel. Comparisons to analytical predictions at nextto-leading-logarithmic accuracy with leading hadronization correction implemented from experimental extractions of the CSS kernel in Drell-Yan measurements are presented. The analytical predictions describe the measured data within 20% in the perturbative regime, with surprising agreement in the non-perturbative regime as well. These results are compatible with the universality of the CSS kernel in the context of jet substructure.

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