A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Direct observation of the dead-cone effect in quantum chromodynamics (2022)

ALICE Collaboration. (2022). Direct observation of the dead-cone effect in quantum chromodynamics. Nature, 605(7910), 440-446. https://doi.org/10.1038/s41586-022-04572-w

JYU-tekijät tai -toimittajat

Julkaisun tiedot

Julkaisun kaikki tekijät tai toimittajat: ALICE Collaboration

Lehti tai sarja: Nature

ISSN: 0028-0836

eISSN: 1476-4687

Julkaisuvuosi: 2022

Ilmestymispäivä: 18.05.2022

Volyymi: 605

Lehden numero: 7910

Artikkelin sivunumerot: 440-446

Kustantaja: Nature Publishing Group

Julkaisumaa: Britannia

Julkaisun kieli: englanti

DOI: https://doi.org/10.1038/s41586-022-04572-w

Julkaisun avoin saatavuus: Avoimesti saatavilla

Julkaisukanavan avoin saatavuus: Osittain avoin julkaisukanava

Julkaisu on rinnakkaistallennettu (JYX): https://jyx.jyu.fi/handle/123456789/82673

Julkaisu on rinnakkaistallennettu: https://arxiv.org/abs/2106.05713

Lisätietoja: Publisher Correction: https://doi.org/10.1038/s41586-022-05026-z

Tiivistelmä

In particle collider experiments, elementary particle interactions with large momentum transfer produce quarks and gluons (known as partons) whose evolution is governed by the strong force, as described by the theory of quantum chromodynamics (QCD)1. These partons subsequently emit further partons in a process that can be described as a parton shower2, which culminates in the formation of detectable hadrons. Studying the pattern of the parton shower is one of the key experimental tools for testing QCD. This pattern is expected to depend on the mass of the initiating parton, through a phenomenon known as the dead-cone effect, which predicts a suppression of the gluon spectrum emitted by a heavy quark of mass mQ and energy E, within a cone of angular size mQ/E around the emitter3. Previously, a direct observation of the dead-cone effect in QCD had not been possible, owing to the challenge of reconstructing the cascading quarks and gluons from the experimentally accessible hadrons. We report the direct observation of the QCD dead cone by using new iterative declustering techniques4,5 to reconstruct the parton shower of charm quarks. This result confirms a fundamental feature of QCD. Furthermore, the measurement of a dead-cone angle constitutes a direct experimental observation of the non-zero mass of the charm quark, which is a fundamental constant in the standard model of particle physics.

YSO-asiasanat: hiukkasfysiikka; kvanttiväridynamiikka; kvarkit

Liittyvät organisaatiot

OKM-raportointi: Kyllä

Raportointivuosi: 2022

Alustava JUFO-taso: 3