A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at √sNN = 5.44 TeV (2021)
ALICE Collaboration. (2021). First measurement of coherent ρ0 photoproduction in ultra-peripheral Xe–Xe collisions at √sNN = 5.44 TeV. Physics Letters B, 820, Article 136481. https://doi.org/10.1016/j.physletb.2021.136481
JYU-tekijät tai -toimittajat
Julkaisun tiedot
Julkaisun kaikki tekijät tai toimittajat: ALICE Collaboration
Lehti tai sarja: Physics Letters B
ISSN: 0370-2693
eISSN: 1873-2445
Julkaisuvuosi: 2021
Volyymi: 820
Artikkelinumero: 136481
Kustantaja: Elsevier BV
Julkaisumaa: Alankomaat
Julkaisun kieli: englanti
DOI: https://doi.org/10.1016/j.physletb.2021.136481
Julkaisun avoin saatavuus: Avoimesti saatavilla
Julkaisukanavan avoin saatavuus: Kokonaan avoin julkaisukanava
Julkaisu on rinnakkaistallennettu (JYX): https://jyx.jyu.fi/handle/123456789/77456
Julkaisu on rinnakkaistallennettu: https://arxiv.org/abs/2101.02581
Tiivistelmä
The first measurement of the coherent photoproduction of ρ0 vector mesons in ultra-peripheral Xe–Xe collisions at sNN=5.44 TeV is presented. This result, together with previous HERA γp data and γ–Pb measurements from ALICE, describes the atomic number (A) dependence of this process, which is particularly sensitive to nuclear shadowing effects and to the approach to the black-disc limit of QCD at a semi-hard scale. The cross section of the Xe+Xe→ρ0+Xe+Xe process, measured at midrapidity through the decay channel ρ0→π+π−, is found to be dσ/dy=131.5±5.6(stat.)−16.9+17.5(syst.) mb. The ratio of the continuum to resonant contributions for the production of pion pairs is also measured. In addition, the fraction of events accompanied by electromagnetic dissociation of either one or both colliding nuclei is reported. The dependence on A of cross section for the coherent ρ0 photoproduction at a centre-of-mass energy per nucleon of the γA system of WγA,n=65 GeV is found to be consistent with a power-law behaviour σ(γA→ρ0A)∝Aα with a slope α=0.96±0.02(syst.). This slope signals important shadowing effects, but it is still far from the behaviour expected in the black-disc limit.
YSO-asiasanat: hiukkasfysiikka; ydinfysiikka
Liittyvät organisaatiot
OKM-raportointi: Kyllä
Raportointivuosi: 2021
JUFO-taso: 2