First measurement of prompt and non-prompt D.sup.⁎+./sup. vector meson spin alignment in pp collisions at √s=13 TeV

Acharya, S.; Adamová, Dagmar; Adler, A.; Aglieri Rinella, G.; Bielčík, J.; Bielčíková, Jana; Broz, M.; Contreras, J. G.; Filová, V.; Grecká, Ekaterina; Grund, D.; Herman, T.; Isakov, Artem; Kotliarov, Artem; Krupová, D. M.; Křížek, Filip; Křížková Gajdošová, K.; Kushpil, Svetlana; Petráček, V.; Šafařík, K.; Torres, S. R.; Závada, Petr

doi:https://dx.doi.org/10.1016/j.physletb.2023.137920

Počet záznamů: 1

First measurement of prompt and non-prompt D.sup.⁎+./sup. vector meson spin alignment in pp collisions at √s=13 TeV

1.

SYSNO ASEP	0582695
Druh ASEP	J - Článek v odborném periodiku
Zařazení RIV	J - Článek v odborném periodiku
Poddruh J	Článek ve WOS
Název	First measurement of prompt and non-prompt D^⁎+ vector meson spin alignment in pp collisions at √s=13 TeV
Tvůrce(i)	Acharya, S. (IN) Adamová, Dagmar (UJF-V)_{RID, ORCID, SAI} Adler, A. (DE) Aglieri Rinella, G. (CH) Bielčík, J. (CZ) Bielčíková, Jana (UJF-V)_{RID, ORCID, SAI} Broz, M. (CZ) Contreras, J. G. (CZ) Filová, V. (CZ) Grecká, Ekaterina (UJF-V)_ORCID Grund, D. (CZ) Herman, T. (CZ) Isakov, Artem (UJF-V)_{ORCID, SAI} Kotliarov, Artem (UJF-V)_{ORCID, SAI} Krupová, D. M. (CZ) Křížek, Filip (UJF-V)_{RID, ORCID, SAI} Křížková Gajdošová, K. (CZ) Kushpil, Svetlana (UJF-V)_{RID, ORCID, SAI} Petráček, V. (CZ) Šafařík, K. (CZ) Torres, S. R. (CZ) Závada, Petr (FZU-D)_{RID, ORCID}
Celkový počet autorů	1030
Číslo článku	137920
Zdroj.dok.	Physics Letters. B. - : Elsevier - ISSN 0370-2693 Roč. 846, NOV (2023)
Poč.str.	15 s.
Forma vydání	Tištěná - P
Jazyk dok.	eng - angličtina
Země vyd.	NL - Nizozemsko
Klíč. slova	ALICE collaboration ; heavy ion collisions
Obor OECD	Nuclear physics
Výzkumná infrastruktura	CERN-CZ III - 90240 - Fyzikální ústav AV ČR, v. v. i.
Způsob publikování	Open access
Institucionální podpora	FZU-D - RVO:68378271 ; UJF-V - RVO:61389005
UT WOS	001170331200001
EID SCOPUS	85173191408
DOI	10.1016/j.physletb.2023.137920
Anotace	This letter reports the first measurement of spin alignment, with respect to the helicity axis, for D⁎+ vector mesons and their charge conjugates from charm-quark hadronisation (prompt) and from beauty-meson decays (non-prompt) in hadron collisions. The measurements were performed at midrapidity (\|y\|<0.8) as a function of transverse momentum (pT) in proton–proton (pp) collisions collected by ALICE at the centre-of-mass energy s=13TeV. The diagonal spin density matrix element ρ00 of D⁎+ mesons was measured from the angular distribution of the D⁎+→D0(→K−π+)π+ decay products, in the D⁎+ rest frame, with respect to the D⁎+ momentum direction in the pp centre of mass frame. The ρ00 value for prompt D⁎+ mesons is consistent with 1/3, which implies no spin alignment. However, for non-prompt D⁎+ mesons an evidence of ρ00 larger than 1/3 is found. The measured value of the spin density element is ρ00=0.455±0.022(stat.)±0.035(syst.) in the 5<pT<20GeV/c interval, which is consistent with a PYTHIA 8 Monte Carlo simulation coupled with the EVTGEN package, which implements the helicity conservation in the decay of D⁎+ meson from beauty mesons. In non-central heavy-ion collisions, the spin of the D⁎+ mesons may be globally aligned with the direction of the initial angular momentum and magnetic field. Based on the results for pp collisions reported in this letter it is shown that alignment of non-prompt D⁎+ mesons due to the helicity conservation coupled to the collective anisotropic expansion may mimic the signal of global spin alignment in heavy-ion collisions.
Pracoviště	Ústav jaderné fyziky
Kontakt	Markéta Sommerová, sommerova@ujf.cas.cz, Tel.: 266 173 228
Rok sběru	2024
Elektronická adresa	https://doi.org/10.1016/j.physletb.2023.137920

Počet záznamů: 1