https://doi.org/10.1140/epjc/s10052-023-11174-x
Regular Article - Theoretical Physics
Production of double heavy quarkonia at super Z factory
1
Chongqing College of Mobile Telecommunications, 401520, Chongqing, China
2
School of Physics, Shandong University, 250100, Jinan, Shandong, China
Received:
8
August
2022
Accepted:
22
December
2022
Published online:
16
January
2023
Within the color singlet model, we calculate the exclusive production of double charmonia, double bottomonia, and double 
mesons at future super Z factory. The two heavy quarkonia or ’s are either two S-wave Fock states (
), or one S-wave and one P-wave states (
). The top three 
propagated channels in cross sections for double charmonia are 
, and 
. For double bottomonia, they are 
, and 
. For double mesons, they are 
, 
, and 
. Here the uncertainties come from the varying masses of constituent heavy quarks, which bring up to 20% corrections. The cross sections of double mesons are roughly one order of magnitude larger than those of the double bottomonia, and two orders of magnitude larger than those of the double charmonia. To make it helpful for experimental study, we present the total cross sections 
as functions of CM energy 
, as functions of the renormalization scale 
, the angle distributions 
, and the 
distributions 
. We also find that the initial state radiation can bring about 30–40% suppresions when 1%
energy is losing, and cross sections can increase by about 2–3 times or decrease by an order of magnitude when adopting different potential models which becomes the major source of uncertainty. The numerical results show that it might be not optimistic for the experimental observation, but it is still far from excluded at the FCC-ee and also the CEPC running in the Z factory mode.
© The Author(s) 2023
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development.
