TY  - JOUR
AU  - Du, Meng-Lin
AU  - Baru, Vadim
AU  - Guo, Feng-Kun
AU  - Hanhart, Christoph
AU  - Meißner, Ulf-G.
AU  - Nefediev, Alexey
AU  - Strakovsky, Igor
TI  - Deciphering the mechanism of near-threshold $$J/\psi $$ photoproduction
JO  - The European physical journal / C
VL  - 80
IS  - 11
SN  - 1434-6052
CY  - Heidelberg
PB  - Springer
M1  - FZJ-2020-04549
SP  - 1053
PY  - 2020
AB  - The photoproduction of the J/ψ off the proton is believed to deepen our understanding of various physics issues. On the one hand, it is proposed to provide access to the origin of the proton mass, based on the QCD multipole expansion. On the other hand, it can be employed in a study of pentaquark states. The process is usually assumed to proceed through vector-meson dominance, that is the photon couples to a J/ψ which rescatters with the proton to give the J/ψp final state. In this paper, we provide a compelling hint for and propose measurements necessary to confirm a novel production mechanism via the ΛcD¯(∗) intermediate states. In particular, there must be cusp structures at the ΛcD¯(∗) thresholds in the energy dependence of the J/ψ photoproduction cross section. The same mechanism also implies the J/ψ-nucleon scattering lengths of order 1 mfm. Given this, one expects only a minor contribution of charm quarks to the nucleon mass.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000594659200002
DO  - DOI:10.1140/epjc/s10052-020-08620-5
UR  - https://juser.fz-juelich.de/record/887963
ER  -