D-wave effects in diffractive electroproduction of heavy quarkonia from the photon-like V -> Q(Q)over-bar transition

0523755 - ÚJF 2021 RIV US eng J - Journal Article
Křelina, M. - Nemchik, J. - Pasechnik, Roman
D-wave effects in diffractive electroproduction of heavy quarkonia from the photon-like V -> Q(Q)over-bar transition.
European Physical Journal C. Roč. 80, č. 2 (2020), č. článku 92. ISSN 1434-6044. E-ISSN 1434-6052
R&D Projects: GA MŠMT(CZ) LTT17018
Institutional support: RVO:61389005
Keywords : S-wave * D-wave * electroproduction
OECD category: Particles and field physics
Impact factor: 4.590, year: 2020
Method of publishing: Open access
https://doi.org/10.1140/epjc/s10052-020-7678-3

We analyse the validity of a commonly used identification between structures of the virtual photon gamma*-> Q (Q) over bar over bar and vector meson V -> Q (Q) over bar over bartransitions. In the existing studies of S-wave vector-meson photoproduction in the literature, such an identification is typically performed in the light-front (LF) frame while the radial component of the meson wave function is rather postulated than computed from the first principles. The massive photon-like V -> Q (Q) over bar over bar vertex, besides the S-wave component, also contains an extra D-wave admixture in the Q (Q) over bar over bar rest frame. However, the relative weight of these contributions cannot be justified by any reasonable nonrelativistic Q (Q) over bar over bar potential model. In this work, we investigate the relative role of the D-wave contribution starting from the photon-like quarkonium V -> Q (Q) over bar over bar transition in both frames: in the Q (Q) over bar over bar rest frame (with subsequent Melosh spin transform to the LF frame) and in the LF frame (without Melosh transform). In both cases, we employ the same radial wave functions found in the potential approach.
Permanent Link: http://hdl.handle.net/11104/0308052