Comparative analysis of ωp , ϕp , and J/ψp scattering lengths from A2, CLAS, and GlueX threshold measure

Abstract

The high accuracy φ-meson photoproduction data from the CLAS experiment in Hall B of Jefferson Laboratory allow us to determine the near-threshold total cross section of the γp → φp reaction and use it for evaluating the φp scattering length α φp . These data result in an absolute value of |α φp | = (0.063 ± 0.010) fm, which is smaller than the typical hadron size. A comparative analysis of α φp with the previously determined scattering lengths for ωp and J/ψp from the A2 and GlueX experiments is performed.

$ϕ$-meson lepto-production near threshold and the strangeness $D$-term

“…In the appendix, we briefly discuss the connection between the two approaches. Other approaches to φ-meson photo-or lepto-production near threshold can be found in [21][22][23].…”

Threshold Upsilon-meson Photoproduction at EIC and EicC

“…The values of |α V p | for the heavy vector-mesons, as determined in the recent papers [13][14][15] using the VMD model, are smaller than most of the theoretical predictions; see references in Refs. [13][14][15].…”

“…The values of |α V p | for the heavy vector-mesons, as determined in the recent papers [13][14][15] using the VMD model, are smaller than most of the theoretical predictions; see references in Refs. [13][14][15]. As for the Υ case, we are not aware of any theoretical predictions for the Υp scattering length except, related to that, FIG.…”

“…5. The total γp → V p cross section σt derived from the A2 (magenta open circles) [13], CLAS (blue filled circles) [14], and GlueX (red filled triangles) [15], data, and EIC/EicC (yellow filled stars) quasi-data is shown as a function of the centerof-mass momentum q of the final-state particles. The vertical (horizontal) error bars represent the total uncertainties of the data summing statistical and systematic uncertainties in quadrature (energy binning).…”

Perturbative QCD Analysis of Near Threshold Heavy Quarkonium Photoproduction at Large Momentum Transfer

“…[1,2], Kharzeev and collaborators proposed the near threshold photoproduction of heavy quarkonium as a way to measure the trace anomaly contribution to the proton mass [3][4][5][6][7][8][9][10]. It has attracted a strong interest from the community [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] due to potential measurements of these processes at the current and future facilities, including JLab-12GeV [30,31], electron-ion colliders (EIC) in US [32,33] and China [34]. The ultimate goal of these studies is to identify the origin of the proton mass [35].…”