Light-front dynamic analysis of the longitudinal charge density using the solvable scalar field model in (1+1) dimensions
| Autor: | Choi, Yongwoo, Choi, Ho-Meoyng, Ji, Chueng-Ryong, Oh, Yongseok |
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| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Phys. Rev. D 103, 076002 (2021) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.103.076002 |
| Popis: | We investigate the electromagnetic form factor $F(q^2)$ of the meson by using the solvable $\phi^{3}$ scalar field model in $(1+1)$ dimensions. As the transverse rotations are absent in $(1+1)$ dimensions, the advantage of the light-front dynamics (LFD) with the light-front time $x^+ = x^0 + x^3$ as the evolution parameter is maximized in contrast to the usual instant form dynamics (IFD) with the ordinary time $x^0$ as the evolution parameter. In LFD, the individual $x^+$-ordered amplitudes contributing to $F(q^2)$ are invariant under the boost, i.e., frame-independent, while the individual $x^0$-ordered amplitudes in IFD are not invariant under the boost but dependent on the reference frame. The LFD allows to get the analytic result for the one-loop triangle diagram which covers not only the spacelike ($q^{2}<0$) but also timelike region ($q^{2}>0$). Using the analytic results, we verify that the real and imaginary parts of the form factor satisfy the dispersion relations in the entire $q^{2}$ space. Comparing with the results in $(3+1)$ dimensions, we discuss the transverse momentum effects on $F(q^2)$ . We also discuss the longitudinal charge density in terms of the boost invariant variable $\tilde z = p^+ x^-$ in LFD. Comment: 15 pages, 12 figures; Slight changes have been made in the title and abstract. Version to appear in Phys. Rev. D |
| Databáze: | arXiv |
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