论文标题
$ ϕ $梅森质子的电气生产调查质子
Investigation of electroproduction of $ϕ$ mesons off protons
论文作者
论文摘要
我们通过在$ q^2 $ =（0 $ - $ - $ - $ 4）$ Q^2 $ =（0 $ - $ 4）的运动范围内采用树级有效的Lagrangian方法来调查质子目标的$ ϕ $ -Meson电源增生，即$γ^* p \ to ϕp $ \ leq 2 \，\ mathrm {gev}^2 $。除了普遍接受的Pomeron Exchange外，我们还考虑使用Regge方法中的$ T $渠道中的各种介子交换。 $ S $中的直接$ ϕ $ -Meson辐射也被考虑在内。我们发现横向（$σ_{\ mathrm {t}} $）的$ q^2 $依赖性和纵向（$σ_{\ Mathrm {l}} $）跨部门由Pomeron和Pomeron和$（A_0，F_0，F_0，F_0，F_0）$ Scalar Meson Exchandes管理。同时，$（π，η）$ pseudoscalar-和$ f_1（1285）的贡献更加受到压制。干扰横截面的结果（$σ_{\ Mathrm {lt}}，σ_ {\ MathRM {lt}} $）和旋转型矩阵元素表明$ s $ channel helicity helicity helicity kearveration在$ q^2 $ =（1 $ - $ 4）$ 4）$ 4）$ nm =均等不对称的结果$ p \ simeq 0.95 $ at $ w $ = 2.5 GEV，这意味着自然 - 公平交换在反应过程中占主导地位。我们的数值结果与实验数据达成公平的一致性，因此，在考虑的运动范围内，使用我们有效的重新装置模型是合理的。
We investigate $ϕ$-meson electroproduction off the proton target, i.e., $γ^* p \to ϕp$, by employing a tree-level effective Lagrangian approach in the kinematical ranges of $Q^2$ = (0$-$4) $\mathrm{GeV}^2$, $W$ = (2$-$5) GeV, and $|t| \leq 2\,\mathrm{GeV}^2$. In addition to the universally accepted Pomeron exchange, we consider various meson exchanges in the $t$ channel with the Regge method. Direct $ϕ$-meson radiations in the $s$- and $u$-channels are also taken into account. We find that the $Q^2$ dependence of the transverse ($σ_{\mathrm{T}}$) and longitudinal ($σ_{\mathrm{L}}$) cross sections are governed by Pomeron and $(a_0,f_0)$ scalar meson exchanges, respectively. Meanwhile, the contributions of $(π,η)$ pseudoscalar- and $f_1(1285)$ axial-vector-meson exchanges are much more suppressed. The results of the interference cross sections ($σ_{\mathrm{LT}}, σ_{\mathrm{LT}}$) and the spin-density matrix elements indicate that $s$-channel helicity conservation holds at $Q^2$ = (1$-$4) $\mathrm{GeV}^2$. The result of the parity asymmetry yield $P \simeq 0.95$ at $W$ = 2.5 GeV, meaning that natural-parity exchange dominates the reaction process. Our numerical results are in fair agreement with the experimental data and thus the use of our effective Reggeized model is justified over the considered kinematical ranges of $Q^2$, $W$, and $t$.
