Nucleon and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="normal">Δ</mml:mi></mml:math> resonances in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi><mml:mi>p</mml:mi><mml:mo stretchy="false">→</mml:mo><mml:msup><mml:mi>K</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi mathvariant="normal">Σ</mml:mi><mml:mn>0</mml:mn></mml:msup><mml:mo stretchy="false">(</mml:mo><mml:mn>1385</mml:mn><mml:mo stretchy="false">)</mml:mo></mml:math> photoproduction
Ai-Chao Wang, Wen-Ling Wang, Fei Huang
Abstract
The photoproduction of $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\mathrm{\ensuremath{\Sigma}}}^{0}(1385)$ is investigated based on an effective Lagrangian approach using the tree-level Born approximation, with the purpose of understanding the reaction mechanisms and resonance contents and their associated parameters in this reaction. In addition to the $t$-channel $K$ and ${K}^{*}(892)$ exchanges, $s$-channel nucleon ($N$) exchange, $u$-channel $\mathrm{\ensuremath{\Lambda}}$ exchange, and generalized contact term, the exchanges of a minimum number of $N$ and $\mathrm{\ensuremath{\Delta}}$ resonances in the $s$ channel are taken into account in constructing the reaction amplitudes to describe the experimental data. It is found that the most recent differential cross-section data from the CLAS Collaboration can be well reproduced by including one of the $N(1895){1/2}^{\ensuremath{-}}$, $\mathrm{\ensuremath{\Delta}}(1900){1/2}^{\ensuremath{-}}$, and $\mathrm{\ensuremath{\Delta}}(1930){5/2}^{\ensuremath{-}}$ resonances. The reaction mechanisms of $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\mathrm{\ensuremath{\Sigma}}}^{0}(1385)$ are discussed in detail, and the predictions of the beam and target asymmetries for this reaction are given. The cross sections of $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{0}{\mathrm{\ensuremath{\Sigma}}}^{+}(1385)$ are shown to be able to further constrain the theoretical models and pin down the resonance contents for $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\mathrm{\ensuremath{\Sigma}}}^{0}(1385)$.