论文标题
$γγ\至π^+π^-π^0 $反应的现象学模型
Phenomenological model for the $γγ\to π^+π^-π^0$ reaction
论文作者
论文摘要
我们通过包括$ a_2（1320）$共振的生产机制以及$σ/f_0（500）\，π^0 $和$ f_2（1270）\，$ f_2（1270）\，$ f_2（1270）\，$ f_2（1270）\，$ f_2（1270）\，f _2（1270）\，f _2（1270）\，f _2（1270）\，$γ^（1320）$ resonance的生产机制，提出了$γγ\至π^+π^-π^0 $反应的现象学模型。此外，$γγ\toρ^{\ pm}π^{\ mp} \toπ^{+}π^-π^0 $通道，对于在低能区域中的描述是必不可少的，是通过介绍完整的仪表不态和lorentz-covariant the $ pm的$ untergariant和lorentz-covariant Tensors^^^for pm pm^use^$ gouth^use的描述。 π^\ mp $子进程。构建完整的幅度以产生正确的高能恢复行为。在我们的模型中，我们对总横截面的Argus和L3数据进行了非常合理的描述，以及$π^\pmπ^0 $和$π^+π^ - $不变的质量分布。我们还预测，$γγ$质量中心能源的不变质量分布范围从$ 0.8 $ GEV到$ 2.0 $ GEV，这将通过BESIII合作的即将到来的数据进行研究。
We present a phenomenological model for the $γγ\to π^+π^-π^0$ reaction by including the production mechanism of the $a_2(1320)$ resonance, as well as the contributions from the $σ/f_0(500)\, π^0$ and $f_2(1270)\, π^0 $ production channels. Furthermore, the $γγ\toρ^{\pm} π^{\mp}\toπ^{+}π^-π^0$ channel, which is essential for a description in the low-energy region, is investigated carefully by introducing the complete set of gauge invariant and Lorentz-covariant tensors for the $γγ\toρ^\pm π^\mp$ subprocess. The full amplitude is constructed to yield a correct high-energy Regge behavior. Within our model, we achieve a very reasonable description of ARGUS and L3 data of the total cross section, as well as of the $π^\pmπ^0$ and $π^+π^-$ invariant mass distributions. We also predict the invariant mass distributions in the $γγ$ center-of-mass energy range from $0.8$ GeV to $2.0$ GeV, which will be studied by the forthcoming data of the BESIII collaboration.
