Hadron Production at Intermediate Energies and Lund Area Law

The hadron production mechanism in particle collisions is one of the important subjects in the study of strong interaction. In standard model (QCD), hadronization processes belong to a nonperturbative problem for which no practicable calculation is available. Some phenomenological hadronization models were built up, which play important roles in the studies toward the final understanding of strong interaction. The famous Lund string fragmentation model is one of the successful hadronization schemes, which contains several nontrivial dynamical features and describes the general semi-classical picture of hadron production. At high energies, Lund generator JETSET can simulate the processes of hadron production via single photon annihilation well, and predicts the correct properties of the final states. But the application of the Lund model at intermediate energies has been blank. A direct solution is to start from the basic assumptions of Lund model and find the solutions of the area law without adopting any high-energy approximation. Based on the Lund area law, a new generator LUARLW was compiled, which agrees well with BES data between 3–5 GeV (see Figure 1 on page 186).