Breaking of color strings as a source of low-mass leptonic pairs in multiple hadron production

Cross section of leptonic pair production with mass of M ∼ 0.4-0.6 GeV in hadronic interactions is estimated in the central region of rapidities due to tunneling production from vacuum of qq-barll-bar systems in the chromoelectric field of the string. If the yield of ll-bar pairs increases by a factor of ∼ 2-3 due to radiative transitions of qq-bar chains of the string, then in the model of colored strings, for M lying in the region under consideration, one obtains the ll-bar-pair production cross section whose value will be close to the experimental one for the gluonic string tension χg ∼ 0.6-0.8 GeV2