Report

Estimation of charm production cross section in hadronic interactions at high energies s > 1.8 TeV Yu.F. Novoseltsev1, G.M. Vereshkov1,2 1Institute for Nuclear Research of RAS 2Physics Research Institute of Rostov State University Pylos - 2004 1 The analysis is carried out within the frame of phenomenological model of diffractive production and quark statistics based on additive quark model (AQM) We make use of low energy data on charm production and collider data on diffractive dissociation At collider energies 200, 540, 900, 1800 GeV , the values of σppccX (s) were obtained by a quark statistics method It is established, that logarithmic function with universal numerical parameters describes the whole set of low-energy and high-energy data with high accuracy The expected values of cross section are σppccX = 250 ± 15 µb at TEVATRON energy s = 1.96 TeV and 355 ± 22 µb at LHC energy s = 14 TeV Discussion Pylos - 2004 2 The estimation of the total charm production cross section is based on processing of collider data on diffractive dissociation with use of phenomenological model of diffractive charm production and quark statistics. Cross section of diffractive dissociation in pp-interactons: SPS --- √s = 200 GeV, 900 GeV (Ansorge et al., 1986) TEVATRON --- √s = 546 GeV, 1800 Gev (Abe et al., 1994) σDD(pp X) = CDD ln(s/so) The basic assumptions consist in the following: 1) charm production occurs in process of diffractive dissociation; 2) charm production cross section is extracted from total cross section by quark statistics rules: σtot( pp cc + X) ≈ kcc× σDD(pp X), kcc ≈ 0.025 ± 0.004 uu : dd : ss : cc = 1 : 1 : (0.38 ± 0.07) : (0.06 ± 0.01) Pylos - 2004 3 Data on total cross section of charm production at s = 20 − 40 GeV To begin with, we clear up the opportunities of AQM and logarithmic dependence for cross section in the description of data on charm production in pN and N interactions at low energies: σNcc+X(s) = ⅔ σpNcc+X(3s/2) σpNcc+X(s) = CpN ln(s/so) CpN = 28.84 ± 2.10 μb, √so = 18.51 ± 0.36 GeV , 2 = 0.89 Pylos - 2004 (1) 4 σ(pp cc +X) at collider energies √s, GeV σDD, mb 200 546 900 4.8 ± 0.5 7.89 ± 0.33 7.8 ± 0.5 9.46 ± 0.44 σ(pp cc +X) = kcc × σDD , σpp cc +X, μb 1800 120 ± 21 197 ± 32 (2) 195 ± 32 236 ± 38 The obtained values of charm production cross section have the status of model dependent processing collider data Pylos - 2004 5 Joint fit of low-energy and high-energy data on charm production The strip corresponds to 90 % CL Values of C and so in (1) and (3) coincide within the limits of statistical errors (3 ) √ The charm production cross section in hadronic interaction is described by universal logarithmic dependence Pylos - 2004 6 Ideas of phenomenological models of diffractive production and quark statistics were repeatedly tested at processing most various experimental data. These models give reliable quantitative predictions at the accuracy level 10 - 20 % after fixing several parameters by experimental data. Therefore we consider possible to use the results (3) for forecasting cross section of charm production in pp/pp interactions in overaccelerating energy range. Pylos - 2004 7 Forecast of charm production cross section at √s > 1.8 TeV These results mean the flux of “prompt” muons becomes equal to the flux of “conventional” (from ,K-mesons) muons of CR at Eμ = 500 − 600 TeV 8 There are three possible (and alternative) variants of results, each of which represents the certain interest. The measured flux of CR muons within the limits of measurement errors coincides with calibration flux calculated according to the estimation (4). In this case the estimation (4) can be used for testing microscopic models. The measured flux of CR muons will exceed noticeably the calibration value, but the σpp ccX at energies in the region of a break of CR energy spectrum will stay essentially smaller 10 mb. In this case it will be necessary to recognize, that either quark statistics rules become incorrect in the area of high energies, or the new mechanism of charm production, distinct from the diffractive one, is included at these energies. The measured flux of CR muons will correspond formally to σpp ccX > 10 mb This result will mean that VHE muons carry away the energy from EAS forming an observable break of CR spectrum. It is necessary to note, that sources of such big numbers of VHE muons, most likely, are not reduced to charmed particles − a New physics will required for interpretation of such effect. Pylos - 2004 9