Study of charm production in the forward cone at energy ELab ∼ 75 TeV with a two-storey X-ray emulsion chamber exposed at, mountain altitudes

• Main Authors: Borisov A.S., Chubenko A.P., Denisova V.G., Galkin V.I., Guseva Z.M., Kanevskaya E.A., Kogan M.G., Kulikov V.N., Morozov A.E., Mukhamedshin R.A., Puchkov V.S., Nazarov S.I., Pyatovsky S.E., Shoziyoev G.P., Smirnova M.D., Vargasov A.V.
• Format: Article
• Language: English
• Published: EDP Sciences 2015-01-01
• Series: EPJ Web of Conferences
• Online Access: http://dx.doi.org/10.1051/epjconf/20159910004
• ISSN: 2100-014X

The origin of the cosmic ray hadron excess observed in a deep uniform lead X-ray emulsion chamber (XREC) at depths larger than 70 radiation lengths is analyzed. We present preliminary experimental data on the absorption of cosmic ray hadrons in the two-storey XREC with a large air gap exposed at the Tien Shan mountains. The design of the chamber was especially invented to prove the hypothesis on a substantial increase of the charm particle production cross section with energy at ELab ∼ 75 TeV as the main source of the darkness spot excess observed on X-ray films. Experimental data obtained with both a 2-storey XREC and a deep uniform XREC are compared with simulation results calculated with the FANSY 1.0 model. The comparison reveals a qualitative agreement between experimental and simulated data under the assumption of high values of charm particle production cross section at ELab ∼ 75 TeV in the forward kinematic region at xLab > 0.1.