Revised data on γ-families observed in X-ray emulsion chambers of the Experiment PAMIR

Recently essential efforts were made to improve measurement routine with X-ray films exposed in the X-ray emulsion chambers at the Pamirs. Analysis of X-ray emulsion response upon recorded events show that γ-family energy and intensity in early publications were over estimated. The main physical results of the new analysis are presented

Gamma-ray families with halos: Main characteristics and possibilities of using them to estimate the p+He fraction in the mass composition of cosmic rays at energies 1–100 PeV

Characteristics of γ-ray families with halos (XREC, Pamir) and data of experiments with EAS are analyzed to estimate the proton and helium (p+He) fractions in the primary cosmic radiation at E0 = 1–100 PeV. It is shown that at energies E0 ∼ 1–100 PeV the fraction of p+He remains significant, namely, the fraction of p+He is near 40% at E0 = 10 PeV

Gamma-ray families with halos: Main characteristics and possibilities of using them to estimate the p+He fraction in the mass composition of cosmic rays at energies 1–100 PeV

Characteristics of γ-ray families with halos (XREC, Pamir) and data of experiments with EAS are analyzed to estimate the proton and helium (p+He) fractions in the primary cosmic radiation at E0 = 1–100 PeV. It is shown that at energies E0 ∼ 1–100 PeV the fraction of p+He remains significant, namely, the fraction of p+He is near 40% at E0 = 10 PeV

Study of charm production in the forward cone at energy

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

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

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