R. E. Streitmatter

Unaccompanied hadron flux at a depth of 730 g cm-2, 102<E<104 GeV

The energy spectrum of unaccompanied hadrons has been measured at a depth of 730 g cm-2 in the atmosphere. The energy was determined by a deep calorimeter (960 g cm-2) of area 4 m2. For charged hadrons unaccompanied in a 3.3 m2 spark chamber placed above the calorimeter, the observed flux was fitted in the energy range 100

A new measurement of σp-Feinel and σπ-Feinel at high energies

Abstract Measurements of the inelastic cross sections for hadron-iron nucleus interactions over the hadron energy range of 100–3000 GeV are reported. The cross sections were obtained from the observed attenuation of unaccompanied cosmic ray hadron beams inside an iron calorimeter containing wide-gap spark chambers. A transition radiation detector was used to measure directly the pion content of the hadron beam. The hadron-iron inelastic cross section is seen to increase by (12 ± 4)% over the energy interval 150 GeV to 1250 GeV. Using a value of 1.26 for the ratio σp-Fe/σπ-Fe derived from Glauber theory we deduce that the pion-iron inelastic cross section increases by (7.7 ± 3.4)% over this energy interval.

Hadronic cascade curves in iron between 20 and 8000 GeV

Abstract Cascade curves produced by cosmic ray hadrons in an iron calorimeter with depth 960 g cm−2 have been studied in the energy range 100 e −x L(E) , with x in g cm−2, L(E) = (203±21)+(91±8)log10(E/100 GeV)g cm−2 in the range 20 From this study important conclusions can be drawn concerning the use of thin calorimeters.

Neutral to charged ratio for unaccompanied high-energy cosmic-ray hadrons at mountain altitude

The neutral to charged ratio for unaccompanied high-energy cosmic-ray hadrons has been measured at a mountain altitude of 730 g cm-2 with well-defined geometric selection and good statistical precision. The ratio is found to be independent of energy over the energy range of 100 to 3000 GeV and has an average value of 0.37+or-0.02. Using the directly measured pion to proton ratio with transition radiation detectors for hadrons of energy greater than 400 GeV, this result yields a value for the neutron to proton ratio of 0.67+or-0.08, which is significantly different from the value obtained by Pal and Peters (1964) from phenomenological considerations.

A study of albedo from hadronic calorimeter for energies ≈100–2000 GeV☆

Abstract Characteristics of particles emitted backwards from high energy hadrons interacting in a calorimeter are studied. It is shown that there exists a substantial albedo of charged particles, neutrons and photons. The average yield of this albedo increases logarithmically with energy of the hadrons between 100 and 2000 GeV. This study shows that measurements of the charge of the particle or the number of particles, incident on the calorimeter, with detectors juxtaposed with the calorimeter are of limited value.

Observation of energetic delayed hadrons in extensive air showers–new massive particles?

We report the results of a search for massive relatively long lived particles that has been carried out in an experiment performed at the Sacramento Ridge Cosmic Ray Laboratory in Sunspot, New Mexico (2900 meters altitude) during 1975–1976. Comparison of the experimental data with detailed Monte Carlo simulations provides evidence for the production of new massive particles at high energies.

Composition of primary cosmic rays above 1013 eV from the study of time distributions of energetic hadrons near air shower cores

An experimental study of the distribution of arrival time of energetic hadrons relative to associated air shower particles has been made at a mountain altitude of 730 g.cm−2. Monte Carlo simulations of the expermental observations have shown that these observations are sensitive to the composition of primary cosmic rays of energies 1013–1015 eV. The energy spectra of primary protons and iron group nuclei required to understand these observations are (dN/dE)protons=1.5×104 E−2.71±0.06 m−2 sr−1 sec−1 Gev−1 (dN/dE)Fegroup=1.27 E−2.36±0.06 m−2 sr−2 sec−1 Gev−1 respectively, where E is energy per nucleon, indicating that iron group nuclei are the dominant component of primary cosmic rays at air shower energies of 1014–1016 eV.