Anomalous interactions of secondary particles emitted from relativistic heavy primary interactions

1968 ◽  
Vol 46 (5) ◽  
pp. 343-358 ◽  
Author(s):  
B. Judek
Keyword(s):  
Cross Section ◽  
Cosmic Ray ◽  
Secondary Particles ◽  
Nuclear Interactions ◽  
Charged Secondary ◽  
Singly Charged

Interaction mean free paths of relativistic secondary particles emitted from interactions of heavy primary cosmic-ray nuclei in emulsions were measured. The results show that among the Be, Li, He, and singly charged secondary nuclei there are particles present which interact with a cross section several times higher than the expected geometrical value. The stars produced by these particles have the characteristics of ordinary nuclear interactions. There appears to be no interpretation of these observations in terms of any known particle phenomena.

MULTIFRACTAL STUDY OF SINGLY CHARGED PARTICLES PRODUCED IN 32S INDUCED Ag/Br INTERACTIONS AT CERN

2008 ◽  
Vol 17 (05) ◽  
pp. 802-816 ◽  
Author(s):  
GURMUKH SINGH ◽  
MALAY KUMAR GHOSH ◽  
AMITABHA MUKHOPADHYAY
Keyword(s):  
Incident Energy ◽  
Charged Particles ◽  
Fractal Dimensions ◽  
Multifractal Spectrum ◽  
Monte Carlo Code ◽  
Fractal Nature ◽  
Secondary Particles ◽  
Statistical Fluctuations ◽  
Charged Secondary ◽  
Singly Charged

In this contribution, we describe an investigation of the fractal nature of non-statistical fluctuations in the density distribution of singly charged secondary particles produced in 32 S - Ag / Br interactions in emulsion target at incident energy of 200A GeV. The experimental results have been compared with those obtained from an event sample simulated by the Lund Monte Carlo code FRITIOF. Besides obtaining the fractal dimensions and a smooth multifractal spectrum, show that the results can be used to determine universal parameters such as the Levy index, and the multifractal specific heat.

EVAPORATION NEUTRONS FROM COSMIC RAY NUCLEAR INTERACTIONS IN VARIOUS ELEMENTS

1956 ◽  
Vol 34 (3) ◽  
pp. 288-303 ◽  
Author(s):  
K. W. Geiger
Keyword(s):  
Cosmic Rays ◽  
Cross Section ◽  
Cross Sections ◽  
Boron Trifluoride ◽  
Cosmic Ray ◽  
Atomic Weight ◽  
Nuclear Interactions ◽  
The Mean ◽  
Neutron Multiplicities ◽  
Interaction Cross Sections

Production of evaporation neutrons from nuclear interactions by cosmic rays is investigated in C, Al, Fe, Cu, Pb, and Bi. Boron trifluoride counters in a paraffin moderator in which the element under study is placed serve to detect the evaporation neutrons. A cosmic ray telescope allows the consideration of ionizing neutron-producing particles separately and it is found that of the total neutrons 14.6% are produced by ionizing particles. The mean neutron multiplicities are worked out and they show an increase with the two-thirds power of the atomic weight of the element in which the interactions take place. Also, the rate of interactions is calculated and this gives the relative interaction cross-sections which are found to increase slightly more with atomic weight than expected if the cross-section is geometric. An estimate of the intensity of the N-component is made and discussed in connection with measurements published by other authors.

Further Study of the Anomalous Behavior of Secondary Particles Emitted from Heavy Primary Interactions

1972 ◽  
Vol 50 (18) ◽  
pp. 2082-2095 ◽  
Author(s):  
B. Judek
Keyword(s):  
Free Path ◽  
Relative Intensity ◽  
Cosmic Ray ◽  
Mean Free Path ◽  
Anomalous Behavior ◽  
Tentative Conclusion ◽  
Secondary Particles ◽  
Anomalous Component ◽  
Angular Interval ◽  
Singly Charged

Interaction lengths of singly charged relativistic secondary particles emitted from interactions of very heavy cosmic ray nuclei in emulsions were measured by systematic following of their tracks through the stack. The primary energies were determined by the "knock on" electron method. The results show that particles from interactions with primary energies between 1 and 5 GeV/nucleon emitted in the angular interval [Formula: see text] (θev is the expected RMS angle for evaporation protons) have significantly shorter mean free paths. The variation of the observed mean free paths with distance from the primary interactions shows a transition from short to normal interaction lengths at about 3 cm which indicates the presence of some anomalous component interacting with a very short mean free path of a few cm and relative intensity of order of 10%. This result cannot be accounted for by any known particle or interaction. Considerations of emission angles and types of stars produced by the secondary particles lead to a tentative conclusion that particles exhibiting the anomalously short interaction lengths are scattered fragments of the incident nuclei.

Nuclear interactions of the secondary particles of high-energy cosmic-ray « jets »

1963 ◽  
Vol 28 (6) ◽  
pp. 1238-1245 ◽  
Author(s):  
E. Farrow ◽  
C. F. Gauld ◽  
C. B. A. McCusker ◽  
J. Malos ◽  
K. Nishikawa ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
High Energy ◽  
Secondary Particles ◽  
Nuclear Interactions

An excess radio signal in the Abell 4038 cluster

2020 ◽  
Vol 500 (4) ◽  
pp. 5583-5588
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Spectral Data ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, various instruments, such as the Large Area Telescope (LAT) on the Fermi Gamma Ray Space Telescope, the Alpha Magnetic Spectrometer (AMS) and the Dark Matter Particle Explorer(DAMPE), have been used to detect the signals of annihilating dark matter in our Galaxy. Although some excesses of gamma rays, antiprotons and electrons/positrons have been reported and are claimed to be dark matter signals, the uncertainties of the contributions of Galactic pulsars are still too large to confirm the claims. In this paper, we report on a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming a thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we obtain very large test statistic (TS) values, TS > 45, for four popular annihilation channels, which correspond to more than 6σ statistical preference. This reveals a possible potential signal of annihilating dark matter. In particular, our results are also consistent with the recent claims of dark matter mass, m ≈ 30–50 GeV, annihilating via the $\rm b\bar{b}$ quark channel with the thermal annihilation cross-section. However, at this time, we cannot exclude the possibility that a better background cosmic ray model could explain the spectral data without recourse to dark matter annihilations.

scholarly journals A possible radio signal of annihilating dark matter in the Abell 4038 cluster

2019 ◽  
Vol 495 (1) ◽  
pp. L124-L128 ◽  
Author(s):  
Man Ho Chan ◽  
Chak Man Lee
Keyword(s):  
Dark Matter ◽  
Cross Section ◽  
Radio Signal ◽  
Dark Matter Particle ◽  
Cosmic Ray ◽  
Annihilation Cross Section ◽  
Radio Continuum ◽  
Test Statistic ◽  
Large Area ◽  
Dark Matter Annihilation

ABSTRACT In the past decade, some telescopes [e.g. Fermi-Large Area Telescope (LAT), Alpha Magnetic Spectrometer(AMS), and Dark Matter Particle Explorer(DAMPE)] were launched to detect the signals of annihilating dark matter in our Galaxy. Although some excess of gamma-rays, antiprotons, and electrons/positrons have been reported and claimed as dark matter signals, the uncertainties of Galactic pulsars’ contributions are still too large to confirm the claims. In this Letter, we report a possible radio signal of annihilating dark matter manifested in the archival radio continuum spectral data of the Abell 4038 cluster. By assuming the thermal annihilation cross-section and comparing the dark matter annihilation model with the null hypothesis (cosmic ray emission without dark matter annihilation), we get very large test statistic values >45 for four popular annihilation channels, which correspond to more than 6.5σ statistical preference. This provides a very strong evidence for the existence of annihilating dark matter. In particular, our results also support the recent claims of dark matter mass m ≈ 30–50 GeV annihilating via the bb̄ quark channel with the thermal annihilation cross-section.

scholarly journals On the scattering of fast neutrons by protons

1947 ◽  
Vol 191 (1025) ◽  
pp. 195-209 ◽  
Keyword(s):  
Angular Distribution ◽  
Cross Section ◽  
Cosmic Ray ◽  
Fast Neutrons ◽  
Meson Mass ◽  
Nuclear Forces ◽  
Total Scattering ◽  
Empirical Results ◽  
Meson Theory ◽  
Total Scattering Cross Section

The features of the scattering of fast neutrons by protons are calculated using the Møller- Rosenfeld version of the meson theory of nuclear forces. The experimental results of Occhialini & Powell are used to check the predicted angular distribution of the scattered particles and to determine the mass of the meson; the meson mass indicated is about 215 electronic masses, which agrees with the mass of cosmic ray mesons. The total scattering cross-section predicted by the theory agrees with the empirical results.

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