HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

20 latex pages, 1 figure added via figures command

Scientific paper

10.1103/PhysRevD.52.6682

We consider the production of $^3$He and $^2$H by $^4$He photodisintegration initiated by non-thermal energy releases during early cosmic epochs. We find that this process cannot be the predominant source of primordial $^2$H since it would result in anomalously high $^3$He/D ratios in conflict with standard chemical evolution assumptions. We apply this fact to constrain topological defect models of highest energy cosmic ray (HECR) production. Such models have been proposed as possible sources of ultrahigh energy particles and gamma-rays with energies above $10^{20}$eV. The constraints on these models derived from $^4$He-photodisintegration are compared to corresponding limits from spectral distortions of the cosmic microwave background radiation (CMBR) and from the observed diffuse gamma-ray background. It is shown that for reasonable primary particle injection spectra superconducting cosmic strings, unlike ordinary strings or annihilating monopoles, cannot produce the HECR flux at the present epoch without violating at least the $^4$He-photodisintegration bound. The constraint from the diffuse gamma-ray background rules out the dominant production of HECR by the decay of Grand Unification particles in models with cosmological evolution assuming standard fragmentation functions. Constraints on massive black hole induced photodisintegration are also discussed.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and HELIUM PHOTODISINTEGRATION AND NUCLEOSYNTHESIS: IMPLICATIONS FOR TOPOLOGICAL DEFECTS, HIGH ENERGY COSMIC RAYS, AND MASSIVE BLACK HOLES will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-202591

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.