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Chen Jacoby

Publications and source records attributed to Chen Jacoby.

4 recordsLinked to original sources

Some Comments on the `Quirks' Scenario

We discuss various aspects of models with long-lived or stable colored particles. In particular we focus on an ideal Quirk model with electroweak neutral heavy (O(TeV)) particles which carry ordinary color and another $ SU'(3)$ color with a very low scale $Λ'$. We show that contrary to what one might think, such a model is cosmologically consistent and evades many "Pitfalls" even for very low O(10 eV) $Λ'$ and without assuming a low reheat temperature. We also show that the expected production of Quirks by cosmic rays which are incorporated in heavy Isotopes in Ocean water is consistent with the highly stringent bounds on the latter. This evades a real threat to the Quirk model which would have excluded it regardless of Cosmology. Finally we briefly comment on possible LHC signatures.

hep-ph

The Relic Abundance of Massive Colored Particles after a Late Hadronic Annihilation Stage

We discuss the relic abundance of massive long lived colored particles with mass of the order of 1 TeV. We first examine the case where the massive colored particles have the standard color only. Next we consider the "Quirk Model" suggested by M. Luty, in which the colored particles transform under an additional non-abelian gauge group with a scale much smaller than the particles' mass. In both cases, the relic abundance is reduced via a "late" hadronic annihilation stage. In the second case the relic Quirks bind to ordinary quarks forming fractional charged objects and also anomalous heavy isotopes, and the bounds on the relic abundance become extremely severe. The force between Quirks, however, has a new confining part that manifests via macroscopic strings and the resulting efficient "very late" annihilations reduce the relic abundance to acceptable levels. The prospects of creating and detecting such particles at LHC and the fate of the particles created are discussed.

hep-ph

Some Comments on an MeV Cold Dark Matter Scenario

We discuss several aspects of astroparticle physics pertaining to a new model with MeV cold dark matter particles, which annihilate to electron-positron pairs in a manner yielding the correct CDM density required today, and explaining the enhanced electron-positron annihilation line from the center of the Galaxy. We note that the mass of the vector meson mediating the annihilations, should exceed the mass of CDM particle, and comment on possible enhancement due to CDM clustering, on the detectability of the new CDM, and on particle physics models incorporating this scenario.

hep-ph

Enhanced Emission and Accumulation of Antiprotons and Positrons from Supersymmetric Dark Matter

We estimate the amount of antiprotons and positrons in cosmic rays due to neutralino annihilations in the galactic halo assuming that dark matter tends to cluster and that these clusters are not disturbed by tidal forces. We find that, assuming neutralinos annihilate mostly to gauge bosons, the amount of antiprotons should exceed the number seen at BESS, whereas the increase in positron flux is below the present detection threshold.

hep-ph