Strange quark matter fragmentation in astrophysical events

The conjecture of Bodmer-Witten-Terazawa suggesting a form of quark matter (Strange Quark Matter) as the ground state of hadronic interactions has been studied in laboratory and astrophysical contexts by a large number of authors. If strange stars exist, some violent events involving these compact objects, such as mergers and even their formation process, might eject some strange matter into the interstellar medium that could be detected as a trace signal in the cosmic ray flux. To evaluate this possibility, it is necessary to understand how this matter in bulk would fragment in the form of strangelets (small lumps of strange quark matter in which finite effects become important). We calculate the mass distribution outcome using the statistical multifragmentation model and point out several caveats affecting it. In particular, the possibility that strangelets fragmentation will render a tiny fraction of contamination in the cosmic ray flux is discussed.Comment: 13 pages, 4 figure

Interaction of strangelets with ordinary nuclei

Strangelets (hypothetical stable lumps of strange quarkmatter) of astrophysical origin may be ultimately detected in specific cosmic ray experiments. The initial mass distribution resulting from the possible astrophysical production sites would be subject to reprocessing in the interstellar medium and in the earth's atmosphere. In order to get a better understanding of the claims for the detection of this still hypothetic state of hadronic matter, we present a study of strangelet-nucleus interactions including several physical processes of interest (abrasion, fusion, fission, excitation and de-excitation of the strangelets), to address the fate of the baryon number along the strangelet path. It is shown that, although fusion may be important for low-energy strangelets in the interstellar medium (thus increasing the initial baryon number A), in the earth's atmosphere the loss of the baryon number should be the dominant process. The consequences of these findings are briefly addressed

Color-flavor locked strange matter and strangelets at finite temperature

It is possible that a system composed of up, down and strange quarks consists the true ground state of nuclear matter at high densities and low temperatures. This exotic plasma, called strange quark matter (SQM), seems to be even more favorable energetically if quarks are in a superconducting state, the so-called color-flavor locked state. Here are presented calculations made on the basis of the MIT bag model considering the influence of finite temperature on the allowed parameters characterizing the system for stability of bulk SQM (the so-called stability windows) and also for strangelets, small lumps of SQM, both in the color-flavor locking scenario. We compare these results with the unpaired SQM and also briefly discuss some astrophysical implications of them. Also, the issue of strangelet's electric charge is discussed. The effects of dynamical screening, though important for non-paired SQM strangelets, are not relevant when considering pairing among all three flavor and colors of quarks.Comment: 17 pp. 15 figs., to appear in Phys. Rev.