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[hep-th/0610267] An Electroweak Oscillon

Posted: November 07 2006
by Tommy Anderberg
Very interesting paper for several reasons:

- Could provide a minimal (i.e. non-exotic) dark matter candidate reminescent of the "encapsulated atoms" idea of astro-ph/0512454, especially if it turns out to be further stabilized by fermions.

- Unless I've missed something, it's the first dynamically stable, non-trivial electroweak field configuration found since dynamically stable Z-strings were ruled out by rising experimental limits on the Higgs mass, way back in the early 90s. What else is there in "known" territory that hasn't been found yet?

- The computational time required to evolve the electroweak (boson only) equations over 100000 time steps on a modest ~40^3 grid (if I'm reading this correctly) was 72*24 = 1728 hours = 72 days using 2 GHz Opterons. A bit depressing if you happen to be contemplating the possibility of evolving large-scale, random initial configurations numerically (guess why...) and don't own a supercomputer. :(

Maybe I should go BOINC myself.

Addendum: lest I fall in the ubiquitous premature-conclusion trap, I now (November 16, 2006) remind myself that it's really boson-sector-only Z-strings that have been determined to be unstable (for physical values of the weak mixing angle and Higgs mass; see e.g. hep-ph/9402207). In the presence of fermions, things may yet turn out to be different. A (far from exhaustive) search turns up some interesting recent work by Oliver Schröder on Z-strings stabilizing by binding very large numbers of fermions: hep-th/0601196, hep-th/0607092, QFEXT05 presentation.

Also, Nagasawa and Brandenberger have argued that Z strings are stabilized by plasma effects from the electroweak phase transition all the way down to recombination (!) (hep-ph/0207246).