In light of recent interest in minimal extensions of the Standard Model and gauge singlet scalar cold dark matter, we provide an arXiv preprint of the paper, published as Phys.Rev. D50 (1994) 3637, which presented the first detailed analysis of gauge singlet scalar cold dark matter. AbstractWe consider a very simple extension of the standard model in which one or more gauge singlet scalars S i couples to the standard model via an interaction of the formwhere H is the standard model Higgs doublet. The thermal relic density of S scalars is calculated as a function of λ S and the S mass m S . The regions of the (m S , λ S ) parameter space which can be probed by present and future experiments to detect scattering of S dark matter particles from Ge nuclei, and to observe upward-moving muons and contained events in neutrino detectors due to high-energy neutrinos from annihilations of S dark matter particles in the Sun and Earth, are discussed. Present experimental bounds place only very weak constraints on the possibility of thermal relic S scalar dark matter. The next generation of cryogenic Ge detectors and of large area (10 4 m 2 ) neutrino detectors will be able to investigate most of the parameter space corresponding to thermal relic S scalar dark matter with m S < ∼ 50GeV, while a 1 km 2 detector would in general be able to detect thermal relic S scalars with m S < ∼ 100GeV as a dark matter candidate and would be able to detect up to m S < ∼ 500GeV or more if the Higgs boson is lighter than 100GeV.

We show that Q-balls naturally exist in the Minimal Supersymmetric Standard Model (MSSM) with soft SUSY breaking terms of the minimal N=1 SUGRA type. These are associated with the F-and D-flat directions of the scalar potential once radiative corrections are taken into account. We consider two distinct cases, corresponding to the "H u L" (slepton) direction with L-balls and the "u c d c d c " and "u c u c d c e c " (squark) directions with B-balls. The L-ball always has a small charge, typically of the order of 1000, whilst the B-ball can have an arbitrarily large charge, which, when created cosmologically by the collapse of an unstable Affleck-Dine condensate, is likely to be greater than 10 14 . The B-balls typically decay at temperatures less than that of the electroweak phase transition, leading to a novel version of Affleck-Dine baryogenesis, in which the B asymmetry comes from Q-ball decay rather than condensate decay. This mechanism can work even in the presence of additional L violating interactions or B −L conservation, which would rule out conventional Affleck-Dine baryogenesis. 1 enqvist@pcu.helsinki.fi; 2 mcdonald@outo.helsinki.fi

We show that a gauge singlet scalar S, with a coupling to the Higgs doublet of the form l S S y SH y H and with the S mass entirely generated by the Higgs expectation value, has a thermally generated relic density V S ഠ 0.3 if m S ഠ ͑2.9 10.5͒ ͑V S ͞0. [3,4]. Observationally, the density profile of galaxies in the inner few kiloparsecs appears to be much shallower than predicted by numerical simulations (the central density of dark matter halos being 50 times smaller than the CCDM prediction for dwarf galaxies and roughly independent of halo mass [2,5]), while the number of dwarf galaxies in the local group is an order of magnitude fewer than predicted [3,4]. In addition, the CCDM predictions for the Tully-Fisher relation [6,7] and the stability of galactic bars in high surface brightness spiral galaxies [8] are not in agreement with what is observed, indicating lower density galaxy cores than predicted by CCDM. Although there is at present considerable uncertainty regarding the interpretation of observations and simulations [9,10], it has nevertheless been argued that all the discrepancies between observations and simulations may be understood as indicating that dark matter halos in CCDM simulations are more centrally concentrated than observed [11].In order to overcome the possible deficiencies of CCDM halos, one suggestion has been that the cold dark matter particles have a nondissipative self-interaction [12,13], and it has been shown that such cold, nondissipative selfinteracting dark matter (SIDM) can be effective in alleviating the various problems of CCDM [11]. Scattering of dark matter particles stops gravitational accretion at the center of the halo and so allows a smooth core to form. Simulations with SIDM [11,14] are able to simultaneously account for the observed density profiles of galactic halos and the number of subhalos [11]. In the future SIDM may be strongly constrained by gravitational lensing observations of the shape of cluster halos [15][16][17] and by the formation of massive black holes at the centers of galaxies, which is enhanced by self-interactions of dark matter particles [18].In order to be able to account for the observed properties of dark matter halos, the requirement on the mass M and

The Main Injector Neutrino Oscillation Search (MINOS) experiment uses an acceleratorproduced neutrino beam to perform precision measurements of the neutrino oscillation parameters in the "atmospheric neutrino" sector associated with muon neutrino disappearance. This long-baseline experiment measures neutrino interactions in Fermilab's NuMI neutrino beam with a near detector at Fermilab and again 735 km downstream with a far detector in the Soudan Underground Laboratory in northern Minnesota. The two detectors are magnetized steel-scintillator tracking calorimeters. They are designed to be as similar as possible in order to ensure that differences in detector response have minimal impact on the comparisons of event rates, energy spectra and topologies that are essential to MINOS measurements of oscillation parameters. The design, construction, calibration and performance of the far and near detectors are described in this paper.