Dark Matter and the Baryon Asymmetry

We present a mechanism to generate the baryon asymmetry of the Universe which preserves the net baryon number created in the Big Bang. If dark matter particles carry baryon number $B_X$, and $\sigma^{\rm annih}_{\bar{X}} < \sigma^{\rm annih}_{X}$, the $\bar{X}$'s freeze out at a higher temperature and have a larger relic density than $X$'s. If m_X \lsi 4.5 B_X GeV and the annihilation cross sections differ by $\mathcal{O}$(10%) or more, this type of scenario naturally explains the observed $\Omega_{DM} \approx 5 \Omega_b$. Two concrete examples are given, one of which can be excluded on observational grounds

Detecting Gluino-Containing Hadrons

When SUSY breaking produces only dimension-2 operators, gluino and photino masses are of order 1 GeV or less. The gluon-gluino bound state has mass 1.3-2.2 GeV and lifetime > 10^{-5} - 10^{-10} s. This range of mass and lifetime is largely unconstrained because missing energy and beam dump techniques are ineffective. With only small modifications, upcoming K^0 decay experiments can study most of the interesting range. The lightest gluino-containing baryon (uds-gluino) is long-lived or stable; experiments to find it and the uud-gluino are also discussed.Comment: 13 pp, 1 figure (uuencoded). Descendant of hep-ph/9504295, hep-ph/9508291, and hep-ph/9508292, focused on experimental search techniques. To be published in Phys Rev Let

Connection between a possible fifth force and the direct detection of Dark Matter

If there is a fifth force in the dark sector and dark sector particles interact non-gravitationally with ordinary matter, quantum corrections generically lead to a fifth force in the visible sector. We show how the strong experimental limits on fifth forces in the visible sector constrain the direct detection cross section, and the strength of the fifth force in the dark sector. If the latter is comparable to gravity, the spin-independent direct detection cross section must typically be <~ 10^{-55} cm^2. The anomalous acceleration of ordinary matter falling towards dark matter is also constrained: \eta_{OM-DM} <~ 10^{-8}.Comment: 4 pages, 2 figures. v3: contains a more detailed treatment of the spin-dependence of the effective interaction between dark matter and ordinary matte

Experiments to Find or Exclude a Long-Lived, Light Gluino

Gluinos in the mass range ~1 1/2 - 3 1/2 GeV are absolutely excluded. Lighter gluinos are allowed, except for certain ranges of lifetime. Only small parts of the mass-lifetime parameter space are excluded for larger masses unless the lifetime is shorter than ~ 2 10^{-11} (m_{gluino}/ GeV) sec. Refined mass and lifetime estimates for R-hadrons are given, present direct and indirect experimental constraints are reviewed, and experiments to find or definitively exclude these possibilities are suggested.Comment: 27 pp, latex with 1 uufiled figure, RU-94-35. New version amplifies discussion of some points and corresponds to version for Phys. Rev.

Vibration effects on heat transfer in cryogenic systems Quarterly progress report no. 1, Jun. 1 - Aug. 31, 1966

Vibration effects on natural convection and fluid transport properties in cryogenic system

A Comparison of Occupied and Unoccupied Sharp-Tailed Grouse Habitat in Montana

The sharp-tailed grouse (Tympanuchus phasianellus) was once present throughout the state of Montana. The species was extirpated in Montana west of the Continental Divide by the late 2000’s, while healthy populations still exist east of the Continental Divide. We compared key habitat components important to sharp-tailed grouse survival in occupied areas east of the Divide to unoccupied areas west of the Divide. We measured vegetative variables related to nesting, brood-rearing, and wintering habitat requirements in 3 occupied study areas and 4 unoccupied study areas during the spring of 2015. Habitat Suitability Index scores were calculated for nesting and brood-rearing. Habitat Suitability Index averages show habitat in the Blackfoot valley to be most suitable for sustaining a sharp-tailed grouse population, habitat in the Bitterroot valley to be potentially suitable, and habitat in Drummond and in the Mission Valley to be unsuitable at this time. These results suggest that the Blackfoot and Bitterroot valleys may contain suitable habitat for a potential sharp-tailed grouse reintroduction

Possible manifestation of heavy stable colored particles in cosmology and cosmic rays

We discuss the cosmological implications as well as possible observability of massive, stable, colored particles which often appear in the discussion of physics beyond the standard model. We argue that if their masses are more than a few hundred GeV and if they saturate the halo density and/or occur with closure density of the universe, they are ruled out by the present WIMP search experiments as well as the searches for anomalous heavy isotopes of ordinary nuclei. We then comment on the possibility that these particles as well as the monopoles could be responsible for the ultra high energy cosmic rays with energy $\geq 10^{20}$ eV and point out that their low inelasticity argues against this.Comment: 9 pages; UMD-PP-98-1

Mass distributions for nuclear disintegration from fission to evaporation

By a proper choice of the excitation energy per nucleon we analyze the mass distributions of the nuclear fragmentation at various excitation energies. Starting from low energies (between 0.1 and 1 MeV/nucleon) up to higher energies about 12 MeV/n, we classified the mass yield characteristics for heavy nuclei (A>200) on the basis of Statistical Multifragmentation Model. The evaluation of fragment distribution with the excitation energy show that the present results exhibit the same trend as the experimental ones.Comment: 5 pages, 3 figure