545 research outputs found

    Virginia’s Land Mammals: Past and Present, With Some Thoughts About Their Possible Future

    Get PDF
    Mammals encountered today in Virginia’s forests and fields include native and nonnative species, feral populations, and free-ranging pets. We examine factors that have influenced Virginia’s terrestrial mammal fauna since the arrival of European colonists in the 1600s and some of the factors that are shaping the fauna today. We look in depth at changes since Handley and Patton’s (1947) first complete monograph on Virginia mammals and augment Linzey’s (1998) book, The Mammals of Virginia. We include current nomenclature, baseline information, and references to comprehensive literature. We discuss some of the current and developing anthropogenic factors that have impacted, or that likely will impact, our native land mammals as well as factors that bode well for many species, especially in areas of conservation of habitat

    No New Symmetries of the Vacuum Einstein Equations

    Get PDF
    In this note we examine some recently proposed solutions of the linearized vacuum Einstein equations. We show that such solutions are {\it not} symmetries of the Einstein equations, because of a crucial integrability condition.Comment: 9 pages, Te

    Quantum Hall States of Gluons in Quark Matter

    Full text link
    We have recently shown that dense quark matter possesses a color ferromagnetic phase in which a stable color magnetic field arises spontaneously. This ferromagnetic state has been known to be Savvidy vacuum in the vacuum sector. Although the Savvidy vacuum is unstable, the state is stabilized in the quark matter. The stabilization is achieved by the formation of quantum Hall states of gluons, that is, by the condensation of the gluon's color charges transmitted from the quark matter. The phase is realized between the hadronic phase and the color superconducting phase. After a review of quantum Hall states of electrons in semiconductors, we discuss the properties of quantum Hall states of gluons in quark matter in detail. Especially, we evaluate the energy of the states as a function of the coupling constant. We also analyze solutions of vortex excitations in the states and evaluate their energies. We find that the states become unstable as the gauge coupling constant becomes large, or the chemical potential of the quarks becomes small, as expected. On the other hand, with the increase of the chemical potential, the color superconducting state arises instead of the ferromagnetic state. We also show that the quark matter produced by heavy ion collisions generates observable strong magnetic field 1015\sim 10^{15} Gauss when it enters the ferromagnetic phase.Comment: 11 pages, 2 figure

    Keys to the Mammals and Mammal Skulls of the Northern Coastal Plain of Virginia

    Get PDF
    This publication is designed to function as a tool for the identification of mammal species that occur on the Coastal Plain of northern Virginia. We provide whole-body and skull keys to the 40 species that occur in this region. Baseline data for this work were collected during several studies conducted on Fort A.P. Hill, Caroline County. The intended audience includes interested naturalists, teachers, students, field biologists, and natural resource managers

    Mammals of Fort A. P. Hill, Caroline County, Virginia and Vicinity

    Get PDF
    Fort A.P. Hill (APH) is a 30,329 ha military training installation (U.S. Army) located in the upper Coastal Plain of Caroline County, Virginia. It was formed in 1941 and named in honor of Civil War Confederate Lt. General Ambrose Powell Hill. The current landscape includes a mosaic of habitats that range from old fields to hardwood forests. Forty species of mammals are known to exist on or near the installation. These include one marsupial, five insectivores, 9 chiropterans, one lagomorph, 12 rodents, 10 carnivores, and one cervid. We have studied many of the species on APH since 1997. In this paper we describe the physical environment of the area and 7 important habitats used by mammals. We also summarize the ecology and natural history of each species and provide statistical summaries of original measurements from mammals caught on the installation. The results of several recent studies on APH allow us to describe habitat affiliations and relative abundance of most of the mammals native to the mid-Atlantic region. Old fields and clearcuts support a total of 20 species, including several found predominately in this habitat. Pine stands and pine plantations support the fewest number of mammal species (17) of any habitat on the installation. Mixed pine and hardwood forests, hardwood forests, and riparian forests support the largest number of species (29-36). With the possible exception of pine plantations, the habitat mosaic found on APH provides abundant resources for mammal communities. We also include an evaluation of age and health attributes of the deer population and describe the hunting program on the base. Number of deer harvested annually 1985-2000 varied from 460 to 1765. Management activities since 1996 when the deer population exceeded carrying capacity have improved herd health. Because much of Caroline County and eastern Virginia is in extensive agriculture and the remaining hardwood forests are being clearcut, APH is becoming a valuable habitat island for the mammalian fauna of the upper Coastal Plain of Virginia and the mid-Atlantic region

    Scalars from Top-condensation Models at Hadron Colliders

    Get PDF
    We study the production and decay of neutral scalars and pseudo-scalars at hadron colliders, in theories where the top-quark mass is the result of a ttˉt\bar t condensate. We show that the dominant decay channel for masses below the ttˉt\bar t threshold is the flavor changing mode tctc. This is a consequence of the non-universal nature of the underlying interactions in all top-condensation models and provides a model-independent signature of these scenarios. We show that an upgraded Tevatron is sensitive to a sizeable region of the interesting parameter space and that the LHC will highly constrain these models through this flavor violating channel.Comment: 4 pages, 4 figures. Minor changes in figures for readibility. final version to appear in PR

    Large Possible retardation effects of quark confinement on the meson spectrum II

    Full text link
    We present the results of a study of heavy-light-quark bound states in the context of the reduced Bethe-Salpeter equation with relativistic vector and scalar interactions. We find that satisfactory fits may also be obtained when the retarded effect of the quark-antiquark interaction is concerned.Comment: 11 pages, RevTex, to appear in PR

    Classical glueballs in non-Abelian Born-Infeld theory

    Full text link
    It is shown that the Born-Infeld-type modification of the quadratic Yang-Mills action suggested by the superstring theory gives rise to classical particle-like solutions prohibited in the standard Yang-Mills theory. This becomes possible due to the scale invariance breaking by the Born-Infeld non-linearity. New classical glueballs are sphaleronic in nature and exhibit a striking similarity with the Bartnik-McKinnon solutions of the Yang-Mills theory coupled to gravity.Comment: Revtex, 4 pages, 2 eps figure

    Top quark associated production of topcolor pions at hadron colliders

    Get PDF
    We investigate the associated production of a neutral physical pion with top quarks in the context of topcolor assisted technicolor. We find that single-top associated production does not yield viable rates at either the Tevatron or LHC. tt-associated production at the Tevatron is suppressed relative to Standard Model ttH, but at the LHC is strongly enhanced and would allow for easy observation of the main decay channels to bottom quarks, and possible observation of the decay to gluons.Comment: 13 pages, 4 figures, submitted to PR
    corecore