393 research outputs found

    Cannibalism, warfare, and drought in the Mesa Verde region during the twelfth century A.D.

    Get PDF
    The existence of cannibalism has emerged as one of the most controversial issues in the archaeology of the American Southwest. In this paper, we examine this issue by presenting the results of our investigation at 5MT10010, a small early Pueblo III habitation site in southwestern Colorado. Battered, broken bones from seven individuals were discovered in two adjacent pithouses at 5MT10010. Mixed and incomplete remains of four adults and an adolescent were recovered from the floor and ventilator shaft of one pithouse; the remains of two subadults were found on the floor and in various subfeatures of the second. Cut marks and percussion scars implicate humans in the disarticulation and reduction of these bodies. Evidence of heat exposure on some bone fragments and laboratory analyses of a human coprolite recovered from one of the pithouses support the interpretation that people prepared and consumed human body parts. The discovery of disarticulated human remains at 5MT10010 is one of a number of similar finds in the northern Southwest. Analysis of cases from the Mesa Verde region indicates a sharp increase in cannibalism around A.D. 1150, a time of drought and the collapse of the Chaco system. The causes, consequences, and nature of this apparent outbreak of cannibalism are examined in light of 5MT10010 and other recent finds

    Glimpses of the Octonions and Quaternions History and Todays Applications in Quantum Physics

    Full text link
    Before we dive into the accessibility stream of nowadays indicatory applications of octonions to computer and other sciences and to quantum physics let us focus for a while on the crucially relevant events for todays revival on interest to nonassociativity. Our reflections keep wandering back to the BrahmaguptaBrahmagupta FibonaccFibonacc two square identity and then via the EulerEuler four square identity up to the DegenDegen GgravesGgraves CayleyCayley eight square identity. These glimpses of history incline and invite us to retell the story on how about one month after quaternions have been carved on the BroughamianBroughamian bridge octonions were discovered by JohnJohn ThomasThomas GgravesGgraves, jurist and mathematician, a friend of WilliamWilliam RowanRowan HamiltonHamilton. As for today we just mention en passant quaternionic and octonionic quantum mechanics, generalization of CauchyCauchy RiemannRiemann equations for octonions and triality principle and G2G_2 group in spinor language in a descriptive way in order not to daunt non specialists. Relation to finite geometries is recalled and the links to the 7stones of seven sphere, seven imaginary octonions units in out of the PlatoPlato cave reality applications are appointed . This way we are welcomed back to primary ideas of HeisenbergHeisenberg, WheelerWheeler and other distinguished fathers of quantum mechanics and quantum gravity foundations.Comment: 26 pages, 7 figure

    The Λ\Lambda(1600): A Strange Hybrid Baryon

    Full text link
    We use the method of QCD sum rules to investigate a possible hybrid baryon with the quantum numbers of the Λ\Lambda. Using a current composed of uds quarks in a color octet and a gluon, a strange hybrid, the ΛH\Lambda_H is found about 500 MeV above the Λ\Lambda, and we identify it as the Λ(1600)\Lambda(1600). Using our sigma/glueball model we predict a large branching fraction for the ΛHΛ+σ(ππ\Lambda_H \to \Lambda + \sigma(\pi\pi resonance), and the experimental search for this decay mode could provide a test of the hybrid nature of the /Lambda(1600)/Lambda(1600).Comment: Revtex file, 3 Figure

    Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe

    Measurement of the Lambda(b) cross section and the anti-Lambda(b) to Lambda(b) ratio with Lambda(b) to J/Psi Lambda decays in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    The Lambda(b) differential production cross section and the cross section ratio anti-Lambda(b)/Lambda(b) are measured as functions of transverse momentum pt(Lambda(b)) and rapidity abs(y(Lambda(b))) in pp collisions at sqrt(s) = 7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Lambda(b) decays reconstructed in the exclusive final state J/Psi Lambda, with the subsequent decays J/Psi to an opposite-sign muon pair and Lambda to proton pion, using a data sample corresponding to an integrated luminosity of 1.9 inverse femtobarns. The product of the cross section times the branching ratio for Lambda(b) to J/Psi Lambda versus pt(Lambda(b)) falls faster than that of b mesons. The measured value of the cross section times the branching ratio for pt(Lambda(b)) > 10 GeV and abs(y(Lambda(b))) < 2.0 is 1.06 +/- 0.06 +/- 0.12 nb, and the integrated cross section ratio for anti-Lambda(b)/Lambda(b) is 1.02 +/- 0.07 +/- 0.09, where the uncertainties are statistical and systematic, respectively.Comment: Submitted to Physics Letters

    Search for new physics in events with opposite-sign leptons, jets, and missing transverse energy in pp collisions at sqrt(s) = 7 TeV

    Get PDF
    A search is presented for physics beyond the standard model (BSM) in final states with a pair of opposite-sign isolated leptons accompanied by jets and missing transverse energy. The search uses LHC data recorded at a center-of-mass energy sqrt(s) = 7 TeV with the CMS detector, corresponding to an integrated luminosity of approximately 5 inverse femtobarns. Two complementary search strategies are employed. The first probes models with a specific dilepton production mechanism that leads to a characteristic kinematic edge in the dilepton mass distribution. The second strategy probes models of dilepton production with heavy, colored objects that decay to final states including invisible particles, leading to very large hadronic activity and missing transverse energy. No evidence for an event yield in excess of the standard model expectations is found. Upper limits on the BSM contributions to the signal regions are deduced from the results, which are used to exclude a region of the parameter space of the constrained minimal supersymmetric extension of the standard model. Additional information related to detector efficiencies and response is provided to allow testing specific models of BSM physics not considered in this paper.Comment: Replaced with published version. Added journal reference and DO

    Searching for Higgs : From LEP towards LHC

    Full text link
    After a brief introduction to the theoretical basis of the Higgs mechanism for generating the masses of elementary particles, the experimental searches for Higgs particles will be summarized, from bounds at LEP to inferences for LHC. The report will focus on the Standard Model, though some central results on extended Higgs systems, as conjectured for example in supersymmetric theories, will also be recapitulated. Alternative scenarios based on spontaneous symmetry breaking by novel strong interactions are adumbrated at the theoretical level.Comment: Added reference

    Projected WIMP sensitivity of the LUX-ZEPLIN dark matter experiment

    Get PDF
    LUX-ZEPLIN (LZ) is a next-generation dark matter direct detection experiment that will operate 4850 feet underground at the Sanford Underground Research Facility (SURF) in Lead, South Dakota, USA. Using a two-phase xenon detector with an active mass of 7 tonnes, LZ will search primarily for low-energy interactions with weakly interacting massive particles (WIMPs), which are hypothesized to make up the dark matter in our galactic halo. In this paper, the projected WIMP sensitivity of LZ is presented based on the latest background estimates and simulations of the detector. For a 1000 live day run using a 5.6-tonne fiducial mass, LZ is projected to exclude at 90% confidence level spin-independent WIMP-nucleon cross sections above 1.4 × 10-48cm2 for a 40 GeV/c2 mass WIMP. Additionally, a 5σ discovery potential is projected, reaching cross sections below the exclusion limits of recent experiments. For spin-dependent WIMP-neutron(-proton) scattering, a sensitivity of 2.3 × 10−43 cm2 (7.1 × 10−42 cm2) for a 40 GeV/c2 mass WIMP is expected. With underground installation well underway, LZ is on track for commissioning at SURF in 2020

    Modeling Host Genetic Regulation of Influenza Pathogenesis in the Collaborative Cross

    Get PDF
    Genetic variation contributes to host responses and outcomes following infection by influenza A virus or other viral infections. Yet narrow windows of disease symptoms and confounding environmental factors have made it difficult to identify polymorphic genes that contribute to differential disease outcomes in human populations. Therefore, to control for these confounding environmental variables in a system that models the levels of genetic diversity found in outbred populations such as humans, we used incipient lines of the highly genetically diverse Collaborative Cross (CC) recombinant inbred (RI) panel (the pre-CC population) to study how genetic variation impacts influenza associated disease across a genetically diverse population. A wide range of variation in influenza disease related phenotypes including virus replication, virus-induced inflammation, and weight loss was observed. Many of the disease associated phenotypes were correlated, with viral replication and virus-induced inflammation being predictors of virus-induced weight loss. Despite these correlations, pre-CC mice with unique and novel disease phenotype combinations were observed. We also identified sets of transcripts (modules) that were correlated with aspects of disease. In order to identify how host genetic polymorphisms contribute to the observed variation in disease, we conducted quantitative trait loci (QTL) mapping. We identified several QTL contributing to specific aspects of the host response including virus-induced weight loss, titer, pulmonary edema, neutrophil recruitment to the airways, and transcriptional expression. Existing whole-genome sequence data was applied to identify high priority candidate genes within QTL regions. A key host response QTL was located at the site of the known anti-influenza Mx1 gene. We sequenced the coding regions of Mx1 in the eight CC founder strains, and identified a novel Mx1 allele that showed reduced ability to inhibit viral replication, while maintaining protection from weight loss
    corecore