The olduvai buffalo Pelorovis and the origin of Bos

The origin of the genus Bos is a debated issue. From ∼0.5 Ma until historic times, the genus is well known in the Eurasian large mammal 13 assemblages, where it is represented by Bos primigenius. This species has a highly derived cranial anatomy that shows important morphological 14 differences from other Plio-Pleistocene Eurasian genera of the tribe Bovini such as Leptobos, Bison, Proamphibos-Hemibos, and Bubalus. The 15 oldest clear evidence of Bos is the skull fragment ASB-198-1 from the middle Pleistocene (∼0.6–0.8 Ma) site of Asbole (Lower Awash Valley, 16 Ethiopia). The first appearance of Bos in Europe is at the site of Venosa-Notarchirico, Italy (∼0.5–0.6 Ma). Although the origin of Bos has 17 traditionally been connected with Leptobos and Bison, after a detailed anatomical and morphometric study we propose here a different origin, 18 connecting the middle Pleistocene Eurasian forms of B. primigenius with the African Late Pliocene and early Pleistocene large size member of the 19 tribe Bovini Pelorovis sensu stricto. The dispersal of the Bos lineage in Western Europe during middle Pleistocene times seems to coincide with 20 the arrival of the Acheulean tool technology in this continent

Search for Supersymmetry with a dominant R-Parity violating LQD‾LQ\overline{D} Coupling in e+e−e^+ e^- Collisions at centre-of-mass energies of 130 GeV to 172 GeV

A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQDbar coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130-172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m_0=500 GeV/c^2 and tan(beta)=sqrt(2) charginos with masses smaller than 81 GeV/c^2 and neutralinos with masses smaller than 29 GeV/c^2 are excluded at the 95% confidence level for any generation structure of the LQDbar coupling

A Study of Single W Production in e+e−e^{+}e^{-} Collisions at s\sqrt{s} = 161 - 183 GeV

Single W production is studied in the data recorded with the ALEPH detector at LEP at centre-of-mass energies between 161 and 183 GeV. The cross section is measured to be sigma_W=0.41+-0.17 (stat) +-0.04 (syst) pb at 183 GeV, consistent with the Standard Model expectation. Limits on non-standard WWgamma couplings are deduced as -1.6 < kg < 1.5 (lg=0) and -1.6 < lg < 1.6 (kg=1) at 95% C.L. A search for effectively invisible decays of the W boson in W pair production is performed, leading to an upper limit on the branching ratio of 1.3% (\Gamma_inv= 27 MeV) at 95% C.L