Optical Emission rom Electron Irradiated Thin Gold Foils (open access)

Optical Emission rom Electron Irradiated Thin Gold Foils

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Date: September 10, 1963
Creator: Hammer, D. C.; Arakawa, E. T.; Emerson, L. C. & Birkhoff, R. D.
System: The UNT Digital Library
DECAY PROPERTIES OF THE E HYPERON AND E RESONANCES (open access)

DECAY PROPERTIES OF THE E HYPERON AND E RESONANCES

A sample of 2500 {Xi}{sup -} and 500 {Xi}{sup 0} hyperons, produced in {Xi}K, {Xi}K{pi}, and {Xi}K{pi}{pi} final states by K{sup -} (in H{sub 2}) at incident momenta of 1.7 to 2.7 BeV/c, has been analyzed. The data are from an exposure (K-63) of 26 events/{mu}b in the 72-inch bubble chamber; approximately 85% of the {Xi}{sup -} events and 60% of the {Xi}{sup 0} events have been analyzed. For the {Xi}, they determine the spin and decay parameters a{sub {Xi}} and {Phi}{sub {Xi}} = tan{sup -1} ({beta}{sub {Xi}}/{Gamma}{sub {Xi}}). Combining their data with 900 {Xi}{sup -} and 150 {Xi}{sup 0} events from an earlier experiment (K-72), they obtain the following results: (1) {Xi} spin - J = 1/2 favored over J = 3/2 by {approx} 2.5 standard deviations; (2) {Xi} decay parameters (assuming a{sub {Lambda}} = 0.647 {+-} 0.048) - a{sub {Xi}{sup -}} = -0.398 {+-} 0.041, {Phi}{sub {Xi}{sup -}} = 9.8{sup o} {+-} 9.0{sup o}; a{sub {Xi}{sup 0}} = -0.413 {+-} 0.104. They observe {Xi}*(1530) and {Xi}*(1817); their data are insufficient for analysis of suggested {Xi}* resonances at 1705 and 1933 MeV. They measure the {Xi}*(1530) electromagnetic mass difference {Delta}m = m({Xi}*{sup -}) = m({Xi}*{sup 0}) = 2.0 {+-} …
Date: September 10, 1966
Creator: Merrill, Jr., Deane W.
System: The UNT Digital Library
The Higgs boson in the Standard Model theoretical constraints and a direct search in the wh channel at the Tevatron (open access)

The Higgs boson in the Standard Model theoretical constraints and a direct search in the wh channel at the Tevatron

We have presented results in two different yet strongly linked aspects of Higgs boson physics. We have learned about the importance of the Higgs boson for the fate of the Standard Model, being either only a theory limited to explaining phenomena at the electroweak scale or, if the Higgs boson lies within a mass range of 130 &lt; m<sub>H</sub> &lt; 160 GeV the SM would remain a self consistent theory up to highest energy scales O(m<sub>Pl</sub>). This could have direct implications on theories of cosmological inflation using the Higgs boson as the particle giving rise to inflation in the very early Universe, if it couples non-minimally to gravity, an effect that would only become significant at very high energies. After understanding the immense meaning of proving whether the Higgs boson exists and if so, at which mass, we have presented a direct search for a Higgs boson in associated production with a W boson in a mass range 100 &lt; m<sub>H</sub> &lt; 150 GeV. A light Higgs boson is favored regarding constraints from electroweak precision measurements. As a single analysis is not yet sensitive for an observation of the Higgs boson using 5.3 fb<sup>-1</sup> of Tevatron data, we set limits …
Date: September 10, 2010
Creator: Huske, Nils Kristian & (Germany)], Bielefeld Univ.
System: The UNT Digital Library
Measurement of the Decay B to Omega L Nu with the BaBar Detector and Determination of V_Ub (open access)

Measurement of the Decay B to Omega L Nu with the BaBar Detector and Determination of V_Ub

We measure the branching fraction of the exclusive charmless semileptonic decay B {yields} {omega}{ell}{nu}{sub {ell}}, where {ell} is either an electron or a muon, with the charged B meson recoiling against a tag B meson decaying in the charmed semileptonic modes B {yields} D{ell}{nu}{sub {ell}} or B {yields} D*{ell}{nu}{sub {nu}}. The measurement is based on a dataset of 426.1 fb{sup -1} of e{sup +}e{sup -} collisions at a CM energy of 10.58 GeV recorded with the BABAR detector at the PEP-II asymmetric B Factory located at the SLAC National Accelerator Laboratory. We also calculate the relevant B {yields} {omega} hadronic form factors to determine the magnitude of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub ub}|.
Date: September 10, 2010
Creator: Nagel, Martin
System: The UNT Digital Library