Robert W. Birge

Bio: Robert W. Birge is an academic researcher from Harvard University. The author has contributed to research in topics: Neutron & Proton emission. The author has an hindex of 3, co-authored 6 publications receiving 35 citations.

Proton-proton scattering at 105 mev and 75 mev

Abstract: The proton-proton differential scattering cross section has been measured at 105 Mev and at 75 Mev by using the internal beam of the Harvard cyclotron. Scintillation counters detected the scattered and recoil protons in coincidence while the beam current was monitored by measuring the absolute activity of ${\mathrm{C}}^{11}$ formed in the polyethylene scattering foil. The cross section as a function of angle in the center-of-mass system appears to be isotropic within statistical deviation. It has the values 5.4\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}27}$ ${\mathrm{cm}}^{2}$ and 6.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}27}$ ${\mathrm{cm}}^{2}$ at 105 Mev and 75 Mev respectively, with an estimated error of twenty percent.

Bevatron K-Mesons

Abstract: Author(s): Birge, Robert W.; Haddock, Roy P.; Kerth, Leroy T.; Peterson, James R.; Sandweiss, Jack; Stork, Donald H.; Whitehead, Marian N.

Space Charge Limited Currents

Abstract: Publisher Summary This chapter provides an overview of the space charge limited currents. The simplest cases of space charge limited flow occur when the trajectories of the charge carriers are straight lines—that is, rectilinear flow. In these cases, all the mathematical quantities involved may be expressed in terms of a single space coordinate so that this group of problems is referred to as “one-dimensional.” This does not infer that the electrodes themselves are one-dimensional. The electrode systems in which rectilinear flow occurs are parallel planes, coaxial circular cylinders, and concentric spheres. In the plane and cylindrical cases, it is assumed that the electrodes are infinite in extent, or else that guard electrodes are provided to prevent fringing electric fields at the boundary of the electrodes. In this chapter, concepts related to space charge are explained and space charge limited currents at relativistic velocities are studied. In the chapter, the effect of filament voltage drop is analyzed and the effect of magnetic field of heating current is also elaborated in detail.

Cross Sections for Elementary Particle Interactions

Abstract: Cross section data for interactions of nucleons, antinucleons, mesons (K), and mesons ( pi ) are compiled and discussed. At high energies, specific features common to particles of different kinds exist. Information on phenomena occurring in the region of very small space-time scales may be obtained. Most of the data is obtained from experiments using accelerators in which large particle- beam densities facilitate precision measurements. Weak neutrino reactions at high energies are discussed. (L.N.N.)

Decay characteristics and masses of positive K Mesons produced by the Bevatron

Abstract: A large emulsion stack exposed to the positive K beam at the Berkeley 6 GeV Bevatron has been used to measure the mass of the K-particles and their abundances. The masses for the decay modes Kμ2, Kπ2 and τ were obtained by measurement of the mean range of the secondaries. In addition, masses for all modes compared to the proton mass were measured by the range-momentum method. The abundances were determined by following and blob-counting secondaries. The data are : Type Abundances % Primary Mass (mfe) Mass from Secondary Range (mfe) τ 5.56 ± 0.41 966.3 ± 2.1 966.1 ± 0.7 τ´ 2.15 ± 0.47 967.7 ± 4 ─ Kfμ2 58.2 ± 3.0 967.2 ± 2.2 965.8 ± 2.4 Kfπ2 28.9 ± 2.7 966.7 ± 2.0 962.8 ± 1.8 Kfμ3 2.83 ± 0.95 969 ± 5 ─ Kfe3 3.23 ± 1.30 967 ± 8 ─

Absorption Cross Sections for 134 MeV Protons

Abstract: The absorption cross sections for 134 MeV protons of carbon, aluminium, copper, cadmium and lead have been measured by a transmission method. The results are consistent with the predictions of the usual optical theory for high energy nuclear cross sections.

Effects of fermionic singlet neutrinos on high- and low-energy observables

Abstract: In this doctoral thesis, we study both low- and high-energy observables related to massive neutrinos. Neutrino oscillations have provided indisputable evidence in favour of non-zero neutrino masses and mixings. However, the original formulation of the Standard Model cannot account for these observations, which calls for the introduction of new Physics. Among many possibilities, we focus here on the inverse seesaw, a neutrino mass generation mechanism in which the Standard Model is extended with fermionic gauge singlets. This model offers an attractive alternative to the usual seesaw realisations since it can potentially have natural Yukawa couplings (O(1)) while keeping the new Physics scale at energies within reach of the LHC. Among the many possible effects, this scenario can lead to deviations from lepton flavour universality. We have investigated these signatures and found that the ratios R_K and R_π provide new, additional constraints on the inverse seesaw. We have also considered the embedding of the inverse seesaw in supersymmetric models. This leads to increased rates for various lepton flavour violating processes, due to enhanced contributions from penguin diagrams mediated by the Higgs and Z bosons. Finally, we also found that the new invisible decay channels associated with the sterile neutrinos present in the supersymmetric inverse seesaw could significantly weaken the constraints on the mass and couplings of a light CP-odd Higgs boson.