A5033062305- Physics of Superconductivity and Magnetism
- Particle physics theoretical and experimental studies
- Superconducting Materials and Applications
- Quantum Chromodynamics and Particle Interactions
- Advanced Condensed Matter Physics
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle Detector Development and Performance
- Astrophysics and Cosmic Phenomena
- Muon and positron interactions and applications
- Magnetic and transport properties of perovskites and related materials
- High-pressure geophysics and materials
- Superconductivity in MgB2 and Alloys
- Nuclear physics research studies
- Atomic and Subatomic Physics Research
- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Magnetic properties of thin films
- Particle Accelerators and Free-Electron Lasers
- Rare-earth and actinide compounds
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear Physics and Applications
- Nuclear Materials and Properties
Tel Aviv University
2022
University of Houston
2010-2021
Brown University
1999-2005
Providence College
1999
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso
1998
Micron (United States)
1997
TU Dresden
1997
Bielefeld University
1994-1997
Istituto Nazionale di Fisica Nucleare, Sezione di Torino
1997
Ericsson (Netherlands)
1997
From a sample of hadronic events produced in ${e}^{+}{e}^{\ensuremath{-}}$ collisions, semileptonic decays heavy particles have been isolated and used to obtain measurement for the bottom-quark lifetime [1.8\ifmmode\pm\else\textpm\fi{}0.6 (stat.)\ifmmode\pm\else\textpm\fi{}0.4(syst.)]\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}12}$ sec.
Photoproduction cross sections for neutral $\ensuremath{\pi}$, $\ensuremath{\eta}$, $\ensuremath{\rho}$, and $\ensuremath{\varphi}$ mesons have been measured at the Stanford Linear Accelerator Center photon energies between 5 17.8 GeV, $t$ (four-momentum transfer squared) -0.12 -1.4 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$, using a missing-mass technique. The pion production lower is characterized by fast falloff with increasing $|t|$ small values, dip $t=\ensuremath{-}0.5$...
Scintillation counters in coincidence were used as detectors of neutrons and protons produced pi /sup -/ capture by complex nuclei. By measuring neutrons, it was hoped to establish whether nuclei involves two nucleons, if does, use the process study ratio neutron--proton pairs proton--proton pairs. The mesons stopped Li, C, Al, S, Cu, Pb targets. In order test spatial correlation ejected measurements made with 90 180 deg from each other. results obtained are given coincidences a function...
Spatial distributions of persistent magnetic field trapped by sintered and melt-textured ceramic-type high-temperature superconductor (HTS) samples have been studied. The can be reproduced a model the current consisting two components: (i) surface Js (ii) uniform volume Jv. This + Jv gives satisfactory account spatial distribution different types HTS samples. moment calculated, based on model, result agrees well with that measured standard vibrating sample magnetometer (VSM). As consequence,...
A measurement was made of the number neutron-proton coincidences observed when 320-Mev bremsstrahlung bombarded D, Li, Be, C, O, Al, Ti, Cu, Sn, and Pb. If one normalizes data for pairs in a nucleus (i.e., by dividing $\frac{\mathrm{NZ}}{A}$) it is found that decrease as $A$ increases.It possible to quantitatively account this dependence correcting probability two nucleons will escape from inside without either having collision. The function nuclear radius, $R$, mean free path,...
We present an analysis of muon events with all multiplicities collected during 21804 h operation the first Large Volume Detector tower. The measured angular distribution intensity has been converted to "depth–vertical-intensity" relation in depth range from 3 12 km w.e. this allowed us derive power index γ primary all-nucleon spectrum: γ=2.78±0.05. standard rock and comparison data other experiments done. also derived vertical spectrum at sea level.Received April...
Received 12 November 1965DOI:https://doi.org/10.1103/PhysRevLett.16.35©1966 American Physical Society
Experiments are described on the photoproduction of high energy neutron-proton pairs from complex nuclei. The results provide further confirmation and some clarification quasideuteron model Levinger.In these experiments targets D, Li, O bombarded by a 340-Mev bremsstrahlung beam. In one set measurements, intended to check kinematical features model, we have observed angular spread $n\ensuremath{-}p$ coincidences which arises momentum distribution nucleons in These observations were...
The previously reported studies of the high-energy photoejection neutrons and protons showed basic validity "quasi-deuteron" model. Due to motion in a complex nucleus one observes that kinematics disintegration are modified from those photodisintegration free deuteron at rest. modification was measured for Li, C, O, Al, Cu an attempt compare "average" momentum nucleons these nuclei.It is found Fermi distribution (with $T=0\ifmmode^\circ\else\textdegree\fi{}$) does not fit observed data. A...
Abstract Fourier transform (FT) Raman spectra of the cell walls three species fungi are reported for first time, namely (i) Agaricus bisporus , a fruiting bud, (ii) Mortierella genus and (iii) Mucor genus. Some molecular assignments proposed major vibrational features attributed to chitin, N ‐acetylglucosamine ( R )‐glucan. Preliminary studies indicate that it is possible use FT‐Raman spectroscopy discriminate between different mixed in culture media.
A study of persistent, trapped magnetic field has been pursued with high-temperature superconducting (HTS) materials. The main effort is to the feasibility utilization HTS fabricate magnets for various devices. field, when not in saturation, proportional applied field. Thus, it should be possible replicate complicated configurations melt-textured YBa2Cu3O7 (MT-Y123) material, bypassing need wires. Presently, materials have developed from which 1.5 T, at 77 K, can fabricated. Much higher...
Identification of muons in hadronic events from ${e}^{+}{e}^{\ensuremath{-}}$ annihilation observed the MAC detector at storage ring PEP provides flavor tagging heavy primary quarks. A sample enriched $b\overline{b}$ production is obtained and $b$-quark fragmentation function inferred momentum spectrum muons. The $b$ quark found to fragment predominantly with high values $z$, $〈{z}_{b}〉=0.8\ifmmode\pm\else\textpm\fi{}0.1$, have an over-all semimuonic branching fraction...
An experiment has been performed to investigate single-quantum annihilation of positrons in the field high-$Z$ nuclei. This mode observed and absolute magnitude, energy dependence, $Z$ dependence cross section measured. Backgrounds which might contaminate derived signals have semiempirically investigated found be an order magnitude or more below rate identified as annihilation. The data on counting its positron agree with calculations Jaeger Hulme. agrees a proportional ${Z}^{5}$.
A study of field trapping by the incomplete Meissner effect was performed on YBa2Cu3O7−x at 77 K both sintered and oriented grain samples. Fields up to BT=1280 G have been trapped in small, grain, planar Circulating persistent current densities 4800 A/cm2 are calculated. Based these values hollow cylinders 2 cm i.d. will trap fields 6000 G. Initial creep is about 10%/week for types Creep rate varies as (BT/BT,max)2. BT, due an external B0, BT∝(1−e−cB0/BT,max). Lamination mosaic assembly...
We report on cross-sectional measurements the photoproduction of ${\ensuremath{\pi}}^{0}$ and ${\ensuremath{\eta}}^{0}$ mesons hydrogen for a range in $t$ -0.2 to -0.9 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ energies 6.0-16.0 GeV. The sharp dip observed at lower $t=\ensuremath{-}0.5$ production becomes less pronounced higher energies. This implies Regge framework ${B}^{0}$ meson trajectory dominates Our one angular distribution 6.0 GeV shows no as do data.
A production run of 60 melt-textured YBCO trapped field magnets (TFMs), 2 cm in diameter, is reported. The TFMs have pinning centers Y211 and (Pt0.4U0.6)YBa3O6 deposits also damage tracks ions from uranium fission. resulting average at the center seed-side surface 〈BT(r = 0)〉 2.04 T 77 K. rms spread BT 5.9%. TFM samples rejected due to problems with SmBCO seeds totaled ~10%, an additional 2% were lost cracking under magnetic pressure. Methods significantly reduce these losses are discussed....
A search in ${e}^{+}{e}^{\ensuremath{-}}$ annihilation for final states which contain only a single energetic photon has been performed at $\sqrt{s}=29$ GeV with the MAC detector PEP. The upper limit on an anomalous signal interpreted terms of mass limits supersymmetric particles under assumption radiative pair production either photons or neutrinos. For electron ($\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{e}$) this is ${m}_{\stackrel{\ifmmode \~{}\fi{}}{e}}>37$ GeV/${\mathit{c}}^{2}$ 90%...
Precise results are reported for the $\ensuremath{\tau}$-lepton lifetime and several $\ensuremath{\tau}$ branching ratios obtained with MAC detector operating at PEP $\sqrt{s}=29$ GeV. We find ${\ensuremath{\tau}}_{\ensuremath{\tau}}=(3.15\ifmmode\pm\else\textpm\fi{}0.36\ifmmode\pm\else\textpm\fi{}0.4)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}$ sec. Results topological ${B}_{1}$, ${B}_{3}$, ${B}_{5}$ ($\ensuremath{\tau}$ decaying into 1, 3, 5 charged particles)...
The production of $\ensuremath{\psi}(3.1)$ mesons is reported for the reactions ${\ensuremath{\pi}}^{\ensuremath{-}}+\mathrm{Fe}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}+{\ensuremath{\mu}}^{\ensuremath{-}}+\mathrm{anything}$, at 200 GeV, and $p+\mathrm{Fe}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}+{\ensuremath{\mu}}^{\ensuremath{-}}+\mathrm{anything}$, 240 GeV. For $\ensuremath{\psi}$ production, distributions in $x\ensuremath{\equiv}\frac{{P}_{L}}{{P}_{\mathrm{beam}}}$...
We report measurements of the differential cross sections ${\ensuremath{\rho}}^{0}$- and $\ensuremath{\phi}$-meson photo-production on hydrogen for a range square four-momentum transfer $t$ from -0.2 to -0.9 ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ incident photon energies 6.5 17.8 GeV. find that obtained ${\ensuremath{\rho}}^{0}$ production are in good agreement with vector-dominance model.
We report on persistent field in a quasipermanent magnet made of high temperature superconductor. The material has an average 40% molar excess Y, relative to Y1Ba2Cu3O7 and been irradiated with energy light ions at 200 MeV. magnet, which traps 1.52 T 77.3 K, nearly 4 64.5 K. No evidence giant flux jump or sample cracking was observed.