ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your search history is empty.
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Mixing of tensor mesons and tensor meson dominance is used to investigate decays of the new particles. We find good agreement of experiment and the quark-gluon mixing scheme of Fritzsch and jackson, which we extend with some modifications to tensor mesons. General features of the scheme have consequences forall meson multiplets, which are in agreement with experiment. Some numerical consequences for additional flavors are worked out.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 229 (1969), S. 206-208 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Performing the equal-time limit under the integral of the spectral representation for the vacuum expectation value of the current commutator it is shown (as already suggested by models) that the vacuum expectation value of the equal-time commutator of a hermitean charge and the divergence of the corresponding (hermitean) vector or axial vector current (“σ-term”) vanishes only if the current is conserved. This then implies that a nonconserved hermitean charge cannot annihilate the vacuum, in agreement with Coleman's theorem.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We systematically exploit the reported data on $$F_2^{\gamma p} ,F_2^{\gamma n} ,\sigma ^{vN} ,\sigma ^{\bar vN} ,\left\langle {xy} \right\rangle _{vN} ,\left\langle {xy} \right\rangle _{\bar vN} ,\left\langle {1 - y} \right\rangle _{vN} $$ and $$\left\langle {1 - y} \right\rangle _{\bar vN} $$ in order to test various versions of the quark parton model and to obtain further predictions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract K-, L andM-shell ionization cross sections have been measured for 23 elements, 12≦Z≦92, after bombardment with relativistic electrons, 15≦E 065MeV, by means of high resolution semiconductor detectors and a recently developed gas-scintillation proportional counter. For constant electron bombarding energyE 0 the ionization cross sections follow a power law dependence,σ∽Z −α, and forE 0=50MeV we deducedα =2.45±0.02 for theK shell andα=3.00 ±0.09 for theL shell. The observedZ dependence exhibits significant systematic deviations from theoretical predictions which exceed the experimental values up to 15 % at lowZ elements for theK shell and on the average about 11% for theL andM shell. The same behaviour of too low experimental values, i.e. an overestimation by the theory, is observed for the energy dependence of the cross sections for all shells. A scaling behaviour describing theZ andE 0 dependence for allK-, L andM-shell data points is observed which also predicts the experimental values by other groups at lower and higher energies correctly. The comparsion of the measuredLΒ/Lα, andLγ/Lα intensity ratios for highZ elements with the values obtained by other groups in the energy range 0.3≦E0≦1,000 MeV exhibits an increase with bombarding energy that cannot merely be explained by the energy dependence of the subshellionization cross sections for theL shell. An attempt to explain this effect with the change of the Coster-Kronig transition probability is described.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract TheK-electron capture probability,P K, in the allowed and non-unique first-forbidden transitions is measured by observing coincidences betweenK x rays and γ rays. The following results are obtained. In Gd151 decayP K to the 349.8 keV level is 0.713 ± 0.015 andP K to the 307.4 keV level is 0.813 ± 0.020. It is also deduced that the decay energyQ EC is 491 −9 +14 keV and the spin of the 307.4 keV level is 7/2. In Dy159 decayP K to the 58.0 keV level is found to be 0.803 ± 0.032.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The K-shell fluorescence yield of Al, Ca, V and Mn has been measured by bombarding thin solid targets of 0.5–4.0μg/cm2 on 6–10μg/cm2 carbon backing with relativistic electrons of 30 and 60 MeV and by simultaneous detection of the x-ray and Auger yield by means of a Si(Li) detector and an electrostatic electron spectrometer, respectively. While the values obtained for25Mn (ωK=0.310 −0.020 +0.023 ) and23V(ωK=0.252 −0.018 +0.020 ) agree within their accuracy with known experimental and theoretical data, are the values of20Ca (ωK=0.127 −0.011 +0.013 ) and13Al(ωK=0.027±0.005) lower than experimental or recommended empirical values.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1434-601X
    Keywords: 21.60.−n ; 23.40.−s ; 25.30.−c
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A set of phenomenological wave functions has been derived to describe the14N ground state and the isospin triplet consisting of the14C ground state, the first excited state of14N at 2.313 MeV and the14O ground state. Elastic and inelastic electron scattering form factors, the magnetic moment of the14N ground state and the shape factors in theβ ± decay have been employed in a multiparameter fitting procedure to determine the amplitudes of the wave functions inL-S coupling. The inclusion of the beta decay observables in the fit has become possible for the first time since exact formulas for the shape factor in higher order do exist. The set of wave functions deduced exhibit predominately anL=0 contribution for the 0+; 1 states andL=1 and 2 contributions of nearly equal weight for the 1+; 0 state. It was observed that the inclusion of the shape factors allowed a more stringent determination of the amplitudes compared to previous attempts reported in the literature and led in the case of the 0+; 1 states to wave functions that show a small but noticeable difference within the isospin triplet. Besides the observables used for the fit, the radiative widthΓ γ (M1) of the 2.313 MeV state in14N can be described quite well with the derived wave functions, and in addition it has become possible to predict the pathological largeft − value of the14C decay and theft + value of the14O decay precisely. The wave functions are also applied to calculate the14N(γ,π +) cross section.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Applying an absorber technique, the experimental shape and width of a parametric x-radiation line has been determined. The 9 keV radiation was produced by bombarding a diamond crystal of 55 μm thickness with electrons of 6.8 MeV. The variance of the spectral line distribution was found to depend on the tilt angle of the crystal and to have a magnitude of σ=51 eV. Simulations based on a Monte Carlo method exhibit that the observed variance is mainly influenced by multiple scattering of electrons passing through the crystal ((approximate)43 eV) and the finite detector opening ((approximate)18 eV), leaving for the intrinsic linewidth a value of the order of 1 eV. The spectral density of the line was found to be J(approximate)10−7 photons/(electron×sr×eV). © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using the continuous wave electron beam of the new Darmstadt superconducting electron accelerator and high intensity axial channeling in a diamond crystal, the possibility for the production of an intense tunable photon source in the x-ray region is investigated. Due to low emittance of the machine and its high current it has become possible, for the first time, to produce channeling radiation in the energy region of a few keV with an intensity of up to 2×1010 photons/s in an x-ray energy window of 10%. This is six orders of magnitude more than what has been observed previously.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1434-6079
    Keywords: 32.30.Rj ; 32.80.Hd ; 34.50.Fa
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have developed a method to determineL-subshell ionization cross sections and report here on the first measurements of electron inducedL-subshell cross sections for target elements (29≦Z≦79) at electron bombarding energies between 50≦E 0≦200 keV. The method involves the detection of characteristic X rays by means of a high resolution flat crystal spectrometer of known reflectivity and is based on the correlation of measured X ray intensities, Auger- and Coster-Kronig yields and radiative transition probabilities with theL-subshell cross section.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...