J.W.A. den Herder

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Publications (9)0 Total impact

Chapter: Electrodisintegration of 3He investigated with the (e,e′X) reaction

P. H. M. Keizer, J. F. J. v. d. Brand, J. W. A. den Herder, E. Jans, L. Lapikás, E. N. M. Quint, P. K. A. de Witt Huberts

01/2006: pages 381-382;
Chapter: Study of the proton optical potential with the (E,E′P) reaction

H. P. Blok, J. F. J. van den Brand, H. Hendriks, J. W. A. den Herder, E. Jans, P. H. M. Keizer, L. Lapikâs, E. N. M. Quint, G. van der Steenhbven, P. K. A. de Witt Huberts

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ABSTRACT: The (e,e'p) reaction allows to study details. of the optical-model potential, for which elastic scattering data are not sensitive, The preliminary analysis of our data,especially for transitions where the nuclear interior contributes considerably, suggests that a standard OM with Saxon-Woods shaped potentials is not adequate. In a further analysis we will try, within the constraint of a good description of elastic scattering data, to find an optical potential that yields: a better description of the (e,e'p) results. Microscopic and relativistic potentials will be included in that study.

01/1970: pages 249-254;
Article: Single-particle properties of 51V and 90Zr studied with the (e,e'p) reaction

J.W.A. den Herder, H.P. Blok, E. Jans, P.H.M. Keizer, L. Lapikás, E.N.M. Quint, G. van der Steenhoven, P.K.A. de Witt Huberts

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ABSTRACT: Proton spectral functions for the reactions 51V(e, e'p) and 90Zr(e, e'p) have been obtained with the coincidence setup at NIKHEF-K. The coincidence cross sections up to 21 MeV excitation energy were measured in the missing momentum range −40 < Pm < 280 MeV/c with an absolute precision of 4%. The achieved 130 keV energy resolution allowed to deduce momentum distributions for transitions to many discrete final states. A CDWIA analysis of the measured yielded rms radii of the single-particle orbitals and spectroscopic factors for the various transitions. The uncertainties in the analysis due to the treatment of the final-state interaction could be reduced by a combined analysis of the present data and elastic proton-scattering data in the same mass and energy region. The extracted spectroscopic factors are compared to those deduced from the (d3, He) reaction. The strength in the continuum (up to Ex = 21 MeV) has been decomposed into various orbital components by using the dependence of on the values of n and l. Whereas in general the orbit radii and the binding energies are in fair agreement with the results of mean-field calculations, the total spectroscopic strength for valence orbits is only 40–60% of the single-particle sum-rule estimate. For deep-hole states we find 60–80%. These values are about 15% smaller than the predictions of recent mean-field calculations that include correlations. Possible origins of this difference are discussed.

Nuclear Physics A. 490(3):507-555.
Source
Available from: L. Lapikás

Article: High-resolution (e,e'p) study of the 1/2+ state at 6.79 MeV in 11B

G. van der Steenhoven, H.P. Blok, J.W.A. den Herder, E. Jans, P.H.M. Keizer, L. Lapikás, E.N.M. Quint, P.K.A. de Witt Huberts, G.W.R. Dean, P.J. Brussaard, P.W.M. Glaudemans, D. Zwarts

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ABSTRACT: The spectral function for the reaction 12C(e,e′p) 11B leading to the 1/2+ state at 6.79 MeV in 11B has been measured. The excitation of this non-normal parity state indicates the presence of wave function components beyond the 1p shell. A shell-model calculation, performed in a large configuration space, yields a fair description of the shape of the momentum distribution.
Article: Evidence for Partial Occupancy of the 3s_1/2 Proton Orbital in 208-Pb

H. Nann, E.N.M. Quint, A.M. van der Berg, J. F. J. van den Brand, R. Ent, J.W.A. den Herder, E. Jans, G. Kramer, J.B.J.M. Lanen, L. Lapikas, G. van der Steenhoven, P.K.A. de Witt Huberts, B. Barnett, H. Clement, P. Grabmayr, G. J. Wagner, B. Frois, D. Goutte

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ABSTRACT: This research was sponsored by the National Science Foundation Grant NSF PHY 87-14406
Article: Proton Knockout from the 1f_7/2 Orbital in 40-Ca and 48-Ca

H. Nann, A.M. van der Berg, H.P. Blok, J. F. J. van den Brand, R. Ent, J.W.A. den Herder, C W de Jager, E. Jans, G. J. Kramer, J. Lanen, J. Lapikas, E.N.M. Quint, G. van der Steenhoven, P.K.A. de Witt Huberts, G. Wagner

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ABSTRACT: This research was sponsored by the National Science Foundation Grant NSF PHY 87-14406
Article: Relative Spectroscopic Factors of 3S Proton Holes in 206-Pb and 208-Pb

H. Nann, S. Klein, P. Grabmayr, G. J. Wagner, J.F.J. van der Brand, J.W.A. den Herder, E. Jans, P.H.M. Keizer, L. Lapikas, E.N.M. Quint, G. van der Steenhoven, P.K.A. de Witt Huberts, B. Frois, D. Goutte

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ABSTRACT: This research was sponsored by the National Science Foundation Grant NSF PHY 87-14406
Article: Deuteron knockout from 3He with the (e,e'd) reaction

P.H.M. Keizer, P.C. Dunn, J.W.A. Den Herder, E. Jans, A. Kaarsgaarn, L. Lapikás, E.N.M. Quint, P.K.A. De Witt Huberts, H. Postma, J.M. Laget

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ABSTRACT: The coupling of a virtual photon to correlated proton-neutron pairs is studied in a 3He(e,e'd)1H coincidence experiment at momentum transfers of q=350–450 MeV/c and at recoil momenta k=0–200 MeV/c. The data are well reproduced by a calculation including a diagrammatic expansion of the final state interaction.

Physics Letters B.
Article: Fragmentation of the 1f-hole strength in 90Zr studied with the (e,e′p) reaction

J.W.A. Den Herder, P.C. Dunn, E. Jans, P.H.M. Keizer, L. Lapiḱas, E.N.M. Quint, P.K.A. De Witt Huberts, H.P. Blok, G. Van Der Steenhoven

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ABSTRACT: The proton-hole spectral function of 90Zr has been measured up to 20 MeV excitation energy by means of the (e,e′p) coincidence reaction. The deduced spectroscopic factors and fragmentation of the 1f-hole states are compared with results from hadronic reactions and with mean-field theory.

Physics Letters B.