Author
B. M. K. Nefkens
Other affiliations: University of California
Bio: B. M. K. Nefkens is an academic researcher from University of California, Los Angeles. The author has contributed to research in topics: Crystal Ball & Meson. The author has an hindex of 34, co-authored 176 publications receiving 3532 citations. Previous affiliations of B. M. K. Nefkens include University of California.
Topics: Crystal Ball, Meson, Pion, Neutron, Photon
Papers published on a yearly basis
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TL;DR: In this article, the authors reviewed the data and theory relevant to understand charge symmetry breaking in hadronic mass spittings, interactions and decay rates; nucleon-nucleon interactions; nuclear reactions; and binding energies of mirror nuclei.
334 citations
University of Edinburgh1, University of Mainz2, University of Glasgow3, Petersburg Nuclear Physics Institute4, University of Basel5, George Washington University6, University of California, Los Angeles7, Lebedev Physical Institute8, University of Tübingen9, University of Giessen10, Mount Allison University11, Kent State University12, The Catholic University of America13
TL;DR: In this article, the size and shape of the skin on (208)Pb were extracted from coherent pion photoproduction cross sections measured using the Crystal Ball detector together with the Glasgow tagger at the MAMI electron beam facility.
Abstract: Information on the size and shape of the neutron skin on (208)Pb is extracted from coherent pion photoproduction cross sections measured using the Crystal Ball detector together with the Glasgow tagger at the MAMI electron beam facility. On exploitation of an interpolated fit of a theoretical model to the measured cross sections, the half-height radius and diffuseness of the neutron distribution are found to be c(n)=6.70±0.03(stat.) fm and a(n)=0.55±0.01(stat.)(-0.03)(+0.02)(sys.) fm, respectively, corresponding to a neutron skin thickness Δr(np)=0.15±0.03(stat.)(-0.03)(+0.01)(sys.) fm. The results give the first successful extraction of a neutron skin thickness with an electromagnetic probe and indicate that the skin of (208)Pb has a halo character. The measurement provides valuable new constraints on both the structure of nuclei and the equation of state for neutron-rich matter.
181 citations
Petersburg Nuclear Physics Institute1, University of California, Los Angeles2, California Institute of Technology3, Brookhaven National Laboratory4, Abilene Christian University5, Indiana University6, Argonne National Laboratory7, Arizona State University8, George Washington University9, Kent State University10, Karlsruhe Institute of Technology11, University of Maryland, College Park12, Valparaiso University13
TL;DR: In this article, the differential and total cross sections and the Lambda polarization for the reaction K{sup -}p{yields}{eta}{Lambda} from threshold to p{sub K}-=770 MeV/c were measured.
Abstract: We present measurements of the differential and total cross sections and the {Lambda} polarization for the reaction K{sup -}p{yields}{eta}{Lambda} from threshold to p{sub K}-=770 MeV/c, with much better precision than previous measurements. Our cross-section data show a remarkable similarity to the SU(3) flavor-related {pi}{sup -}p{yields}{eta}n cross-section results. The reaction K{sup -}p{yields}{eta}{Lambda} at threshold is dominated by formation of the intermediate {Lambda}(1670)1/2- state.
162 citations
TL;DR: In this article, the SPES2 spectrometer was used to investigate rare {eta} decays with the presence of strong final state interaction, and the angular distribution is nearly isotropic, consistent with {ital S} wave production.
Abstract: The reaction {ital pd}{r_arrow}{sup 3}He{eta} has been studied with the SPES2 spectrometer, for proton energies between 0.2 MeV and 11 MeV above threshold. The total cross section rises from 0.25 to 0.40 {mu}b in this region. The observed energy dependence can be attributed to the strong final state interaction. The angular distribution is nearly isotropic, consistent with {ital S} wave production. A measurement of the {ital pd}{r_arrow}{sup 3}He{pi}{sup +}{pi}{sup {minus}} cross section in the threshold region is also presented. The setup, which is capable of producing 10{sup 5} tagged {eta}/s with only a few percent background, is used to investigate rare {eta} decays. {copyright} {ital 1996 The American Physical Society.}
97 citations
TL;DR: In this paper, the gamma p -Õ eta p differential cross sections were determined for 120 energy bins and the full range of the production angles, showing a dip near W = 1680 MeV in the total cross section caused by a substantial dip in eta production at forward angles.
Abstract: The gamma p - = W >= 1.87 GeV). Bremsstrahlung photons produced by the 1.5-GeV electron beam of the Mainz Microtron MAMI-C and momentum analyzed by the Glasgow tagging spectrometer were used for the eta-meson production. Our accumulation of 3.8 x 10(6) gamma p -< eta p -< 3 pi(0) p -< 6 gamma p events allows a detailed study of the reaction dynamics. The gamma p -< eta p differential cross sections were determined for 120 energy bins and the full range of the production angles. Our data show a dip near W = 1680 MeV in the total cross section caused by a substantial dip in eta production at forward angles. The data are compared to predictions of previous SAID and MAID partial-wave analyses and to the latest SAID and MAID fits that included our data.
94 citations
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TL;DR: This biennial Review summarizes much of particle physics, using data from previous editions.
12,798 citations
TL;DR: Herwig++ as mentioned in this paper is a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, leptonhadron and hadron-hadron collisions, with special emphasis on the correct description of radiation from heavy particles.
Abstract: In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of important hard scattering processes are available, together with an interface via the Les Houches Accord to specialized matrix element generators for additional processes. The simulation of Beyond the Standard Model (BSM) physics includes a range of models and allows new models to be added by encoding the Feynman rules of the model. The parton-shower approach is used to simulate initial- and final-state QCD radiation, including colour coherence effects, with special emphasis on the correct description of radiation from heavy particles. The underlying event is simulated using an eikonal multiple parton-parton scattering model. The formation of hadrons from the quarks and gluons produced in the parton shower is described using the cluster hadronization model. Hadron decays are simulated using matrix elements, where possible including spin correlations and off-shell effects. Comment: 153 pages, program and additional information available from http://projects.hepforge.org/herwig . Updated description to Herwig++ version 2.3 and added one author
1,829 citations
TL;DR: Herwig++ as mentioned in this paper is a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, leptonhadron and hadron-hadron collisions, together with a number of important hard scattering processes.
Abstract: In this paper we describe Herwig++ version 2.3, a general-purpose Monte Carlo event generator for the simulation of hard lepton-lepton, lepton-hadron and hadron-hadron collisions. A number of important hard scattering processes are available, together with an interface via the Les Houches Accord to specialized matrix element generators for additional processes. The simulation of Beyond the Standard Model (BSM) physics includes a range of models and allows new models to be added by encoding the Feynman rules of the model. The parton-shower approach is used to simulate initial- and final-state QCD radiation, including colour coherence effects, with special emphasis on the correct description of radiation from heavy particles. The underlying event is simulated using an eikonal multiple parton-parton scattering model. The formation of hadrons from the quarks and gluons produced in the parton shower is described using the cluster hadronization model. Hadron decays are simulated using matrix elements, where possible including spin correlations and off-shell effects.
1,519 citations
TL;DR: In this article, the nuclear forces can be derived using effective chiral Lagrangians consistent with the symmetries of QCD, and the status of the calculations for two and three nucleon forces and their applications in few-nucleon systems are reviewed.
Abstract: Nuclear forces can be systematically derived using effective chiral Lagrangians consistent with the symmetries of QCD. I review the status of the calculations for two- and three-nucleon forces and their applications in few-nucleon systems. I also address issues like the quark mass dependence of the nuclear forces and resonance saturation for four-nucleon operators.
1,455 citations
1,177 citations