Coherent π^\circ photoproduction from ^4He

F. Rambo; P. Achenbach; J. Ahrens; H. -J. Arends; R. Beck; S. J. Hall; V. Hejny; P. Jennewein; S. S. Kamalov; M. Kotulla; B. Krusche; V. Kuhr; R. Leukel; V. Metag; R. Novotny; V. Olmos de Leon; A. Schmidt; M. Schumacher; U. Siodlaczek; F. Smend; H. Str"oher; J. Weiss; F. Wissmann; M. Wolf

doi:10.1016/s0375-9474(99)00383-8

Home/Archive/arXiv

arXiv · nucl-ex/9907020

Coherent π^\circ photoproduction from ^4He

View original source ↗Read source document ↗Export metadata ↓

Abstract

Differential cross sections and beam asymmetries for coherent π^\circ photoproduction from ^4He in the Δenergy-range have been measured with high statistical and systematic precisions using both decay photons for identifying the process.The experiment was performed at the MAinz MIcrotron using the TAPS photon spectrometer and the Glasgow/Mainz tagged photon facility. The differential cross sections are in excellent agreement with predictions based on the DWIA if an appropriate parametrization of the Δ-nuclear interaction is applied. The beam asymmetries are interpreted in terms of degrees of linear polarization of collimated coherent bremsstrahlung. The expected increase of the degree of linear polarization with decreasing collimation angle is confirmed. Agreement with calculations is obtained on a few-percent level of precision in the maxima of the coherent peaks.

Explore related subjects

nucl-ex

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

F. Rambo, P. Achenbach, J. Ahrens, H. -J. Arends, R. Beck, S. J. Hall, V. Hejny, P. Jennewein, S. S. Kamalov, M. Kotulla, B. Krusche, V. Kuhr, R. Leukel, V. Metag, R. Novotny, V. Olmos de Leon, A. Schmidt, M. Schumacher, U. Siodlaczek, F. Smend, H. Str"oher, J. Weiss, F. Wissmann, M. Wolf. 1999-07-30. Coherent π^\circ photoproduction from ^4He. https://doi.org/10.1016/s0375-9474(99)00383-8

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Reinvestigation of the Yield of the Trinity Device

Previous published analyses of trinitite to determine the yield of the Trinity nuclear explosion used various estimates of the fraction of fission products that became incorporated in trinitite. Furthermore, these studies utilized nuclear data that has subsequently been revised. Utilizing a planar germanium detector, we observed gamma rays produced by the decays of both 137Cs and 239Pu from four samples of trinitite. From the observed 137Cs/239Pu ratios of and a simple analysis method based on current nuclear data and weapons debris studies, we find an average yield of 9.1+-4.5 kilotons from our four samples. While this result is substantially lower than the established total yield of 21 kilotons, it is in reasonable agreement that attributable to fissions in the 239Pu core alone.

nucl-ex↗

arXiv2026

Search for neutrinoless quadruple beta decay of $^{136}$Xe in PandaX-4T detector

The observation of neutrinoless quadruple beta decay (0$\nu$4$\beta$) in the absence of neutrinoless double beta decay (0$\nu$2$\beta$) has been argued to provide a strong indication that neutrinos are Dirac particles. We report a search for 0$\nu$4$\beta$ decay of $^{136}\text{Xe}$ using a total $^{136}\text{Xe}$ exposure of 148.4 kg$\cdot$yr, collected during the commissioning and the first science runs of the PandaX-4T experiment. No significant excess of events over the background is observed. A lower limit on the 0$\nu$4$\beta$ decay half-life of $^{136}\text{Xe}$ is set at 6.01 x $10^{24}$ yr at the 90% confidence level. This result establishes the most stringent constraint on this process in xenon, demonstrating the unique capability of the PandaX-4T detector in probing lepton number violation and shedding light on the fundamental nature of neutrinos.

nucl-ex↗

arXiv2026

Island of Inversion in neutron-rich cobalt isotopes revealed from mass measurements

Mass measurements of the ground and isomeric states of $^{68-70}$Co have been performed using the JYFLTRAP Penning-trap mass spectrometer at the IGISOL facility. The masses were measured, either for the first time for the isomeric states of $^{68}$Co and $^{70}$Co, or with greatly improved precision for the others, removing ambiguities in the mass surface beyond $N=40$. The ordering of the low and high-spin states in $^{68}$Co and $^{70}$Co has also been established. The results, supported by Large-Scale Shell Model and Discrete Non-Orthogonal Shell-Model calculations, show a gradual lowering of intruder states with increasing neutron number, eventually leading to an inversion in $^{70}$Co. These findings clarify previously proposed contradictory interpretations. Finally, we demonstrate the importance of including induced effective 3N forces for a consistent description of binding energies in the island of inversion near $N=40$.

nucl-ex↗