Measurement of ${}^6\mathrm{H}$ ground state energy in an electron scattering experiment at MAMI-A1

Abstract

For the first time the neutron-rich hydrogen isotope ${}^6\mathrm{H}$ was produced in an electron scattering experiment in the reaction ${}^7\mathrm{Li}(\mathrm{e},{\mathrm{e}}^{\prime }\mathrm{p}{\pi }^{+}{)}^6\mathrm{H}$ using the spectrometer facility of the A1 Collaboration at the Mainz Microtron accelerator. By measuring the triple coincidence between the scattered electron, the produced proton, and ${\pi }^{+}$, the missing mass spectrum of ${}^6\mathrm{H}$ was obtained. A clear peak above ${}^3$H+n+n+n energy threshold was seen resulting in a ground state energy of ${}^6\mathrm{H}$ at $2.3\pm 0.5(stat.)\pm 0.4(syst.)$ MeV with a width of $1.9\pm 1.0(stat.)\pm 0.4(syst.)$ MeV. This work challenges the understandings of multi-nucleon interactions and presents a new method to study light neutron-rich nuclei with electron scattering experiments.

6 pages, 4 figures

References in corpus (6)

• Observation of Lambda H-4 hyperhydrogen by decay-pion spectroscopy in electron scattering
• Ab initio calculations of 5H resonant states
• Low-$Q^2$ elastic electron-proton scattering using a gas jet target
• The ${}^6$H states studied in the ${}^2\text{He}{(}^8\text{He}{,}^4\text{He})$ reaction and evidence of extremely correlated character of the ${}^5$H ground state
• ${}^7$H ground state as a ${}^3$H+4n resonance
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Cited by in corpus (1)

• Method to search for the triple-neutron state in an electron scattering experiment