Speaker
Dr.
Evgeny Konobeevski
(Institute for Nuclear research)
Description
The goal of this work is an experimental study of neutron-neutron interaction and, in particular, of mechanisms of *nn*-correlations in few-nucleon systems. According to [1] strong discrepancies of experimental data and theory observed in nd- and pd-breakup reactions [2, 3] can be explained by a significant strengthening of nn- and pp-correlations of attractive character in the third nucleon field in 3H (pnn) and 3He (ppn) systems.
In this work the *d* + 2H → *p + p + n +n* reaction is studied at 15 MeV deuteron beam of U-120 cyclotron of Skobel’tsyn Institute of Nuclear Physics, Moscow State University. In this reaction, the correlated nn- and pp- singlet pairs can be formed dynamically in the intermediate state. Thus, the measured nn- and pp-correlations, in particular, energies of *nn* (*pp*) singlet quasi-bound states can appear different than those inherent for a free nn- and pp-systems.
For the first time, in a kinematically complete experiment the energy of quasi-bound state of 2n-system is determined. The energy of the nn 1S0 state is determined by comparing experimental time-of-flight spectrum of the neutron from the breakup of 2n-system with simulation spectra depending on this energy. The obtained value Enn = 76 $\pm$ 6 keV is significantly lower than energies (120 – 160 keV) recalculated from the experimental values of 1S0 nn-scattering length [3-5], that perhaps indicates an effective enhancement of nn-interaction in the intermediate state of studied reaction. This work was partly supported by RFBR under grant N16-32-00743.
1. Konobeevski E.S., Kukulin V.I., Zuyev S.V. et al. Bull. Russ. Acad. Sci. 78, 341 (2014).
2. Witala H. and Glöckle W. Phys. Rev. C 83, 034004 (2011).
3. Ruan X.S. et al. Phys. Rev. C 75, 057001 (2007).
4. Huhn V. et al. Phys. Rev. C 63, 014003 (2000).
5. Gonzales Trotter D. E. et al. Phys. Rev. C 73, 034001 (2006).
Primary author
Dr.
Evgeny Konobeevski
(Institute for Nuclear research)
Co-authors
Mr.
Alexander Kasparov
(Institute for Nuclear Research)
Dr.
Andrey Spassky
(Skobel’tsyn Institute of Nuclear Physics)
Dr.
Michail Mordovskoy
(Institute for Nuclear Research)
Dr.
Sergey Zuyev
(Institute for Nuclear Research)
Dr.
Viktor Lebedev
(Skobel’tsyn Institute of Nuclear Physics)
