20 research outputs found
New Evidence for Supernarrow Dibaryons Production in pd Interactions
The analysis of new experimental data, obtained at the Proton Linear
Accelerator of INR, with the aim to search for supernarrow dibaryons in the
and reactions is presented. Narrow peaks with an
experimental width of 5 MeV at masses of 1904, 1926, and 1942 MeV have been observed in missing mass spectra. In the missing
mass spectra, the peaks at , 986, and
1003 MeV have been found. The analysis of the data obtained leads to the
conclusion that the observed peaks in spectra are most likely
supernarrow dibaryons, the decay of which into two nucleons is forbidden by the
Pauli exclusion principle. An alternative interpretation of the spectra by
assuming a decay of the supernarrow dibaryons in "exotic baryon states" with
masses is discussed.Comment: 17 pages, 6 figures. Considerably expanded version accepted for
publication in Eur. Phys. J. A; a discussion, 4 figures and several
references have been added, the title has been change
Fishing for Narrow Dibaryons in pd->pX Reaction
An analysis of experimental data, obtained at the Linear Accelerator of INR,
is carried out with the aim of searching for supernarrow dibaryons in the
reactions pd->p+X and pd->p+pX_1. Dibaryons with masses 1904\pm 2, 1926\pm 2,
and 1942\pm 2 MeV have been observed in M_{X} missing mass spectra. In M_{X_1}
missing mass spectra, the peaks have been found at M_{X_1}=966\pm 2, 986\pm 2,
and 1003\pm 2 MeV. These values of M_{X_1} coincide with the ones obtained by a
simulation of a decay of the dibaryons into \gamma+pn. The analysis of the data
obtained leads to the conclusion that the observed dibaryons are supernarrow
dibaryons, the decay of which into two nucleons is forbidden by the Pauli
exclusion principle. A possible interpretation of exited nucleon states with
small masses is suggested.Comment: 4 pages, 2 figures, aipproc.sty (included); Proceedings of the VII
Conference "Intersections Between Particle and Nuclear Physics", Quebec,
Canada, May 23-27, 200
A Possibility of Detecting Fast Neutrons in a 10B Solid-gas Detector
The possibility of detecting thermal and fast neutrons in 10B solid-gas detector is considered. The simulation of the neutron detection process shows a significant difference in the detector signals caused by neutrons of different energies. An experimental verification of the detector’s operation was performed using W-Be photoneutron source with different ratio of fast and thermal neutrons incident on the detector. The measured amplitude spectra of the signals for different neutron energies were compared with the simulation results. The qualitative agreement between experimental and calculated data indicates the possibility of using this detector for recording thermal and fast neutrons
Analysis of Data Measured with a Neutron Detector Based on a Boron-10 and Helium-3 Counter on a Source of Photoneutrons
Extraction of neutron-neutron scattering length from nn coincidence-geometry nd breakup data
We report preliminary results of a kinematically complete experiment on measurement of nd breakup reaction yield
at neutron beam RADEX of Institute for Nuclear Research (Moscow, Russia). In the experiment two secondary neutrons are detected in geometry of neutron-neutron final-state interaction. Data are obtained at energy of incident neutrons En = 40 - 60 MeV for various divergence angles of two neutrons ΔΘ = 4, 6, 8º. 1S0 neutron-neutron scattering length ann were determined by comparison of the experimental dependence of reaction yield on the relative energy of two secondary neutrons with results of simulation depending on ann. For En = 40 MeV and ΔΘ = 6º (the highest statistics in the experiment) the value ann = -17.9 ± 1.0 fm is obtained. The further improving of accuracy of the experiment and more rigorous theoretical analysis will allow one to remove the existing difference in ann values obtained in different experiments
tand for testing neutron scintillation detectors
Testing stand of plastic scintillation detectors of neutrons is described. Detectors are irradiated by the beam of 14 MeV neutrons produced in d + t Æ n + 4 He reaction using the ING-07 neutron generator. The neutrons obtained pass through the forming shielding collimator made of borated polyethylene (70 × 90 × 125 cm3 with through slit of 0.5 × × 6 cm2). Formation of narrow collimated beam allows one to study the spatial resolution of the neutron detectors (possibility of determination of the point of interaction of neutron with the detector substance) that is necessary for optimization of time resolution of detectors. The stand also allows to measure the absolute efficiency of detectors of various lengths at neutron energy of 14 MeV