New Evidence for Supernarrow Dibaryons Production in pd Interactions

TL;DR

This paper reports the experimental observation of narrow peaks in proton-deuteron interactions, providing evidence for supernarrow dibaryons that cannot decay into two nucleons, with potential implications for exotic baryon states.

Contribution

The study presents new experimental evidence for supernarrow dibaryons in pd interactions, identifying specific mass peaks and discussing their possible exotic decay modes.

Findings

Observed narrow peaks at 1904, 1926, and 1942 MeV in missing mass spectra.

Identified peaks at 966, 986, and 1003 MeV in $M_{X_1}$ spectra.

Concluded peaks are likely supernarrow dibaryons with forbidden decay channels.

Abstract

The analysis of new experimental data, obtained at the Proton Linear Accelerator of INR, with the aim to search for supernarrow dibaryons in the $pd\to ppX_1$ and $pd\to pdX_2$ reactions is presented. Narrow peaks with an experimental width of 5 MeV at masses of 1904$\pm 2$, 1926$\pm 2$, and 1942$\pm 2$ MeV have been observed in missing mass $M_{pX_1}$ spectra. In the missing mass $M_{X_1}$ spectra, the peaks at $M_{X_1}=966\pm 2$, 986$\pm 2$, and 1003$\pm 2$ MeV have been found. The analysis of the data obtained leads to the conclusion that the observed peaks in $M_{pX_1}$ 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 $M_{X_1}$ is discussed.