Search for neutron-antineutron oscillations in the Fréjus detector

Restriction on the neutron-antineutron oscillations from the SNO data on the deuteron stability

“…The neutron-antineutron transition induced by the baryon number violating interaction (ΔB = 2) pre dicted within some variants of GUT has been dis cussed in many papers since 1970 [1], see [2][3][4][5][6][7]. Experimental results of searches for such transition are available, in vacuum (reactor experiments [8], and ref erences therein), in nucleus 16 O [9] and in Fe nucleus [10], in neutron magnetic trap [11], see [3,12].…”

“…Recalculation of the quantity or from existing data on nuclei stability [9,10,13] is somewhat model dependent, and different authors obtained somewhat different results, within about one order of magnitude, see, e.g., discussion in [18,20,21]. In the case of nuclei the n-line with the transition ampli tude is the element of any amplitude describing the nucleus decay A (A -2) + mesons, where A -2 denotes a nucleus or some system of baryons with baryonic number A -2.…”

Connection between νn→ν¯n¯ reactions and n−Hao1 2020Phys. Rev. D3010View full textAdd to dashboardCite

“…The constraints on nucleon instability can be determined through the measurements of two decay modes, such as n-n oscillations [25][26][27][28][29][30] and the dineutron decay: nn →νν [46]. Such decay modes violate B and (B + L) but the dineutron decay preserves (B − L).…”

“…Eq. (27) and Eq. (29) depend on the neutrino mass m ν in a different way but we could adjust the parameters, such as g, f , and δm, so that both of them can be incorporated into the analysis in a compatible way.…”

“…At the quark level, B, (B + L), and (B − L) violations can only be described by high dimensional operators associated with some large mass scales and thus the effect is greatly suppressed and usually considered to be undetectable at low energies [32]. The lower limits on n-n oscillation times for neutrons in matter are derived from the stability of nuclei [25][26][27][28][29][30]. However, the instability of nuclei induced by external low-energy solar neutrinos has not been excluded because of the detector thresholds.…”