Related papers: On the suppression of the $n\bar{n}$ transitions i…
The models of $n\bar{n}$ transitions in the medium based on unitary $S$-matrix are considered. The time-dependence and corrections to the models are studied. The lower limits on the free-space $n\bar{n}$ oscillation time are obtained as…
The present state of the $n\bar{n}$ transition problem is briefly outlined. The models based on the diagram technique for direct reactions, potential description of $\bar{n}$-medium interaction and field-theoretical approach are considered.…
The new model of $n\bar{n}$ transitions in nuclei based on unitary $S$-matrix is considered. The $|in>$-state of nucleus is described by single-particle shell model. The dynamical process part is calculated by means of field-theoretical…
We summarize our study of the neutron-antineutron transition in medium and nuclei in the framework of the field-theoretical approach. The models based on the diagram technique for direct reactions, potential description of…
It is shown that there is a double counting in the standard model of $n\bar {n}$ mixing in the medium, resulting in full cancellation of leading terms. The direct calculation of $n\bar{n}$ transition followed by annihilation is performed.…
We show that there is a double counting in the standard model of $n\bar{n}$ mixing in the medium, resulting in full cancellation of leading terms. The direct calculation of $n\bar{n}$ transition, annihilation is performed. For lower limit…
An upper limit on $n-\bar n$ oscillations can be obtained from the stability of matter. This relation has been worked out theoretically and together with data yields $\tau_{n\bar n} > (1 - 2)\times 10^8 sec$. A recent publication claims a…
The corrections to the model of $n\bar{n}$ transitions in the medium and additional baryon-number-violating processes are considered. We focus on the time-dependence since it is different for the $n\bar{n}$ transition followed by…
Restriction on the neutron-antineutron oscillation time in vacuum is obtained from latest SNO data on the deuteron stability, $\tau_D\,>\,3.01^.10^{31}$ years. Calculation performed within the quantum field theory based diagram technique…
The relationship between the lower limit on the nuclear stability lifetime as derived from the non disappearance of `stable` nuclei ($T_{d}~\gtrsim~5.4~\times~10^{31}$ yr), and the lower limit thus implied on the oscillation time $(\tau_{n…
The observation of neutron to antineutron oscillation would be the first experimental evidence to show that baryon number is not a conserved quantity. It also provides an answer to the hypothesized post-sphaleron baryogenesis mechanism…
In this article, we reevaluate supernovae (SN) constraints on the diffusion time of neutrinos for a family of extensions of the Standard Model that incorporate new light scalar and vector mediators. We compute the neutrino mean free path,…
A search for neutron-antineutron ($n-\bar{n}$) oscillation was undertaken in Super-Kamiokande using the 1489 live-day or $2.45 \times 10^{34}$ neutron-year exposure data. This process violates both baryon and baryon minus lepton numbers by…
We refute a recent claim by Nazaruk that the limits placed on the free--space neutron--antineutron oscillation time $\tau_{{n\bar n}}$ can be improved by many orders of magnitude with respect to the estimate $\tau_{{n\bar…
We expose a grave drawback hidden in the standard model of neutron-antineutron transitions in a medium. Correcting it, one improves a limit on the free-space neutron-antineutron oscillation time by 31 orders of magnitude.
Existing bounds on the neutron-antineutron mass mixing, $\epsilon_{n\bar n} < {\rm few} \times 10^{-24}$ eV, impose a severe upper limit on $n - \bar n$ transition probability, $P_{n\bar n}(t) < (t/0.1 ~{\rm s})^2 \times 10^{-18}$ or so,…
The idea of a hidden sector of mirror partners of elementary particles has attracted considerable interest as a possible candidate for dark matter. Recently it was pointed out by Berezhiani and Bento that the present experimental data…
This work investigates the effects of time-varying media, where optical properties change over time, on electromagnetic wave propagation, focusing on plane waves and free-electron evanescent waves. We introduce a switching parameter,…
Models that postulate the existence of hidden sectors address contemporary questions, such as the source of baryogenesis and the nature of dark matter. Among the possible mixing processes, neutron-to-hidden-neutron oscillations have been…
Using known estimates for the kaon--antikaon transitions, the mean lifetime of the muon and the mean lifetime of the tau, we place new and stronger constraints on the scales of the multi-fractional theories with weighted and…