https://doi.org/10.1140/epjc/s10052-019-6995-x
Letter
Neutron lifetime puzzle and neutron–mirror neutron oscillation
1
Dipartimento di Fisica e Chimica, Università di L’Aquila, 67100, Coppito, L’Aquila, Italy
2
INFN, Laboratori Nazionali del Gran Sasso, 67010, Assergi, L’Aquila, Italy
* e-mail: zurab.berezhiani@lngs.infn.it
Received:
13
November
2018
Accepted:
22
May
2019
Published online:
10
June
2019
Standard Model, with its present precision, predicts the neutron 
-decay time 
s which is perfectly compatible with the neutron lifetime measured in the trap experiments 
s. However, the lifetime measured in the beam experiments via counting the protons produced by -decay 
, 
s, is deviated from 
by 9 seconds (
). This discrepancy can be explained via the neutron n conversion into mirror neutron 
, its dark partner from parallel mirror sector. Provided that n and have a tiny mass splitting 
eV, in magnetic fields of few Tesla used in beam experiments, 
transition is resonantly enhanced converting a 1
fraction of neutrons into mirror neutrons which decay in invisible mode 
. Thus less protons are produced and the measured value 
appears larger than the true decay time 
.
© The Author(s), 2019
