2022/01/18 by Prajwal Mohanmurthy, P. Mohanmurthy, A. R. Young +5 · 7 citations
Chemistry · Physics and Astronomy · #Atomic and Subatomic Physics Research #Chemistry #Classical mechanics #Dipole #Electric dipole moment #Moment (physics) #Neutron #Neutron electric dipole moment #Nuclear Physics and Applications #Nuclear physics #Oscillation (cell signaling) #Physics #Quantum, superfluid, helium dynamics #hep-ex #nucl-ex
paper · pdf · open access · doi:10.3390/sym14030487
published in Symmetry 14(3), 487 (Multidisciplinary Digital Publishing Institute) · 12 pages, 2 figures, 1 table. References edited
arxiv created 2022/01/18 · openalex publication_date 2022/02/28 · arxiv updated 2022/03/01 · openalex created_date 2022/03/02 · openalex updated_date 2026/08/06
Baryon number violation is a key ingredient of baryogenesis. It has been hypothesized that there could also be a parity-conjugated copy of the standard model particles, called mirror particles. The existence of such a mirror universe has specific testable implications, especially in the domain of neutral particle oscillation, viz. the baryon number violating neutron to mirror-neutron (n-n') oscillation. Consequently, there were many experiments that have searched for n-n' oscillation, and imposed constraints upon the parameters that describe it. All the previous efforts searched for n-n' oscillation by comparing the relative number of ultracold neutrons that survive after a period of storage for one or both of the two cases: (i) comparison of zero applied magnetic field to a non-zero applied magnetic field, and (ii) comparison where the orientation of the applied magnetic field was reversed. However, n-n' oscillations also lead to variations in the precession frequency of polarized neutrons upon flipping the direction of the applied magnetic field. For the first time, we used the data from the latest search for the neutron electric dipole moment [Phys. Rev. Lett. 124, 081803 (2020)] to constrain n-n' oscillation. After compensating for the systematic effects that affect the ratio of precession frequencies of ultracold neutrons and cohabiting 199Hg-atoms, chief among which was due to their motion in non-uniform magnetic field, we constrained any further perturbations due to n-n' oscillation. We thereby provide a lower limit on the n-n' oscillation time constant of τnn'/√(|cos(β)|) > 5.7~s, 0.36~μT'<B'<1.01~μT' (95% C.L.), where β is the angle between the applied magnetic field and the ambient mirror magnetic field. This constraint is the best available in the range of 0.36~μT'<B'<0.40~μT'.