The changes in the mean-square charge radius (relative to 209 Bi), magnetic dipole, and electric ... more The changes in the mean-square charge radius (relative to 209 Bi), magnetic dipole, and electric quadrupole moments of 187;188;189;191 Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187;188;189 Bi g , manifested by a sharp radius increase for the ground state of 188 Bi relative to the neighboring 187;189 Bi g. A large isomer shift was also observed for 188 Bi m. Both effects happen at the same neutron number, N ¼ 105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.
Electronic factors for the field and mass isotope shifts in the 6 p 2 P3/2 → 7 s 2 S1/2 (535 nm),... more Electronic factors for the field and mass isotope shifts in the 6 p 2 P3/2 → 7 s 2 S1/2 (535 nm), 6 p 2 P1/2 → 6 d 2 D3/2 (277 nm), and 6 p 2 P1/2 → 7 s 2 S1/2 (378 nm) transitions in neutral thallium were calculated within the high-order relativistic coupled cluster approach. These factors were used to reinterpret previous experimental isotope shift measurements in terms of charge radii of a wide range of Tl isotopes. Good agreement between theoretical and experimental King-plot parameters was found for the 6 p 2 P3/2 → 7 s 2 S1/2 and 6 p 2 P1/2 → 6 d 2 D3/2 transitions. It was shown that the value of the specific mass shift factor for the 6 p 2 P3/2 → 7 s 2 S1/2 transition is not negligible compared with the value of normal mass shift in contrast to what had been suggested previously. Theoretical uncertainties in the mean square charge radii were estimated. They were substantially reduced compared with the previously ascribed ones and amounted to less than 2.6%. The achieved accur...
Using parity-nonconserving spin-spin coupling to measure the Tl nuclear anapole moment in a TlF molecular beam, 2023
An experiment utilizing a TlF molecular beam is being developed by the CeNTREX collaboration to s... more An experiment utilizing a TlF molecular beam is being developed by the CeNTREX collaboration to search for hadronic interactions that violate both time-reversal (T ) and parity (P) invariance. Here, we propose to use the same beam to look for a T -invariance conserving but P-nonconserving (PNC) effect induced by the anapole moment of the Tl nucleus, via a vector coupling of the two nuclear spins in TlF. To measure the nuclear anapole moment, the dc electric and magnetic fields in CeNTREX are replaced by rf fields resonant with a nuclear spin-flip transition. We adapt the relativistic coupled-cluster method in combination with relativistic density functional theory for the calculation of the molecular PNC spin-spin vector coupling constant that links the experimental signal with the anapole moment. The value of the P-conserving spin-spin coupling constant calculated within the same approach is found to be in good agreement with available experimental data.
The present constraint on the space parity (P) and time reflection invariance (T ) violating elec... more The present constraint on the space parity (P) and time reflection invariance (T ) violating electron electric dipole moment (eEDM) is based on the observation of the electron spin precession in an external electric field using the ThO molecule. We propose an alternative approach: observation of the P, T -odd Faraday effect in an external electric field using the cavity-enhanced polarimetric scheme in combination with a molecular beam crossing the cavity. Our theoretical simulation of the proposed experiment with the PbF and ThO molecular beams show that the present constraint on the eEDM in principle can be improved by a few orders of magnitude.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2021
The photon-spin-dependent (PS) contribution to the ordinary Faraday effect—optical rotation in an... more The photon-spin-dependent (PS) contribution to the ordinary Faraday effect—optical rotation in an external magnetic field H ⃗ is well known. This contribution is proportional to factor ( s ⃗ p h ⋅ H ⃗ ) where s ⃗ p h is the photon spin. Recently a P , T -odd Faraday effect—optical rotation in an external electric field E ⃗ —was discussed as a promising tool for observation of the electron electric dipole moment in the intra-cavity absorption spectroscopy. In the present paper, we introduce the PS contribution to the P , T -odd Faraday rotation effect. This contribution is proportional to ( s ⃗ p h ⋅ E ⃗ ) and has to be taken into account in the calculations of the P , T -odd Faraday effect.
The P , T -odd Faraday effect (i.e., rotation of the polarization plane of light propagating thro... more The P , T -odd Faraday effect (i.e., rotation of the polarization plane of light propagating through a medium in presence of the external electric field due to P , T symmetry violating interactions) is considered for several atomic species: Ra, Pb, Tl, Hg, Cs, and Xe. Corresponding theoretical simulation of P , T -odd Faraday experiment, with already achieved intracavity absorption spectroscopy characteristics and parameters, is performed. The results show that the magnetic dipole transitions in the Tl and Pb atoms as well as the electric dipole transitions in the Ra, Hg and Cs atoms are favorable for the observation of the P , T -odd Faraday optical rotation. The estimation of the rotation angle of the light polarization plane demonstrates that recently existing boundaries for the electron electric dipole moment can be improved by one-two orders of magnitude.
The changes in the mean-square charge radius (relative to 209 Bi), magnetic dipole, and electric ... more The changes in the mean-square charge radius (relative to 209 Bi), magnetic dipole, and electric quadrupole moments of 187;188;189;191 Bi were measured using the in-source resonance-ionization spectroscopy technique at ISOLDE (CERN). A large staggering in radii was found in 187;188;189 Bi g , manifested by a sharp radius increase for the ground state of 188 Bi relative to the neighboring 187;189 Bi g. A large isomer shift was also observed for 188 Bi m. Both effects happen at the same neutron number, N ¼ 105, where the shape staggering and a similar isomer shift were observed in the mercury isotopes. Experimental results are reproduced by mean-field calculations where the ground or isomeric states were identified by the blocked quasiparticle configuration compatible with the observed spin, parity, and magnetic moment.
Electronic factors for the field and mass isotope shifts in the 6 p 2 P3/2 → 7 s 2 S1/2 (535 nm),... more Electronic factors for the field and mass isotope shifts in the 6 p 2 P3/2 → 7 s 2 S1/2 (535 nm), 6 p 2 P1/2 → 6 d 2 D3/2 (277 nm), and 6 p 2 P1/2 → 7 s 2 S1/2 (378 nm) transitions in neutral thallium were calculated within the high-order relativistic coupled cluster approach. These factors were used to reinterpret previous experimental isotope shift measurements in terms of charge radii of a wide range of Tl isotopes. Good agreement between theoretical and experimental King-plot parameters was found for the 6 p 2 P3/2 → 7 s 2 S1/2 and 6 p 2 P1/2 → 6 d 2 D3/2 transitions. It was shown that the value of the specific mass shift factor for the 6 p 2 P3/2 → 7 s 2 S1/2 transition is not negligible compared with the value of normal mass shift in contrast to what had been suggested previously. Theoretical uncertainties in the mean square charge radii were estimated. They were substantially reduced compared with the previously ascribed ones and amounted to less than 2.6%. The achieved accur...
Using parity-nonconserving spin-spin coupling to measure the Tl nuclear anapole moment in a TlF molecular beam, 2023
An experiment utilizing a TlF molecular beam is being developed by the CeNTREX collaboration to s... more An experiment utilizing a TlF molecular beam is being developed by the CeNTREX collaboration to search for hadronic interactions that violate both time-reversal (T ) and parity (P) invariance. Here, we propose to use the same beam to look for a T -invariance conserving but P-nonconserving (PNC) effect induced by the anapole moment of the Tl nucleus, via a vector coupling of the two nuclear spins in TlF. To measure the nuclear anapole moment, the dc electric and magnetic fields in CeNTREX are replaced by rf fields resonant with a nuclear spin-flip transition. We adapt the relativistic coupled-cluster method in combination with relativistic density functional theory for the calculation of the molecular PNC spin-spin vector coupling constant that links the experimental signal with the anapole moment. The value of the P-conserving spin-spin coupling constant calculated within the same approach is found to be in good agreement with available experimental data.
The present constraint on the space parity (P) and time reflection invariance (T ) violating elec... more The present constraint on the space parity (P) and time reflection invariance (T ) violating electron electric dipole moment (eEDM) is based on the observation of the electron spin precession in an external electric field using the ThO molecule. We propose an alternative approach: observation of the P, T -odd Faraday effect in an external electric field using the cavity-enhanced polarimetric scheme in combination with a molecular beam crossing the cavity. Our theoretical simulation of the proposed experiment with the PbF and ThO molecular beams show that the present constraint on the eEDM in principle can be improved by a few orders of magnitude.
Journal of Physics B: Atomic, Molecular and Optical Physics, 2021
The photon-spin-dependent (PS) contribution to the ordinary Faraday effect—optical rotation in an... more The photon-spin-dependent (PS) contribution to the ordinary Faraday effect—optical rotation in an external magnetic field H ⃗ is well known. This contribution is proportional to factor ( s ⃗ p h ⋅ H ⃗ ) where s ⃗ p h is the photon spin. Recently a P , T -odd Faraday effect—optical rotation in an external electric field E ⃗ —was discussed as a promising tool for observation of the electron electric dipole moment in the intra-cavity absorption spectroscopy. In the present paper, we introduce the PS contribution to the P , T -odd Faraday rotation effect. This contribution is proportional to ( s ⃗ p h ⋅ E ⃗ ) and has to be taken into account in the calculations of the P , T -odd Faraday effect.
The P , T -odd Faraday effect (i.e., rotation of the polarization plane of light propagating thro... more The P , T -odd Faraday effect (i.e., rotation of the polarization plane of light propagating through a medium in presence of the external electric field due to P , T symmetry violating interactions) is considered for several atomic species: Ra, Pb, Tl, Hg, Cs, and Xe. Corresponding theoretical simulation of P , T -odd Faraday experiment, with already achieved intracavity absorption spectroscopy characteristics and parameters, is performed. The results show that the magnetic dipole transitions in the Tl and Pb atoms as well as the electric dipole transitions in the Ra, Hg and Cs atoms are favorable for the observation of the P , T -odd Faraday optical rotation. The estimation of the rotation angle of the light polarization plane demonstrates that recently existing boundaries for the electron electric dipole moment can be improved by one-two orders of magnitude.
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