Using a composition of convective instability indices to predict the occurrence of polar mesocyclones in the Arctic region of Russia

The article presents a brief description of the developed technological line for the automatic prediction of the occurrence of polar mesocyclones in the Arctic region of Russia. Technological line includes a block of numerical simulation Polar WRF with the setting of initial and boundary conditions according to the GFS model, a block for calculating convective instability indices, a block for calculating the probability fields of polar mesocyclone nucleation using regional thresholds for selected indices, a visualization subsystem that allows to select an area with a given probability of detecting a perturbation. The paper gives a description of the proposed method for predicting polar mesocyclones, and justifies the use of a number of convective indices as prognostic predictors. For the convective indices used, regional threshold values were determined, the excess of which in a given direction in a limited area increases the probability of a polar mesocyclone occurring in this zone. The operation of the developed forecasting technological line is described. The results of prognostic calculations for a number of mesocyclones observed in 2022 are demonstrated. Estimates of the justification of the forecast based on the results of continuous operation of the technology in test mode from January to December 2022 are presented

E1 amplitudes, lifetimes, and polarizabilities of the low-lying levels of atomic ytterbium

The results of ab initio calculation of E1 amplitudes, lifetimes,and polarizabilities for several low-lying levels of ytterbium are reported. The effective Hamiltonian for the valence electrons has been constructed in the frame of CI+MBPT method and solutions of many electron equation are found.Comment: 11 pages, submitted to Phys.Rev.

Stringent bounds to spatial variations of the electron-to-proton mass ratio in the Milky Way

The ammonia method to probe variations of the electron-to-proton mass ratio, Delta_mu/mu, is applied for the first time to dense prestellar molecular clouds in the Milky Way. Carefully selected sample of 21 NH_3/CCS pairs observed in the Perseus molecular cloud provide the offset Delta V (CCS-NH_3)= 36+/-7_{stat}+/-13.5_{sys} m/s . A similar offset of Delta V = 40.8 +/- 12.9_{stat} m/s between NH_3 (J,K) = (1,1) and N_2H+ J = 1-0 has been found in an isolated dense core L183 by Pagani et al. (2009). Overall these observations provide a safe bound of a maximum offset between ammonia and the other molecules at the level of Delta V < 100 m/s. This bound corresponds to Delta_mu/mu < 1E-7, which is an order of magnitude more sensitive than available extragalactic constraints. Taken at face value the measured Delta V shows positive shifts between the line centers of NH_3 and these two other molecules and suggest a real offset, which would imply a Delta_mu/mu about 4E-8. If Delta_mu/mu follows the gradient of the local gravitational potential, then the obtained results are in conflict with laboratory atomic clock experiments in the solar system by 5 orders of magnitude, thus requiring a chameleon-type scalar field model. New measurements involving other molecules and a wider range of objects along with verification of molecular rest frequencies are currently planned to confirm these first indications.Comment: 7 pages +2 figures. Galileo Galilei Institute Conferences on Dark Matter and Dark Energ

Time-reversal violating rotation of polarization plane of light in gas placed in electric field

Rotation of polarization plane of light in gas placed in electric field is considered. Different factors causing this phenomenon are investigated. Angle of polarization plane rotation for transition 6S_{1/2} - 7S_{1/2} in cesium (lambda=539 nm) is estimated. The possibility to observe this effect experimentally is discussed.Comment: 10 pages, Late

КОРРЕЛЯЦИОННАЯ ЗАВИСИМОСТЬ КЛИНИКО-МОРФОЛОГИЧЕСКИХ ПРОЯВЛЕНИЙ И БИОМЕХАНИЧЕСКИХ ПАРАМЕТРОВ У БОЛЬНЫХ С ДЕГЕНЕРАТИВНЫМ СПОНДИЛОЛИСТЕЗОМ L4 ПОЗВОНКА

The study included 59 operated patients with spondylolisthesis L4 vertebra of I degree. All the patients were held clinical-anamnestic, neurological, radiological, radiopaque and biomechanical studies, MRI, CT, as well as puncture performed provocative tests. Revealed correlation of clinical manifestations of degenerative spondylolisthesis L4 and biomechanical parameters of the shape and orientation of the lumbar spine. The most pronounced clinical and morphological changes detected at the level of spondylolisthesis and adjacent segments in the group with hyperlordosis and excessive tilt angle of the chord forward, which is confirmed by MRI, CT, and carried out a disco-puncture provocative tests. A variety of pathological changes of the lumbar spine at L4 vertebra degenerative spondylolisthesis correlated with the biomechanical parameters violation of the shape and orientation of the spine in the sagittal plane.В исследование включено 59 пациентов, оперированных по поводу спондилолистеза L4 позвонка I степени. Всем больным были проведены клинико-анамнестическое, неврологическое, рентгенологическое, рентгенконтрастное и биомеханическое исследования, МРТ, МСКТ, а также выполнены пункционных провокационных проб. Выявлена корреляционная зависимость клинических проявлений дегенеративного спондилолистеза L4 и биомеханических параметров формы и ориентации поясничного отдела позвоночника. Наиболее выраженные клинико-морфологические изменения выявлены на уровне спондилолистеза и смежных сегментов в группе с гиперлордозом и избыточным наклоном угла хорды вперед, что подтверждается данными МРТ, МСКТ и проведенными диско-пункционными провокационными тестами. Разнообразие патоморфологических изменений поясничного отдела позвоночника при дегенеративном спондилолистезе L4 позвонка коррелирует с нарушением биомеханических параметров формы и ориентации позвоночника в сагиттальной плоскости

Measurement of the 6s - 7p transition probabilities in atomic cesium and a revised value for the weak charge Q_W

We have measured the 6s - 7p_{1/2,3/2} transition probabilities in atomic cesium using a direct absorption technique. We use our result plus other previously measured transition rates to derive an accurate value of the vector transition polarizability \beta and, consequently, re-evaluate the weak charge Q_W. Our derived value Q_W=-72.65(49) agrees with the prediction of the standard model to within one standard deviation.Comment: 4 pages, 2 figure

Parity nonconservation in heavy atoms: The radiative correction enhanced by the strong electric field of the nucleus

Parity nonconservation due to the nuclear weak charge is considered. We demonstrate that the radiative corrections to this effect due to the vacuum fluctuations of the characteristic size larger than the nuclear radius $r_0$ and smaller than the electron Compton wave-length $\lambda_C$ are enhanced because of the strong electric field of the nucleus. The parameter that allows one to classify the corrections is the large logarithm $\ln(\lambda_C/r_0)$. The vacuum polarization contribution is enhanced by the second power of the logarithm. Although the self-energy and the vertex corrections do not vanish, they contain only the first power of the logarithm. The value of the radiative correction is 0.4% for Cs and 0.9% for Tl, Pb, and Bi. We discuss also how the correction affects the interpretation of the experimental data on parity nonconservation in atoms.Comment: 4 pages, 3 figures, RevTe

Limits on the monopole magnetic field from measurements of the electric dipole moments of atoms, molecules and the neutron

A radial magnetic field can induce a time invariance violating electric dipole moment (EDM) in quantum systems. The EDMs of the Tl, Cs, Xe and Hg atoms and the neutron that are produced by such a field are estimated. The contributions of such a field to the constants, $\chi$ of the T,P-odd interactions $\chi_e {\bf N} \cdot {\bf s}/s$ and $\chi_N {\bf N} \cdot {\bf I}/I$ are also estimated for the TlF, HgF and YbF molecules (where ${\bf s}$ (${\bf I}$) is the electron (nuclear) spin and ${\bf N}$ is the molecular axis). The best limit on the contact monopole field can be obtained from the measured value of the Tl EDM. The possibility of such a field being produced from polarization of the vacuum of electrically charged magnetic monopoles (dyons) by a Coulomb field is discussed, as well as the limit on these dyons. An alternative mechanism involves chromomagnetic and chromoelectric fields in QCD.Comment: Uses RevTex, 16 pages, 4 postscript figures. An explanation of why there is no orbital contribution to the EDM has been added, and the presentation has been improved in genera