The article examines the synthesis and electrophysical properties of spinel ferrite ZnFe2O4, produced using the sol–gel method with a solid-state finishing process; as well as through classical ceramic technology with mechanochemical activation. The study includes a detailed analysis of the phase composition and crystalline structure using X-ray diffraction; infrared spectroscopy; mass spectrometry; and thermogravimetric and differential thermal analyses. These methods help identify thermal effects and the stages of synthesis. Impedance spectroscopy is used to investigate the electrophysical properties, revealing a significant influence of firing temperature on electrical ionic conductivity. The results show that the electrophysical properties differ based on the synthesis conditions and methods. This suggests potential applications for ZnFe2O4 as a cathode material in metal-ion batteries. The work highlights the importance of optimizing synthesis conditions to achieve high-performance characteristics in electrode materials.

Samarium hydrogen iodate Sm(IO3)3HIO3 was successfully synthesized by the unconven-tional low-temperature solution-melt method, its structure was determined by X-ray dif-fraction analysis of single crystals. This compound crystallizes in the monoclinic space group P21/c with lattice parameters: a = 10.4637(6) Å, b = 7.4629(5) Å, c = 14.0174(13) Å, β = 110.53(0), Z = 6. In the studied structure, samarium atoms are surrounded by 8 ox-ygen atoms in a polyhedron in the form of a distorted square antiprism. The iodate groups are linked through common oxygen atoms of the SmO8 antiprism into a three-dimensional framework. The compound was characterized by X-ray diffraction, IR and NQR spectros-copy and EDX analysis.

We present the study of the decay J/ψ → ρπ . The results are based on of 5.2 million J/ψ events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured to be ℬ ( J/ψ → ρπ ) = (2 . 072 ± 0 . 017 ± 0 . 062) ∙ 10 − 2 and ℬ ( J/ψ → π + π − π 0 ) = (1 . 878 ± 0 . 013 ± 0 . 051) ∙ 10 − 2 , where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.

Using the entire BaBar Υ(4S) data set, the first two-dimensional unbinned angular analysis of the semileptonic decay B→ D ℓ^- ν_ℓ is performed, employing hadronic reconstruction of the tag-side B meson from Υ(4S)→ BB. Here, ℓ denotes the light charged leptons e and μ. A novel data-driven signal-background separation procedure with minimal dependence on simulation is developed. This procedure preserves all multi-dimensional correlations present in the data. The expected sin^2θ_ℓ dependence of the differential decay rate in the Standard Model is demonstrated, where θ_ℓ is the lepton helicity angle. Including input from the latest lattice QCD calculations and previously available experimental data, the underlying form factors are extracted using both model-independent (BGL) and dependent (CLN) methods. Comparisons with lattice calculations show flavor SU(3) symmetry to be a good approximation in the B_(s)→ D_(s) sector. Using the BGL results, the CKM matrix element |V_cb|=(41.09± 1.16)× 10^-3 and the Standard Model prediction of the lepton-flavor universality violation variable ℛ(D)=0.300± 0.004, are extracted. The value of |V_cb| from B→ D ℓ^- ν_ℓ tends to be higher than that extracted using B→ D ℓ^- ν_ℓ. The Standard Model ℛ(D) calculation is at a 1.97σ tension with the latest HFLAV experimental average.

Silver cluster compounds Ag2[B12Cl12](1), (Ag(CH3CN)4)2[B12Cl12] (2), and (Ag(CH3CN)2)2[B12Cl12] (3) with very different types of silver environment in crystals were synthesized and investigated using X-ray diffraction analysis (XRD), X-ray phase analysis and nuclear quadrupole resonance (35Cl NQR). Non-covalent interactions of chlorines with surrounding atoms were identified and analyzed using 35Cl NQR spectroscopy. The results were compared with those of XRD to show that the "short" contacts between atomic nuclei do not necessarily indicate the presence of an attraction interaction between the corresponding atoms. Numerous weak interhalogen Cl center dot center dot center dot Cl interactions were revealed in 1, while the Ag center dot center dot center dot Cl ineractions seem to be weakened due to high coordination number of silver atom. In 2, no Ag center dot center dot center dot Cl interactions were detected by X-ray diffraction, while non-covalent Cl center dot center dot center dot C, Cl center dot center dot center dot H and Cl center dot center dot center dot Cl interactions were found. As the NQR spectra indicated, interhalogen interactions in 2 appeared to be the strongest of all the others. In 3, interhalogen Cl center dot center dot center dot Cl interactions were the weakest, the largest contribution to the electric field gradient on the Cl atoms being made by silver atoms.

A technologically feasible process has been proposed for the preparation of a LiNbO3:Mg,B growth charge from a Li2CO3 + Nb2O5 + MgO + H3BO3 mixture. Using such a growth charge, we have grown LiNbO3:Mg,B crystals with a highly uniform dopant distribution. High-speed evaluation of optical homogeneity has shown that the LiNbO3:Mg,B crystals have high optical quality. Using amplitude–frequency response and d333 piezoelectric modulus measurements, we have demonstrated a high degree of unipolarity of the LiNbO3:Mg,B crystals. The optical damage resistance and homogeneity of the LiNbO3:Mg,B crystals have been assessed using photoinduced light scattering and laser conoscopy. The results suggest that LiNbO3:Mg,B crystals with a weak photorefractive effect can be regarded as a new optical material for laser light conversion.

High-energy cosmic-ray research via the detection of Cherenkov radiation from extensive air showers was begun in the Tunka valley (50 km to the west from the southern extremity of Lake Baikal) in the early 1990s. A series of large arrays combined into the TAIGA (Tunka Advanced Instrument for cosmic-ray physics and Gamma Astronomy) astrophysical facility and designed to study gamma rays and charged cosmic rays have been created in the elapsed time. Descriptions of the facility arrays and the main results obtained while investigating high-energy cosmic rays are presented. Plans for a further development of the astrophysical facility are discussed.

Particle identification system based on Focusing Aerogel RICH (FARICH) detector is considered as an option for the future experiments at the Super Charm-Tau Factory (Russia). We present the progress of FARICH R & D at the Budker Institute of Nuclear Physics. New samples of focusing 4-layer aerogels with maximal refractive index 1.065 were produced in 2020-2021. First beam test results with relativistic electrons demonstrate single photon resolution (SPR) of 9 divided by 10 mrad. According to simulation results, the aerogels with such SPR are able to provide mu/pi-separation at the level of more than 3 standard deviations for tracks with momentum 1.5 GeV/c. The first version of electronics to readout SiPM arrays based on TDC implemented on FPGA (FPGA-TDC) was developed and manufactured.

Three salts based on perchlorinated closo-dodecaborate anion, Cs-2[B12Cl12]*2MeCN (1), K-2[B12Cl12]*7MeCN (2), and (Ph4P)(2)[B12Cl12] (3) were synthesized and characterized using B-11, H-1, C-13 NMR, X-ray diffraction and 35Cl nuclear quadrupole resonsnce (NQR) spectroscopy. The latter was for the first time applied for identification of noncovalent interactions Cl...X in closo-dodecaborate clusters. Subtle perturbations of the cluster electron density caused by weak noncovalent Cl...X interactions were detected hence selecting from the whole totality of measured interatomic << short >> contacts those which really participated in noncovalent interactions. It has been shown that X-ray structural information based on measuring the distances between atomic nuclei can be substantially sup-plemented with the Cl-35 NQR data on the features of the electronic distribution in these compounds. According to the Cl-35 NQR results, the alkali cations in 2*7MeCN, unlike in 1*2MeCN, do not participate in noncovalent in-teractions with Cl atoms whereas the X-ray diffraction analysis found a number of K...Cl distances shorter than the sum of vdW radii.

In an experiment with the SND detector at the VEPP-2000 $$e^{+}e^{-}$$ collider, the cross sections for the processes $$e^{+}e^{-}\to K^{+}K^{-}\pi^{0}$$ and $$e^{+}e^{-}\to\phi\pi^{0}$$ were measured at collision energies of $$\sqrt{s}=1.28{-}2.00$$ GeV in the center-of-mass frame. The results agree with the results of earlier measurements in the BABAR experiment and have a commensurate precision.

Three salts of perchlorinated sulfonium and ammonium derivatives of tetrabuthylammonium nonachloro-closo- decaborate, (n-Bu4N)(2)[2-B10Cl9-cyclo-S(CH2)(4)S-B10Cl9] (1), (n-Bu4N)[2-B10Cl9-cyclo-S(C2H4)(2)O] (2) and (n- Bu4N)[1-B10Cl9N(n-Pr-3)] (3) are synthesized and characterized using IR, B-11, H-1, C-13 NMR, X-Ray and Cl-35 NQRspectroscopy. The noncovalent interactions involving chlorine atoms were identified by Cl-35 NQR spectra. The results were discussed in comparison with those of X-ray diffraction analysis which are based on measuring contacts shorter than the sum of van der Waals (vdW) radii of atoms. It has been found that the crystal lattice of 2 exhibits dynamic properties strongly different from those of 1 and 3. Whereas the Cl-35 NQR spectra of the latters were extremely wide (up to 1200 kHz), the spectrum of 2 demonstrated a narrowing of almost an order of magnitude (up to 120 kHz) which indicated a significant weakening of the tendency for the formation of intermolecular bonds by chlorine atoms of this cluster.

The article surveys the first 35Cl NQR results on detecting and characterizing noncovalent interactions in systems assembling [B10Cl10]2− clusters via halogen atoms. A number of compounds of decachloro-closo-decaborates with alkali metal or organic cations as well as with silver(I), copper(II) and iron(II) complexes were studied using 35Cl NQR and X-ray diffraction. The main interest of this survey is a capability of chlorine atoms to participate in noncovalent interactions with organic cations, ligand and solvent molecules without touching upon issues of synthesis. Whereas X-ray diffraction establishes the noncovalent interactions relying on the sum of vdW radii which serves as the basic and sometimes the only experimental criterion for identifying such interactions, the 35Cl NQR technique registers subtle perturbations in electron density distribution on the chlorine site caused by secondary interactions Cl···X. They adequately split the 35Cl NQR spectra thus selecting from the entire set of interatomic contacts those actually induced by noncovalent interactions.

The excellent particle identification (PID) system is needed for the successful execution of the broad experimental program at future Super C-tau Factory (SCTF) in Novosibirsk. The main requirements for the PID system are the following: good pi/K-separation in whole operational momentum range and good mu/pi-separation in the momentum range from 0.4 up to 1.2 GeV/c. The RICH detector based on focusing aerogel (FARICH) could provide good pi/K-separation from 0.4 GeV/c and mu/pi-separation in the momentum range from 0.4 up to 1.5 GeV/c. The method FARICH is described, beam test results are presented and the status of multilayer aerogel production is given.

The reaction between copper(II) acetate and Phen in the presence of [B10Cl10](2-) anion affords mononuclear copper(II) complex [CuPhen(2)(CH3CO2)](2)[B10Cl10]center dot[CuPhen(CH3CO2)(2)]. Continuous heating of the latter in DMSO results in triply-bridged binuclear copper(II) complex [Cu(2)Phen(2)(CH3CO2)(2)OH](2)[B10Cl10] isolated from the reaction solution as a DMSO solvate hydrate [Cu(2)Phen(2)(CH3CO2)(2)OH](2)[B10Cl10]center dot 3DMSO center dot 0.5H(2)O. Both complexes are studied by IR, B-11 NMR, and X-ray diffraction; the binuclear complex is studied by Cl-35 NQR and EPR spectroscopies as well as X-ray powder diffraction technique. Despite the short Cu-Cu distance revealed by X-ray diffraction analysis in the binuclear cationic complex (3.234 angstrom), no interactions between copper atoms are detected by EPR spectroscopy. According to Cl-35 NQR studies, chlorine atoms bound with equatorial boron vertices of the boron cage participate in non-covalent interactions with H atoms of Phen molecules.

Local magnetic fields Hloc exceeding significantly the magnetic fields produced by nuclear magnetic moments (a few gauss) have been detected in bismuth compounds with valence s and p electrons, which are generally believed to be diamagnetic, by the methods based on measuring the parameters of nuclear quadrupole interactions. Anomalies in the magnetic properties of BiSbO4 and Bi4Si3O12 were clearly manifested when analyzing the line shapes in their 209Bi NQR spectra. The quartet of lines for the lower transition ν1 (Δm = 1/2–3/2) in the spectrum of Bi4Si3O12 in zero external magnetic field and the doublets for the lines of all other transitions in the spectrum of BiSbO4 at unique crystallographic positions of bismuth atoms in the crystal lattices of the compounds suggest a magnetic nature of the splittings. The most probable values of Hloc in these compounds are those in the range from 40 to 100 G.