Âdernaâ fizika

Metastasis is one of the main causes of relapse and subsequent high mortality from cancer. Metastases can contain very few cells and spread throughout the body. Despite the existing variety of diagnostic imaging methods, in practice, the resolution of none of them allows one to unambiguously diagnose the presence of a tumor (clump of cancer cells) smaller than 1–2 mm in size. After surgery and tumor removal, patients are typically offered chemotherapy, external beam radiation therapy, or α- or β-emitter radionuclide therapy. This therapy has side effects that lead to additional risks and may interfere with continued treatment. Recently, a number of works, in contrast to the traditional approach, have proposed using “short-range” radionuclides instead of α- or β-emitters [1–3]. It is convenient to use Auger or conversion electron emitters as “short-acting” therapeutic agents. Auger electrons and conversion electrons have a short range and high specific linear energy loss in biological tissue; they are capable of damaging cells within a few tens of microns, but do not have a radiotoxic effect over l ng distances, without damaging healthy cells and tissues. The most efficient and convenient Auger and conversion electron emitters for practical use include 103mRh (

The possibility of refining the energy of the nuclear isomer 229mTh with the energy of 8.36 eV, the most likely candidate for the role of a nuclear frequency standard, using resonant optical pumping is discussed. Attention is focused on the broadening of theresonance in order toreduce scanning time. The proposed twophoton method uses radical broadening of the isomer line due to mixing with an electronic transition. This method is not burdened by cross-section reduction, in contrast with internal-conversion-based resonance broadening or intended extra-broadening of the spectral line of a scanning laser. In the case under consideration, it turns out to be two orders of magnitude more effective. It applies to both ionized and neutral thorium atoms. The realization of the method supposes excitation of both the nucleus and the electron shell in the final state.

The first neutrinos from the proton-proton collisions at an energy of 13.6 TeV were registered in the pseudorapidity range of 7.2 > η > 8.4 in the SND@LHC experiment at CERN. SND@LHC is an autonomous experiment based on a compact hybrid detector for detecting high-energy neutrinos at the Large Hadron Collider. The detector allows to distinguish the interactions of the neutrinos of all three flavors and to investigate the process of the charmed particles’ generation in the pseudorapidity region inaccessible to other experiments at the LHC. The aim of the experiment is also to study the scattering of weakly interacting particles on the electrons and protons of the target.

Principle optical scheme of the neutrino beam production channel based on the accelerator complex U-70 is considered. In order to extract the required pulse interval of π-mesons, a two-magnetic system with a “field” lens with a one-way deflection of the parent particle beam and full compensation of the dispersion is proposed. In this scheme the decay part of the channel is deflected with respect to the direction of the primary proton beam aiming at the target. The main computational characteristics of the neutrino beam at the far detector at a distance of 2595 km from the end of the decaying part of the channel as well as the parameters of the parent π mesons at the beginning of the decaying part are discussed.

In the framework of the Standard Model, the values of branching ratios and differential distributions for four-lepton decays