Physics of Particles and Nuclei Letters最新文献

Abstract

The software infrastructure of the BM@N experiment contains a set of various information systems that are essential for the work with experimental and simulated data on all processing stages, including the collection, storage, intermediate processing and physics analysis. Some examples of the systems are the Electronic Logbook Platform, Condition Database and Event Metadata System. In case one of such systems stops functioning, the work with BM@N data by collaboration members gets either impossible or, at least, much less productive. Due to this fact, the timely detection of possible failures in the systems because of software or hardware failures is fairly important. The developed Monitoring Service is used to check the availability and health status of the information systems. This includes measuring, storing, visualizing monitored parameters, such as CPU, memory and disk utilization, DBMS functioning parameters, response times of databases and API endpoints, ping round-trip times, as well as sending alert notifications in case of malfunctions. The current implementation of the BM@N Monitoring Service is presented in detail. A related task of building highly available information services is also briefly noted.

Abstract

The conversion of protons to positrons at the horizon of a black hole (BH) is considered. It is shown that the process may efficiently proceed for BHs with masses in the range ( sim {{10}^{{18}}})–({{10}^{{21}}}) g. It is argued that the electric charge of BH acquired by the proton accretion to BH could create electric field near BH horizon close to the critical Schwinger one. It leads to efficient electron-positron pair production, when electrons are back captured by the BH while positrons are emitted into outer space. Annihilation of these positrons with electrons in the interstellar medium may at least partially explain the origin of the observed 511 keV line.

Abstract

The influence on elastic scattering angular distribution (ESAD) and total fusion (TF) excitation function of couplings to breakup channel has been investigated for ⁹Be + ²⁰⁹Bi system at near and above barrier energies. The three body continuum discretized coupled channel (CDCC) calculations, (two body (⁸Be + n) projectile and target), are performed by making use of the code FRESCO. The ESADs are found to be in good accord with experimental observations. However, an enhancement is observed in the CDCC predictions of total fusion excitation function with respect to the data when breakup couplings are taken into account.

The article evaluates the amplitude suppression for the relict gravitational waves with a frequency of ({{10}^{{ - 16}}}- {{10}^{{ - 18}}}) Hz due to their conversion into electromagnetic waves under the influence of a cosmological magnetic field during the era of radiation dominance (RD). At first, a system of equations was obtained for the joint propagation of gravitational and electromagnetic waves in an external magnetic field in the Friedmann–Lemaitre–Robertson–Walker metric and the interaction of electromagnetic waves with the primary plasma was taken into account. Then the resulting system is solved numerically in the approximation of a uniform cosmological magnetic field with a strength corresponding to the modern value of 1 nG (for the RD epoch the magnetic field strength increases as the inverse scale factor squared). Finally a conclusion was made about the insignificant influence of the considered conversion effect on the amplitude of long-wave relic gravitational waves.

Abstract

Vibrational spectroscopic features of ibuprofen and ketoprofen (non-steroidal anti-inflammatory drugs) were determined as a result of joint analysis of experimental and DFT-calculated data. There is a good agreement between the experimental (IR, Raman) and calculated (BP86/def2-SVP) vibrational frequencies of ibuprofen and ketoprofen.

Abstract

The (alpha )-decay half-lives of superheavy nuclei with (100 leqslant Z leqslant 120) are comprehensively analyzed using the axially deformed relativistic mean field (RMF) formalism for the NL3* parameter set. We employ RMF binding energies to determine the (alpha )-decay energies and make a comparison with both the available experimental data and the theoretical results obtained from the global nuclear mass model WS4. The four distinct formulae, specifically the modified scaling law Brown, modified Viola-Seaborg, Yibin et al. formula, and its modified form are used to calculate the decay half-lives and examine the numerical correlation between the half-life (({{T}_{{1/2}}})) for each (alpha )-decay energy. We notice that ({{T}_{{1/2}}}) is significantly dependent on the decay formula in terms of isospin asymmetry and decay energy. We also noticed that modified scaling law Brown formula estimates of half-lives agreed comparatively better with the experiment as compared to others. Moreover, the present investigation provides significant information on the stability of the superheavy island considered for ongoing and/or future experiments.

Abstract

Results of the measurements of neutron spectra at two points at the intense resonance neutron source (IREN) of the JINR’s Laboratory of Neutron Physics are presented. Powerful neutron fluxes are obtained using an electron accelerator and the thick tungsten target, in which neutrons are produced by bremsstrahlung gamma-quanta of electrons hitting the target. The tungsten target is placed in a cylindrical vessel filled with water. Neutron spectra were obtained using a multisphere Bonner spectrometer at two points behind biological shielding. Based on the spectra obtained, the effective neutron dose rates at the measurement points were determined, which is of importance both for assessing the radiation situation at IREN and for comparison with the readings of neutron dosimeters of the automated radiation monitoring system.

Abstract

Circle fit routines are used in helix reconstruction for tracking and in ring reconstruction for particle ID. While accurate fits can be achieved with iterative fits, often resolution can be relaxed in favor of speed. We present and compare two flash-algorithms in terms of resolution, CPU speed and mathematical advantage (linearity). The second algorithm is novel.

Abstract

The Electron String Ion Source (ESIS) is type of electron beam ion source working in a reflex mode under specific conditions [1]. The operation is based on step-by-step ionization of the ions by hitting with electrons of an electron string. ESIS is a complex facility and ion trap control system is its important part. It affects ion beam formation process and transfer to NICA HILAC. The version, which is under operation now is based on resistance divider. The new system is based on independent modules and could make operation process more flexible. The paper describes development of the ESIS ion trap control system electronics, its modifications and operation process.

We consider a four-dimensional quantum field theory with weakly interacting ultraviolet fixed points up to four loop order for gauge, three loop to Yukawa and quartic scalar beta functions. We compute them for a (SU({{N}_{c}})) gauge theory coupled to ({{N}_{f}}) fundamental fermions and elementary scalars. Moreover, we found fixed point couplings, field and mass anomalous dimensions, and scaling exponents up to the first three non-trivial orders in a small Veneziano parameter. Further, we investigate the size of the conformal window.