Physics of Atomic Nuclei最新文献

{"title":"Klein–Gordon Equations, Equations of Relativistic Quantum Hydrodynamics, and Quantum Shocks in Describing Collisions of Atomic Nuclei","authors":"A. T. D’yachenko","doi":"10.1134/S106377882470056X","DOIUrl":"10.1134/S106377882470056X","url":null,"abstract":"<p>Equations of quantum relativistic hydrodynamics are obtained from an effective Klein–Gordon equation with allowance for dissipation. The inclusion of dissipation in the Klein–Gordon equation entails the need for introducing an additional thermal term and an equation for it. This leads to a closed system of equations that takes into account nonequilibrium processes and which makes it possible to describe the dynamics of collisions between atomic nuclei and to calculate the yields of secondaries. Solving these equations permits identifying quantum shocks and tracing the time evolution of the emerging hot spot. The calculated spectra of protons emitted in heavy-ion collisions are contrasted against available experimental data.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"646 - 658"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross Section of the Process ({e^{+}e^{-}to nbar{n}}) near the Threshold","authors":"M. N. Achasov,&nbsp;A. Yu. Barnyakov,&nbsp;E. V. Bedarev,&nbsp;K. I. Beloborodov,&nbsp;A. V. Berdyugin,&nbsp;A. G. Bogdanchikov,&nbsp;A. A. Botov,&nbsp;T. V. Dimova,&nbsp;V. P. Druzhinin,&nbsp;V. N. Zhabin,&nbsp;Yu. M. Zharinov,&nbsp;L. V. Kardapoltsev,&nbsp;A. S. Kasaev,&nbsp;A. A. Kattsin,&nbsp;D. P. Kovrizhin,&nbsp;A. A. Korol,&nbsp;A. S. Kupich,&nbsp;A. P. Kryukov,&nbsp;A. P. Lysenko,&nbsp;N. A. Melnikova,&nbsp;N. Yu. Muchnoi,&nbsp;A. E. Obrazovsky,&nbsp;E. V. Pakhtusova,&nbsp;K. V. Pugachev,&nbsp;S. A. Rastigeev,&nbsp;Yu. A. Rogovsky,&nbsp;A. I. Senchenko,&nbsp;S. I. Serednyakov,&nbsp;Z. K. Silagadze,&nbsp;I. K. Surin,&nbsp;Yu. V. Usov,&nbsp;A. G. Kharlamov,&nbsp;D. E. Chistyakov,&nbsp;Yu. M. Shatunov,&nbsp;S. P. Sherstyuk,&nbsp;D. A. Shtol","doi":"10.1134/S1063778824700637","DOIUrl":"10.1134/S1063778824700637","url":null,"abstract":"<p>The <span>(e^{+}e^{-}to nbar{n})</span> cross section was measured at center of mass (c.m.) energies from the threshold to 1908 MeV. The experiment to measure the cross section has been carried out at the VEPP-2000 <span>(e^{+}e^{-})</span> collider in 13 energy points. The SND detector is used to detect the produced neutron–antineutrons (<span>(nbar{n})</span>) events. A special time measurement system on the calorimeter was used to select the time-delayed <span>(nbar{n})</span> events. The measured <span>(e^{+}e^{-}to nbar{n})</span> cross section is 0.4–0.6 nb. The neutron effective timelike form factor in the energy range under study varies from 0.3 to 0.6.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"604 - 613"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling of Local Strong Parity Non-Conservation Effects in Relativistic Heavy-Ion Collisions","authors":"V. N. Kovalenko,&nbsp;V. V. Petrov","doi":"10.1134/S1063778824600428","DOIUrl":"10.1134/S1063778824600428","url":null,"abstract":"<p>The violation of spatial parity symmetry (<span>(P)</span>) in strong interactions have never been observed experimentally. However a <span>(P)</span>-breaking term can be included in the QCD Lagrangian. Hence, the local parity symmetry breaking can occur due to large topological fluctuations at high temperature with dynamic generation of nontrivial topological charge configurations. A necessary condition for observing these effects is a sufficiently large space dimension and a long lifetime of a hot drop of QCD medium, which is available in central nuclear collisions at the LHC. In order to study the effects caused by local <span>(P)</span>-breaking in relativistic heavy-ion collisions we integrated them in Monte Carlo generators. Based on the analysis of the Monte Carlo data on the studied observables, taking into account the responses of the detecting systems of the ALICE facility under LHC Run 2 and Run 3 conditions, recommendations will be given on the criteria for selecting events, tracks, and choosing kinematic variables in terms of increasing sensitivity to the effects of local parity non-conservation.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"639 - 645"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410403","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the Neutrino Channel at the U-70 Accelerator Complex with Parent Particle Beam Deflection","authors":"F. N. Novoskoltsev,&nbsp;R. Yu. Sinyukov,&nbsp;A. A. Sokolov","doi":"10.1134/S1063778824700613","DOIUrl":"10.1134/S1063778824700613","url":null,"abstract":"<p>The optical scheme of the channel based on quadrupole lenses for neutrino beam formation at the accelerator complex U-70 is considered. A dual-magnet system with a field lens and full dispersion compensation is proposed to extract the required momentum interval of <span>(pi)</span> mesons. In this optical scheme, the decay part of the channel is rotated relative to the direction of the primary proton beam to the target. The main calculated 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 <span>(pi)</span> mesons at the beginning of the decaying part are discussed.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"614 - 619"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of High-Energy Neutrinos at the Large Hadron Collider","authors":"N. S. Konovalova,&nbsp;N. M. Okateva,&nbsp;N. G. Polukhina,&nbsp;Zh. T. Sadykov,&nbsp;N. I. Starkov,&nbsp;E. N. Starkova,&nbsp;M. M. Chernyavsky,&nbsp;T. V. Shchedrina","doi":"10.1134/S1063778824700558","DOIUrl":"10.1134/S1063778824700558","url":null,"abstract":"<p>The first neutrinos from the proton–proton collisions at an energy of 13.6 TeV were registered in the pseudorapidity range of <span>(7.2&lt;eta&lt;8.4)</span> 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 distinguishing the interactions of the neutrinos of all three flavors and investigating the process of the charmed particles’ generation in the pseudorapidity range unexplored to other experiments at the LHC. The experiment is also aimed at studying the scattering of weakly interacting particles on the electrons and protons of the target.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"594 - 603"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rare Decays of ({D_{s}}) Mesons to Three Charged Leptons and a Neutrino within the Standard Model","authors":"A. V. Danilina,&nbsp;N. V. Nikitin","doi":"10.1134/S1063778824700583","DOIUrl":"10.1134/S1063778824700583","url":null,"abstract":"<p>The branching ratios of the four-lepton decays <span>(D_{s}^{-}tomu^{+}mu^{-}{bar{nu}}_{e}e^{-})</span> and <span>(D_{s}^{-}to e^{+}e^{-}{bar{nu}}_{mu}mu^{-})</span> are found on the basis of the Standard Model, and the respective single-differential distributions are obtained and analyzed within this framework. The contributions of virtual-photon emission by the <span>(s)</span> and <span>(c)</span> quarks of the <span>(D_{s}^{-})</span> meson and virtual-photon bremsstrahlung by a final-state charged lepton are taken into account in the calculations. Virtual-photon emission by the <span>(s)</span> quark is described on the basis of the vector-meson-dominance model.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"625 - 638"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Two-Photon Resonance Mechanism of Optical Pumping of the 8.3-eV ({}^{boldsymbol{229m}})Th Isomer in Neutral Atoms","authors":"F. F. Karpeshin","doi":"10.1134/S1063778824700546","DOIUrl":"10.1134/S1063778824700546","url":null,"abstract":"<p>The possibility of refinement upon the energy of the 8.36-eV <span>({}^{229m})</span>Th nuclear isomer, which is the most probable candidate for a nuclear reference value for frequency, by means of resonance optical pumping is discussed. Attention is given primarily to the problem of broadening the resonance with the aim of reducing the time of scanning. The proposed two-photon method uses a sharp broadening of the isomer line owing to mixing with an electron transition. In contrast to internal-conversion-induced resonance broadening or a deliberate extra-broadening of the pumping-laser spectral line, this method is not adversely affected by the reduction of cross section. In the case being considered, it is two orders of magnitude more efficient and is applicable both to ionized and to neutral thorium atoms. The implementation of the method entails the excitation of both the nucleus involved and the electron shell in the final state.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"586 - 593"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photoneutron Reaction Cross Sections for ({}^{{90}})Zr in Different Experiments","authors":"V. V. Varlamov,&nbsp;A. I. Davydov,&nbsp;I. A. Mostakov,&nbsp;V. N. Orlin","doi":"10.1134/S1063778824700595","DOIUrl":"10.1134/S1063778824700595","url":null,"abstract":"<p>Reliability of the data on partial photoneutron reactions on <span>({}^{90})</span>Zr obtained in the experiment carried out on the beam of bremsstrahlung was investigated using the experimental-theoretical method for partial reaction cross section evaluation based on objective physical criteria. It is found out that (<span>(gamma)</span>, <span>(1n)</span>) and (<span>(gamma)</span>, <span>(2n)</span>) reaction cross sections obtained using the corrections calculated via statistical theory to the neutron yield cross section <span>(sigma(gamma,xn)=sigma(gamma,1n)+2sigma(gamma,2n))</span> satisfy physical criteria of data reliability. The integrated characteristics of the cross sections of the reactions (<span>(gamma)</span>, <span>(1n)</span>) and (<span>(gamma)</span>, <span>(2n)</span>) in which the distinct structural features were obtained, and the experimentally measured neutron yield cross section <span>(sigma)</span>(<span>(gamma)</span>, <span>(xn)</span>) agree with those of evaluated cross sections. This shows that information on <span>({}^{90})</span>Zr partial reactions competition obtained using statistical theory satisfies physical criteria of data reliability. The evaluated reaction cross sections are compared in detail with analogous data obtained before using the results of experiments carried out on the beams of quasimonoenergetic annihilation photons.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"575 - 585"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement of the Rates of the ({}^{{102}})Pd(({n,gamma}))({}^{{103}})Pd and ({}^{{102}})Ru(({n,gamma}))({}^{{103}})Ru Reactions in the Horizontal Channel of the IR-8 Reactor at the NRC Kurchatov Institute","authors":"V. A. Zagryadsky,&nbsp;K. O. Korolev,&nbsp;Ya. M. Kravets,&nbsp;T. M. Kuznetsova,&nbsp;A. V. Kurochkin,&nbsp;K. A. Makoveeva,&nbsp;I. I. Skobelin,&nbsp;A. N. Strepetov,&nbsp;T. A. Udalova","doi":"10.1134/S1063778824700571","DOIUrl":"10.1134/S1063778824700571","url":null,"abstract":"<p>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 note of them allows unambiguously diagnosing 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 <span>(alpha)</span>- or <span>(beta)</span>-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 <span>(alpha)</span>- or <span>(beta)</span>-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 long distances, without damaging healthy cells and tissues. The most efficient and convenient Auger and conversion electron emitters for practical use include <span>({}^{103m})</span>Rh (<span>(T_{1/2}=56.1)</span> min), which has the lowest ratio of the number of <span>(gamma)</span> quanta to electrons [1] and can be obtained by a generator method. The predecessors of <span>({}^{103m})</span>Rh (<span>(T_{1/2}=56.1)</span> min) in the generator can be <span>({}^{103})</span>Ru (<span>(T_{1/2}=39.247)</span> days) or <span>({}^{103})</span>Pd (<span>(T_{1/2}=16.99)</span> days). In order to clarify the prospects for producing these precursors, we have measured the rates of <span>({}^{102})</span>Ru(<span>(n,gamma)</span>)<span>({}^{103})</span>Ru and <span>({}^{102})</span>Pd(<span>(n,gamma)</span>)<span>({}^{103})</span>Pd reactions upon neutron irradiation of metal ruthenium of natural isotopic composition and metal palladium, enriched in the <span>({}^{102})</span>Pd isotope to 96.36<span>(%)</span>, in a horizontal experimental channel of the IR-8 reactor.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"571 - 574"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410498","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of a Xenon Gamma Spectrometer for Dosimetry in Boron–Neutron Capture Therapy","authors":"I. F. Khimmatov,&nbsp;S. E. Ulin","doi":"10.1134/S1063778824700601","DOIUrl":"10.1134/S1063778824700601","url":null,"abstract":"<p>One of the main problems associated with the implementation of neutron capture therapy in clinical practice, requiring a solution, is the determination of absorbed dose. The only method that directly allows measuring the absorbed does is gamma spectrometry based on the detection of gamma rays with an energy of 478 keV. This article considers the possibility of using a xenon gamma spectrometer, which has high radiation resistance to neutron fluxes. The GEANT4 software package was used to study the neutron capture therapy process and conduct corresponding calculations.</p>","PeriodicalId":728,"journal":{"name":"Physics of Atomic Nuclei","volume":"87 5","pages":"620 - 624"},"PeriodicalIF":0.3,"publicationDate":"2024-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142410494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}