Ab-initio determination of Bose-Hubbard parameters for two ultracold atoms in an optical lattice using a three-well potential

We calculate numerically the exact energy spectrum of the six dimensional problem of two interacting Bosons in a three-well optical lattice. The particles interact via a full Born-Oppenheimer potential which can be adapted to model the behavior of the s-wave scattering length at Feshbach resonances. By adjusting the parameters of the corresponding Bose-Hubbard (BH) Hamiltonian the deviation between the numerical energy spectrum and the BH spectrum is minimized. This defines the optimal BH parameter set which we compare to the standard parameters of the BH model. The range of validity of the BH model with these parameter sets is examined, and an improved analytical prediction of the interaction parameter is introduced. Furthermore, an extended BH model and implications due to the energy dependence of the scattering length and couplings to higher Bloch bands at a Feshbach resonance are discussed.Comment: 14 pages, 11 figures; typos and minor errors corrected, five references added, next-to-nearest neighbor hopping included in extended Bose-Hubbard mode

Influence of a tight isotropic harmonic trap on photoassociation in ultracold homonuclear alkali gases

The influence of a tight isotropic harmonic trap on photoassociation of two ultracold alkali atoms forming a homonuclear diatomic is investigated using realistic atomic interaction potentials. Confinement of the initial atom pair due to the trap leads to a uniform strong enhancement of the photoassociation rate to most, but also to a strongly suppressed rate for some final states. Thus tighter traps do not necessarily enhance the photoassociation rate. A further massive enhancement of the rate is found for strong interatomic interaction potentials. The details of this interaction play a minor role, except for large repulsive interactions for which a sharp window occurs in the photoassociation spectrum as is known from the trap-free case. A comparison with simplified models describing the atomic interaction like the pseudopotential approximation shows that they often provide reasonable estimates for the trap-induced enhancement of the photoassociation rate even if the predicted rates can be completely erroneous.Comment: 19 pages, 17 figure

РАЗВИТИЕ СТРАТЕГИЧЕСКОГО МЕНЕДЖМЕНТА ЭНЕРГОСБЫТОВЫХ КОМПАНИЙ В РОССИЙСКОЙ ФЕДЕРАЦИИ

Strategic for power selling companies (PSC) are buying, selling and investment activities. Buying activities are to be planned, selling activities predicted and both optimized by PSC on the basis of price and consumer number dynamics with due account of other factors. Very important is to develop the market of derivative instruments (derivatives) as part of the risk management mechanism at all levels including that of the state, to use up-to-date and ecologically favorable technologies as well as renewable energy sources with due account of ecology improvement measurement costs.Стратегическими для энергосбытовых компаний (ЭСК) являются следующие виды деятельности: закупочная, сбытовая и инвестиционная. Планирование закупочной деятельности, прогнозирование сбытовой деятельности и их оптимизация должны осуществляться ЭСК на основе изучения динамики цен, количества потребителей и других показателей. Необходимо, в том числе на государственном уровне, развивать рынок производных инструментов (деривативов) как составной части механизма управления рисками, внедрять современные технологии, использовать экологически чистые и возобновляемые источники электроэнергии, учитывать материальные последствия решения экологических проблем

ОЦЕНКА ОПЕРАЦИОННЫХ РИСКОВ ЭНЕРГОСБЫТОВЫХ КОМПАНИЙ

There are the following main operation risks typical for Russian power-selling companies (PSC): imperfection of legal documents related to functioning of such companies; lack of any officially approved calculation method for regulated tariffs of energy to population including uncertainty in the procedure of translating the energy to population at regulated costs; continuously growing debts on the part of energy consumers. Offered in the article is most effective PSC operation risk comparative estimation model. While comparing PSC operation risks typical for the energy provision industry, multiplication coefficients and other industry specific indices are to be used.Основные операционные риски энергосбытовых компаний (ЭСК) России: несовершенство нормативных документов, связанных с функционированием этих компаний; отсутствие официальной методики расчета регулируемых тарифов для населения, в том числе неопределенность порядка трансляции населению электроэнергии по регулируемым ценам; постоянный рост задолженности энергопотребителей. Для оценки рисков ЭСК в качестве наиболее эффективной предложена модель сравнительной оценки. При сравнении отраслевых операционных рисков ЭСК необходимо использовать отраслевые мультипликаторы и другие специфические энергосбытовые показатели

Astenic syndrome in you students with different online-behaviors during the pandemic of new coronavirus infection COVID-19

Introduction. An urgent problem in many countries of the world is the growth of comorbid diseases and conditions associated with the pathological use of the Internet, including functional somatic disorders, which include asthenic syndrome.Purpose of the study. To study the frequency of occurrence of asthenic syndrome schoolchildren with different online behavior during the coronavirus pandemic.Materials and methods. The method of random sampling was used to examine 1 148 adolescents at the age of 11–18 years, of which 535 (46.6%) were boys and 613 (53.4%) were girls. The frequency of occurrence was analyzed in the entire sample of the surveyed, as well as in the comparison groups, formed by gender: 1 gr. – boys (n = 535), 2 gr. – girls (n = 613), age: 1 gr. – 11–14 years old (m + d) (n = 837) and 2 gr. – 15–18 years old (m + d) (n = 311), type of online behavior: 1 gr. – with adaptive use of the Internet, 2 gr. – with maladaptive internet use, 3 gr. – with pathological use of the Internet and type of Internet addiction.Results. The frequency of adaptive use of the Internet was 37.0%, with maladaptive – 49.9% and with pathological – 13.1% of the total sample of  the surveyed. The content structure of  the online behavior of  Tuvan schoolchildren includes the  presence of a game Internet addiction in 4.4% of the surveyed, dependence on social networks – in 12.5%, mixed IА – in 2.4% and undifferentiated IА – in 5.0%. The frequency of asthenic syndrome is 12.2% of all surveyed.Conclusion. A more pronounced association of asthenic syndrome in schoolchildren with maladaptive online behavior indicates the negative impact of the computer and the Internet on the body and justifies the need for a personalized approach to these contingents

Properties of Neutral Charmed Mesons in Proton--Nucleus Interactions at 70 GeV

The results of treatment of data obtained in the SERP-E-184experiment "Investigation of mechanisms of the production of charmed particles in proton-nucleus interactions at 70 GeV and their decays" by irradiating the active target of the SVD-2 facility consisting of carbon, silicon, and lead plates, are presented. After separating a signal from the two-particle decay of neutral charmed mesons and estimating the cross section for charm production at a threshold energy {\sigma}(c\v{c})=7.1 \pm 2.4(stat.) \pm 1.4(syst.) \mub/nucleon, some properties of D mesons are investigated. These include the dependence of the cross section on the target mass number (its A dependence); the behavior of the differential cross sections d{\sigma}/dpt2 and d{\sigma}/dxF; and the dependence of the parameter {\alpha} on the kinematical variables xF, pt2, and plab. The experimental results in question are compared with predictions obtained on the basis of the FRITIOF7.02 code.Comment: 9 pages, 9 figures,3 table

Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

SVD-2 experiment data have been analyzed to search for an exotic baryon state, the $\Theta^+$-baryon, in a $pK^0_s$ decay mode at $70 GeV/c$ on IHEP accelerator. The reaction $pA \to pK^0_s+X$ with a limited multiplicity was used in the analysis. The $pK^0_s$ invariant mass spectrum shows a resonant structure with $M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2$ and $\Gamma < 24 MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6 \sigma$. The mass and width of the resonance is compatible with the recently reported $\Theta^+$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\bar{s}$) baryon state. The total cross section for $\Theta^+$ production in pN-interactions for $X_F\ge 0$ was estimated to be $(30\div120) \mu b$ and no essential deviation from A-dependence for inelastic events $(\sim A^{0.7})$ was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte