On spiral superfluidity in the Fermi-liquid model

In this work we propose a model of description of a superfluid Fermi liquid with a spiral ordering by spins. The method of description is similar to that of description of spiral magnetics. Self-consistency equations for the order parameter are obtained. The transition temperature and order parameter in case of interaction similar to the Skyrme interaction are numerically calculated. The transition temperature and the order parameter, are proved to reach their maximal value under spirality distinct from zero

Анализ и оценка неопределенности параметров, использованных при расчетах доз внутреннего облучения от трития

Assessment of committed effective dose and the uncertainty of its calculation for different variants of 3H intake: 1) homogeneous and chronic, 2) single, is considered by the example of internal tritium doses that workers had got. It has been shown that in case of conditional measurement of 3H concentration in urine sample the estimate of tritium dose may vary within two orders of magnitude in the 95% confidence interval. The most effective way to reduce the range of uncertainty of dose estimation is to replace a quarterly monitoring with a monthly one. It leads to reduction of the range of uncertainty by one order of magnitude

Superfluidity of a condensate with np pairing correlations in asymmetric nuclear matter

Influence of asymmetry on superfluidity of nuclear matter with triplet-singlet pairing of nucleons (in spin and isospin spaces) is considered within the framework of a Fermi-liquid theory. Solutions of self-consistent equations for the energy gap at T=0 are obtained. It is shown, that if the chemical potentials of protons and neutrons are determined in the zero gap width approximation, then the energy gap for some values of density and asymmetry parameter of nuclear matter demonstrates double-valued behavior. However, with account for the feedback of pairing correlations through the normal distribution functions of nucleons two-valued behavior of the energy gap turns into universal one-valued behavior. At T=0 the energy gap has a discontinuities as a function of density in a narrow layer model. These discontinuities depend on the asymmetry parameter

Equilibrium of intense electron beam in coaxial undulator with partially shielded cathode in guide homogeneous magnetic field

For the initial radii of charged-particle beam in a coaxial magnetic undulator with partially shielded cathode we formulate the equilibrium equations, which enforce the defocusing self-electric field compensation by the longitudinal and azimuthal components of self-magnetic field of the electron beam and account for the undulator focusing through the first (leading) harmonic of the undulator magnetic field. Numerical solutions of the equilibrium equations in a coaxial magnetic undulator with shielded and non-shielded cathode are analyzed and compared.Сформулированы уравнения равновесия для начальных радиусов электронного пучка, на которых дефокусирующее влияние собственного электрического поля компенсируется фокусирующими силами ондулятора и продольной и азимутальной компонент собственного магнитного поля электронного пучка с учетом первой (доминирующей) гармоники ондуляторного магнитного поля в коаксиальном магнитном ондуляторе с частично экранированным катодом. Сравниваются численные решения уравнений равновесия в коаксиальном магнитном ондуляторе с экранированным и неэкранированным катодамиСформулювані рівняння рівноваги для початкових радіусів електронного пучка, на яких дефокусуючий вплив власного електричного поля компенсується фокусуючими силами ондулятора та поздовжньої і азимутальної компонент власного магнітного поля електронного пучка з урахуванням першої (домінуючої) гармоніки ондуляторного магнітного поля в коаксіальному магнітному ондуляторі з частково екранованим катодом. Порівнюються чисельні рішення рівнянь рівноваги в коаксіальному магнітному ондуляторі з екранованим та неекранованим катодами

Search for dark matter produced in association with a hadronically decaying vector boson in pp collisions at sqrt (s) = 13 TeV with the ATLAS detector

A search is presented for dark matter produced in association with a hadronically decaying W or Z boson using 3.2 fb−1 of pp collisions at View the MathML sources=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Events with a hadronic jet compatible with a W or Z boson and with large missing transverse momentum are analysed. The data are consistent with the Standard Model predictions and are interpreted in terms of both an effective field theory and a simplified model containing dark matter

Measurement of the View the tt production cross-section using eμ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

This paper describes a measurement of the inclusive top quark pair production cross-section (σtt¯) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σtt¯ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σtt¯ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Search for TeV-scale gravity signatures in high-mass final states with leptons and jets with the ATLAS detector at sqrt [ s ] = 13TeV

A search for physics beyond the Standard Model, in final states with at least one high transverse momentum charged lepton (electron or muon) and two additional high transverse momentum leptons or jets, is performed using 3.2 fb−1 of proton–proton collision data recorded by the ATLAS detector at the Large Hadron Collider in 2015 at √s = 13 TeV. The upper end of the distribution of the scalar sum of the transverse momenta of leptons and jets is sensitive to the production of high-mass objects. No excess of events beyond Standard Model predictions is observed. Exclusion limits are set for models of microscopic black holes with two to six extra dimensions

Search for resonances in the mass distribution of jet pairs with one or two jets identified as b-jets in proton–proton collisions at √s=13TeV with the ATLAS detector

Searches for high-mass resonances in the dijet invariant mass spectrum with one or two jets identi-fied as b-jets are performed using an integrated luminosity of 3.2fb−1of proton–proton collisions with a centre-of-mass energy of √s=13TeVrecorded by the ATLAS detector at the Large Hadron Collider. Noevidence of anomalous phenomena is observed in the data, which are used to exclude, at 95%credibility level, excited b∗quarks with masses from 1.1TeVto 2.1TeVand leptophobic Z bosons with masses from 1.1TeVto 1.5TeV. Contributions of a Gaussian signal shape with effective cross sections ranging from approximately 0.4 to 0.001pb are also excluded in the mass range 1.5–5.0TeV

Measurement of the double-differential high-mass Drell-Yan cross section in pp collisions at √s = 8 TeV with the ATLAS detector

This paper presents a measurement of the double-differential cross section for the Drell-Yan Z/γ∗ → ℓ+ℓ− and photon-induced γγ → ℓ+ℓ− processes where ℓ is an electron or muon. The measurement is performed for invariant masses of the lepton pairs, mℓℓ, between 116 GeV and 1500 GeV using a sample of 20.3 fb−1 of pp collisions data at centre-of-mass energy of √s = 8 TeV collected by the ATLAS detector at the LHC in 2012. The data are presented double differentially in invariant mass and absolute dilepton rapidity as well as in invariant mass and absolute pseudorapidity separation of the lepton pair. The single-differential cross section as a function of mℓℓ is also reported. The electron and muon channel measurements are combined and a total experimental precision of better than 1% is achieved at low mℓℓ. A comparison to next-to-next-to-leading order perturbative QCD predictions using several recent parton distribution functions and including next-to-leading order electroweak effects indicates the potential of the data to constrain parton distribution functions. In particular, a large impact of the data on the photon PDF is demonstrated