V.A. Kuzmin

Russian Academy of Sciences | RAS · Institute of Nuclear Research

Краткое сообщение, аннотации и ключевых нет

The spectral-kinetic characteristics of the singlet and triplet excited states of octaphenyl-substituted erbium phthalocyanine are established. It is shown that the compound has high values of the quantum yields of fluorescence (0.50) and singlet oxygen (0.43). The lifetimes of the excited singlet (4.9 ns) and triplet states (1.4 ms) are determined...

In order to increase the bioavailability of water-insoluble pyropheophorbide-a (PPP-a) methyl ester, its liposomal form is prepared and the physicochemical and photochemical properties of this form are studied. The quantum yield of ¹O2 is found to have a bell-shaped dependence on the concentration of PPP-a in the lipid phase of liposomes with the m...

The paper presents a method for determining the parameters characterizing the features of the pore space structure of rocks continuously along the section, based on the results of well-log data interpretation. The results of the well-log data interpretation are presented with diagrams of average values of pore and channel diameters calculated conti...

The photoinduced electron transfer from ascorbic acid as a donor to the dication of the bis-carbocyanine dye (BCD2+) in its triplet state was studied by flash photolysis. The differential absorption spectrum of the BCD•+ radical cation was recorded and its decay kinetics was measured. Possible mechanisms for the deactivation of this radical were pr...

The existing laboratory unit of aspiration thermal massometry, based on the measurement of weight and temperature during drying of rock sample in the air flow, meets the petrophysical tasks of studying oil and gas collectors. At the same time, it has the potential to improve the research accuracy. The paper proposes a modernized facility for studyi...

The Vuktyl oil and gas condensate field of the Timan-Pechora province was discovered in 1964. The field is currently in the final stages of development, its hydrocarbon reserves are nearly exhausted. In order to expand the resource base of the field, research was undertaken to estimate the matrix oil reserves in the gas-saturated part of the Vuktyl...

The work substantiates the location of liquid hydrocarbons (LH – oil and retrograde condensate) in the dynamic, filtering part of the capacitive volumes of gas-saturated productive deposits of gas condensate and oil and gas condensate fields (GCF and OGCF). The necessity of the development and bench modeling of the production of LH from gas-saturat...

The results of studying the structural features of the pore space in lower Cretaceous polymictic sandstones from prospective sediments on the territory of the Republic of Kalmykia (East Biryuzak area) by the method of scanning electron microscopy are presented. Microstructural parameters are obtained for modeling filtration processes, “digital core...

The methods and results of electron microscopic study of the microstructure of siliceous-carbonate rocks of the domanikoid type are shown. For this purpose, both standard methods for studying the surface of sample chips and a polished surface for microprobe studies and a specially developed method for cathode luminescence study of the pore space ar...

The kinetics of the reversible recombination of the 2-phenyl-(I), 2-p-methoxyphenyl-(111, and 2-p-nitrophenyl-3-oxo-2,3-dihydrobenzothiophene-2-y1 (111) radicals R + R-' D (1) have been investigated. Recombination rate constants of R(1-111) have been determined in different solvents (2kl-lo9 M-' s-'). The rate of reaction (I) with R(1-111) decrease...

p>Shaped catalysts are widely used in steam reforming. A comprehensive mathematical model able to predict and compare performance of different shaped catalysts is developed. The two-dimensional pseudo homogeneous model accounts for heat transfer between the tube wall and catalyst bed, conductivity and diffusivity in the radial direction in the pack...

The authors describe conception of structure-trapped volumes in oil-and-gas saturated rock pore space, forming due to big ratio (≫1) of pore and capillaries sections. An experimental method of structure-trapped oil-and-gas saturation index and dynamic porosity index measuring is brought in the article. Proposed method is found on direct-flow capill...

Complex analysis of core samples from carbonate petroleum source rock of the Artinskian stage of Dimitrovskoye gas-and-oil field in the Orenburg Region enabled to determine the lithology of rocks under study, the structure of reservoir storage volume, and reveal the patterns of organic matter distribution. As a result of integrated petrophysical, g...

Dynamics of transformations of excited states and active transient species generated in the photolysis of nitrated 1,2-dihydroquinolines (N-DHQ) has been studied by femto- and nanosecond laser pulse photolysis. Spectral and kinetic parameters of primary photophysical and photochemical processes have been determined, and their dependence on the subs...

We present a measurement of the time-integrated flavor-specific semileptonic charge asymmetry in the decays of B_{s}^{0} mesons that have undergone flavor mixing, a_{sl}^{s}, using B_{s}^{0}(B[over ¯]_{s}^{0})→D_{s}^{∓}μ^{±}X decays, with D_{s}^{∓}→ϕπ^{∓} and ϕ→K^{+}K^{-}, using 10.4 fb^{-1} of proton-antiproton collisions collected by the D0 detec...

We present a search for the standard model Higgs boson using events with two oppositely charged leptons and large missing transverse energy as expected in H→WW decays. The events are selected from data corresponding to 8.6 fb-1 of integrated luminosity in pp̅ collisions at √s=1.96 TeV collected with the D0 detector at the Fermilab Tevatron Collider...

Using data corresponding to an integrated luminosity of 1.3 fb-1, we observe a narrow mass state decaying into Υ(1S)+γ, where the Υ(1S) meson is detected by its decay into a pair of oppositely charged muons, and the photon is identified through its conversion into an electron-positron pair. The significance of this observation is 5.6 standard devia...

This report describes a search for associated production of W and Higgs bosons based on data corresponding to an integrated luminosity of L≈5.3 fb-1 collected with the D0 detector at the Fermilab Tevatron pp̅ Collider. Events containing a W→ℓν candidate (with ℓ corresponding to e or μ) are selected in association with two or three reconstructed jet...

We present a measurement of the elastic differential cross section dσ(pp̅ →pp̅ )/dt as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of ≈31 nb-1 collected with the D0 detector using dedicated Tevatron pp̅ Collider operating conditions at √s=1.96 TeV and covers the range 0.26<|t|<1.2 GeV2...

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a $W$ boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and {\dzero} collaborations have measured the top quark's...

We study the processes pp̅ →WZ→ℓ±νℓ+ℓ- and pp̅ →ZZ→ℓ+ℓ-νν̅ , where ℓ=e or μ. Using 8.6 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron collider, we measure the WZ production cross section to be 4.50-0.66+0.63 pb which is consistent with, but slightly larger than, the prediction of the standard model. The ZZ cro...

We measure the Λb0 lifetime in the fully reconstructed decay Λb0→J/ψΛ0 using 10.4 fb-1 of pp̅ collisions collected with the D0 detector at √s=1.96 TeV. The lifetime of the topologically similar decay channel B0→J/ψKS0 is also measured. We obtain τ(Λb0)=1.303±0.075(stat)±0.035(syst) ps and τ(B0)=1.508±0.025(stat)±0.043(syst) ps. Using these measurem...

We describe a model-independent search for physics beyond the standard model in lepton final states. We examine 117 final states using 1.1 fb-1 of pp̅ collisions data at √s=1.96 TeV collected with the D0 detector. We conclude that all observed discrepancies between data and model can be attributed to uncertainties in the standard model background m...

We study WW and WZ production with ℓνqq (ℓ=e,μ) final states using data collected by the D0 detector at the Fermilab Tevatron Collider corresponding to 4.3  fb(-1) of integrated luminosity from pp collisions at sqrt[s]=1.96  TeV. Assuming the ratio between the production cross sections σ(WW) and σ(WZ) as predicted by the standard model, we measure...

We give a detailed description of the measurement of the W boson mass, MW, performed on an integrated luminosity of 4.3 fb-1, which is based on similar techniques as used for our previous measurement done on an independent data set of 1 fb-1 of data. The data were collected using the D0 detector at the Fermilab Tevatron Collider. This data set yiel...

We derived a general formula for the action for O(3)-invariant tunneling processes at false vacuum decay in general relativity. A general classification of bubble shell Euclidean trajectories is elaborated and explicit expressions for bounces for a number of processes like spontaneous vacuum creation of a double bubble (in particular in the vicinit...

We present a search for Kaluza-Klein (KK) particles predicted by models with universal extra dimensions (UED) using a data set corresponding to an integrated luminosity of 7.3 fb(-1), collected by the D0 detector at a pp center-of-mass energy of 1.96 TeV. The decay chain of KK particles can lead to a final state with two muons of the same charge. T...

We report on a search for charged massive long-lived particles (CMLLPs), based on 5.2  fb(-1) of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp collider. We search for events in which one or more particles are reconstructed as muons but have speed and ionization energy loss (dE/dx) inconsistent with muons produced...

We report a search for a narrow tt̅ resonance that decays into a lepton+jets final state based on an integrated luminosity of 5.3 fb-1 of proton-antiproton collisions at √s=1.96 TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the production cross section of such a resonance multiplied by its branching...

We present a measurement of pp̅ →Zγ→ℓ+ℓ-γ (ℓ=e, μ) production with a data sample corresponding to an integrated luminosity of 6.2 fb-1 collected by the D0 detector at the Fermilab Tevatron pp̅ Collider. The results of the electron and muon channels are combined, and we measure the total production cross section and the differential cross section dσ...

We report the combination of recent measurements of the helicity of the W boson from top quark decay by the CDF and D0 collaborations, based on data samples corresponding to integrated luminosities of 2.7 - 5.4 fb^-1 of ppbar collisions collected during Run II of the Fermilab Tevatron Collider. Combining measurements that simultaneously determine t...

We report an updated measurement of the CP-violating phase, ϕsJ/ψϕ, and the decay-width difference for the two mass eigenstates, ΔΓs, from the flavor-tagged decay Bs0→J/ψϕ. The data sample corresponds to an integrated luminosity of 8.0 fb-1 accumulated with the D0 detector using pp̅ collisions at √s=1.96 TeV produced at the Fermilab Tevatron collid...

We present a search for the pair production of scalar top quarks ($\tilde{t}_{1}$), the lightest supersymmetric partners of the top quarks, in $p\bar{p}$ collisions at a center-of-mass energy of 1.96 TeV, using data corresponding to an integrated luminosity of {7.3 $fb^{-1}$} collected with the \dzero experiment at the Fermilab Tevatron Collider. E...

Reversible photoreaction was found upon irradiation of the long-wavelength absorption band of 8-nitro-6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline (N-DHQ) (λex> 450 nm), and no reaction was observed upon irradiation of the short-wavelength absorption band (290 < λex> 350 nm). The spectral and kinetic parameters for three transient species formed o...

We present a measurement of the ratio of events with correlated t and t ̅t spins to the total number of t ̅t events. This ratio f is evaluated using a matrix-element-based approach in 729 t ̅t candidate events with a single lepton ℓ (electron or muon) and at least four jets. The analyzed p ̅p collisions data correspond to an integrated luminosity o...

We present a search for pair production of doubly charged Higgs bosons in the processes qq¯→H(++)H(--) decaying through H(±±)→τ(±)τ(±),μ(±)τ(±),μ(±)μ(±). The search is performed in pp¯ collisions at a center-of-mass energy of √s = 1.96 TeV using an integrated luminosity of up to 7.0 fb(-1) collected by the D0 experiment at the Fermilab Tevatron Col...

A search for single-top production, ep→etX, has been made with the ZEUS detector at HERA using an integrated luminosity of . Events from both the leptonic and hadronic decay channels of the W boson resulting from the decay of the top quark were sought. For the leptonic mode, the search was made for events with isolated high-energy leptons and signi...

We present a measurement of forward-backward asymmetry in top quark-antiquark production in proton-antiproton collisions in the final state containing a lepton and at least four jets. Using a data set corresponding to an integrated luminosity of 5.4 fb-1, collected by the D0 experiment at the Fermilab Tevatron Collider, we measure the tt̅ forward-b...

We measure the cross section and the difference in rapidities between photons and charged leptons for inclusive W(→lν) + γ production in eγ and μγ final states. Using data corresponding to an integrated luminosity of 4.2  fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider, the measured cross section times branching fraction for...

We present measurements of production cross sections of single top quarks in pp̅ collisions at √s=1.96 TeV in a data sample corresponding to an integrated luminosity of 5.4 fb-1 collected by the D0 detector at the Fermilab Tevatron Collider. We select events with an isolated electron or muon, an imbalance in transverse energy, and two, three, or fo...

Preferential CO methanation in a reformate gas was investigated over 10wt.% Ni/CeO2 pelleted catalyst in the fixed-bed reactor. It provided the reduction of the CO concentration in the reformate gas to less than 10ppm over wide temperature interval (250–300°C), while keeping hydrogen consumption relatively low.The design, scale-out, and operation o...

We considered propagation of Ultra High Energy Cosmic Rays (UHECR) through the galaxy. We investigated models with sources of UHECR distributed in the same way as Cold Dark Matter (CDM) in a self-consistent way, taking into account both extra-galactic and Galactic contributions. Using a very simple toy model of galactic magnetic field we showed tha...

We present a search for associated Higgs boson production in the process pp̅ →W/ZH→ℓ±ℓ′±+X in ee, eμ, and μμ final states. The search is based on data collected by the D0 experiment at the Fermilab Tevatron Collider at √s=1.96 TeV corresponding to 5.3 fb-1 of integrated luminosity. We require two isolated leptons (electrons or muons) with the same...

We present a measurement of the relative branching fraction, Rf0/ϕ, of Bs0→J/ψf0(980), with f0(980)→π+π-, to the process Bs0→J/ψϕ, with ϕ→K+K-. The J/ψf0(980) final state corresponds to a CP-odd eigenstate of Bs0 that could be of interest in future studies of CP violation. Using 8 fb-1 of data recorded with the D0 detector at the Fermilab Tevatron...

We present a search for the standard model Higgs boson and a fermiophobic Higgs boson in the diphoton final states based on 8.2  fb(-1) of pp collisions at sqrt[s]=1.96  TeV collected with the D0 detector at the Fermilab Tevatron Collider. No excess of data above background predictions is observed and upper limits at the 95% C.L. on the cross secti...

We present an updated measurement of the anomalous like-sign dimuon charge asymmetry Aslb for semileptonic b-hadron decays in 9.0 fb-1 of pp̅ collisions recorded with the D0 detector at a center-of-mass energy of √s=1.96 TeV at the Fermilab Tevatron collider. We obtain Aslb=(-0.787±0.172(stat)±0.093(syst))%. This result differs by 3.9 standard devi...

We report results from a search for neutral Higgs bosons produced in association with b quarks using data recorded by the D0 experiment at the Fermilab Tevatron Collider and corresponding to an integrated luminosity of 7.3 fb(-1). This production mode can be enhanced in several extensions of the standard model (SM) such as in its minimal supersymme...

We present a measurement of the ratio of top quark branching fractions R=B(t→Wb)/B(t→Wq), where q can be a d, s, or b quark, in the lepton+jets and dilepton tt final states. The measurement uses data from 5.4 fb(-1) of pp collisions collected with the D0 detector at the Fermilab Tevatron Collider. We measure R=0.90±0.04, and we extract the Cabibbo-...

We present a direct measurement of the mass difference between top and antitop quarks (Δm) in lepton+jets tt̅ final states using the “matrix element” method. The purity of the lepton+jets sample is enhanced for tt̅ events by identifying at least one of the jets as originating from a b quark. The analyzed data correspond to 3.6 fb-1 of pp̅ collision...

We present a search for pair production of a fourth generation t' quark and its antiparticle, followed by their decays to a W boson and a jet, based on an integrated luminosity of 5.3 fb(-1) of proton-antiproton collisions at √s = 1.96  TeV collected by the D0 Collaboration at the Fermilab Tevatron Collider. We set upper limits on the t' ̄t' produc...

We measure the top quark mass (m(t)) in p ̄p collisions at a center of mass energy √s = 1.96 TeV using dilepton t ̄t→W(+)bW(-) ̄b→ℓ(+)ν(ℓ)bℓ(-) ̄ν(ℓ) ̄b events, where ℓ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb(-1) collected with the D0 detector at the Fermilab Tevatron...

We measure the mass dependence of the forward-backward charge asymmetry in 157 553 pp̅ →Z/γ*→e+e- interactions, corresponding to 5.0 fb-1 of integrated luminosity collected by the D0 experiment at the Fermilab Tevatron Collider at √s=1.96 TeV. The effective weak mixing angle (θeffℓ) from this process involving predominantly the first generation of...

We determine the fraction of tt events with spin correlation, assuming that the spin of the top quark is either correlated with the spin of the top antiquark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study tt spin correlation. We use tt → W+ b W- b → ℓ+ νbℓ- ν b final states...

We present a search for the pair production of first generation scalar leptoquarks (LQ) in data corresponding to an integrated luminosity of 5.4 fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider in p (p) over bar collisions at root s = 1.96 TeV. In the channel LQLQ -> eqv(e)q', where q, q' are u or d quarks, no significant exc...

The spectral and kinetic parameters of transient species generated in the irradiation of 6-ethoxy-2,2,4-trimethyl-8-nitro-1,2-dihydroquinoline were examined by stationary and pulse photolysis in the solvents: heptane, acetonitrile, methanol, and ethanol. Upon excitation of the long-wavelength absorption band (λex > 450 nm), a reversible photochemic...

The phase composition and texture of nickel catalysts supported on ribbon porous nickel with a magnesium oxide underlayer were investigated by X-ray diffraction, low-temperature nitrogen adsorption, and electron microscopy combined with energy dispersive X-ray microanalysis. The MgO underlayer was obtained by impregnation the porous nickel with a M...

We search for resonant WW or WZ production by using up to 5.4 fb(-1) of integrated luminosity collected by the D0 experiment in run II of the Fermilab Tevatron Collider. The data are consistent with the standard model background expectation, and we set limits on a resonance mass by using the sequential standard model W' boson and the Randall-Sundru...

We present a study of the dijet invariant mass spectrum in events with two jets produced in association with a W boson in data corresponding to an integrated luminosity of 4.3 fb(-1) collected with the D0 detector at √s = 1.96 TeV. We find no evidence for anomalous resonant dijet production and derive upper limits on the production cross section of...

We present the first measurement of the color representation of the hadronically decaying W boson in tt̅ events, from 5.3 fb-1 of integrated luminosity collected with the D0 experiment. A novel calorimeter-based vectorial variable, “jet pull,” is used, sensitive to the color-flow structure of the final state. We find that the fraction of uncolored...

We present a search for the production of a heavy gauge boson, W', that decays to third-generation quarks, by the D0 Collaboration in ppbar collisions at sqrt(s)= 1.96 TeV. We set 95% confidence level upper limits on the production cross section times branching fraction. For the first time, we set limits for arbitrary combinations of left- and righ...

We present a search for the standard model Higgs boson (H) in pp collisions at sqrt(s)=1.96  TeV in events containing a charged lepton (ℓ), missing transverse energy, and at least two jets, using 5.4  fb(-1) of integrated luminosity recorded with the D0 detector at the Fermilab Tevatron Collider. This analysis is sensitive primarily to Higgs bosons...

We present a new measurement of the production cross section σ(pp̅ →ZZ) at a center-of-mass energy √s=1.96 TeV, obtained from the analysis of the four charged lepton final state ℓ+ℓ-ℓ′+ℓ′- (ℓ, ℓ′=e or μ). We observe ten candidate events with an expected background of 0.37±0.13 events. The measured cross section σ(pp̅ →ZZ)=1.26-0.37+0.47(stat)±0.14(...

Data recorded by the D0 experiment at the Fermilab Tevatron Collider are analyzed to search for neutral Higgs bosons produced in association with b quarks. The search is performed in the three-b-quark channel using multijet-triggered events corresponding to an integrated luminosity of 5.2 fb-1. In the absence of any significant excess above backgro...