932 research outputs found

    Automated Correctness Proof of Algorithm Variants in Elliptic Curve Cryptography

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    The Elliptic Curve Cryptography (ECC) is widely known as secure and reliable cryptographic scheme. In many situations the original cryptographic algorithm is modified to improve its efficiency in terms like power consumption or memory consumption which were not in the focus of the original algorithm. For all this modification it is crucial that the functionality and correctness of the original algorithm is preserved. In particular, various projective coordinate systems are applied in order to reduce the computational complexity of elliptic curve encryption by avoiding division in finite fields. This work investigates the possibilities of automated proofs on the correctness of different algorithmic variants. We introduce the theorems which are required to prove the correctness of a modified algorithm variant and the lemmas and definitions which are necessary to prove these goals. The correctness proof of the projective coordinate system transformation has practically been performed with the help of the an interactive formal verification system XeriFun

    Secondary Beam Monitors for the NuMI Facility at FNAL

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    The Neutrinos at the Main Injector (NuMI) facility is a conventional neutrino beam which produces muon neutrinos by focusing a beam of mesons into a long evacuated decay volume. We have built four arrays of ionization chambers to monitor the position and intensity of the hadron and muon beams associated with neutrino production at locations downstream of the decay volume. This article describes the chambers' construction, calibration, and commissioning in the beam.Comment: Accepted for publication in Nucl. Instr. Meth.

    The CKM Matrix and The Unitarity Triangle: Another Look

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    The unitarity triangle can be determined by means of two measurements of its sides or angles. Assuming the same relative errors on the angles (α,β,γ)(\alpha,\beta,\gamma) and the sides (Rb,Rt)(R_b,R_t), we find that the pairs (γ,β)(\gamma,\beta) and (γ,Rb)(\gamma,R_b) are most efficient in determining (ϱˉ,ηˉ)(\bar\varrho,\bar\eta) that describe the apex of the unitarity triangle. They are followed by (α,β)(\alpha,\beta), (α,Rb)(\alpha,R_b), (Rt,β)(R_t,\beta), (Rt,Rb)(R_t,R_b) and (Rb,β)(R_b,\beta). As the set \vus, \vcb, RtR_t and β\beta appears to be the best candidate for the fundamental set of flavour violating parameters in the coming years, we show various constraints on the CKM matrix in the (Rt,β)(R_t,\beta) plane. Using the best available input we determine the universal unitarity triangle for models with minimal flavour violation (MFV) and compare it with the one in the Standard Model. We present allowed ranges for sin2β\sin 2\beta, sin2α\sin 2\alpha, γ\gamma, RbR_b, RtR_t and ΔMs\Delta M_s within the Standard Model and MFV models. We also update the allowed range for the function FttF_{tt} that parametrizes various MFV-models.Comment: "published version. few typos corrected, results unchanged

    Remark on the Theoretical Uncertainty in B0B^0-Bˉ0\bar{B}^0 Mixing

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    We re-examine the theoretical uncertainty in the Standard Model expression for B0B^0-Bˉ0\bar{B}^0 mixing. We focus on lattice calculations of the ratio ξ\xi, needed to relate the oscillation frequency of Bs0B^0_s-Bˉs0\bar{B}^0_s mixing to VtdV_{td}. We replace the usual linear chiral extrapolation with one that includes the logarithm that appears in chiral perturbation theory. We find a significant shift in the ratio ξ\xi, from the conventional 1.15±0.051.15\pm0.05 to ξ=1.32±0.10\xi=1.32\pm0.10.Comment: Lattice2002(heavyquark), 3 pages, 3 figure

    Probing Yukawa Unification with K and B Mixing

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    We consider corrections to the unification of down-quark and charged-lepton Yukawa couplings in supersymmetric GUTs, which links the large nu_tau-nu_mu mixing angle to b -> s transitions. These corrections generically occur in simple grand-unified models with small Higgs representations and affect s -> d and b -> d transitions via the mixing of the corresponding right-handed superpartners. On the basis of a specific SUSY-SO(10) model, we analyze the constraints from K-Kbar and B-Bbar mixing on the additional \tilde{d}_R-\tilde{s}_R rotation angle theta. We find that epsilon_K already sets a stringent bound on theta, theta^{max}=O(1 degree), indicating a very specific flavor structure of the correction operators. The impact of the large neutrino mixings on the unitarity triangle analysis is also briefly discussed, as well as their ability to account for the sizeable CP-violating phase observed recently in B_s -> psi phi decays.Comment: 19 pages. Discussion in Sec. 5.2 slightly extended; minor numerical modifications in Secs. 5.1 to 5.4, conclusions unchanged. Version to appear in JHE

    Unitarity Triangles and the Search for New Physics

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    Assuming that the Kobayashi-Maskawa mechanism gives the dominant contribution to CP violation at low energies, we propose a novel way of testing the flavour sector of the Standard Model which has the potencial for discovering New Physics. Using 3 x 3 unitarity of the V_{CKM} matrix and choosing a complete set of rephasing invariant phases, we derive a set of exact relations in terms of measurable quantities, namely moduli of V_{CKM} and arguments of rephasing invariant quartets. These tests complement the usual analysis in the \rho, \eta plane and, if there is New Physics, may reveal its source.Comment: 20 pages, 7 figures, uses tcilate

    Experimental study of direct photon emission in K- --> pi- pi0 gamma decay using ISTRA+ detector

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    The branching ratio in the charged-pion kinetic energy region of 55 to 90 MeV for the direct photon emission in the K- --> pi- pi0 gamma decay has been measured using in-flight decays detected with the ISTRA+ setup operating in the 25 GeV/c negative secondary beam of the U-70 PS. The value Br(DE)=[0.37+-0.39(stat)+-0.10(syst)]*10^(-5) obtained from the analysis of 930 completely reconstructed events is consistent with the average value of two stopped-kaon experiments, but it differs by 2.5 standard deviations from the average value of three in-flight-kaon experiments. The result is also compared with recent theoretical predictions.Comment: 13 pages, 8 figure

    Strength and Plastic Properties of TiNiMoFeCu Alloys

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    В работе исследованы пористые сплавы TiNi49,9-xMo0,1Fe0,1Cux(где x = 0, 1, 3, 6, 10 ат.%), полученные методом (СВС). Показано, что существенное влияние на формирование поверхностей разрушения оказывает сформированная структура сплавов. Установлено, что многообразие проявления свойств сплавов с увеличением легирующей добавки от 1 до 10 ат.% Cu определяется как составом материала, так и температурой деформации.In this work, porous alloys TiNi49,9-xMo0.1Fe0.1Cux (where x = 0, 1, 3, 6, 10 at.%) Obtained by the (SHS) method are investigated. It is shown that the formed structure of the alloys has a significant effect on the formation of fracture surfaces. It was found that, the variety of properties of properties of alloys with the alloying additive formula from 1 to 10 at.% Cu is determined by both the composition of the material and the temperature of deformation.Исследование выполнено за счет гранта Российского научного фонда (проект № 19-79-10045).The research was carried out at the expense of a grant from the Russian science foundation (project No. 19-79-10045)

    Methods to Determine Neutrino Flux at Low Energies:Investigation of the Low ν\nu Method

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    We investigate the "low-ν\nu" method (developed by the CCFR/NUTEV collaborations) to determine the neutrino flux in a wide band neutrino beam at very low energies, a region of interest to neutrino oscillations experiments. Events with low hadronic final state energy ν<νcut\nu<\nu_{cut} (of 1, 2 and 5 GeV) were used by the MINOS collaboration to determine the neutrino flux in their measurements of neutrino (νμ\nu_\mu) and antineutrino (\nub_\mu) total cross sections. The lowest νμ\nu_\mu energy for which the method was used in MINOS is 3.5 GeV, and the lowest \nub_\mu energy is 6 GeV. At these energies, the cross sections are dominated by inelastic processes. We investigate the application of the method to determine the neutrino flux for νμ\nu_\mu, \nub_\mu energies as low as 0.7 GeV where the cross sections are dominated by quasielastic scattering and Δ\Delta(1232) resonance production. We find that the method can be extended to low energies by using νcut\nu_{cut} values of 0.25 and 0.50 GeV, which is feasible in fully active neutrino detectors such as MINERvA.Comment: 25 pages, 32 figures, to be published in European Physics Journal

    Development and validation of a quantitative HPLC/MS/MS method for the determination of piperacillin in blood plasma

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    Reduced mortality in patients with sepsis taking piperacillin is possible when they receive a long-term infusion, which improves the effect of antimicrobials. However, such piperacillin therapy requires therapeutic drug monitoring, the use of the latest analytical equipment and developed methods for the quantitative determination of piperacilli
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