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D. A. Maksimov

Publications and source records attributed to D. A. Maksimov.

At least 19 recordsLinked to original sources
arXiv2026

General aspects of internal noise in spiking neural networks

This study examines the impact of additive and multiplicative noise on both a single leaky integrate-and-fire (LIF) neuron and a trained spiking neural network (SNN). Noise was introduced at different stages of neural processing, including the input current, membrane potential, and output spike generation. The results show that multiplicative noise applied to the membrane potential has the most detrimental effect on network performance, leading to a significant degradation in accuracy. This is primarily due to its tendency to suppress membrane potentials toward large negative values, effectively silencing neuronal activity. To address this issue, input pre-filtering strategies were evaluated, with a sigmoid-based filter demonstrating the best performance by shifting inputs to a strictly positive range. Under these conditions, additive noise in the input current becomes the dominant source of performance degradation, while other noise configurations reduce accuracy by no more than 1\%, even at high noise intensity. Additionally, the study compares the effects of common and uncommon noise across neuron populations in hidden layer, revealing that SNNs exhibit greater robustness to common noise. Overall, the findings identify the most critical noise mechanisms affecting SNNs and provide practical approaches for improving their robustness.

cs.NE↗
arXiv2026

Internal noise in deep neural networks: interplay of depth, neuron number, and noise injection step

This paper examines the influence of internal Gaussian noise on the performance of deep feedforward neural networks, focusing on the role of the noise injection stage relative to the activation function. Two scenarios are analyzed: noise introduced before and after the activation function, for both additive and multiplicative noise influence. The case of noise before activation function is similar to perturbations in the input channel of neuron, while the noise introduced after activation function is analogous to noise occurring either within the neuron itself or in its output channel. The types of noise and the method of their introduction were inspired by analog neural networks. The results show that the activation function acts as an effective nonlinear filter of noise. Networks with noise introduced before the activation function consistently achieve higher accuracy than those with noise applied after it, with additive noise being more effectively suppressed in this case. For noise introduced after the activation function, multiplicative noise is less detrimental than additive noise, and earlier hidden layers contribute more significantly to performance degradation due to cumulative noise amplification governed by the statistical properties of subsequent weight matrices. The study also demonstrates that pooling-based noise reduction is effective in both cases when noise is introduced before and after the activation function, consistently improving network performance.

cs.NE↗
arXiv2025

The branching fraction measurements of $J/ψ$ decay into $ρη$ and $ϕη$ final states

We present measurements of the branching fractions for the $J/ψ$ meson decays into the $ρη$ and $ϕη$ final states, based on data collected with the KEDR detector at the VEPP-4M collider. The data set consisted of 4.93 million $J/ψ$ events. The resulting branching fractions are: - $\mathcal{B}(J/ψ\to ρη) = (2.04 \pm 0.58 \pm 0.39)\times 10^{-4}$, - $\mathcal{B}(J/ψ\to ϕη) = (7.82 \pm 1.17 \pm 0.58) \times 10^{-4}$, where the first uncertainty is statistical and the second one is systematic. In the study of the $ρη$ decay, the dynamics of $J/ψ\toπ^+π^-η$ is analyzed. The hints from contributions of $ρ(1450)η$ and $a^{\pm}_2π^{\mp}$ intermediate states are observed. Additional measured branching fractions in the model that includes $ρ(1450)η$ and $a^{\pm}_2π^{\mp}$ are: - $\mathcal{B}(J/ψ\to π^+π^-η) = (4.73 \pm 0.49 \pm 1.17)\times10^{-4}$, - $\mathcal{B}(J/ψ\to (a_2^+π^- + a_2^- π^+)) = (1.05\pm 0.37 \pm 0.34)\times 10^{-3}$, - $\mathcal{B}(J/ψ\to ρ(1450)η\to π^+π^-η) < 1.51 \times 10^{-4}$, at a confidence level of 90\%. All results are consistent with previous studies.

hep-ex↗
arXiv2025

New measurement of D0 and D+ meson masses with the KEDR detector

Using the 4.9 pb$^{-1}$ statistics collected at the peak of the $ψ(3770)$ resonance with the KEDR detector at the VEPP-4M electron-positron collider, we measured the masses of the neutral and charged D mesons: $M_{D^0} = 1865.100 \pm 0.210 (stat) \pm 0.046 (syst) MeV,$ and $M_{D^+} = 1869.560 \pm 0.288 (stat) \pm 0.109 (syst) MeV$.

hep-ex↗
arXiv2023

Measurement of the branching fraction of $J/ψ\rightarrowρπ$ at KEDR

We present the study of the decay $J/ψ\rightarrow ρπ$. The results are based on of 5.2~million $J/ψ$ events collected by the KEDR detector at the VEPP-4M collider. The branching fractions are measured to be $\B(J/ψ\rightarrow ρπ) = \big(2.072\pm 0.017 \pm 0.062 \big)\cdot 10^{-2}$ and $\B(J/ψ\rightarrow π^+π^-π^0) = \big(1.878 \pm 0.013 \pm 0.051 \big)\cdot 10^{-2}$, where the first uncertainties are statistical and the second systematic. Our results are more precise than the previous relative measurements.

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arXiv2018

Precise measurement of $R_{\text{uds}}$ and $R$ between 1.84 and 3.72 GeV at the KEDR detector

The present work continues a series of the KEDR measurements of the $R$ value that started in 2010 at the VEPP-4M $e^+e^-$ collider. By combining new data with our previous results in this energy range we measured the values of $R_{\text{uds}}$ and $R$ at nine center-of-mass energies between 3.08 and 3.72 GeV. The total accuracy is about or better than $2.6\%$ at most of energy points with a systematic uncertainty of about $1.9\%$. Together with the previous precise $R$ measurement at KEDR in the energy range 1.84-3.05 GeV, it constitutes the most detailed high-precision $R$ measurement near the charmonium production threshold.

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arXiv2018

Measurement of $Γ_{ee}\times\mathcal{B}_{μμ}$ for $ψ(2S)$ meson

The product of the electronic width of the $ψ(2S)$ meson and the branching fraction of its decay to the muon pair was measured in the $e^{+}e^{-} \to ψ(2S) \to μ^{+}μ^{-}$ process using nine data sets corresponding to an integrated luminosity of about 6.5 pb$^{-1}$ collected with the KEDR detector at the VEPP-4M electron-positron collider: \[ Γ_{ee}\times\mathcal{B}_{μμ} = 19.3 \pm 0.3 \pm 0.5 ~\text{eV}. \] Adding the previous KEDR results on hadronic and leptonic channels, the values of the $ψ(2S)$ electronic width were obtained under two assumptions: either with the assumption of lepton universality \[ Γ_{ee} = 2.279 \pm 0.015 \pm 0.042 ~\text{keV} \] or without it, summing up hadronic and three independent leptonic channels: \[ Γ_{ee} = 2.282 \pm 0.015 \pm 0.042 ~\text{keV}. \]

hep-ex↗
arXiv2018

Measurement of $Γ_{ee}(J/ψ)$ with KEDR detector

The product of the electronic width of the $J/ψ$ meson and the branching fractions of its decay to hadrons and electrons has been measured using the KEDR detector at the VEPP-4M $e^+e^-$ collider. The obtained values are: $Γ_{ee}(J/ψ) = 5.550 \pm 0.056 \pm 0.089 \, \text{keV}, $ $Γ_{ee}(J/ψ) \cdot \mathcal{B}_\text{hadrons}(J/ψ) = 4.884 \pm 0.048 \pm 0.078 \, \text{keV}, $ $Γ_{ee}(J/ψ) \cdot \mathcal{B}_{ee}(J/ψ) = 0.3331 \pm 0.0066 \pm 0.0040 \, \text{keV}.$ The uncertainties shown are statistical and systematic, respectively. Using the result presented and the world-average value of the electronic branching fraction, one obtains the total width of the $J/ψ$ meson: $Γ= 92.94 \pm 1.83 \, \text{keV}.$ These results are consistent with the previous experiments.

hep-ex↗
arXiv2016

Measurement of $R$ between 1.84 and 3.05 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have determined the values of $R$ at thirteen points of the center-of-mass energy between 1.84 and 3.05 GeV. The achieved accuracy is about or better than $3.9\%$ at most of the energy points with a systematic uncertainty less than $2.4\%$.

hep-ex↗
arXiv2015

Measurement of $R_{\text{uds}}$ and $R$ between 3.12 and 3.72 GeV at the KEDR detector

Using the KEDR detector at the VEPP-4M $e^+e^-$ collider, we have measured the values of $R_{\text{uds}}$ and $R$ at seven points of the center-of-mass energy between 3.12 and 3.72 GeV. The total achieved accuracy is about or better than $3.3\%$ at most of energy points with a systematic uncertainty of about $2.1\%$. At the moment it is the most accurate measurement of $R(s)$ in this energy range.

hep-ex↗
arXiv2014

Measurement of $J/ψ\toγη_{\rm c}$ decay rate and $η_{\rm c}$ parameters at KEDR

Using the inclusive photon spectrum based on a data sample collected at the $J/ψ$ peak with the KEDR detector at the VEPP-4M $e^+e^-$ collider, we measured the rate of the radiative decay $J/ψ\toγη_{\rm c}$ as well as $η_{\rm c}$ mass and width. Taking into account an asymmetric photon lineshape we obtained $Γ^0_{γη_{\rm c}}=2.98\pm0.18 \phantom{|}^{+0.15}_{-0.33}$ keV, $M_{η_{\rm c}} = 2983.5 \pm 1.4 \phantom{|}^{+1.6}_{-3.6}$ MeV/$c^2$, $Γ_{η_{\rm c}} = 27.2 \pm 3.1 \phantom{|}^{+5.4}_{-2.6}$ MeV.

hep-ex↗
arXiv2014

Measurement of the ratio of the leptonic widths $Γ_{ee}/Γ_{μμ}$ for the $J/ψ$ meson

The ratio of the electron and muon widths of the $J/ψ$ meson has been measured using direct $J/ψ$ decays in the KEDR experiment at the VEPP-4M electron-positron collider. The result $Γ_{ee}(J/ψ)/Γ_{μμ}(J/ψ)=1.0022\pm0.0044\pm0.0048\ (0.65\%)$ is in good agreement with the lepton universality. The experience collected during this analysis will be used for a $J/ψ$ lepton width determination with up to 1% accuracy.

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arXiv2013

Parameters of charmonium states from KEDR

We report results of experiments performed with the KEDR detector at the VEPP-4M $e^+e^-$ collider. They include final results for the mass and other parameters of the $J/ψ$, $ψ(2S)$ and $ψ(3770)$ and $J/ψ\toγη_c$ branching fraction determination.

hep-ex↗
arXiv2012

Measurement of ψ(3770) parameters

We report the final results of a study of the ψ(3770) meson using a data sample collected with the KEDR detector at the VEPP-4M electron-positron collider. The data analysis takes into account the interference between the resonant and nonresonant $D\bar{D}$ production, where the latter is related to the nonresonant part of the energy-dependent form factor $F_D$. The vector dominance approach and several empirical parameterizations have been tried for the nonresonant $F_D^{\NR}(s)$. Our results for the mass and total width of ψ(3770) are M = 3779.2 ^{+1.8}_{-1.7} ^{+0.5}_{-0.7} ^{+0.3}_{-0.3} MeV, Γ=24.9 ^{+4.6}_{-4.0} ^{+0.5}_{-0.6} ^{+0.2}_{-0.9} MeV, where the first, second and third uncertainties are statistical, systematic and model, respectively. For the electron partial width two possible solutions have been found: (1) Γ_{ee} = 154 ^{+79}_{-58} ^{+17}_{-9} ^{+13}_{-25} eV, (2) Γ_{ee} = 414 ^{+72}_{-80} ^{+24}_{-26} ^{+90}_{-10} eV. Our statistics are insufficient to prefer one solution to another. The solution (2) mitigates the problem of non-$D\bar{D}$ decays but is disfavored by potential models. It is shown that taking into account the resonance--continuum interference in the near-threshold region affects resonance parameters, thus the results presented can not be directly compared with the corresponding PDG values obtained ignoring this effect.

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arXiv2011

Measurement of main parameters of the ψ(2S) resonance

A high-precision determination of the main parameters of the ψ(2S) resonance has been performed with the KEDR detector at the VEPP-4M e^{+}e^{-} collider in three scans of the ψ(2S) -- ψ(3770) energy range. Fitting the energy dependence of the multihadron cross section in the vicinity of the ψ(2S) we obtained the mass value M = 3686.114 +- 0.007 +- 0.011 ^{+0.002}_{-0.012} MeV and the product of the electron partial width by the branching fraction into hadrons Γ_{ee}*B_{h} = 2.233 +- 0.015 +- 0.037 +- 0.020 keV. The third error quoted is an estimate of the model dependence of the result due to assumptions on the interference effects in the cross section of the single-photon e^{+}e^{-} annihilation to hadrons explicitly considered in this work. Implicitly, the same assumptions were employed to obtain the charmonium leptonic width and the absolute branching fractions in many experiments. Using the result presented and the world average values of the electron and hadron branching fractions, one obtains the electron partial width and the total width of the ψ(2S): Γ_{ee} =2.282 +- 0.015 +- 0.038 +- 0.021 keV, Γ= 296 +- 2 +- 8 +- 3 keV. These results are consistent with and more than two times more precise than any of the previous experiments.

hep-ex↗
arXiv2011

Measurement of J/psi leptonic width with the KEDR detector

We report a new precise determination of the leptonic widths of the J/psi meson performed with the KEDR detector at the VEPP-4M $e^{+}e^{-}$ collider. The measured values of the J/psi parameters are: Γ_{ee}\timesΓ_{ee}/Γ= 0.3323 \pm 0.0064 (stat.) \pm 0.0048 (syst.) keV Γ_{ee}\timesΓ_{μμ}/Γ=0.3318 \pm 0.0052 (stat.) \pm 0.0063 (syst.) keV. Assuming $eμ$ universality and using the table value of the branching ratios the leptonic Γ_{ll}= 5.59 \pm 0.12 keV width and the total Γ=94.1 \pm 2.7 keV widths were obtained. We also discuss in detail a method to calculate radiative corrections at a narrow resonance.

hep-ex↗
arXiv2010

Measurement of B(J/psi->eta_c gamma) at KEDR

We present a study of the inclusive photon spectrum from 6.3 million J/psi decays collected with the KEDR detector at the VEPP-4M e+e- collider. We measure the branching fraction of the radiative decay J/psi -> eta_c gamma, eta_c width and mass. Taking into account an asymmetric photon line shape we obtain: M(eta_c) = (2978.1 +- 1.4 +- 2.0) MeV/c^2, Gamma(eta_c) = (43.5 +- 5.4 +- 15.8) MeV, B(J/psi->eta_c gamma) = (2.59 +- 0.16 +- 0.31)%$.

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