Publications by authors named "Isakov A"

Article Synopsis
  • The Letter reports the most accurate measurement so far of the matter-antimatter imbalance during Pb-Pb collisions at a high energy level of 5.02 TeV.
  • It utilizes the Statistical Hadronization framework to determine precise values for the electric charge and baryon chemical potentials, μ_{Q} and μ_{B}.
  • The analysis of antiparticle-to-particle yield ratios shows that the collisions create a system that is generally baryon-free and electrically neutral at midrapidity.
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Context: The coronavirus disease 2019 (COVID-19) pandemic devastated societies and economies worldwide. Given the major disruptions to higher education, reflection on university responses to the COVID-19 pandemic may provide insights for future outbreaks.

Objective: Here, we describe the epidemiology of COVID-19 on the Emory University campus during the 2020-2021 academic year and provide an evaluation of the performance of a university-led program with the purpose of describing the effectiveness of efforts to augment the public health authority's case investigation and contact tracing efforts during a public health emergency.

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The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions.

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K^{+}K^{-} pairs may be produced in photonuclear collisions, either from the decays of photoproduced ϕ(1020) mesons or directly as nonresonant K^{+}K^{-} pairs. Measurements of K^{+}K^{-} photoproduction probe the couplings between the ϕ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere.

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Article Synopsis
  • - This Letter discusses the measurement of ridge yields from charged hadron angular correlations in proton-proton collisions at a high energy of 13 TeV, specifically within certain pseudorapidity and transverse momentum ranges.
  • - The research extends ridge yield measurements to low charged-particle multiplicity regions, where typically a strong interacting medium is not expected to form during collisions.
  • - Findings indicate that ridge yields in pp collisions are significantly higher than those observed in e^{+}e^{-} collisions, suggesting that processes in e^{+}e^{-} annihilations do not significantly influence long-range correlations in proton-proton interactions.
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Article Synopsis
  • The ALICE detector measured the cross section for incoherent photonuclear production of J/ψ vector mesons, focusing on the Mandelstam |t| variable, during ultraperipheral collisions of Pb nuclei at a very high energy of 5.02 TeV.
  • The measurement was conducted within a rapidity interval of |y|<0.8 and covers a specific range of Bjorken-x values.
  • Analysis showed that models without quantum fluctuations in the gluon density predicted a much steeper |t|-dependence than observed, but including these fluctuations improved the models' alignment with the data.
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The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.

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Article Synopsis
  • Understanding how parton mass and Casimir color factors affect heavy quark emissions is key to studying quantum chromodynamics (QCD).
  • This research presents the first experimental constraint on the charm-quark splitting function, obtained through measurements in proton-proton collisions at 13 TeV.
  • Findings indicate that charm quarks show a steeper splitting function compared to gluons and light quarks, experiencing fewer emissions with a lower likelihood of large-angle emissions.
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The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process).

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Article Synopsis
  • * A notable negative correlation between the production of antiprotons and antideuterons was found across various collision centralities.
  • * Comparisons with theoretical models show that while a coalescence calculation explains certain statistical features, it struggles with the specifics of antiproton-antideuteron correlations, whereas thermal-statistical models can align with observations but imply different correlation volumes.
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The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5  GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE.

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We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.

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Background: Gestational diabetes mellitus (GDM) is a common complication of pregnancy associated with serious adverse outcomes for mothers and their offspring. Achieving glycaemic targets is the mainstream in the treatment of GDM in order to improve pregnancy outcomes. As GDM is usually diagnosed in the third trimester of pregnancy, the time frame for the intervention is very narrow.

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Clinical characteristics and pathomorphological manifestations in 69 patients aged 18 to 86 years with a fatal outcome of the disease were examined in order to analyze the causes of severe course and high mortality of generalized forms meningococcal infection. It was found that the main clinical form was meningococcemia (90%), in the majority in combination with meningitis (52%). The fulminant course in 77% of patients with meningococcal sepsis manifested itself as a sudden onset, rapid development of typical symptoms.

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The electrochemical behavior of rhenium ions in the molten KF-KBF-BO salt was systematically studied, and pure metallic rhenium was obtained at the cathode. The processes of rhenium ions reduction and diffusion in molten KF-KBF-BO were determined using cyclic voltammetry, stationary galvanostatic and polarization curves analyses. The values of diffusion coefficients were 3.

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Few reports have described how university programs have controlled COVID-19 outbreaks. Emory University established a case investigation and contact tracing program in June 2020 to identify and mitigate transmission of SARS-CoV-2 in the Emory community. In February 2021, this program identified a surge in COVID-19 cases.

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The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV is presented in this Letter.

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Several meta-analyses found an association between low maternal serum 25-hydroxyvitamin D (25(OH)D) level and gestational diabetes mellitus (GDM). However, some of them reported significant heterogeneity. We examined the association of serum 25(OH)D concentration measured in the first and in the second halves of pregnancy with the development of GDM in Russian women surveyed in the periods of 2012−2014 and 2018−2021.

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The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle.

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Article Synopsis
  • This article discusses the analysis of groomed jet substructure in proton-proton (pp) and lead-lead (Pb-Pb) collisions using the ALICE detector at a collision energy of 5.02 TeV.
  • The study employs a soft drop grooming algorithm to isolate hard parton splittings and measures the groomed jet momentum splitting fraction and radius, revealing distinct behavior in jet structure under different collision conditions.
  • Notably, a narrowing of the groomed jet radius distribution in Pb-Pb collisions suggests changes in jet angular structure due to quark-gluon plasma, while no significant differences are observed in momentum splitting fractions, contributing valuable insights into jet energy-loss mechanisms.
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Case: A 54-year-old woman with chronic lumbar radiculopathy due to grade II spondylolisthesis at lumbar 4 to 5 developed acute cauda equina syndrome (CES) after an elective lumbar decompression, and fusion was delayed because of statewide bans on elective procedures during the pandemic. The diagnosis was made largely through telehealth consultation and eventually prompted urgent neurosurgical intervention.

Conclusion: This case report illustrates a rare presentation of acute CES and highlights some of the challenges of practicing clinical medicine in the midst of a pandemic.

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The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13  TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions.

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The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13  TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels.

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