Пахлова Галина Владимировна
Московский институт электроники и математики им. А.Н. Тихонова
Профессиональные интересы
Должности
- Ведущий научный сотрудник — Московский институт электроники и математики им. А.Н. Тихонова, Международная лаборатория физики элементарных частиц
Био
- · Начала работать в НИУ ВШЭ в 2020 году.
- · Научно-педагогический стаж: 4 года.
Образование
- 2011 · Доктор физико-математических наук: Высшая аттестационная комиссия Республика Болгария
- 1994 · Кандидат физико-математических наук: Институт теоретической и экспериментальной физики
- 1984 · Специалитет: Московский инженерно-физический институт, специальность «Экспериментальная ядерная физика», квалификация «Инженер-физик»
Идентификаторы исследователя
- ORCID:
0000-0001-7518-3022 - ResearcherID:
C-5378-2014 - SPIN РИНЦ:
1406-3272 - Google Scholar: https://scholar.google.com/citations?view_op=list_works&hl=en&user=fFiMLk0AAAAJ&gmla=AJsN-F7mn-IyCnEj_Ug1RmF450uvfNhIP59Uxymi_BKjMGYOUB8KunCrnueLqUiIeo_gIyW4wBX8b-M5m79_triQ4PcDP35zFxATkp5JZ_5okKDfZW6pyWs
- Scopus AuthorID:
35234620700
Публикации (189)
Measurements of the branching fractions of Ξ+c→Σ+K0S, Ξ+c→Ξ0π+, and Ξ+c→Ξ0K+ at Belle and Belle II
2025 в печати · ARTICLE · en
Using 983.0 fb−1 and 427.9 fb−1 data samples collected with the Belle and Belle II detectors at the KEKB and SuperKEKB asymmetric energy e+e− colliders, respectively, we present studies of the Cabibbo-favored Ξ+c decays Ξ+c→Σ+K0S and Ξ+c→Ξ0π+, and the singly Cabibbo-suppressed decay Ξ+c→Ξ0K+. The ratios of branching fractions of Ξ+c→Σ+K0S and Ξ+c→Ξ0K+ relative to that of Ξ+c→Ξ−π+π+ are measured for the first time, while the ratio (Ξ+c→Ξ0π+)/(Ξ+c→Ξ−π+π+) is also determined and improved by an order of magnitude in precision. The measured branching fraction ratios are (Ξ+c→Σ+0)(Ξ+c→Ξ−π+π+)=0.067±0.007±0.003, (Ξ+c→Ξ0π+)(Ξ+c→Ξ−π+π+)=0.251±0.005±0.010, (Ξ+c→Ξ0+)(Ξ+c→Ξ−π+π+)=0.017±0.003±0.001. Additionally, the ratio (Ξ+c→Ξ0K+)/(Ξ+c→Ξ0π+) is measured to be 0.068±0.010±0.004. Here, the first and second uncertainties are statistical and systematic, respectively. Multiplying the ratios by the branching fraction of the normalization mode, (Ξ+c→Ξ−π+π+)=(2.9±1.3)%, we obtain the following absolute branching fractions (Ξ+c→Σ+K0S)=(0.194±0.021±0.009±0.087), (Ξ+c→Ξ0π+)=(0.728±0.014±0.027±0.326), (Ξ+c→Ξ0K+)=(0.049±0.007±0.003±0.022).
Measurement of the Branching Fraction of Λ+c→pK0Sπ0 at Belle
2025 в печати · ARTICLE · en
We report a precise measurement of the ratio of branching fractions (Λ+c→pK0Sπ0)/(Λ+c→pK−π+) using 980 fb−1 of e+e− data from the Belle experiment. We obtain a value of (Λ+c→pK0Sπ0)/(Λ+c→pK−π+)=0.339±0.002±0.009, where the first and second uncertainties are statistical and systematic, respectively. This Belle result is consistent with the previous measurement from the CLEO experiment but has a fivefold improvement in precision. By combining our result with the world average (Λ+c→pK−π+), we obtain the absolute branching fraction (Λ+c→pK0Sπ0)=(2.12±0.01±0.05±0.10)%, where the uncertainties are statistical, systematic, and the uncertainty in the absolute branching fraction scale (Λ+c→pK−π+), respectively. This measurement can shed light on hadronic decay mechanisms in charmed baryon decays.
Measurement of B → K*(892)γ decays at Belle II
2025 в печати · ARTICLE · en
We present measurements of B→K∗(892)γ decays using 365fb−1 of data collected from 2019 to 2022 by the Belle~II experiment at the SuperKEKB asymmetric-energy e+e− collider. The data sample contains (387±6)×106 Υ(4S) events. We measure branching fractions () and CP asymmetries (CP) for both B0→K∗0γ and B+→K∗+γ decays. The difference in CP asymmetries (ΔCP) and the isospin asymmetry (Δ0+) between these neutral and charged channels are also measured. We obtain the following branching fractions and CP asymmetries: (B0→K∗0γ)=(4.14±0.10±0.11)×10−5, (B+→K∗+γ)=(4.04±0.13+0.13−0.15)×10−5, CP(B0→K∗0γ)=(−3.3±2.3±0.4)%, and CP(B+→K∗+γ)=(−0.7±2.9±0.5)%. The measured difference in CP asymmetries is ΔCP=(+2.6±3.8±0.6)%, and the measured isospin asymmetry is Δ0+=(+4.8±2.0±1.8)%. The first uncertainties listed are statistical and the second are systematic. These results are consistent with world-average values and theory predictions.
Determination of |Vub| from simultaneous measurements of untagged B0→π−ℓ+νℓ and B+→ρ0ℓ+νℓ decays
2025 в печати · ARTICLE · en
We present a measurement of |Vub| from a simultaneous study of the charmless semileptonic decays B0→π−ℓ+νℓ and B+→ρ0ℓ+νℓ, where ℓ=e,μ. This measurement uses a data sample of 387 million BB⎯⎯⎯⎯ meson pairs recorded by the Belle~II detector at the SuperKEKB electron-positron collider between 2019 and 2022. The two decays are reconstructed without identifying the partner B mesons. We simultaneously measure the differential branching fractions of B0→π−ℓ+νℓ and B+→ρ0ℓ+νℓ decays as functions of q2 (momentum transfer squared). From these, we obtain total branching fractions B(B0→π−ℓ+νℓ)=(1.516±0.042(stat)±0.059(syst))×10−4 and B(B+→ρ0ℓ+νℓ)=(1.625±0.079(stat)±0.180(syst))×10−4. By fitting the measured B0→π−ℓ+νℓ partial branching fractions as functions of q2, together with constraints on the non-perturbative hadronic contribution from lattice QCD calculations, we obtain |Vub| = (3.93±0.09±0.13±0.19)×10−3. Here, the first uncertainty is statistical, the second is systematic, and the third is theoretical.
Search for a dark Higgs boson produced in association with inelastic dark matter at the Belle II experiment
2025 в печати · ARTICLE · en
Inelastic dark matter models that have two dark matter particles and a massive dark photon can reproduce the observed relic dark matter density without violating cosmological limits. The mass splitting between the two dark matter particles χ1 and χ2, with m(χ2)>m(χ1), is induced by a dark Higgs field and a corresponding dark Higgs boson h′. We present a search for dark matter in events with two vertices, at least one of which must be displaced from the interaction region, and missing energy. Using a 365fb−1data sample collected at Belle II, which operates at the SuperKEKB e+e− collider, we observe no evidence for a signal. We set upper limits on the product of the production cross section σ(e+e−→h′χ1χ2), and the product of branching fractions (χ2→χ1e+e−)×(h′→x+x−), where x+x− indicates μ+μ−,π+π−, or K+K−, as functions of h′ mass and lifetime at the level of 10−1fb. We set model-dependent upper limits on the dark Higgs mixing angle at the level of 10−5 and on the dark photon kinetic mixing parameter at the level of 10−3. This is the first search for dark Higgs bosons in association with inelastic dark matter.
Measurement of B+→τ+ντ branching fraction with a hadronic tagging method at Belle II
2025 в печати · ARTICLE · en
We present a measurement of the branching fraction of B+→τ+ντ decays using (387±6)×106 Υ(4S) collected between 2019 and 2022 with the Belle II detector at the SuperKEKB e+e− collider. We reconstruct the accompanying B− meson using the hadronic tagging method, while B+→τ+ντ candidates are identified in the recoil. We find evidence for B+→τ+ντ decays at 3.0 standard deviations, including systematic uncertainties. The measured branching fraction is (B+→τ+ντ)=[1.24±0.41(stat.)±0.19(syst.)]×10−4.
Charged-hadron identification at Belle II
2025 в печати · ARTICLE · en
The Belle II experiment’s ability to identify particles critically affects the sensitivity of its measurements. We describe Belle II’s algorithms for identifying charged particles and evaluate their performance in separating pions, kaons, and protons using 426 1/fb of data collected at the energy-asymmetric e+e- collider SuperKEKB in 2019–2022 at center-of-mass energies at and near the mass of the Y(4S).
Measurement of the D0→K−π+e+e− branching fraction and search for D0→π+π−e+e− and D0→K+K−e+e− decays at Belle
2025 в печати · ARTICLE · en
We present a study of the rare charm meson decays D0→K+K−e+e−, π+π−e+e−, and K−π+e+e− using a 942 fb−1 data set collected by the Belle detector at the KEKB asymmetric-energy e+e− collider. We use D0 candidates identified by the charge of the pion in D∗→D0π decays and normalize the branching fractions to D0→K−π+π−π+ decays. The branching fraction for decay D0→K−π+e+e− is measured to be (39.6 ± 4.5 (stat) ± 2.9 (syst)) × 10−7, with the dielectron mass in the ρ/ω mass region 675
Measurement of the e+e−→π+π−π0 cross section in the energy range 0.62-3.50 GeV at Belle II
2024 в печати · ARTICLE · en
We report a measurement of the 𝑒+𝑒− →𝜋+𝜋−𝜋0 cross section in the energy range from 0.62 to 3.50 GeV using an initial-state radiation technique. We use an 𝑒+𝑒− data sample corresponding to 191 fb−1 of integrated luminosity, collected at a center-of-mass energy at or near the ϒ(4𝑆)resonance with the Belle II detector at the SuperKEKB collider. Signal yields are extracted by fitting the two-photon mass distribution in 𝑒+𝑒− →𝜋+𝜋−𝜋0𝛾 events, which involve a 𝜋0 →𝛾𝛾 decay and an energetic photon radiated from the initial state. Signal efficiency corrections with an accuracy of 1.6% are obtained from several control data samples. The uncertainty on the cross section at the 𝜔and 𝜙 resonances is dominated by the systematic uncertainty of 2.2%. The resulting cross sections in the 0.62–1.80 GeV energy range yield 𝑎3𝜋𝜇 =[48.91 ±0.23(stat) ±1.07(syst)] ×10−10 for the leading-order hadronic vacuum polarization contribution to the muon anomalous magnetic moment. This result differs by 2.5 standard deviations from the most precise current determination.
Measurement of CP asymmetries in B0→η′K0s decays at Belle II
2024 в печати · ARTICLE · en
We describe a measurement of charge-parity (𝐶𝑃) violation asymmetries in 𝐵0 →𝜂′𝐾0S decays using Belle II data. We consider 𝜂′ →𝜂( →𝛾𝛾)𝜋+𝜋− and 𝜂′ →𝜌( →𝜋+𝜋−)𝛾 decays. The data were collected at the SuperKEKB asymmetric-energy 𝑒+𝑒− collider between the years 2019 and 2022, and contain (387 ±6) ×106 bottom-antibottom meson pairs. We reconstruct 829 ±35 signal decays and extract the 𝐶𝑃 violating parameters from a fit to the distribution of the proper-decay-time difference between the two 𝐵 mesons. The measured direct and mixing-induced 𝐶𝑃 asymmetries are 𝐶𝜂′𝐾0S =−0.19 ±0.08 ±0.03 and 𝑆𝜂′𝐾0S =+0.67 ±0.10 ±0.03, respectively, where the first uncertainties are statistical and the second are systematic. These results are in agreement with current world averages and standard model predictions.
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