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)
Search for the decay B0s→η′η
2021 · ARTICLE · en
We report the results of the first search for the decay B0s → η0η using 121.4 fb−1 of data collected at the Υð5SÞ resonance with the Belle detector at the KEKB asymmetric-energy eþe− collider. We observe no significant signal and set a 90% confidence-level upper limit of 6.5 × 10−5 on the branching fraction of this decay.
Measurement of the masses and widths of the Σc(2455)+ and Σc(2520)+ baryons
2021 · ARTICLE · en
Using 980 fb-1 of data collected with the Belle detector operating at the KEKB asymmetric-energy e+e- collider, we report the measurements of the masses, and the first measurements of the instrinsic widths, of the ςc(2455)+ and ςc(2520)+ charmed baryons. We find M(ςc(2455)+)-M(Λc+)=166.17±0.05-0.07+0.16 MeV/c2, Γ(ςc(2455)+)=2.3±0.3±0.3 MeV/c2, M(ςc(2520)+)-M(Λc+)=230.9±0.5-0.1+0.5 MeV/c2, and Γ(ςc(2520)+)=17.2-2.1-0.7+2.3+3.1 MeV/c2, where the uncertainties are statistical and systematic, respectively. These measurements can be used to test models of the underlying quark structure of the ςc states.
Measurement of branching fractions and search for CP violation in D0→π+π−η, D0→K+K−η, and D0→ϕη at Belle
2021 · ARTICLE · en
We measure the branching fractions and CP asymmetries for the singly Cabibbo-suppressed decays D0 → π+π−η, D0 → K+K−η, and D0 → ϕη, using 980 fb−1 of data from the Belle experiment at the KEKB e+e− collider. We obtain (𝐷0→𝜋+𝜋−𝜂)=[1.22±0.02(stat)±0.02(syst)±0.03(ref)]×10−3,(𝐷0→𝐾+𝐾−𝜂)=[1.80+0.07−0.06(stat)±0.04(syst)±0.05(ref)]×10−4,(𝐷0→𝜙𝜂)=[1.84±0.09(stat)±0.06(syst)±0.05(ref)]×10−4,B(D0→π+π−η)=[1.22±0.02(stat)±0.02(syst)±0.03(Bref)]×10−3,B(D0→K+K−η)=[1.80−0.06+0.07(stat)±0.04(syst)±0.05(Bref)]×10−4,B(D0→ϕη)=[1.84±0.09(stat)±0.06(syst)±0.05(Bref)]×10−4, where the third uncertainty (Bref) is from the uncertainty in the branching fraction of the reference mode D0 → K−π+η. The color-suppressed decay D0 → ϕη is observed for the first time, with very high significance. The results for the CP asymmetries are 𝐴𝐶𝑃(𝐷0 𝜋+𝜋−𝜂)=[0.9±1.2(stat)±0.5(syst)]%,𝐴𝐶𝑃(𝐷0→𝐾+𝐾−𝜂)=[−1.4±3.3(stat)±1.1(syst)]%,𝐴𝐶𝑃 (𝐷0→𝜙𝜂)=[−1.9±4.4(stat)±0.6(syst)]%.ACP(D0 π+π−η)=[0.9±1.2(stat)±0.5(syst)]%,ACP(D0→K+K−η)=[−1.4±3.3(stat)±1.1(syst)]%,ACP (D0→ϕη)=[−1.9±4.4(stat)±0.6(syst)]%. The results for D0 → π+π−η are a significant improvement over previous results. The branching fraction and ACP results for D0 → K+K−η, and the ACP result for D0 → ϕη, are the first such measurements. No evidence for CP violation is found in any of these decays.
Search for lepton-flavor-violating tau-lepton decays to lγ at Belle
2021 · ARTICLE · en
Charged lepton flavor violation is forbidden in the Standard Model but possible in several new physics scenarios. In many of these models, the radiative decays τ± → ℓ±γ (ℓ = e, μ) are predicted to have a sizeable probability, making them particularly interesting channels to search at various experiments. An updated search via τ± → ℓ±γ using full data of the Belle experiment, corresponding to an integrated luminosity of 988 fb−1, is reported for charged lepton flavor violation. No significant excess over background predictions from the Standard Model is observed, and the upper limits on the branching fractions, B(τ± → μ±γ) ≤ 4.2 × 10−8and B(τ± → e±γ) ≤ 5.6 × 10−8, are set at 90% confidence level.
Search for B+→K+ν¯¯¯ν Decays Using an Inclusive Tagging Method at Belle II
2021 · ARTICLE · en
A search for the flavor-changing neutral-current decay B+→K+νν¯ is performed at the Belle II experiment at the SuperKEKB asymmetric energy electron-positron collider. The results are based on a data sample corresponding to an integrated luminosity of 63fb−1 collected at the Υ(4S)resonance and a sample of 9fb−1 collected at an energy 60MeV below the resonance. A novel measurement method is employed, which exploits topological properties of the B+→K+νν¯ decay that differ from both generic bottom-meson decays and light-quark pair production. This inclusive tagging approach offers a higher signal efficiency compared to previous searches. No significant signal is observed. An upper limit on the branching fraction of B+→K+νν¯ of 4.1×10−5 is set at the 90% confidence level.
Search for B0→τ±l∓ (l=e, μ) with a hadronic tagging method at Belle
2021 · ARTICLE · en
We present a search for the lepton-flavor-violating decays B0→τ±ℓ∓, where ℓ=(e,μ), using the full data sample of 772×106 BB¯ pairs recorded by the Belle detector at the KEKB asymmetric-energy e+e− collider. We use events in which one B meson is fully reconstructed in a hadronic decay mode. The τ± lepton is reconstructed indirectly using the momentum of the reconstructed B and that of the ℓ∓ from the signal decay. We find no evidence for B0→τ±ℓ∓ decays and set upper limits on their branching fractions at 90% confidence level of B(B0→τ±μ∓)
Measurements of q(2) moments of inclusive B -> X(c)l(+)upsilon(l) decays with hadronic tagging
2021 · ARTICLE · en
We present the measurement of the first to fourth order moments of the four-momentum transfer squared, q(2), of inclusive B -> X(c)l(+)upsilon(l) decays using the full Belle dataset of 711 fb(-1) of integrated luminosity at the gamma(4S) resonance where l = e, mu. The determination of these moments and their systematic uncertainties open new pathways to determine the absolute value of the Cabibbo-Kobayashi-Maskawa matrix element V (cb) using a reduced set of matrix elements of the heavy quark expansion. In order to identify and reconstruct the X-c system, we reconstruct one of the two B-mesons using machine learning techniques in fully hadronic decay modes. The moments are measured with progressively increasing threshold selections on q(2) starting with a lower value of 3.0 GeV2 in steps of 0.5 GeV2 up to a value of 10.0 GeV2. The measured moments are further unfolded, correcting for reconstruction and selection effects as well as QED final state radiation. We report the moments separately for electron and muon final states and observe no lepton flavor universality violating effects.
Search for B0 decays to invisible final states (+γ) at Belle
2020 · ARTICLE · en
We report searches for B0→invisible and B0→invisible+γ decays, where the energy of the photon is required to be larger than 0.5 GeV. These results are obtained from a 711 fb-1 data sample that contains 772×106BB¯ pairs and was collected near the ϒ(4S) resonance with the Belle detector at the KEKB e+e- collider. We observe no significant signal for either decay and set upper limits on their branching fractions at 90% confidence level of B(B0→invisible)
Dalitz analysis of D0 →k-π+η decays at Belle
2020 · ARTICLE · en
We present the results of the first Dalitz plot analysis of the decay D0→K-π+η. The analysis is performed on a data set corresponding to an integrated luminosity of 953 fb-1 collected by the Belle detector at the asymmetric-energy e+e- KEKB collider. The Dalitz plot is well described by a combination of the six resonant decay channels K̄∗(892)0η, K-a0(980)+, K-a2(1320)+, K̄∗(1410)0η, K∗(1680)-π+ and K2∗(1980)-π+, together with Kπ and Kη S-wave components. The decays K∗(1680)-→K-η and K2∗(1980)-→K-η are observed for the first time. We measure ratio of the branching fractions, B(D0→K-π+η)B(D0→K-π+)=0.500±0.002(stat)±0.020(syst)±0.003(BPDG). Using the Dalitz fit result, the ratio B(K∗(1680)→Kη)B(K∗(1680)→Kπ) is measured to be 0.11±0.02(stat)-0.04+0.06(syst)±0.04(BPDG); this is much lower than the theoretical expectations (≈1) made under the assumption that K∗(1680) is a pure 13D1 state. The product branching fraction B(D0→[K2∗(1980)-→K-η]π+)=(2.2-1.9+1.7)×10-4 is determined. In addition, the πη′ contribution to the a0(980)± resonance shape is confirmed with 10.1σ statistical significance using the three-channel Flatté model. We also measure B(D0→K̄∗(892)0η)=(1.41-0.12+0.13)%. This is consistent with, and more precise than, the current world average (1.02±0.30)%, deviates with a significance of more than 3σ from the theoretical predictions of (0.51-0.92)%. © 2020 authors.
Update of inclusive cross sections of single and pairs of identified light charged hadrons
2020 · ARTICLE · en
We report new measurements of the production cross sections of pairs of charged pions and kaons as a function of their fractional energies using various fractional-energy definitions. Two different fractional-energy definitions were used and compared to the conventional fractional-energy definition reported previously. The new variables aim at either identifying dihadron cross sections in terms of single-hadron fragmentation functions, or to provide a means of characterizing the transverse momentum created in the fragmentation process. The results were obtained applying the updated initial-state radiation correction used in other recent Belle publications on light-hadron production cross sections. In addition, production cross sections of single charged pions, kaons, and protons were also updated using this initial-state radiation correction. The cross sections are obtained from a 558 fb-1 data sample collected at the γ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. © 2020 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/" Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3
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