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Пахлов Павел Николаевич

Московский институт электроники и математики им. А.Н. Тихонова

Профиль на hse.ru ↗ тел.: 00000
Публикаций
126
Языков
2
Наград
3
Конференций
2
Профиль Публикации (126) Курсы (2)

Профессиональные интересы

физика элементарных частиц

Должности

  • Ведущий научный сотрудник — Московский институт электроники и математики им. А.Н. Тихонова, Международная лаборатория физики элементарных частиц
  • Профессор — Московский институт электроники и математики им. А.Н. Тихонова, Департамент электронной инженерии

Био

  • · Начал работать в НИУ ВШЭ в 2020 году.
  • · Научно-педагогический стаж: 8 лет.

Образование

  • 2008 · Доктор физико-математических наук: Высшая аттестационная комиссия Республика Болгария
  • 1990 · Специалитет: Московский физико-технический институт, специальность «Прикладная математика и физика», квалификация «Инженер-физик»

Опыт работы

  • · 2000 - н.в.: профессор кафедры физики элемнтарных частиц МФТИ
  • · 2009 - н.в.: профессор кафедры экспериментальной ядерной физики и космофизики МИФИ
  • · 2020 - н.в.: профессор кафедры дискретной математики МИЭМ ВШЭ

Награды и поощрения

  • · Надбавка за публикацию в журнале из Списка А (и приравненном к нему научном издании) (2025–2026, 2024–2025, 2023–2024)
  • · Надбавка за публикацию в международном рецензируемом научном издании (2021–2022)
  • · Лучший преподаватель — 2021–2022

Гранты и проекты

  • — · на соискание учёной степени кандидата наук

Конференции (2)

Показать все
  • · 2024: The 2024 International Workshop on Future Tau Charm Facilities (Хефей). Доклад: On possibility to measure all Michel parameters at SCTF
  • · 2020: 5th International Conference on Particle Physics and Astrophysics (Москва). Доклад: Recent experimental results in B physics

Идентификаторы исследователя

Публикации (126)

Determination of the CKM angle ϕ3 from a combination of Belle and Belle II results

2024 в печати · ARTICLE · en

We report a determination of the CKM angle ϕ3, also known as γ, from a combination of measurements using samples of up to 711 fb−1 from the Belle experiment and up to 362 fb−1 from the Belle II experiment. We combine results from analyses of B+ → DK+, B+ → Dπ+, and B+ → D*K+ decays, where D is an admixture of D0 and mesons, in a likelihood fit to obtain ϕ3 = (75.2 ± 7.6)°. We also briefly discuss the interpretation of this result.

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Study of Υ(10753) decays to π+π−Υ(nS) final states at Belle II

2024 в печати · ARTICLE · en

We present an analysis of the process e+e− → π+π−Υ(nS) (where n = 1, 2, or 3) reconstructed in 19.6 fb−1 of Belle II data during a special run of the SuperKEKB collider at four energy points near the peak of the Υ(10753) resonance. By analyzing the mass distribution of the π+π−Υ(nS) system and the Born cross sections of the e+e− → π+π−Υ(nS) process, we report the first observation of Υ(10753) decays to the π+π−Υ(1S) and π+π−Υ(2S) final states, and find no evidence for decays to π+π−Υ(3S). Possible intermediate states in the π+π−Υ(1S, 2S) transitions are also investigated, and no evidence for decays proceeding via the or f0(980)Υ(nS) intermediate states is found. We measure Born cross sections for the e+e− → π+π−Υ(nS) process that, combined with results from Belle, obtain the mass and width of Υ(10753) to be (10756.6 ± 2.7 ± 0.9) MeV/c2 and (29.0 ± 8.8 ± 1.2) MeV, respectively. The relative ratios of the Born cross sections at the Υ(10753) resonance peak are also reported for the first time.

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Measurement of the energy dependence of the e+e− →BB ,BB*, and B*B* cross sections at Belle II

2024 в печати · ARTICLE · en

We report measurements of the e+e− → , , and cross sections at four energies, 10653, 10701, 10746 and 10805 MeV, using data collected by the Belle II experiment. We reconstruct one B meson in a large number of hadronic final states and use its momentum to identify the production process. In the first 2 – 5 MeV above threshold, the e+e− → cross section increases rapidly. This may indicate the presence of a pole close to the threshold.

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Measurements of the branching fractions B(B0-bar → D*+ π−) and B(B0-bar → D*+ K−) and tests of QCD factorization

2023 · ARTICLE · en

Using (771.6±10.6)×106 B¯B meson pairs recorded by the Belle experiment at the KEKB e+e−collider, we report the branching fractions B(¯B0→D*+π−)=(2.62±0.02±0.09)×10−3 and B(¯B0→D*+K−)=(2.22±0.06±0.08)×10−4; the quoted uncertainties are statistical and systematic, respectively. A measurement of the ratio of these branching fractions is also presented, RK/π=B(¯B→D*+K−)/B(¯B→D*+π−)=(8.41±0.24±0.13)×10−2, where systematic uncertainties due to the D*+ meson reconstruction cancel out. Furthermore, we report a new QCD factorization test based on the measured ratios for ¯B→D*+h− and ¯B→D*+ℓ−ν decays at squared momentum transfer values equivalent to the mass of the h=π or K hadron. The parameters |a1(h)|are measured to be |a1(π)|=0.884±0.004±0.003±0.016 and |a1(K)|=0.913±0.019±0.008±0.013, where the last uncertainties account for all external inputs. These values are approximately 15% lower than those expected from theoretical predictions. Subsequently, flavor SU(3) symmetry is tested by measuring the ratios for pions and kaons, |a1(K)|2/|a1(π)|2=1.066±0.042±0.018±0.023, as well as for different particle species. The ratio is consistent with unity and therefore no evidence for SU(3) symmetry breaking effects is found at the 5% precision level.

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Evidence of a new excited charmed baryon decaying to Σc(2455)0,++π±

2023 · ARTICLE · en

We present the study of (B) over bar (0) -> Sigma(c)(2455)(0, + +) pi(+/-)(p) over bar decays based on 772 x 10(6) B (B) over bar events collected with the Belle detector at the KEKB asymmetric-energy e(+) e(-) collider. The Sigma(c)(2455)(0, + +) candidates are reconstructed via their decay to Lambda(+)(c)x(-/+) and Lambda(+)(c) decays to pK(-)pi(+), pK(S)(0), and Lambda pi(+) final states. The corresponding branching fractions are measured to be B((B) over bar (0) -> Sigma(c)(2455)(0)pi(+)(p) over bar) = (1.09 +/- 0.06 +/- 0.07) x 10(-4) and B((B) over bar (0) -> Sigma(c)(2455)(+ +)pi(-)(p) over bar) = (1.84 +/- 0.11 +/- 0.12) x 10(-4), which are consistent with the world average values with improved precision. A new structure is found in the M-Sigma c(2455)0,M- + + pi +/- spectrum with a significance of 4.2 sigma including systematic uncertainty. The structure is possibly an excited Lambda(+)(c) and is tentatively named Lambda(c)(2910)(+). Its mass and width are measured to be (2913.8 +/- 5.6 +/- 3.8) MeV/c(2) and (51.8 +/- 20.0 +/- 18.8) MeV, respectively. The products of branching fractions for the Lambda(c)(2910)(+) are measured to be B((B) over bar (0) -> Lambda(c)(2910)(+)(p) over bar) x B(Lambda(c)(2910)(+) -> Sigma(c)(2455)(0)pi(+)) = (9.5 +/- 3.6 +/- 1.6) x 10(-6) and B((B) over bar (0) -> Lambda(c)(2910)(+)(p) over bar) x B(Lambda(c)(2910)(+) -> Sigma(c)(2455)(+ +)pi(-)) = (1.24 +/- 0.35 +/- 0.10) x 10(-5). Here, the first and second uncertainties are statistical and systematic, respectively.

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Measurement of two-photon decay width of χc2(1P) in γγ → χc2(1P) → J/ψγ at Belle

2023 · ARTICLE · en

We report the measurement of the two-photon decay width of chi c2(1P) in two-photon processes at the Belle experiment. We analyze the process gamma gamma ->chi c2(1P)-> J/psi gamma, J/psi -> l(+)l(-) (l=e or mu) using a data sample of 971 fb(-1) collected with the Belle detector at the KEKB e(+)e(-) collider. In this analysis, the product of the two-photon decay width of chi c2(1P) and the branching fraction is determined to be gamma gamma gamma(chi c2(1P))B(chi c2(1P)-> J/psi gamma)B(J/psi -> l(+)l(-))=14.8 +/- 0.3(stat.) +/- 0.7(syst.) eV, which corresponds to gamma gamma gamma(chi c2(1P)) = 653 +/- 13(stat.) +/- 31(syst.) +/- 17(B.R.) eV, where the third uncertainty is from B(chi c2(1P)-> J/psi gamma) and B(J/psi -> l(+)l(-)).

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First search for the weak radiative decays Λc+ → Σ+γ and Ξc0 → Ξ0 γ

2023 · ARTICLE · en

We present the first search for the weak radiative decays A+c -> E+gamma and E0 c -> 80 gamma using a data sample of 980 fb-1 collected by the Belle detector operating at the KEKB asymmetric-energy e+e- collider. There are no evident A+c -> E+gamma or 80c -> E0 gamma signals. Taking the decays A+c -> pK-x-+ and E0c -> Z-1-x-+ as normalization channels, the upper limits at 90% credibility level on the ratios of branching fractions B(A+c -> E+gamma)=B(A+c -> pK-x-+) 80 gamma)=B(80c -> Z-1-x-+) E+gamma) E0 gamma)

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Measurement of the branching fractions for Cabibbo-suppressed decays D+ → K+K−π+π0 and D(s)+ → K+π−π+π0 at Belle

2023 · ARTICLE · en

We present measurements of the branching fractions for the singly Cabibbo-suppressed decays D+ -K+K-x-+x-0 and D+s -K+x--x-+x-0, and the doubly Cabibbo-suppressed decay D+ -K+x--x-+x-0, based on 980 fb-1 of data recorded by the Belle experiment at the KEKB e+e- collider. We measure these modes relative to the Cabibbo-favored modes D+ -K-x-+x-+x-0 and D+s -K+K-x-+x-0. Our results for the ratios of branching fractions are B(D+ -K+K-x-+x-0)/B(D+ -K-x-+x-+x-0) = (11.32 +/- 0.13 +/- 0.26)%, B(D+ -K+x--x-+x-0)/B(D+ -K-x-+x-+x-0) = (1.68 +/- 0.11 +/- 0.03)%, and B(D+s -K+x--x-+x-0)/ B(D+s -K+K-x-+x-0) = (17.13 +/- 0.62 +/- 0.51)%, where the uncertainties are statistical and systematic, respectively. The second value corresponds to (5.83 +/- 0.42) x tan4 BC, where BC is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for B(D+ -K-x-+x-+x-0) and B(D+s -K+K-x-+x-0) yields B(D+ -K+K-x-+x-0) = (7.08 +/- 0.08 +/- 0.16 +/- 0.20) x 10-3, B(D+ -K+x--x-+x-0) = (1.05 +/- 0.07 +/- 0.02 +/- 0.03) x 10-3, and B(D+s -K+x--x-+x-0) = (9.44 +/- 0.34 +/- 0.28 +/- 0.32) x 10-3, where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction.

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Measurement of branching fractions of Λc+ → p K0S K0S and Λc+ → p K0S η at Belle

2023 · ARTICLE · en

We present a study of a singly Cabibbo-suppressed decay A+c -pK0SK0S and a Cabibbo-favored decay A+c -pK0St7 based on 980 fb-1 of data collected by the Belle detector, operating at the KEKB energy-asymmetric e+e- collider. We measure their branching fractions relative to A+c -pK0S: B(A+c -pK0SK0S)=B(A+c -pK0S) = (1.48 +/- 0.08 +/- 0.04) x 10-2 and B(A+c -pK0St7)=B(A+c -pK0S) = (2.73 +/- 0.06 +/- 0.13) x 10-1. Combining with the world average B(A+c -pK0S), we have the absolute branching fractions, B(A+c -pK0SK0S) = (2.35 +/- 0.12 +/- 0.07 +/- 0.12) x 10-4 and B(A+c -pK0St7) = (4.35 +/- 0.10 +/- 0.20 +/- 0.22) x 10-3. The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the uncertainty on B(A+c -pK0S). The mode A+c -pK0 SK0S is observed for the first time and has a statistical significance of > 10 sigma. The branching fraction of A+c -pK0St7 has been measured with a threefold improvement in precision over previous results and is found to be consistent with the world average.

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Search for rare decays B+ → Ds*+η, Ds*+K0, D+η, and D+K0

2023 · ARTICLE · en

We present a study of rare decay modes B+->. D(s)(+)h(0), B+-> D-s(*)+h(0) and B+ -> D(+)h(0), where h(0) denotes the neutral meson eta or K-0, using a data sample of (772 +/- 10) x 10(6) B (B) over bar events produced at the.(sic) (4S) resonance. The data were collected by the Belle detector operating at the asymmetric-energy KEKB collider. We find no evidence for these decays, so we set upper limits at the 90% confidence level on the branching fractions of B+ -> D(s)(+)h(0), D(s)(*)(+)h(0), and D(+)h(0) decay modes. Along with these rare decay modes, we report improved measurements of the color-suppressed decay branching fractions B((B) over bar (0)->. D-0 eta) = (26.6 +/- 1.2 +/- 2.1) x 10(-5) and B((B) over bar (0) -> D-0(K) over bar (0)) = (5.6 +/- 0.5 +/- 0.2) x 10(-5). The first and second quoted uncertainties are statistical and systematic, respectively.

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Курсы (2)