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)
Measurement of the mass and width of the Λc(2625)+ charmed baryon and the branching ratios of Λc(2625)+ → Σc0π+ and Λc(2625)+ → Σc++π−
2023 · ARTICLE · en
Using the entire data sample of 980 fb(-1) collected at or near the gamma(4S) resonance with the Belle detector operating at the KEKB asymmetric-energy e(+)e(-) collider, we report the measurement of the mass, width, and the branching ratios of the Lambda(c) (2625)(+) charmed baryon. The mass difference between Lambda(c)(2625)(+) and Lambda(+)(c) is measured to be M(Lambda(c)(2625)(+)) - M(Lambda(+)(c)) = 341.518 +/- 0.006 +/- 0.049 MeV/c(2). The upper limit on the width is measured to be Gamma(Lambda(c)(2625)(+)) Lambda(+)(c)pi(+)pi(-) are measured to be B(Lambda(c) (2625)(+)->Sigma(0)(c)pi(+))/B(Lambda(c) (2625)(+)-> Lambda(+)(c) pi(+)pi(-)) = (5.19 +/- 0.23 +/- 0.40)% and B(Lambda(c) (2625)(+)->Sigma(++)(c)pi(-))/B(Lambda(c) (2625)(+)-> Lambda(+)(c) pi(+)pi(-)) = (5.13 +/- 0.26 +/- 0.32)% where the first and second uncertainties are statistical and systematic, respectively. These measurements can be used to further constrain the parameters of the underlying theoretical models.
Measurement of the B+/B0 production ratio in e+e− collisions at the ϒ(4S) resonance using B → J/ψ(ℓℓ)K decays at Belle
2023 · ARTICLE · en
We measure the ratio of branching fractions for the gamma(4S) decays to B+/B- and B-0(B) over barB(0) using B+ -> J/psi(ll)K+ and B-0 -> J/psi(ll)K-0 samples, where J/psi(ll) stands for J/psi -> l(+)l(-) (l = e or mu), with 711 fb(-1) of data collected at the gamma(4S) resonance with the Belle detector. We find the decay rate ratio of gamma(4S) -> B-0(B) over barB(0) over gamma(4S) -> B-0(B) over barB(0) to be 1.065 +/- 0.012 +/- 0.019 +/- 0.047, which is the most precise measurement to date. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainty is due to the assumption of isospin symmetry in B -> J/psi(ll)K.
Measurement of the branching fraction and search for CP violation in D0 → KS0KS0π+π− decays at Belle
2023 · ARTICLE · en
We measure the branching fraction for the Cabibbo-suppressed decay D0 -> K0SK0S pi+pi- and search for CP violation via a measurement of the CP asymmetry ACP as well as the T-odd triple-product asymmetry aTCP. We use 922 fb-1 of data recorded by the Belle experiment, which ran at the KEKB asymmetric-energy e+e- collider. The branching fraction is measured relative to the Cabibbo-favored normalization channel D0 -> K0S pi+pi-; the result is B(D0 -> K0SK0S pi+pi-)=[4.79 +/- 0.08(stat)+/- 0.10(syst)+/- 0.31(norm)]x10-4, where the first uncertainty is statistical, the second is systematic, and the third is from uncertainty in the normalization channel. We also measure ACP=[-2.51 +/- 1.44(stat)+0.11-0.10(syst)]%, and aTCP=[-1.95 +/- 1.42(stat)+0.14-0.12(syst)]%. These results show no evidence of CP violation.
Search for X(3872)→π+π−π0 at Belle
2023 · ARTICLE · en
We present a search for the decay X(3872)-> pi(+)pi(-) pi(0) in the (772 +/- 11 ) 10(6) gamma (4S) -> B B-bar data sample collected at the Belle detector, where the X(3872) thorn is produced in B +/- -> (KX)-X-+/-(3872) and B-0 -> (KSX)-X-0(3872) decays. We do not observe a signal, and set 90% credible upper limits for two different models of the decay processes: if the decay products are distributed uniformly in phase space, B(X(3872) -> pi(+)pi(-)pi(0) ) (0) pair in the process X(3872) -> D-0 over bar (D) over bar (0) thorn c:c: -> D-0 (D) over bar (0)pi(0) -> pi(+)pi(-) pi(0), B(X(3872) -> pi(+) pi(-) pi(0) )
Two-particle angular correlations in e+e− collisions to hadronic final states in two reference coordinates at Belle
2023 · ARTICLE · en
We present the analysis of two-particle angular correlations using coordinate systems defined with the conventional beam axis and the event thrust axis. We propose the latter as a good representation for the correlation structure interpretation in the e(+)e(-) collision system. The e(+)e(-) collisions to hadronic final states at center-of-mass energies of vs = 10.52 GeV and 10.58 GeV are recorded by the Belle detector at KEKB. In this paper, results on the first dataset are supplementary to the previous Belle publication [1]. At the same time, the latter is the first two-particle correlation measurement at collision energy on the Y(4S) resonance and is sensitive to its decay products. Measurements are reported as a function of the charged-particle multiplicity. Finally, a qualitative understanding of the correlation structure is discussed using a combination of Monte Carlo simulations and experimental data.
Search for the decay Bs → π0π0 at Belle
2023 · ARTICLE · en
We report the results of the first search for the decay B0s→π0π0 using 121.4 fb−1 of data collected at the Υ(5S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We observe no signal and set a 90% confidence level upper limit of 7.7×10−6 on the B0s→π0π0 decay branching fraction.
Search for CP violation and measurement of branching fractions and decay asymmetry parameters for Lambda(+)(c) -> Lambda h(+) and Lambda(+)(c) -> Sigma(0)h(+) (h = K, pi)
2023 · ARTICLE · en
We report a study of Lambda(+)(c)-> Lambda h(+) and Lambda(+)(c)-> Sigma(0)h(+) (h = K, pi) decays based on a data sample of 980 fb(-1) collected with the Belle detector at the KEKB energy-asymmetric e(+)e(-) collider. The first results of direct CP asymmetry in two-body singly Cabibbo-suppressed (SCS) decays of charmed baryons are measured, A(CP)(dir)(Lambda(+)(c)-> Lambda K+) = +0.021 +/- 0.026 +/- 0.001 and A(CP)(dir)(Lambda(+)(c)-> Sigma K-0(+)) = +0.025 +/- 0.054 +/- 0.004. We also make the most precise measurement of the decay asymmetry parameters (alpha) for the four modes of interest and search for CP violation via the alpha-induced CP asymmetry (A(CP)(alpha)). We measure A(CP)(alpha)(Lambda(+)(c)-> Lambda K+) = -0.023 +/- 0.086 +/- 0.071 and A(CP)(alpha)(Lambda(+)(c)-> Sigma K-0(+)) = +0.08 +/- 0.35 +/- 0.14, which are the first A(CP)(alpha) results for SCS decays of charmed baryons. We search for Lambda-hyperon CP violation in Lambda(+)(c)-> Lambda(+)(c)-> (Lambda, Sigma(0))pi(+) and find A(CP)(alpha)(Lambda -> p pi(-)) = +0.013 +/- 0.007 +/- 0.011. This is the first time that hyperon CP violation has been measured via Cabibbo-favored charm decays. No evidence of baryon CP violation is found. We also obtain the most precise branching fractions for two SCS Lambda(c+) decays, B(Lambda(+)(c) -> Lambda K+) = (6.57 +/- 0.17 +/- 0.11 +/- 0.35) x 10(-4) and B(Lambda(+)(c) -> Sigma K-0(+)) = (3.58 +/- 0.19 +/- 0.06 +/- 0.19) x 10(-4). The first uncertainties are statistical and the second systematic, while the third uncertainties come from the uncertainties on the world average branching fractions of Lambda(+)(c)-> (Lambda, Sigma(0))pi(+).
First observation of Λπ+ and Λπ− signals near the K N (I = 1) mass threshold in Λc+ → Λπ+π+π− decay
2023 · ARTICLE · en
Using the data sample of 980 fb-1 collected with the Belle detector operating at the KEKB asymmetric -energy e+e- collider, we present the results of an investigation of the Az+ and Az- invariant mass distributions looking for substructure in the decay A+c -> Az+z+z-. We find a significant signal in each mass distribution. When interpreted as resonances, we find for the Az+ (Az-) combination a mass of 1434.3 +/- 0.6(stat) +/- 0.9(syst) MeV=c2 [1438.5 +/- 0.9(stat) +/- 2.5(syst) MeV=c2], an intrinsic width of 11.5 +/- 2.8(stat) +/- 5.3(syst) MeV=c2 [33.0 +/- 7.5(stat) +/- 23.6(syst) MeV=c2] with a significance of 7.5u (6.2u). As these two signals are very close to the over bar KN threshold, we also investigate the possibility of a over bar KN cusp, and find that we cannot discriminate between these two interpretations due to the limited size of the data sample.
Study of e+e− → Σ0Σ0 and Σ+Σ− by Initial State Radiation Method at Belle
2023 · ARTICLE · en
The processes e+e−→Σ0Σ-bar0 and e+e−→Σ+Σ-bar− are studied using initial-state-radiation events in a sample of 980 fb−1 collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. The cross sections from the mass threshold to 3 GeV/c2 and the effective form factors of Σ0 and Σ+ are measured. In the charmonium region, we observe the decays J/ψ→Σ0Σ-bar0 and J/ψ→Σ+Σ-bar− and determine the respective branching fractions.
First observation of B → D1(→ Dπ+π−)ℓ+νℓ and measurement of the B → D(*)πℓ+νℓ and B → D(*)π+π−ℓ+νℓ branching fractions with hadronic tagging at Belle
2023 · ARTICLE · en
We report measurements of the ratios of branching fractions for B→¯D(*)πℓ+νℓ and B→¯D(*)π+π−ℓ+νℓ relative to B→¯D∗ℓ+νℓ decays with ℓ=e, μ. These results are obtained from a data sample that contains 772×106B¯B pairs collected near the Υ(4S) resonance with the Belle detector at the KEKB asymmetric energy e+e− collider. Fully reconstructing both B mesons in the event, we obtain B(B0→¯D0π−ℓ+νℓ)B(B0→D*−ℓ+νℓ)=(7.23±0.36±0.14)%, B(B+→D−π+ℓ+νℓ)B(B+→¯D*0ℓ+νℓ)=(6.78±0.24±0.18)%, B(B0→¯D*0π−ℓ+νℓ)B(B0→D*−ℓ+νℓ)=(11.10±0.48±0.23)%, B(B+→D*−π+ℓ+νℓ)B(B+→¯D*0ℓ+νℓ)=(9.50±0.33±0.34)%, B(B0→D−π+π−ℓ+νℓ)B(B0→D*−ℓ+νℓ)=(2.91±0.37±0.26)%, B(B+→¯D0π+π−ℓ+νℓ)B(B+→¯D*0ℓ+νℓ)=(3.10±0.26±0.22)%, B(B0→D*−π+π−ℓ+νℓ)B(B0→D*−ℓ+νℓ)=(0.99±0.43±0.20)%, B(B+→¯D*0π+π−ℓ+νℓ)B(B+→¯D*0ℓ+νℓ)=(1.25±0.27±0.15)%, where the uncertainties are statistical and systematic, respectively. These are the most precise measurements of these branching fraction ratios to date. The invariant mass spectra of the Dπ, D∗π, and Dππ systems are studied, and the branching fraction products B(B0→D*−2ℓ+νℓ)×B(D*−2→¯D0π−)=(0.157±0.015±0.005)%, B(B+→¯D*00ℓ+νℓ)×B(¯D*00→D−π+)=(0.054±0.022±0.005)%, B(B+→¯D*02ℓ+νℓ)×B(¯D*02→D−π+)=(0.163±0.011±0.008)%, B(B0→D−1ℓ+νℓ)×B(D−1→¯D*0π−)=(0.306±0.050±0.029)%, B(B0→D'−1ℓ+νℓ)×B(D'−1→¯D*0π−)=(0.206±0.068±0.025)%, B(B0→D*−2ℓ+νℓ)×B(D*−2→¯D*0π−)=(0.051±0.040±0.010)%, B(B+→¯D01ℓ+νℓ)×B(¯D01→D*−π+)=(0.249±0.023±0.015)%, B(B+→¯D'01ℓ+νℓ)×B(¯D'01→D*−π+)=(0.138±0.036±0.009)%, B(B+→¯D*02ℓ+νℓ)×B(¯D*02→D*−π+)=(0.137±0.026±0.009)%, B(B0→D−1ℓ+νℓ)×B(D−1→D−π+π−)=(0.102±0.013±0.009)%, B(B+→¯D01ℓ+νℓ)×B(¯D01→¯D0π+π−)=(0.105±0.011±0.009)%, are extracted. This is the first observation of the decays B→¯D1ℓ+νℓ with D1→Dπ+π−.
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