DSA Faculty
API
← к списку преподавателей

Болдырев Алексей Сергеевич

Факультет компьютерных наук

Профиль на hse.ru ↗ тел.: 27266
Публикаций
26
Языков
3
Наград
5
Конференций
3
Профиль Публикации (274) Курсы (12)

Профессиональные интересы

Физика высоких энергийМашинное обучение и анализ данных

Должности

  • Научный сотрудник — Факультет компьютерных наук, Институт искусственного интеллекта и цифровых наук, Научно-учебная лаборатория методов анализа больших данных
  • Доцент — Факультет компьютерных наук, Департамент больших данных и информационного поиска
  • Приглашенный преподаватель — НИУ ВШЭ в Нижнем Новгороде, Факультет менеджмента, Департамент маркетинга и предпринимательства

Био

  • · Начал работать в НИУ ВШЭ в 2018 году.
  • · Научно-педагогический стаж: 13 лет.

Образование

  • 2013 · Кандидат физико-математических наук
  • 2010 · Специалитет: Московский государственный университет им. М.В. Ломоносова, специальность «Физика атомного ядра и частиц», квалификация «Физик»

Опыт работы

  • · 2020: Научный сотрудник Научно-учебной лаборатории методов анализа больших данных НИУ ВШЭ ( настоящее время)
  • · 2020: Доцент Департамента больших данных и информационного поиска ( настоящее время) Постдок НИУ ВШЭ (2018–2020) Старший научный сотрудник Института ядерной физики им. Д.В. Скобельцына, МГУ им. М.В. Ломоносова (2017–2018)
  • · Младший научный сотрудник Физического института им. П.Н. Лебедева РАН (2006-2017) Научный сотрудник Института ядерной физики им. Д.В. Скобельцына МГУ им. М.В. Ломоносова (2016) Стипендия TRIL, Международный центр теоретической физики Абдуса Салама (ICTP) (2015–2016) Научный сотрудник Института ядерной физики им. Д.В. Скобельцына МГУ им. М.В. Ломоносова (2014–2015)

Награды и поощрения

  • · Благодарность НИУ ВШЭ (май 2024)
  • · Благодарственное письмо проректора НИУ ВШЭ (сентябрь 2022)
  • · Надбавка за публикацию в журнале из Списка А (и приравненном к нему научном издании) (2023–2024)
  • · Надбавка за публикацию в международном рецензируемом научном издании (2022–2023, 2021–2022, 2020–2022)
  • · Надбавка за регулярные публикации в международных рецензируемых научных изданиях (2024–2029)

Гранты и проекты

  • — · Факультет компьютерных наук НИУ ВШЭ, Сколтех и Физический институт им. П. Н. Лебедева РАН провели Московскую международную школу физики 2024

Конференции (3)

Показать все
  • · 2022: Second MODE Workshop on Differentiable Programming for Experiment Design (Колумбари, Крит). Доклад: LHCb ECAL optimization
  • · 2021: First MODE Workshop on Differentiable Programming (Лувэн-ла-Нёв). Доклад: Optimization of LHCb calorimeter
  • · 2020: Instrumentation for Colliding Beam Physics (Новосибирск). Доклад: ML-assisted versatile approach to Calorimeter R&D

Идентификаторы исследователя

Публикации (274)

Measurement of the Branching Fraction Ratios 𝑅(𝐷+) and 𝑅(𝐷*+) Using Muonic 𝜏 Decays

2025 · ARTICLE · en

The branching fraction ratios of ¯𝐵0→𝐷+⁢𝜏−⁢¯𝜈𝜏 and ¯𝐵0→𝐷*+⁢𝜏−⁢¯𝜈𝜏 decays are measured with respect to their muonic counterparts, using a data sample corresponding to an integrated luminosity of 2.0 fb−1 collected by the LHCb experiment in proton-proton collisions at √𝑠 =13 TeV. The reconstructed final states are formed by combining 𝐷+ mesons with 𝜏−→𝜇−⁢¯𝜈𝜇⁢𝜈𝜏 candidates, where the 𝐷+ is reconstructed via the 𝐷+ →𝐾−⁢𝜋+⁢𝜋+ decay. The results are 𝑅⁡(𝐷+)=0.249±0.043±0.047, 𝑅⁡(𝐷*+)=0.402±0.081±0.085, where the first uncertainties are statistical and the second systematic. The two measurements have a correlation coefficient of −0.39 and are compatible with the standard model.

DOI ↗ PDF ↗

Long-lived particle reconstruction downstream of the LHCb magnet

2025 · ARTICLE · en

Charged-particle trajectories are usually reconstructed with the LHCb detector using combined information from the tracking devices placed upstream and downstream of the 4 T m dipole magnet. Trajectories reconstructed using only information from the tracker downstream of the dipole magnet, which are referred to as T tracks, have not been used for physics analysis to date. The challenges of the reconstruction of long-lived particles with T tracks for physics use are discussed and solutions are proposed. The feasibility and the tracking performance are studied using samples of long-lived and hadrons decaying between 6.0 and 7.6 m downstream of the proton–proton collision point, thereby traversing most of the magnetic field region and providing maximal sensitivity to magnetic and electric dipole moments. The reconstruction can be expanded upstream to about 2.5 m for use in direct searches of exotic long-lived particles. The data used in this analysis have been recorded between 2015 and 2018 and correspond to an integrated luminosity of 6 . The results obtained demonstrate the possibility to further extend the decay volume and the physics reach of the LHCb experiment.

DOI ↗ PDF ↗

First Determination of the Spin-Parity of Ξ𝑐⁢(3055)+,0 Baryons

2025 · ARTICLE · en

The Ξ0⁢(−)𝑏→Ξ𝑐⁢(3055)+(0)⁢(→𝐷+(0)⁢Λ)⁢𝜋− decay chains are observed, and the spin-parity of Ξ𝑐⁢(3055)+(0) baryons is determined for the first time. The measurement is performed using proton-proton collision data at a center-of-mass energy of √𝑠 =13 TeV, corresponding to an integrated luminosity of 5.4 fb−1, recorded by the LHCb experiment between 2016 and 2018. The spin-parity of the Ξ𝑐⁢(3055)+(0) baryons is determined to be 3/2+ with a significance of more than 6.5⁢𝜎 (3.5⁢𝜎) compared to all other tested hypotheses. The up-down asymmetries of the Ξ0⁢(−)𝑏→Ξ𝑐⁢(3055)+(0)⁢𝜋− transitions are measured to be −0.92±0.10±0.05 (−0.92±0.16±0.22), consistent with maximal parity violation, where the first uncertainty is statistical and the second is systematic. These results support the hypothesis that the Ξ𝑐⁢(3055)+(0) baryons correspond to the first 𝐷-wave 𝜆-mode excitation of the Ξ𝑐 flavor triplet.

DOI ↗ PDF ↗

Deep Learning Approaches for LHCb ECAL Reconstruction

2024 · ARTICLE · en

Calorimeters are a crucial component for most detectors mounted on modern colliders. Their tasks include identifying and measuring the energy of photons and neutral hadrons, recording energetic hadronic jets, and contributing to the identification of electrons, muons, and charged hadrons. To fulfill these many tasks while keeping costs reasonable, the calorimeter construction requires good and thoughtful balancing with other components of the detector. Much harder operation conditions during LHC’s high luminosity Run 5 and beyond bring new technological and computational challenges. This requires optimization of technologies, layouts, readouts, reconstruction algorithms to achieve the best overall physics performance for the limited cost. In the traditional approach, the reconstruction of the physical objects in the calorimeter must be matched to the calorimetric showers simulation used. We present a deep learning-based approach to help utilize raw simulated calorimetric data of varying degrees of detail.

DOI ↗ PDF ↗

Comprehensive analysis of local and nonlocal amplitudes in the B0 → K*0μ+μ− decay

2024 · ARTICLE · en

A comprehensive study of the local and nonlocal amplitudes contributing to the decay B0 → K*0(→ K+π−)μ+μ− is performed by analysing the phase-space distribution of the decay products. The analysis is based on pp collision data corresponding to an integrated luminosity of 8.4 fb−1 collected by the LHCb experiment. This measurement employs for the first time a model of both one-particle and two-particle nonlocal amplitudes, and utilises the complete dimuon mass spectrum without any veto regions around the narrow charmonium resonances. In this way it is possible to explicitly isolate the local and nonlocal contributions and capture the interference between them. The results show that interference with nonlocal contributions, although larger than predicted, only has a minor impact on the Wilson Coefficients determined from the fit to the data. For the local contributions, the Wilson Coefficient C9, responsible for vector dimuon currents, exhibits a 2.1σ deviation from the Standard Model expectation. The Wilson Coefficients C10, C9′ and C10′ are all in better agreement than C9 with the Standard Model and the global significance is at the level of 1.5σ. The model used also accounts for nonlocal contributions from B0 → K*0[τ+τ − → μ+μ−] rescattering, resulting in the first direct measurement of the bsττ vector effective-coupling C9τ.

DOI ↗

Study of $b-$hadron decays to $\Lambda_c^+h^-h^{\prime -}$ final states

2024 · ARTICLE · en

Decays of Ξb− and Ωb− baryons to Λc+h−h′− final states, with h−h′− being π−π−, K−π− and K−K− meson pairs, are searched for using data collected with the LHCb detector. The data sample studied corresponds to an integrated luminosity of 8.7 fb−1 of pp collisions collected at centre-of-mass energies s = 7, 8 and 13 TeV. The products of the relative branching fractions and fragmentation fractions for each signal mode, relative to the B−→Λc+p¯π− mode, are measured, with Ξb−→Λc+K−π−, Ξb−→Λc+K−K− and Ωb−→Λc+K−K− decays being observed at over 5 σ significance. The Ξb−→Λc+K−π− mode is also used to measure the Ξb− production asymmetry, which is found to be consistent with zero. In addition, the B−→Λc+p¯K− decay is observed for the first time, and its branching fraction is measured relative to that of the B−→Λc+p¯π− mode.

DOI ↗

Search for Time-Dependent 𝐶⁢𝑃 Violation in 𝐷0→𝜋+⁢𝜋−⁢𝜋0 Decays

2024 · ARTICLE · en

A measurement of time-dependent 𝐶⁢𝑃 violation in 𝐷0→𝜋+⁢𝜋−⁢𝜋0 decays using a 𝑝⁢𝑝 collision data sample collected by the LHCb experiment in 2012 and from 2015 to 2018, corresponding to an integrated luminosity of 7.7 fb−1, is presented. The initial flavor of each 𝐷0 candidate is determined from the charge of the pion produced in the 𝐷*⁢(2010)+→𝐷0⁢𝜋+ decay. The decay 𝐷0→𝐾−⁢𝜋+⁢𝜋0 is used as a control channel to validate the measurement procedure. The gradient of the time-dependent 𝐶⁢𝑃 asymmetry Δ⁢𝑌 in 𝐷0→𝜋+⁢𝜋−⁢𝜋0 decays is measured to be Δ⁢𝑌=(−1.3±6.3±2.4)×10−4, where the first uncertainty is statistical and the second is systematic, which is compatible with 𝐶⁢𝑃 conservation.

DOI ↗

Amplitude analysis and branching fraction measurement of B+→D∗−D+sπ+ decays

2024 · ARTICLE · en

The decays of the B+ meson to the final state D∗−Ds+π+ are studied in proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9 fb−1. The ratio of branching fractions of the B+→D∗−Ds+π+ and B0→D∗−Ds+ decays is measured to be 0.173 ± 0.006 ± 0.010, where the first uncertainty is statistical and the second is systematic. Using partially reconstructed Ds∗+→Ds+γ and Ds+π0 decays, the ratio of branching fractions between the B+→D∗−Ds∗+π+ and B+→D∗−Ds+π+ decays is determined as 1.31 ± 0.07 ± 0.14. An amplitude analysis of the B+→D∗−Ds+π+ decay is performed for the first time, revealing dominant contributions from known excited charm resonances decaying to the D*−π+ final state. No significant evidence of exotic contributions in the Ds+π+ or D∗−Ds+ channels is found. The fit fraction of the scalar state Tcs¯0∗(2900)++ observed in the B+→D−Ds+π+ decay is determined to be less than 2.3% at a 90% confidence level.

DOI ↗

First observation of $\Lambda_b^{0} \to \Sigma_c^{(*)++} D^{(*)-} K^{-}$ decays

2024 · ARTICLE · en

The four decays, Λ0𝑏→Σ(*)++𝑐⁢𝐷(*)−⁢𝐾−, are observed for the first time using proton-proton collision data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb−1. By considering the Λ0𝑏→Λ+𝑐⁢¯𝐷0⁢𝐾− decay as reference channel, the following branching fraction ratios are measured to be ℬ⁡(Λ0𝑏→Σ++𝑐⁢𝐷−⁢𝐾−)ℬ⁡(Λ0𝑏→Λ+𝑐⁢¯𝐷0⁢𝐾−)=0.282±0.016±0.016±0.005, ℬ⁡(Λ0𝑏→Σ*++𝑐⁢𝐷−⁢𝐾−)ℬ⁡(Λ0𝑏→Σ++𝑐⁢𝐷−⁢𝐾−)=0.460±0.052±0.028, ℬ⁡(Λ0𝑏→Σ++𝑐⁢𝐷*−⁢𝐾−)ℬ⁡(Λ0𝑏→Σ++𝑐⁢𝐷−⁢𝐾−)=2.261±0.202±0.129±0.046, ℬ⁡(Λ0𝑏→Σ*++𝑐⁢𝐷*−⁢𝐾−)ℬ⁡(Λ0𝑏→Σ++𝑐⁢𝐷−⁢𝐾−)=0.896±0.137±0.066±0.018, where the first uncertainties are statistical, the second are systematic, and the third are due to uncertainties in the branching fractions of intermediate particle decays. These initial observations mark the beginning of pentaquark searches in these modes, with more datasets to become available following the LHCb upgrade.

DOI ↗

Search for prompt production of pentaquarks in charm hadron final states

2024 · ARTICLE · en

A search for hidden-charm pentaquark states decaying to a range of Σ𝑐⁢¯𝐷 and Λ+𝑐⁢¯𝐷 final states, as well as doubly charmed pentaquark states to Σ𝑐⁢𝐷 and Λ+𝑐⁢𝐷, is made using samples of proton-proton collision data corresponding to an integrated luminosity of 5.7 fb−1 recorded by the LHCb detector at √𝑠=13 TeV. Since no significant signals are found, upper limits are set on the pentaquark yields relative to that of the Λ+𝑐 baryon in the Λ+𝑐→𝑝⁢𝐾−⁢𝜋+ decay mode. The known pentaquark states are also investigated, and their signal yields are found to be consistent with zero in all cases.

DOI ↗

Курсы (12)