E. A. Kravchenko
A5006599290- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Neutrino Physics Research
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Black Holes and Theoretical Physics
- Computational Physics and Python Applications
- Superconducting Materials and Applications
- Nuclear physics research studies
- Astrophysics and Cosmic Phenomena
- Nuclear Physics and Applications
- Photocathodes and Microchannel Plates
- Radiation Therapy and Dosimetry
- Stochastic processes and statistical mechanics
- Particle accelerators and beam dynamics
- Cosmology and Gravitation Theories
- Radioactive Decay and Measurement Techniques
- Methane Hydrates and Related Phenomena
- Muon and positron interactions and applications
- Advanced NMR Techniques and Applications
Novosibirsk State University
2014-2023
Budker Institute of Nuclear Physics
2013-2022
Siberian Branch of the Russian Academy of Sciences
2012-2022
Boreskov Institute of Catalysis
2001-2019
Taras Shevchenko National University of Kyiv
2016
Russian Academy of Sciences
2013-2015
Laboratoire d’Annecy de Physique des Particules
2002-2006
University of California, Irvine
2005
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2001
University of Cambridge
2001
Based on the full BaBar data sample, we report improved measurements of ratios R(D(*)) = B(B -> D(*) Tau Nu)/B(B l Nu), where is either e or mu. These are sensitive to new physics contributions in form a charged Higgs boson. We measure R(D) 0.440 +- 0.058 0.042 and R(D*) 0.332 0.024 0.018, which exceed Standard Model expectations by 2.0 sigma 2.7 sigma, respectively. Taken together, our results disagree with these at 3.4 level. This excess cannot be explained boson type II two-Higgs-doublet...
We study initial-state radiation events, ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\gamma}}_{\mathrm{ISR}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$, with data collected the BABAR detector. observe an accumulation of events near $4.26\text{ }\text{ }\mathrm{GeV}/{c}^{2}$ in invariant-mass spectrum ${\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}J/\ensuremath{\psi}$. Fits to mass indicate that a broad resonance about is...
We have observed a narrow state near 2.32 GeV/c2 in the inclusive D+sπ0 invariant mass distribution from e+e− annihilation data at energies 10.6 GeV. The width is consistent with experimental resolution. small intrinsic and quantum numbers of final indicate that decay violates isospin conservation. has natural spin-parity low suggests JP=0+ assignment. sample corresponds to an integrated luminosity 91 fb−1 recorded by BABAR detector SLAC PEP-II asymmetric-energy storage ring.Received 11...
We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at PEP-II asymmetric Factory SLAC. This result uses additional sample Upsilon(4S) collected 2001, bringing data available to 32 x 10(6) BB macro pairs. select events which one meson is fully reconstructed a final state containing charmonium and flavor other determined from its decay products. The amplitude asymmetry, standard model proportional sin2 beta, derived time...
We study the decay ${B}^{\ensuremath{-}}\ensuremath{\rightarrow}J/\ensuremath{\psi}{K}^{\ensuremath{-}}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ using $117\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected at $Y(4S)$ resonance with BABAR detector PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ asymmetric-energy storage ring. measure branching fractions $\mathcal{B}$...
We present results on time-dependent CP asymmetries in neutral B decays to several eigenstates. The measurements use a data sample of about 88 x 10(6) Upsilon(4S)-->B(-)B collected between 1999 and 2002 with the BABAR detector at PEP-II asymmetric-energy factory SLAC. study events which one meson is fully reconstructed final state containing charmonium other determined be either B(0) or B(-0) from its decay products. amplitude asymmetry, standard model proportional sin2beta, derived...
The e+e−→pp¯ cross section is determined over a range of pp¯ masses, from threshold to 4.5 GeV/c2, by studying the e+e−→pp¯γ process. data set corresponds an integrated luminosity 232 fb−1, collected with BABAR detector at PEP-II storage ring, e+e− center-of-mass energy 10.6 GeV. mass dependence ratio electric and magnetic form factors, |GE/GM|, measured for masses below 3 GeV/c2; its value found be significantly larger than 1 up 2.2 GeV/c2. We also measure J/ψ→pp¯ ψ(2S)→pp¯ branching...
In a sample of $471\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ events collected with the BABAR detector at PEP-II ${e}^{+}{e}^{\ensuremath{-}}$ collider we study rare decays $B\ensuremath{\rightarrow}{K}^{(*)}{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$, where ${\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ is either or ${\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$. We report results on partial branching fractions and isospin...
We search for the flavor-changing neutral-current decays $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\nu}\overline{\ensuremath{\nu}}$, and invisible $J/\ensuremath{\psi}\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ $\ensuremath{\psi}(2S)\ensuremath{\rightarrow}\ensuremath{\nu}\overline{\ensuremath{\nu}}$ via $B\ensuremath{\rightarrow}{K}^{(*)}J/\ensuremath{\psi}$ $B\ensuremath{\rightarrow}{K}^{(*)}\ensuremath{\psi}(2S)$, respectively, using a data sample of...
We study e+e−→J/ψ cc¯ by measuring the invariant mass distribution recoiling against fully reconstructed J/ψ decays, using 124 fb−1 of data collected at a center-of-mass energy 10.6 GeV with BABAR detector. observe signals for ηc(1S), χc0, and ηc(2S) in recoil distribution, thus confirming previous measurements. measure σ(e+e−→J/ψ+cc¯)B(cc¯→>2 charged) to be 17.6±2.8(stat)−2.1+1.5(syst) fb, 10.3±2.5(stat)−1.8+1.4(syst) 16.4±3.7(stat)−3.0+2.4(syst) fb cc¯=ηc(1S), ηc(2S), respectively.Received...
The process e+e- --> p anti-p gamma is studied using 469 fb-1 of integrated luminosity collected with the BABAR detector at PEP-II collider, an center-of-mass energy 10.6 GeV. From analysis invariant mass spectrum, dependence cross section for measured from threshold to 4.5 ratio electric and magnetic form factors, |G_E/G_M|, asymmetry in proton angular distribution are masses below 3 We also measure branching fractions decays J/psi psi(2S) anti p.
Although CP violation in the B meson system has been well established by factories, there no direct observation of time-reversal violation. The decays entangled neutral mesons into definite flavor states (B(0) or B(0)), and J/ψK(L)(0) ccK(S)(0) final (referred to as B(+) B(-)), allow comparisons between probabilities four pairs T-conjugated transitions, for example, B(0) → B(-) B(0), a function time difference two decays. Using 468 × 10(6) BB produced Υ(4S) collected BABAR detector at SLAC,...
We study the reactions e+e−→e+e−η(') in single-tag mode and measure γγ∗→η(') transition form factors momentum-transfer range from 4 to 40 GeV2. The analysis is based on 469 fb−1 of integrated luminosity collected at PEP-II with BABAR detector e+e− center-of-mass energies near 10.6 GeV.11 MoreReceived 5 January 2011DOI:https://doi.org/10.1103/PhysRevD.84.052001© 2011 American Physical Society
We report the results of a study exclusive charmless semileptonic decays, B^0 --> pi^- l^+ nu, B^+ pi^0 omega eta nu and eta^' (l = e or mu) undertaken with approximately 462x10^6 B\bar{B} pairs collected at Upsilon(4S) resonance BABAR detector. The analysis uses events in which signal B decays are reconstructed loose neutrino reconstruction technique. obtain partial branching fractions several bins q^2, square momentum transferred to lepton-neutrino pair, for nu. From these distributions,...
We perform amplitude analyses of the decays ${B}^{0}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{K}_{S}^{0}$, ${B}^{+}\ensuremath{\rightarrow}{K}^{+}{K}^{\ensuremath{-}}{K}^{+}$, and ${B}^{+}\ensuremath{\rightarrow}{K}_{S}^{0}{K}_{S}^{0}{K}^{+}$, measure $CP$-violating parameters partial branching fractions. The results are based on a data sample approximately $470\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ decays, collected with BABAR detector at PEP-II...
We study the process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}\ensuremath{\psi}(2S){\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ with initial-state-radiation events produced at PEP-II asymmetric-energy collider. The data were recorded BABAR detector center-of-mass energies and near $\mathrm{\ensuremath{\Upsilon}}(\mathrm{nS})$ ($n=2,3,4$) resonances correspond to an integrated luminosity of $520\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. investigate...
We present a measurement of the total branching fraction flavor-changing neutral-current process B->Xsl+l-, along with partial fractions in bins dilepton and hadronic system (Xs) mass, using sample 471x10^6 Upsilon(4S)->BBbar events recorded BaBar detector at PEP-II e+e- collider. B mesons are reconstructed by combining pair, either or mu+mu-, 10 different Xs final states containing exactly one charged neutral kaon, two fewer pions, most pi0. Using sum over these exclusive modes as basis for...
We present a measurement of the direct CP violating asymmetry in decay B0-->K+pi(-) using data sample 227x10(6) Upsilon(4S)-->BB decays collected with BABAR detector at PEP-II asymmetric-energy e(+)e(-) collider SLAC. observe total signal yield nK-(pi(+))+nK+(pi(-))=1606+/-51 and measure (nK-(pi(+))-nK+(pi(-)))/(nK-(pi(+))+nK+(pi(-)))=-0.133+/-0.030(stat)+/-0.009(syst). The probability observing such an absence violation is 1.3x10(-5), corresponding to 4.2 standard deviations.
We measure the branching fraction for flavor-changing neutral-current process B-->X(s)l(+)l(-) with a sample of 89x10(6) Upsilon(4S)-->BBmacr; events recorded BABAR detector at PEP-II e(+)e(-) storage ring. The final state is reconstructed from or micro(+)micro(-) pairs and hadronic system X(s) consisting one K+/- K(0)(S) up to two pions, most pi(0). observe signal 40+/-10(stat)+/-2(syst) extract inclusive B(B-->X(s)l(+)l(-))=(5.6+/-1.5(stat)+/-0.6(exp syst)+/-1.1(model syst))x10(-6)...
The process ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}\ensuremath{\gamma}$ has been studied at a center-of-mass energy near the $\ensuremath{\Upsilon}(4S)$ resonance using $89.3\text{ }\text{ }{\mathrm{f}\mathrm{b}}^{\ensuremath{-}1}$ data sample collected with BABAR detector PEP-II collider. From measured $3\ensuremath{\pi}$ mass spectrum we have obtained products of branching fractions for...
We study the processes e+ e- --> 3(pi+pi-)gamma, 2(pi+pi-pi0)gamma and K+ K- 2(pi+pi-)gamma, with photon radiated from initial state. About 20,000, 33,000 4,000 fully reconstructed events, respectively, have been selected 232 fb-1 of BaBar data. The invariant mass hadronic final state defines effective e+e- center-of-mass energy, so that these data can be compared corresponding direct measurements. From 3(pi+pi-), 2(pi+pi-pi0) 2(pi+pi-) spectra, cross sections for are measured energies...
We present a measurement of time-dependent CP-violating asymmetries in neutral B meson decays collected with the BABAR detector at PEP-II asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider Stanford Linear Accelerator Center. The data sample consists 29.7 ${\mathrm{fb}}^{\mathrm{\ensuremath{-}}1}$ recorded $\ensuremath{\Upsilon}(4S)$ resonance and 3.9 off resonance. One mesons, which are produced pairs $\ensuremath{\Upsilon}(4S),$ is fully reconstructed CP decay modes...
We study the process $e^+e^-\to\pi^+\pi^-\pi^+\pi^-\gamma$, with a hard photon radiated from initial state. About 60,000 fully reconstructed events have been selected 89 $fb^{-1}$ of BaBar data. The invariant mass hadronic final state defines effective \epem center-of-mass energy, so that these data can be compared corresponding direct $e^+e^-$ measurements. From $4\pi$-mass spectrum, cross section for $e^+e^-\to\pi^+\pi^-\pi^+\pi^-$ is measured energies 0.6 to 4.5 $GeV/c^2$. uncertainty in...
With a sample of approximately 89 x 10(6) B(-)B pairs collected with the BABAR detector, we perform search for B meson decays into charmless vector mesons (phi, rho, and K*). We measure branching fractions, determine degree longitudinal polarization, CP violation asymmetries in processes B+-->phiK(*+), B0-->phiK(*0), B+-->rho(0)K(*+), B+-->rho(0)rho(+). also set an upper limit on fraction decay B0-->rho(0)rho(0).