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Angular Analysis of D0→π+π−μ+μ− and D0→K+K−μ+μ− Decays and Search for CP Violation
Physical Review Letters. 2022. Vol. 128. No. 22. Article 221801.
Aaij R., Abdelmotteleb A. S., Abellán Beteta C., Abudinén F., Ackernley T., Arzymatov K., Belavin V., Borisyak M., Boldyrev A., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Mokhnenko S., Philippov A., Popov S., Ratnikov F., Ryzhikov A., Ustyuzhanin A.
The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D0→π+π−μ+μ− and D0→K+K−μ+μ− decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9 fb−1. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry.
Publication based on the results of:
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Nature Communications 2022 No. 13 Article 3351
Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an ...
Added: December 31, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Journal of High Energy Physics 2022 Vol. 2022 No. 3 Article 109
Searches for rare B0sBs0 and B0 decays into four muons are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1. Direct decays and decays via light scalar and J/ψ resonances are considered. No evidence for the six decays searched for is found and upper limits at the 95% confidence level on their ...
Added: December 31, 2022
Aaij R., Adinolfi M., Aiola S. et al., Computing and Software for Big Science 2022 No. 6 Article 1
The Large Hadron Collider beauty (LHCb) experiment at CERN is undergoing an upgrade in preparation for the Run 3 data collection period at the Large Hadron Collider (LHC). As part of this upgrade, the trigger is moving to a full software implementation operating at the LHC bunch crossing rate. We present an evaluation of a ...
Added: December 31, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Physical Review Letters 2022 No. 128 Article 191802
Tests of lepton universality in B0→K0Sℓ+ℓ− and B+→K*+ℓ+ℓ− decays where ℓ is either an electron or a muon are presented. The differential branching fractions of B0→K0Se+e− and B+→K*+e+e− decays are measured in intervals of the dilepton invariant mass squared. The measurements are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9 fb−1 . The results are consistent with the standard ...
Added: December 31, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Physical Review Letters 2022 No. 128 Article 082001
Events containing a Z boson and a charm jet are studied for the first time in the forward region of proton-proton collisions. The data sample used corresponds to an integrated luminosity of 6 fb−1 collected at a center-of-mass energy of 13 TeV with the LHCb detector. In events with a Z boson and a jet, the fraction of charm jets is determined in ...
Added: December 31, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Physical Review Letters 2022 Vol. 128 No. 16 Article 162001
Two narrow resonant states are observed in the Λ0bK−π+ mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6 fb−1. The minimal quark content of the Λ0bK−π+ system indicates that these are excited Ξ0b baryons. The masses of the Ξb(6327)0 and Ξb(6333)0 states are m[Ξb(6327)0]=6327.28+0.23−0.21±0.12±0.24 and m[Ξb(6333)0]=6332.69+0.17−0.18±0.03±0.22 MeV, respectively, with a mass splitting ...
Added: December 31, 2022
Aaij R., Abellán Beteta C., Ackernley T. et al., Nature Physics 2022 No. 18 P. 277-282
The standard model of particle physics currently provides our best description of fundamental particles and their interactions. The theory predicts that the different charged leptons, the electron, muon and tau, have identical electroweak interaction strengths. Previous measurements have shown that a wide range of particle decays are consistent with this principle of lepton universality. This ...
Added: December 29, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Nature Physics 2022 No. 18 P. 751-754
Conventional, hadronic matter consists of baryons and mesons made of three quarks and a quark–antiquark pair, respectively1,2. Here, we report the observation of a hadronic state containing four quarks in the Large Hadron Collider beauty experiment. This so-called tetraquark contains two charm quarks, a uu and a dd quark. This exotic state has a mass of approximately 3,875 MeV and ...
Added: December 31, 2022
Philippov A., Aaij R., Abdelmotteleb A. S. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2022 No. 105 Article L051104
The photon polarization in b→sγ transitions is measured for the first time in radiative b -baryon decays exploiting the unique spin structure of Λ0b→Λγ decays. A data sample corresponding to an integrated luminosity of 6 fb−1 collected by the LHCb experiment in pp collisions at a center-of-mass energy of 13 TeV is used. The photon polarization is measured to be αγ=0.82+0.17+0.04−0.26−0.13, where the first uncertainty is statistical and ...
Added: December 31, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., The European Physical Journal C - Particles and Fields 2022 No. 82 Article 373
A search is performed for massive long-lived particles (LLPs) decaying semileptonically into a muon and two quarks. Two kinds of LLP production processes were considered. In the first, a Higgs-like boson with mass from 30 to 200\,GeV\!/c2\,GeV\!/c2 is produced by gluon fusion and decays into two LLPs. The analysis covers LLP mass values from 10\,GeV\!/c2\,GeV\!/c2 up to ...
Added: December 31, 2022
Aaij R., Abellán Beteta C., Ackernley T. et al., Journal of High Energy Physics 2022 Vol. 2022 No. 1 Article 166
The differential cross-section of prompt inclusive production of long-lived charged particles in proton-proton collisions is measured using a data sample recorded by the LHCb experiment at a centre-of-mass energy of s√s = 13 TeV. The data sample, collected with an unbiased trigger, corresponds to an integrated luminosity of 5.4 nb−1. The differential cross-section is measured as a ...
Added: December 31, 2022
Philippov A., Aaij R., Abdelmotteleb A. S. et al., Journal of High Energy Physics 2022 Article 65
Using proton-proton collision data, corresponding to an integrated luminosity of 9 fb−1 collected with the LHCb detector, seven decay modes of the B+cBc+ meson into a J/ψ or ψ(2S) meson and three charged hadrons, kaons or pions, are studied. The decays B+cBc+ → (ψ(2S) → J/ψπ+π−)π+, B+cBc+ → ψ(2S)π+π−π+, B+cBc+ → J/ψK+π−π+ and B+cBc+ → J/ψK+K−K+ are observed for the first time, and evidence for the B+cBc+ → ψ(2S)K+K−π+, decay ...
Added: December 31, 2022
Aaij R., Beteta C. A., Ackernley T. et al., Journal of High Energy Physics 2022 Vol. 2022 Article 117
Coherent production of J/ψ mesons is studied in ultraperipheral lead-lead collisions at a nucleon-nucleon centre-of-mass energy of 5 TeV, using a data sample collected by the LHCb experiment corresponding to an integrated luminosity of about 10 μb−1. The J/ψ mesons are reconstructed in the dimuon final state and are required to have transverse momentum below 1 GeV. The cross-section ...
Added: December 31, 2022
Aaij R., Abellán Beteta C., Ackernley T. et al., Journal of Instrumentation 2022 Vol. 17 Article P05009
The centrality of heavy-ion collisions is directly related to the created medium in these interactions. A procedure to determine the centrality of collisions with the LHCb detector is implemented for lead-lead collisions at √sNN = 5 TeV and lead-neon fixed-target collisions at √sNN = 69 GeV. The energy deposits in the electromagnetic calorimeter are used to determine ...
Added: December 29, 2022
Ratnikov F., Ustyuzhanin A., EPJ Web of Conferences 2019 Vol. 2014 P. 1-8
Simulation is one of the key components in high energy physics. Historically it relies on the Monte Carlo methods which require a tremendous amount of computation resources. These methods may have difficulties with the expected High Luminosity Large Hadron Collider (HL-LHC) needs, so the experiments are in urgent need of new fast simulation techniques. We ...
Added: October 9, 2019
Serkhacheva N., Gainanova, A., Kuz’micheva G. et al., International Journal of Polymer Analysis and Characterization 2015 Vol. 20 No. 8 P. 743-753
This study produced for the first time composites based on polystyrene microspheres with nano-sized titania synthesized by sulfate and sol-gel methods, as well as commercial Hombifine N, Hombikat UV100, and Degussa P25. The starting samples and the composites were characterized by X-ray diffraction, scanning electron microscopy, nitrogen adsorption capacity, and IR spectroscopy. The highest content ...
Added: December 2, 2015
Маршалко Г. Б., Денисенко Д. В., Рудской В. И. et al., Journal of Experimental and Theoretical Physics 2019 Vol. 128 No. 4 P. 552-559
Following the approach proposed in [3], we estimate resources of a quantum computer required for solving the key search problem of block cipher algorithms Kuznechik and Magma, defined by the national standard GOST R 34.12-2015, with the use of Grover’s quantum algorithm. ...
Added: October 7, 2022
Prudnikov V., Prudnikov P., Malyarenko P. et al., Journal of Experimental and Theoretical Physics 2020 Vol. 130 No. 2 P. 258-273
The influence of various initial magnetizations m0 and structural defects on the nonequilibrium critical behavior of the two-dimensional Ising model is numerically simulated by Monte Carlo methods. Based on analysis of the time dependence of magnetization and the two-time dependences of autocorrelation function and dynamic susceptibility, we revealed the influence of logarithmic corrections and the ...
Added: June 29, 2020
Пенза : ПГУ, 2015
В сборник трудов включены доклады юбилейного ХХ-го Международного симпозиума «Надежность и качество», проходившего с 25 по 31 мая 2015 г. в городе Пензе.
Рассмотрены актуальные проблемы теории и практики повышения надежности и качества; эффективности внедрения инновационных и информационных технологий в фундаментальных научных и прикладных исследованиях, образовательных и коммуникативных системах и средах, экономике и юриспруденции; методов и ...
Added: May 31, 2015
Aaij R., Abdelmotteleb A. S., Abellan Beteta C. et al., Physical Review Letters 2023 Vol. 131 No. 7 Article 071901
https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.131.071901 ...
Added: December 4, 2023
Zelenyi L., Malova H., Grigorenko E. et al., 2019 Vol. 61 P. 1-12
In this article we aim to highlight the problems related to the structure and stability of the
comparatively thin current sheets that were relatively recently discovered by space missions in
the magnetospheres of the Earth and planets, as well as in the solar wind. These magnetoplasma
structures are universal in collisionless cosmic plasmas and can play a key ...
Added: March 22, 2019
Aaij R., Abellán Beteta C., Ackernley T. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2022 Vol. 105 No. 1 Article 012010
An improved measurement of the decay B0s→μ+μ− and searches for the decays B0→μ+μ− and B0s→μ+μ−γ are performed at the LHCb experiment using data collected in proton-proton collisions at s√=7, 8and 13 TeV, corresponding to integrated luminosities of 1, 2 and 6 fb−1, respectively. The B0s→μ+μ− branching fraction and effective lifetime are measured to be Br(B0s→μ+μ−)=(3.09+0.46+0.15−0.43−0.11)×10−9 and τ(B0s→μ+μ−)=(2.07±0.29±0.03) ps, respectively, where the uncertainties include both statistical and systematic contributions. No significant ...
Added: December 29, 2022
Shchur L., Shchur L., Journal of Physics: Conference Series 2015 Vol. 640 P. 012065We extend concept of local simulation times in parallel discrete event simulation (PDES) in order to take into account architecture of the current hardware and software in high-performance computing. We shortly review previous research on the mapping of PDES on physical problems, and emphasise how physical results may help to predict parallel algorithms behaviour.
We extend concept of local simulation times in parallel discrete event simulation (PDES) in order to take into account architecture of the current hardware and software in high-performance computing. We shortly review previous research on the mapping of PDES on physical problems, and emphasise how physical results may help to predict parallel algorithms behaviour. ...
Added: March 8, 2016
Faizullina Kamilla, Pchelintsev Ilya, Burovskiy E., Physical Review E - Statistical, Nonlinear, and Soft Matter Physics 2021 Vol. 104 Article 054501
We study a lattice model of a single magnetic polymer chain, where Ising spins are located on the sites of a lattice self-avoiding walk in $d=2$. We consider the regime where both conformations and magnetic degrees of freedom are dynamic, thus the Ising model is defined on a dynamic lattice and conformations generate an annealed disorder. Using Monte Carlo ...
Added: November 5, 2021