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Observation of the decay Λ0b → χc1pπ−
Journal of High Energy Physics. 2021. Vol. 5. Article 95.
Aaij R., Arzymatov K., Belavin V., Boldyrev A., Borisyak M., Derkach D., Hushchyn M., Karpov M., Maevskiy A., Philippov A., Popov S., Ratnikov F., Ryzhikov A., Ustyuzhanin A., Zunica G.
The Cabibbo-suppressed decay Λ0b → χc1pπ− is observed for the first time us- ing data from proton-proton collisions corresponding to an integrated luminosity of 6 fb−1, collected with the LHCb detector at a centre-of-mass energy of 13 TeV. Evidence for the Λ0b → χc2pπ− decay is also found. Using the Λ0b → χc1pK− decay as normalisation channel, the ratios of branching fractions are measured to be... where the first uncertainty is statistical, the second is systematic and the third is due to the uncertainties in the branching fractions of χc1,2 → J/ψγ decays.
Aaij R., Arzymatov K., Belavin V. et al., Physical Review Letters 2021 Vol. 126 No. 16 Article 161802
We present an angular analysis of the Bþ → Kþð→ K0SπþÞμþμ− decay using 9 fb−1 of pp collision data collected with the LHCb experiment. For the first time, the full set of CP-averaged angular observables is measured in intervals of the dimuon invariant mass squared. Local deviations from standard model predictions are observed, similar to those in previous LHCb analyses of the isospin-partner B0 → K0μþμ− decay. The global tension ...
Added: August 28, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Physical Review Letters 2021 Vol. 127 No. 8 Article 082001
The first observation of exotic states with a new quark content cc ̄us ̄ decaying to the J=ψKþ final state is reported with high significance from an amplitude analysis of the Bþ → J=ψφKþ decay. The analysis is carried out using proton-proton collision data corresponding to a total integrated luminosity of 9 fb−1 collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV. The most significant state, Z ð4000Þþ, ...
Added: August 28, 2021
Shvydkin P., Glazov A., Olness F. et al., The European Physical Journal C - Particles and Fields 2018 Vol. 78 No. 8 P. 1-14
Fits to the final combined HERA deep-inelastic scattering cross-section data within the conventional DGLAP framework of QCD have shown some tension at low x and low Q2. A resolution of this tension incorporating ln(1/x)-resummation terms into the HERAPDF fits is investigated using the xFitter program. The kinematic region where this resummation is important is delineated. ...
Added: August 7, 2018
Park S. -., Aushev T., Mizuk R. et al., Journal of High Energy Physics 2021 Vol. 2021 No. 4 Article 191
We present a search for the dark photon A′ in the B0 → A′A′ decays, where A′ subsequently decays to e+e−, μ+μ−, and π+π−. The search is performed by analyzing 772 × 106 BB events collected by the Belle detector at the KEKB e+e− energy- asymmetric collider at the Υ(4S) resonance. No signal is found in the dark photon mass range0.01GeV/c2≤mA′ ≤2.62GeV/c2,andwesetupperlimitsofthebranchingfraction of B0 → A′A′ at the 90% confidence level. The products of branching fractions, B(B0 → A′A′) × B(A′ → e+e−)2 and B(B0 → A′A′) × B(A′ → μ+μ−)2, have limits ...
Added: December 16, 2021
Сапронов А. А., Aaboud M., Journal of High Energy Physics 2017 Vol. 2017 No. 12 P. 1-78
This paper presents a measurement of the triple-differential cross section for the Drell-Yan process Z/γ * → ℓ + ℓ − where ℓ is an electron or a muon. The measurement is performed for invariant masses of the lepton pairs, m ℓℓ , between 46 and 200 GeV using a sample of 20.2 fb−1of pp collisions data at a centre-of-mass energy of s√=8s=8 TeV collected by the ATLAS detector at the LHC ...
Added: February 26, 2018
Ratnikov F., Journal of High Energy Physics 2018 Vol. 1811 P. 1-35
The production of ϒ(nS) mesons (n = 1, 2, 3) in pPb and Pbp collisions at a centre-of-mass energy per nucleon pair 𝑠NN‾‾‾‾√=8.16sNN=8.16 TeV is measured by the LHCb experiment, using a data sample corresponding to an integrated luminosity of 31.8 nb−1−1. The ϒ(nS) mesons are reconstructed through their decays into two opposite-sign muons. The measurements comprise ...
Added: March 11, 2019
Ratnikov F., Physical Review Letters 2018 Vol. 121 No. 22 P. 222001-1-222001-10
The cross section for prompt antiproton production in collisions of protons with an energy of 6.5 TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of 0.5 nb-1. The target is provided by injecting helium gas into the LHC beam line at the LHCb ...
Added: March 11, 2019
Ratnikov F., Journal of High Energy Physics 2018 Vol. 1808 P. 1-19
The 𝐵0𝑠⎯⎯⎯⎯⎯⎯⎯→𝜒𝑐2𝐾+𝐾−Bs0¯→χc2K+K− decay mode is observed and its branching fraction relative to the corresponding 𝜒𝑐1χc1decay mode, in a ±15MeV/𝑐2±15MeV/c2 window around the 𝜙ϕ mass, is found to be (𝐵0𝑠⎯⎯⎯⎯⎯⎯⎯→𝜒𝑐2𝐾+𝐾−)(𝐵0𝑠⎯⎯⎯⎯⎯⎯⎯→𝜒𝑐1𝐾+𝐾−)=(17.1±3.1±0.4±0.9)%,B(Bs0¯→χc2K+K−)B(Bs0¯→χc1K+K−)=(17.1±3.1±0.4±0.9)%, where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the branching fractions of radiative 𝜒𝑐χc decays. The decay mode 𝐵0𝑠⎯⎯⎯⎯⎯⎯⎯→𝜒𝑐1𝐾+𝐾−Bs0¯→χc1K+K− allows the 𝐵0𝑠Bs0 mass to be measured as 𝑚(𝐵0𝑠)=5366.83±0.25±0.27MeV/𝑐2,m(Bs0)=5366.83±0.25±0.27MeV/c2,where the first uncertainty is statistical ...
Added: March 11, 2019
Aaij R., Abellán Beteta C., Ackernley T. et al., Physical Review C - Nuclear Physics 2021 Vol. 103 No. 6 Article 064905
This article reports the first measurement of prompt χc1 and χc2 charmonium production in nuclear collisions at Large Hadron Collider energies. The cross-section ratio σ(χc2)/σ(χc1) is measured in pPb collisions at sNN=8.16 TeV, collected with the LHCb experiment. The χc1,2 states are reconstructed via their decay to a J/ψ meson, subsequently decaying into a pair of oppositely charged muons, and a photon, which is reconstructed in the calorimeter or ...
Added: August 26, 2021
Aaij R., Beteta C. A., Ackernley T. et al., Journal of High Energy Physics 2021 Article 177
The first full angular analysis of the 𝐵0→𝐷∗−𝐷∗+𝑠B0→D∗−Ds∗+ decay is performed using 6 fb−1 of pp collision data collected with the LHCb experiment at a centre-of-mass energy of 13 TeV. The 𝐷∗+𝑠→𝐷+𝑠𝛾Ds∗+→Ds+γ and D*− → 𝐷⎯⎯⎯⎯⎯0𝜋−D¯0π− vector meson decays are used with the subsequent 𝐷+𝑠Ds+ → K+K−π+ and 𝐷⎯⎯⎯⎯⎯0D¯0 → K+π− decays. All helicity amplitudes and phases are measured, and the longitudinal polarisation fraction is determined to be fL = 0.578 ± 0.010 ± 0.011 with ...
Added: August 26, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Physical Review Letters 2020 Vol. 125 No. 23 Article 231801
A search for the decay K0S → μþμ− is performed using proton-proton collision data, corresponding to an integrated luminosity of 5.6 fb−1 and collected with the LHCb experiment during 2016, 2017, and 2018 at a center-of-mass energy of 13 TeV. The observed signal yield is consistent with zero, yielding an upper limit of BðK0S → ...
Added: August 27, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Physical Review Letters 2021 Vol. 126 No. 8 Article 081804
The first observation of the suppressed semileptonic B0s→K−μ+νμ decay is reported. Using a data sample recorded in pp collisions in 2012 with the LHCb detector, corresponding to an integrated luminosity of 2 fb−1, the branching fraction B(B0s→K−μ+νμ) is measured to be [1.06±0.05(stat)±0.08(syst)]×10−4, where the first uncertainty is statistical and the second one represents the combined systematic ...
Added: August 28, 2021
Ratnikov F., The European Physical Journal C - Particles and Fields 2018 Vol. 78 No. 12 P. 1-12
A search is presented for a Higgs-like boson with mass in the range 45 to 195 GeV/𝑐2GeV/c2 decaying into a muon and a tau lepton. The dataset consists of proton-proton interactions at a centre-of-mass energy of 8 TeV TeV , collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb −1 fb −1 . The tau leptons are reconstructed in both leptonic ...
Added: March 10, 2019
Aaij R., Arzymatov K., Belavin V. et al., Journal of High Energy Physics 2021 Vol. 6 Article 19
Searches for CP violation in the two-body decays 𝐷+(𝑠)→ℎ+𝜋0D(s)+→h+π0 and 𝐷+(𝑠)→ℎ+𝜂D(s)+→h+η (where h+ denotes a π+ or K+ meson) are performed using pp collision data collected by the LHCb experiment corresponding to either 9 fb−1 or 6 fb−1 of integrated luminosity. The π0 and η mesons are reconstructed using the e+e−γ final state, which can proceed as three-body decays π0 → e+e−γ and η → e+e−γ, or via the two-body decays π0 → γγ and η → γγ followed by a photon conversion. The measurements are ...
Added: August 26, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Journal of High Energy Physics 2021 Article 81
Measurements of CP observables in B± → D(*)K± and B± → D(*)π± decays are presented, where D(∗) indicates a neutral D or D∗ meson that is an admixture of meson and anti-meson states. Decays of the D(∗) meson to the Dπ0 and Dγ final states are partially reconstructed without inclusion of the neutral pion or ...
Added: August 28, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Journal of High Energy Physics 2021 Vol. 2021 No. 3 Article 75
The time-dependent CP asymmetries of B0 → π+π− and B0s → K+K− decays are measured using a data sample of pp collisions corresponding to an integrated luminosity of 1.9 fb−1, collected with the LHCb detector at a centre-of-mass energy of 13 TeV. The results are
Cππ=−0.311±0.045±0.015, Sππ=−0.706±0.042±0.013, CKK=0.123±0.034±0.015, SKK=0.164±0.034±0.014, AΔΓKK=−0.83±0.05±0.09,
where the first uncertainties are statistical and ...
Added: August 28, 2021
Norman G., Saitov I., Sartan R., Contributions to Plasma Physics 2019 Vol. 59 No. 6 P. e201800173
Warm dense hydrogen is studied in the region of fluid–fluid phase transition within
the framework of the density functional theory. We report a procedure of obtaining
metastable states and calculate the equation of state. Metastable states are diagnosed by pair correlation functions and values of conductivity. We obtain a strong
overlapping through the density of metastable and equilibrium ...
Added: October 30, 2019
Буров А.А., Герман А. Д., Косенко И. И., Космические исследования 2014 Т. 52 № 4 С. 307-312
The problem of planar oscillations of a pendulum with variable length suspended on the Moon’s surface is considered. It is assumed that the Earth and Moon (or, in the general case, a planet and its satellite, or an asteroid and a spacecraft) revolve around the common center of mass in unperturbed elliptical Keplerian orbits. We ...
Added: November 8, 2014
Han X., Jia S., Yuan L. et al., Journal of High Energy Physics 2023 Vol. 2023 No. 1 Article 55
Using a data sample of 980 fb(-1) collected with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider, we study for the first time the singly Cabibbo-suppressed decays omega(0)(c) -(sic) -pi(+) and omega K--(+) and the doubly Cabibbo-suppressed decay omega(0)(c) -(sic)K--(+). Evidence for an Q0 c signal in the omega(0)(c) -E-pi+ mode is reported with ...
Added: September 16, 2023
IEEE, 2015
Added: March 16, 2015
Aaij R., Beteta C. A., Ustyuzhanin A. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2020 No. 102 P. 071101
The Ξc0 baryon is unstable and usually decays into charmless final states by the c→sud¯ transition. It can, however, also disintegrate into a π- meson and a Λc+ baryon via s quark decay or via cs→dc weak scattering. The interplay between the latter two processes governs the size of the branching fraction B(Ξc0→π-Λc+), first measured ...
Added: December 2, 2020
Зеленый Л. М., Григоренко Е. Е., Малова Х. В. et al., Письма в Журнал экспериментальной и теоретической физики 2018 Т. 108 № 8 С. 586-599
В статье представлены наблюдения токовых конфигураций с магнитным широм в хвосте магнитосферы Земли спутниковым квартетом Cluster, и в солнечном ветре - спутником Wind. Показано, что в токовых конфигурациях с магнитным широм наблюдаются следующие структурные особенности: 1) утолщение токового слоя; 2) распределение плотности плазмы, асимметричное относительно плоскости слоя; 3) формирование асимметричного профиля плотности тока. Рассмотрены кинетические ...
Added: March 5, 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
Guskova M., Shchur V., Shchur L., Lobachevskii Journal of Mathematics 2020 Vol. 41 No. 6 P. 992-995
We simulate the oscillation of the viscous drop in the viscous liquid. We combine methods of chromodynamics model and Shan-Chen pseudo-potential for the immiscible fluids. We measure the frequency of the first nontrivial eigenmode using the initial ellipsoid form of the drop. Drop oscillates about the equilibrium spherical form of radius $R$. Computed frequency as ...
Added: June 2, 2020