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Measurements of the branching fractions B(B- → Λc-Ξ'c0), B(B- → Λc-Ξc(2645)0) and B(B- → Λc-Ξc(2790)0
Physical Review D - Particles, Fields, Gravitation and Cosmology. 2019. Vol. 100. No. 11. P. 1-8.
Using the data sample of 711 fb−1 of Υ(4S) on-resonance data taken by the Belle detector at the KEKB asymmetric-energy electron-positron collider, we present the first measurements of branching fractions of the decays B−→Λ¯−cΞ′0c , B−→Λ¯−cΞc(2645)0 , and B−→Λ¯−cΞc(2790)0 . The signal yields for these decays are extracted from the recoil mass spectrum of the system recoiling against Λ¯−c baryons in selected B− candidates. The branching fraction of B−→Λ¯−cΞc(2790)0 is measured to be (1.1±0.4±0.2)×10−3 , where the first uncertainty is statistical and the second systematic. The 90\% credibility level upper limits on B(B−→Λ¯−cΞ′0c) and B(B−→Λ¯−cΞc(2645)0) are determined to be 6.5×10−4 and 7.9×10−4 , respectively.
Aushev T., Mizuk R., Pakhlova G. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2019 P. 1-7
We report a measurement of time-dependent CP violation in B0→KS0π0π0 decays using a data sample of 772×106 BB pairs collected by the Belle experiment running at the ?(4S) resonance at the KEKB e+e- collider. This decay proceeds mainly via a b→sdd "penguin" amplitude. The results are sin2φ1eff=0.92-0.31+0.27 (stat.) ±0.11 (syst.) and A=0.28±0.21 (stat.) ±0.04 (syst.), ...
Added: June 5, 2020
Aushev T., Mizuk R., Pakhlov P. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2019 Vol. 99 No. 3 P. 1-9
We report the study of B+→pΛ̄K+K- and B+→p̄ΛK+K+ decays using a 772×106 BB̄ pair data sample recorded on the Ï (4S) resonance with the Belle detector at KEKB. The following branching fractions are measured: B(B+→pΛ̄K+K-)=(4.10-0.43+0.45±0.50)×10-6, B(B+→p̄ΛK+K+)=(3.70-0.37+0.39±0.44)×10-6, B(ηc→pΛ̄K-+c.c.)=(2.83-0.34+0.36±0.35)×10-3 and B(B+→pΛ̄φ)=(7.95±2.09±0.77)×10-7, where c.c. denotes the corresponding charge-conjugation process. The intermediate resonance decays are excluded in the four-body ...
Added: June 5, 2020
Aushev T., Mizuk R., Pakhlov P. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2019 Vol. 99 No. 7 P. 1-8
We report the results of a search for the B→Y(4260)K, Y(4260)→J/ψπ+π− decays. This study is based on a data sample corresponding to an integrated luminosity of 711~fb−1 , collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e− collider. We investigate the J/ψπ+π− invariant mass distribution in the range 4.0 to 4.6 ...
Added: June 5, 2020
Aushev T., Mizuk R., Pakhlov P. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2019 Vol. 99 No. 11 P. 1-8
We report a search for X(3872) and X(3915) in B+→χc1π0K+ decays. We set an upper limit of B(B+→X(3872)K+)×B(X(3872)→χc1π0) <8.1×10−6 and B(B+→X(3915)K+)×B(X(3915)→χc1π0) <3.8×10−5 at 90\% confidence level. We also measure B(X(3872)→χc1π0)/B(X(3872)→J/ψπ+π−)<0.97 at 90\% confidence level. The results reported here are obtained from 772×106 BB¯¯¯¯ events collected at the Υ(4S) resonance with the Belle detector at the ...
Added: June 5, 2020
Aushev T., Mizuk R., Pakhlov P. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2019 Vol. 100 No. 3 P. 1-8
We present the first measurements of the absolute branching fractions of Ξ+c decays into Ξ−π+π+ and pK−π+ final states. Our analysis is based on a data set of (772±11)×106 BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB e+e− collider. We measure the absolute branching fraction of B¯0→Λ¯−cΞ+c with the ...
Added: June 5, 2020
Mizuk R., Aushev T., Pakhlov P. et al., Journal of High Energy Physics 2019 P. 1-30
We report a new measurement of the e+e−→Υ(nS)π+π− (n=1,2,3) cross sections at energies from 10.52 to 11.02 GeV using data collected with the Belle detector at the KEKB asymmetric-energy e+e− collider. We observe a new structure in the energy dependence of the cross sections; if described by a Breit-Wigner function its mass and width are ...
Added: June 5, 2020
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
The LHCb C., K. Arzymatov, V. Belavin et al., Journal of High Energy Physics 2020 Vol. 05 Article 140
The ratio of branching fractions of the decays Λb0 {\Lambda}_b^0 Λb0 → pK−^{−}−e+^{+}+e−^{−}− and Λb0 {\Lambda}_b^0 Λb0 → pK−^{−}−μ+^{+}+μ−^{−}−,RpK−1 {R}_{pK}^{-1} RpK−1, is measured for the first time using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb−1^{−1}−1 recorded with the LHCb experiment at center-of-mass energies of 7, 8 and 13 TeV. In the ...
Added: September 17, 2020
Ustyuzhanin A., Derkach D., Rogozhnikov A. et al., Physical Review Letters 2016 Vol. 117 No. 8
A full amplitude analysis of Λ 0 b → J/ψ pπ− decays is performed with a data sample acquired with the LHCb detector from 7 and 8 TeV pp collisions, corresponding to an integrated luminosity of 3 fb−1 . A significantly better description of the data is achieved when, in addition to the previously observed ...
Added: October 23, 2016
Aaij R., Abellán Beteta C., Ackernley T. et al., Chinese Physics C 2021 Vol. 45 No. 9 Article 093002
The first search for the doubly heavy Ω0bc baryon and a search for Ξ0bc baryon are performed using pp collision data collected via the LHCb experiment from 2016 to 2018 at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 5.2fb−1. The baryons are reconstructed via their decays to Λ+cπ− and Ξ+cπ−. No significant excess is found for invariant masses between 6700 and ...
Added: March 18, 2022
Aaij R., Beteta C. A., Borisyak M. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2020 Vol. 102 No. 9 Article 092005
A study of the lineshape of theχc1ð3872Þstate is made using a data sample corresponding to anintegrated luminosity of3fb−1collected inppcollisions at center-of-mass energies of 7 and 8 TeV withthe LHCb detector. Candidateχc1ð3872Þandψð2SÞmesons fromb-hadron decays are selected in theJ=ψπþπ−decay mode. Describing the lineshape with a Breit-Wigner function, the mass splitting betweentheχc1ð3872Þandψð2SÞstates,Δm, and the width of theχc1ð3872Þstate,ΓBW, are ...
Added: December 6, 2020
Aaij R., Beteta C. A., K. Arzymatov et al., Journal of High Energy Physics 2020 Vol. 06 No. 129 P. 1-18
A search is presented for the lepton flavour violating decay B+→K+μ−τ+using a sample of proton--proton collisions at centre-of-mass energies of 7, 8, and 13 TeV, collected with the LHCb detector and corresponding to a total integrated luminosity of 9 fb−1. The τ leptons are selected inclusively, primarily via decays with a single charged particle. The ...
Added: September 16, 2020
LHCb C., Derkach D., Kazeev N. et al., Physical Review Letters 2017 Vol. 119 No. 18 P. 181807-1-181807-9
A search for baryon-number violating Ξb0 oscillations is performed with a sample of pp collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 3 fb−1. The baryon number at the moment of production is identified by requiring that the Ξb0 come from the decay of a resonance Ξb*−→Ξb0π− or Ξb′−→Ξb0π−, and the ...
Added: November 23, 2017
Aaij R., Beteta C. A., A. Boldyrev et al., Journal of High Energy Physics 2020 Vol. 02 No. 049 P. 1-17
A measurement of the Ξ++cc mass is performed using data collected by the LHCb experiment between 2016 and 2018 in pppp collisions at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.6 fb−1fb−1. The Ξ++cc candidates are reconstructed via the decay modes Ξ++cc→Λ+cK−π+π+ and Ξ++cc→Ξ+cπ+. The result, 3621.55±0.23(stat)±0.30(syst)MeV/c2, is the most precise measurement of the Ξ++cc mass to date. ...
Added: September 16, 2020
A S Boldyrev, A Maevsky, Journal of Physics: Conference Series 2017 Vol. 798 No. 1 P. 1-5
Towards the end of LHC Run1, gas leaks were observed in some parts of the Transition Radiation Tracker (TRT) of ATLAS. Due to these leaks, primary Xenon based gas mixture was replaced with Argon based mixture in various parts. Test-beam studies with a dedicated Transition Radiation Detector (TRD) prototype were carried out in 2015 in ...
Added: January 30, 2019
Сапронов А. А., Aad G., Glazov A., Physical Review D - Particles, Fields, Gravitation and Cosmology 2017 Vol. 96 No. 7 P. 072002-1-072002-36
Jet energy scale measurements and their systematic uncertainties are reported for jets measured with the ATLAS detector using proton-proton collision data with a center-of-mass energy of s=13 TeV, corresponding to an integrated luminosity of 3.2 fb-1 collected during 2015 at the LHC. Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells, using the anti-kt ...
Added: August 7, 2018
Aaij R., Beteta C. A., Borisyak M. et al., Physical Review Letters 2020 Vol. 124 No. 4 P. 1-12
Searches are performed for both prompt-like and long-lived dark photons, A′, produced in proton-proton collisions at a center-of-mass energy of 13 TeV. These searches look for A′→μ+μ− decays using a data sample corresponding to an integrated luminosity of 5.5/fb collected with the LHCb detector. Neither search finds evidence for a signal, and 90 confidence-level exclusion ...
Added: September 16, 2020
M. Borisyak, Derkach D., Ratnikov F. et al., The European Physical Journal C - Particles and Fields 2017 Vol. 10 No. C77 P. 678-690
A search for the decay K0S→μ+μ− is performed, based on a data sample of proton-proton collisions corresponding to an integrated luminosity of 3 fb−1, collected by the LHCb experiment at centre-of-mass energies of 7 and 8 TeV. The observed yield is consistent with the background-only hypothesis, yielding a limit on the branching fraction of B(K0S→μ+μ−)<0.8 (1.0)×10−9 ...
Added: October 23, 2017
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Journal of High Energy Physics 2022 Vol. 2022 No. 5 Article 38
The Ξ++ → Ξ′+π+ decay is observed using proton-proton collisions collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4fb−1. The Ξ++ → Ξ′+π+ decay is reconstructed partially, where the photon from the Ξ′+ → Ξ+γ decay is not reconstructed and the pK−π+ final state of the ...
Added: December 30, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Physical Review Letters 2022 Vol. 129 No. 9 Article 091801
The first study of the angular distribution of μþμ− pairs produced in the forward rapidity region via the Drell-Yan reaction pp → γ=Z þ X → lþl− þ X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1 fb−1. The coefficients ...
Added: December 29, 2022
Maevskiy, A., Boldyrev, A, Derkach, D. et al., Journal of High Energy Physics 2019 No. 09(2019)28 P. 1-19
Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9 fb−1 of integrated luminosity at the centre-of-mass energies of 7, 8, and 13 TeV, respectively, the decay Λ0b→χc1Λb0→χc1(3872)pK− with χc1(3872) → J/ψ π+π− is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. It ...
Added: October 22, 2019
Yelton J., Aushev T., Mizuk R. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2020 Article 071103(R
Using 980 fb−1 of data collected with the Belle detector operating at the KEKB asymmetric-energy e^+e^- collider, we report a study of the electromagnetic decays of excited {charmed baryons} Ξc(2790) and Ξc(2815). A clear signal (8.6 standard deviations) is observed for Ξc(2815)0→Ξ0cγ, and we measure:
B[Ξc(2815)0→Ξ0cγ]/B[Ξc(2815)0→Ξc(2645)+π−→Ξ0cπ+π−]=0.41±0.05±0.03.
We also present evidence (3.8 standard deviations) for the similar decay ...
Added: November 27, 2020
Derkach D., Borisyak M., Ustyuzhanin A. et al., Physics Letters B 2016 No. 762 P. 253-262
A time-dependent angular analysis of Bs0→ψ(2S)ϕ decays is performed using data recorded by the LHCb experiment. The data set corresponds to an integrated luminosity of 3.0fb−1 collected during Run 1 of the LHC. The CP -violating phase and decay-width difference of the Bs0 system are measured to be ϕs=0.23−0.28+0.29±0.02rad and ΔΓs=0.066−0.044+0.041±0.007ps−1 , respectively, where the ...
Added: October 21, 2016
The LHCb collaboration -., Aaij R., Abdelmotteleb A. S. et al., Journal of High Energy Physics 2021 Article 107
A search for the doubly charmed baryon 𝛯+𝑐𝑐Ξcc+ is performed in the 𝛯+𝑐𝜋−𝜋+Ξc+π−π+ invariant-mass spectrum, where the 𝛯+𝑐Ξc+ baryon is reconstructed in the pK−π+ final state. The study uses proton-proton collision data collected with the LHCb detector at a centre- of-mass energy of 13 TeV, corresponding to a total integrated luminosity of 5.4 fb−1. No significant signal is observed in the invariant-mass range ...
Added: March 2, 2022