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Precision measurement of the B+c meson mass
Journal of High Energy Physics. 2020. Vol. 07. Article 123.
The LHCb c., Ratnikov F., Ustyuzhanin A., Belavin V., Arzymatov K., Maevskiy A., Ryzhikov A., Derkach D., Hushchyn M., Borisyak M., Boldyrev A., Kazeev N.
A precision measurement of the 𝐵+𝑐Bc+ meson mass is performed using proton- proton collision data collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to a total integrated luminosity of 9.0 fb−1. The 𝐵+𝑐Bc+ mesons are reconstructed via the decays 𝐵+𝑐Bc+→ J/ψπ+, 𝐵+𝑐Bc+→ J/ψπ+π−π+, 𝐵+𝑐→𝐽/𝜓𝑝𝑝⎯⎯⎯𝜋+Bc+→J/ψpp¯π+, 𝐵+𝑐→𝐽/𝜓𝐷+𝑠Bc+→J/ψDs+, 𝐵+𝑐Bc+→ J/ψ D0K+ and 𝐵+𝑐→𝐵0𝑠𝜋+Bc+→Bs0π+. Combining the results of the individual decay channels, the 𝐵+𝑐Bc+ mass is measured to be 6274.47 ± 0.27 (stat) ± 0.17 (syst) MeV/c2. This is the most precise measurement of the 𝐵+𝑐Bc+ mass to date. The difference between the 𝐵+𝑐Bc+ and 𝐵0𝑠Bs0 meson masses is measured to be 907.75 ± 0.37 (stat) ± 0.27 (syst) MeV/c.
Publication based on the results of:
Aaij R., Beteta C. A., Ratnikov F. et al., Physical Review Letters 2020 Vol. 125 P. 011802
An angular analysis of the B0→K∗0(→K+π−)μ+μ− decay is presented using a data set corresponding to an integrated luminosity of 4.7 fb−1 of pp collision data collected with the LHCb experiment. The full set of CP-averaged observables are determined in bins of the invariant mass squared of the dimuon system. Contamination from decays with the K+π− system in an S-wave configuration is taken into ...
Added: September 16, 2020
Ahdida C., Ratnikov F., Ustyuzhanin A. et al., The European Physical Journal C - Particles and Fields 2020 Vol. 80 Article 284
The SHiP experiment is proposed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. About 10^11 muons per spill will be produced in the dump. To design the experiment such that the muon-induced background is minimized, a precise knowledge of the ...
Added: October 14, 2021
Aaij R., Beteta C. A., Arzymatov K. et al., Journal of High Energy Physics 2020 Vol. 6 P. 58
Measurements of CP observables in B±→DK± and B±→Dπ± decays are presented, where D represents a superposition of D0 and D¯0 states. The D meson is reconstructed in the three-body final state K0SK±π∓. The analysis uses samples of B mesons produced in proton-proton collisions, corresponding to an integrated luminosity of 1.0, 2.0, and 6.0 fb−1 collected with the LHCb detector at centre-of-mass energies of s√= 7, 8, and 13 TeV, respectively. These measurements are the most ...
Added: September 16, 2020
Aaij R., Beteta C. A., Ratnikov F. et al., Physical Review Letters 2020 Vol. 124 P. 211802
A search for the decays B0s→e+e−Bs0→e+e− and B0→e+e−B0→e+e− is performed using data collected with the LHCb experiment in proton-proton collisions at center-of-mass energies of 77, 88 and 13TeV13TeV, corresponding to integrated luminosities of 11, 22 and 2fb−12fb−1, respectively. No signal is observed. Assuming no contribution from B0→e+e−B0→e+e− decays, an upper limit of (B0s→e+e−)<9.4(11.2)×10−9B(Bs0→e+e−)<9.4(11.2)×10−9 is obtained at 90(95)%90(95)% confidence level. If no B0s→e+e−Bs0→e+e− contribution is assumed, a limit of (B0→e+e−)<2.5(3.0)×10−9B(B0→e+e−)<2.5(3.0)×10−9 is determined at 90(95)%90(95)% confidence level. These upper limits are ...
Added: September 16, 2020
The LHCb c., Boldyrev A., Derkach D. et al., Journal of High Energy Physics 2020 Vol. 10 Article 156
Searches are performed for a low-mass dimuon resonance, X, produced in proton-proton collisions at a center-of-mass energy of 13 TeV, using a data sample corresponding to an integrated luminosity of 5.1 fb−1−1 and collected with the LHCb detector. The X bosons can either decay promptly or displaced from the proton-proton collision, where in both cases the ...
Added: December 6, 2020
Aaij R., Arzymatov K., Belavin V. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2020 Vol. 102 No. 5 Article 051102(R)
The first observation of the decay B0→D0¯D0K+π− is reported using proton-proton collision data corresponding to an integrated luminosity of 4.7 fb−1 collected by the LHCb experiment in 2011, 2012 and 2016. The measurement is performed in the full kinematically allowed range of the decay outside of the D*− region. The ratio of the branching fraction relative to that of the control channel B0→D*−D0K+ is ...
Added: December 6, 2020
The LHCb c., Ratnikov F., Ustyuzhanin A. et al., Journal of High Energy Physics 2020 Vol. 06 Article 136
A new baryon state is observed in the Λ0bπ+π− mass spectrum with high significance using a data sample of pp collisions, collected with the LHCb detector at centre-of-mass energies s√=7,8 and 13TeV, corresponding to an integrated luminosity of 9fb−1. The mass and natural width of the new state are measured to be
m=6072.3±2.9±0.6±0.2MeV,Γ=72±11±2MeV,
where the first uncertainty is statistical and the second systematic. ...
Added: September 16, 2020
Aaij R., Ratnikov F., Ustyuzhanin A. et al., Physical Review Letters 2020 Vol. 124 No. 22 Article 222001
The Λ+cK− mass spectrum is studied with a data sample of pp collisions at a centre-of-mass energy of 13 TeV corresponding to an integrated luminosity of 5.6 fb−1 collected by the LHCb experiment. Three Ξ0c states are observed with a large significance and their masses and natural widths are measured to be
m(Ξc(2923)0)=2923.04±0.25±0.20±0.14 MeV,Γ(Ξc(2923)0)=7.1±0.8±1.8 MeV,
m(Ξc(2939)0)=2938.55±0.21±0.17±0.14 MeV,Γ(Ξc(2939)0)=10.2±0.8±1.1 MeV,
m(Ξc(2965)0)=2964.88±0.26±0.14±0.14 MeV,Γ(Ξc(2965)0)=14.1±0.9±1.3 MeV,
where the uncertainties are statistical, systematic, and due to the limited ...
Added: September 16, 2020
Ahdida C., Albanese R., Alexandrov A. et al., Journal of Instrumentation 2020 Vol. 15 Article P01027
The Search for Hidden Particles (SHiP) experiment proposal at CERN demands a dedicated dipole magnet for its scattering and neutrino detector. This requires a very large volume to be uniformly magnetized at B>1.2 T, with constraints regarding the inner instrumented volume as well as the external region, where no massive structures are allowed and only an ...
Added: October 14, 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
Ahdida C., Ratnikov F., Ustyuzhanin A. et al., The European Physical Journal C - Particles and Fields 2021 Vol. 81 Article 451
Dark photons are hypothetical massive vector particles that could mix with ordinary photons. The simplest theoretical model is fully characterised by only two parameters: the mass of the dark photon mγD and its mixing parameter with the photon, ε. The sensitivity of the SHiP detector is reviewed for dark photons in the mass range between 0.002 ...
Added: October 14, 2021
Aaij R., Abellán Beteta C., Ackernley T. et al., Physical Review Letters 2022 Vol. 128 No. 4 Article 041801
Branching fraction and effective lifetime measurements of the rare decay B0s→μ+μ− and searches for the decays B0→μ+μ− and B0s→μ+μ−γare reported using proton-proton collision data collected with the LHCb detector at centre-of-mass energies of 7 TeV, 8 TeV and 13 TeV, corresponding to a luminosity of 9 fb−1. The branching fraction Br(B0s→μ+μ−)=(3.09+0.46+0.15−0.43−0.11)×10−9 and the effective lifetime τ(B0s→μ+μ−)=(2.07±0.29±0.03) are measured, where the first uncertainty is statistical and the second systematic. No significant ...
Added: December 29, 2022
Aaij R., Arzymatov K., Belavin V. et al., Journal of High Energy Physics 2021 Vol. 5 Article 95
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, ...
Added: August 28, 2021
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Journal of High Energy Physics 2022 Vol. 2022 No. 1 Article 69
The first search for the rare radiative decay Ξ−𝑏→Ξ−γ is performed using data collected by the LHCb experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1. The Ξ−𝑏→ Ξ−J/ψ channel is used as normalization. No Ξ−𝑏→Ξ−γ signal is found and an upper limit of Br(Ξ−𝑏 → Ξ−γ) < 1.3 × 10−4 at 95% confidence level is ...
Added: December 29, 2022
Aaij R., Abdelmotteleb A. S., Abellán Beteta C. et al., Physical Review D - Particles, Fields, Gravitation and Cosmology 2021 Vol. 104 No. 11 Article 112008
A study of baryon decays to the Dp\Km final state is presented based on a proton-proton collision data sample corresponding to an integrated luminosity of 9\invfb collected with the LHCb detector. Two decays are considered, \Lb→D\proton\Km with D→\Km\pip and D→\Kp\pim, where D represents a superposition of and states. The latter process is expected to be ...
Added: October 15, 2021
М.И.Высоцкий, Долгов А. Д., В.А.Новиков, Успехи физических наук 2016 Т. 186 № 8 С. 869-878
Some important results of the 70 years of theoretical research at the Alikhanov Institute for Theoretical and Experimental Physics (ITEP) are reviewed. ...
Added: January 11, 2018
Boldyrev A., Derkach D., Hushchyn M. et al., / Cornell University. Series 01038 "2109". 2021.
Added: October 7, 2021
Курбатов Е. О., EPJ Web of Conferences 2019 No. 222 P. 02008-02008
A search for the rare leptonic decays was performed, using the proton-proton collision data collected with the LHCb experiment at center-ofmass energies of 8TeV and 13TeV. The following analysis are reviewed in this work:
• Measurements of the B0s → µ+µ− branching fraction and effective lifetime and search for B0 → µ+µ− decays
• Search for the decays B0s → τ+τ− and B0 → τ+τ−
• Search for the lepton-flavour violating decays B0(s) → e±µ∓
• Search ...
Added: November 19, 2019
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
Boldyrev A., Derkach D., Ratnikov F. et al., Reviews in Physics 2023 No. 100085 P. 1-117
The full optimization of the design and operation of instruments whose functioning relies on the interaction of radiation with matter is a super-human task, due to the large dimensionality of the space of possible choices for geometry, detection technology, materials, data-acquisition, and information-extraction techniques, and the interdependence of the related parameters. On the other hand, ...
Added: May 25, 2023
Katushkina O. A., Quemerais E., Izmodenov V.V. et al., JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 2017 Vol. 122 No. 11 P. 10921-10937
In this work, we present for the first time the Lyman α intensities measured by Voyager 1/UVS in 2003–2014 (at 90–130 AU from the Sun). During this period Voyager 1 measured the Lyman α emission in the outer heliosphere at an almost fixed direction close to the upwind (i.e.“ toward the interstellar flow). The data show an unexpected behavior in 2003–2009: the ...
Added: January 26, 2018
Aaij R., Abdelmotteleb A. S., Abellan Beteta C. et al., The European Physical Journal C - Particles and Fields 2023 Vol. 83 Article 543
https://link.springer.com/article/10.1140/epjc/s10052-023-11673-x#Abs1 ...
Added: December 4, 2023
Ружицкая Д. Д., САМОЙЛЕНКО А. А., Иванов А. Д. et al., Optoelectronics, Instrumentation and Data Processing 2017 Vol. 54 No. 1 P. 1-8
This paper presents an algorithm for processing the transmission spectra of whisperinggallery optical microcavities for use as a nanoparticle detector. The algorithm is based on the broadening of the microcavity resonance curve during precipitation of nanoparticles on the microcavity surface. Experimental results on the detection of particles are compared with Langmuir adsorption theory. The contribution ...
Added: May 25, 2018
М. : National Instruments Russia, 2017
Содержание сборника составляют доклады с результатами оригинальных исследований и технических решений, ранее не публиковавшиеся. Мы надеемся, что предлагаемый сборник окажется полезным для специалистов, работающих в различных областях науки и техники, для широкого круга преподавателей, аспирантов и студентов ВУЗов, а также для преподавателей средних школ и технических колледжей. ...
Added: May 10, 2017