# EP Articles

Последние добавления:
2021-11-08
11:29
 Study of ${\mathrm{B}}_{\mathrm{c}}^{+}$ decays to charmonia and three light hadrons / LHCb Collaboration Using proton-proton collision data, corresponding to an integrated luminosity of $9fb^{-1}$ collected with the LHCb detector, seven decay modes of the $B_c^+$ meson into a $J/\psi$ or $\psi(2S)$ meson and three charged hadrons, kaons or pions, are studied. The decays $B_c^+\rightarrow ( \psi(2S) \rightarrow J/\psi \pi^+ \pi^-)\pi^+$, $B_c^+\rightarrow \psi(2S)\pi^+\pi^+\pi^-$, $B_c^+\rightarrow J/\psi K^+\pi^+\pi^-$ and $B_c^+\rightarrow J/\psi K^+K^+K^-$ are observed for the first time, and evidence for the $B_c^+\rightarrow \psi(2S)K^+K^-\pi^+$ decay is found, where $J/\psi$ and $\psi(2S)$ mesons are reconstructed in their dimuon decay modes. [...] arXiv:2111.03001; CERN-EP-2021-216; LHCB-PAPER-2021-034.- Geneva : CERN, 2022-01-13 - 28 p. - Published in : JHEP 2201 (2022) 065 Fulltext: LHCb-PAPER-2021-034 - PDF; 2111.03001 - PDF; document - PDF; Related data file(s): ZIP;

2021-10-07
13:35
 Simultaneous determination of CKM angle $\gamma$ and charm mixing parameters / LHCb Collaboration A combination of measurements sensitive to the $C\!P$ violation angle $\gamma$ of the Cabibbo--Kobayashi--Maskawa unitarity triangle and to the charm mixing parameters that describe oscillations between $D^0$ and $\overline{D}^0$ mesons is performed. Results from the charm and beauty sectors, based on data collected with the LHCb detector at CERN's Large Hadron Collider, are combined for the first time. [...] arXiv:2110.02350; LHCb-PAPER-2021-033; CERN-EP-2021-183; LHCB-PAPER-2021-033.- Geneva : CERN, 2021-12-21 - 32 p. - Published in : JHEP 2112 (2021) 141 Fulltext: document - PDF; 2110.02350 - PDF; LHCb-PAPER-2021-033_v8 - PDF; Related data file(s): ZIP;

2021-09-17
13:44
 Observation of the suppressed $\Lambda_b^0\to D p K^-$ decay with $D\to K^+ \pi^-$ and measurement of its $C\!P$ asymmetry / LHCb Collaboration A study of $\Lambda^0_b$ baryon decays to the $DpK^-$ final state is presented based on a proton-proton collision data sample corresponding to an integrated luminosity of 9fb$^{-1}$ collected with the LHCb detector. Two $\Lambda^0_b$ decays are considered, $\Lambda^0_b\to DpK^-$ with $D\to K^-\pi^+$ and $D\to K^+\pi^-$, where $D$ represents a superposition of $D^0$ and $\overline{D}^0$ states. [...] arXiv:2109.02621; CERN-EP-2021-179; LHCB-PAPER-2021-027.- 2021-12-01 - 14 p. - Published in : Phys. Rev. D 104 (2021) 112008 Fulltext: 2109.02621 - PDF; LHCb-PAPER-2021-027 - PDF; Fulltext from publisher: PDF; Related data file(s): ZIP;

2021-09-16
11:03
 Search for the doubly charmed baryon $\it{\Xi}_{cc}^{+}$ in the $\it{\Xi}_{c}^{+} \pi^{-} \pi^{+}$ final state / LHCb Collaboration A search for the doubly charmed baryon $\it{\Xi}_{cc}^{+}$ is performed in the $\it{\Xi}_{c}^{+} \pi^{-} \pi^{+}$ invariant-mass spectrum, where the $\it{\Xi}_{c}^{+}$ baryon is reconstructed in the $p K^{-} \pi^{+}$ final state. The study uses proton-proton collision data collected with the LHCb detector at a centre-of-mass energy of 13$\mathrm{\,Te\kern -0.1em V}$, corresponding to a total integrated luminosity of 5.4$\,\mathrm{fb}^{-1}$. [...] arXiv:2109.07292; CERN-EP-2021-155; LHCB-PAPER-2021-019.- Geneva : CERN, 2021 - 27 p. - Published in : JHEP 2112 (2021) 107 Fulltext: LHCb-PAPER-2021-019 - PDF; 2109.07292 - PDF; Fulltext from publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-03
13:57
 Measurement of the $W$ boson mass / LHCb Collaboration The $W$ boson mass is measured using proton-proton collision data at $\sqrt{s}=13$ TeV corresponding to an integrated luminosity of 1.7 fb$^{-1}$ recorded during 2016 by the LHCb experiment. With a simultaneous fit of the muon $q/p_T$ distribution of a sample of $W \to \mu\nu$ decays and the $\phi^*$ distribution of a sample of $Z\to\mu\mu$ decays the $W$ boson mass is determined to be \begin{equation*} m_{W} = 80354 \pm 23_{\rm stat} \pm 10_{\rm exp} \pm 17_{\rm theory} \pm 9_{\rm PDF}~\mathrm{MeV}, \end{equation*} where uncertainties correspond to contributions from statistical, experimental systematic, theoretical and parton distribution function sources. [...] arXiv:2109.01113; CERN-EP-2021-170; LHCB-PAPER-2021-024.- Geneva : CERN, 2022-01-10 - 38 p. - Published in : JHEP 2201 (2022) 036 Fulltext: 2021-024 - PDF; 2109.01113 - PDF; document - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-02
11:54
 Updated search for $B_c^+$ decays to two charm mesons / LHCb Collaboration A data set corresponding to an integrated luminosity of $9 \text{\, fb}^{-1}$ of proton-proton collisions collected by the LHCb experiment has been analysed to search for $B_c^+ \to D^{(*)+}_{(s)} (\overline{D})^{(*)0}$ decays. The decays are fully or partially reconstructed, where one or two missing neutral pions or photons from the decay of an excited charm meson are allowed. [...] arXiv:2109.00488; LHCb-PAPER-2021-023; CERN-EP-2021-154; LHCB-PAPER-2021-023.- Geneva : CERN, 2021 - 23 p. - Published in : JHEP 2112 (2021) 117 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-09-02
11:51
 Measurement of $J/\psi$ production cross-sections in $pp$ collisions at $\sqrt{s}=5$ TeV / LHCb Collaboration The production cross-sections of $J/\psi$ mesons in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=5$ TeV are measured using a data sample corresponding to an integrated luminosity of $9.13\pm0.18~\text{pb}^{-1}$, collected by the LHCb experiment. The cross-sections are measured differentially as a function of transverse momentum, $p_{\text{T}}$, and rapidity, $y$, and separately for $J/\psi$ mesons produced promptly and from beauty hadron decays (nonprompt). [...] arXiv:2109.00220; LHCb-PAPER-2021-020,CERN-EP-2021-156; LHCB-PAPER-2021-020.- Geneva : CERN, 2021 - 34 p. - Published in : JHEP 2111 (2021) 181 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-08-24
10:52
 Measurement of the $B^0_s\to\mu^+\mu^-$ decay properties and search for the $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ decays / LHCb Collaboration An improved measurement of the decay $B^0_s\to\mu^+\mu^-$ and searches for the decays $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ are performed at the LHCb experiment using data collected in proton-proton collisions at $\sqrt{s} = 7,~8$ and $13$ TeV, corresponding to integrated luminosities of 1, 2 and 6 fb$^{-1}$, respectively. The $B^0_s\to\mu^+\mu^-$ branching fraction and effective lifetime are measured to be ${\mathcal{B}}(B^0_s\to\mu^+\mu^-)=\left(3.09^{+0.46+0.15}_{-0.43-0.11}\right)\times 10^{-9}$ and $\tau(B^0_s\to\mu^+\mu^-)=(2.07\pm 0.29\pm 0.03)$ ps, respectively, where the uncertainties include both statistical and systematic contributions. [...] arXiv:2108.09283; CERN-EP-2021-133; LHCb-PAPER-2021-008; LHCB-PAPER-2021-008.- 2022-01-01 - 52 p. - Published in : Phys. Rev. D 105 (2022) 012010 Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-08-23
14:45
 Analysis of neutral $B$-meson decays into two muons / LHCb Collaboration Branching fraction and effective lifetime measurements of the rare decay $B^0_s\to\mu^+\mu^-$ and searches for the decays $B^0\to\mu^+\mu^-$ and $B^0_s\to\mu^+\mu^-\gamma$ are 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 ${\mathcal{B}}(B^0_s\to\mu^+\mu^-)=\left(3.09^{+0.46+0.15}_{-0.43-0.11}\right)\times 10^{-9}$ and the effective lifetime $\tau(B^0_s\to\mu^+\mu^-)=(2.07\pm 0.29\pm 0.03)$ are measured, where the first uncertainty is statistical and the second systematic. [...] arXiv:2108.09284; CERN-CERN-EP-2021-132; LHCb-PAPER-2021-007; LHCB-PAPER-2021-007.- Geneva : CERN, 2022-01-25 - 20 p. - Published in : Phys. Rev. Lett. 128 (2022) 041801 Fulltext: PDF; Related data file(s): ZIP;

2021-08-23
10:29
 Search for the radiative $\Xi_b^-\to\Xi^-\gamma$ decay / LHCb Collaboration The first search for the rare radiative decay $\Xi_{b}^{-} \to \Xi^{-} \gamma$ 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 $\Xi_{b}^{-} \to \Xi^{-} J/\psi$ channel is used as normalization. [...] arXiv:2108.07678; CERN-EP-2021-128; LHCB-PAPER-2021-017.- 2022-01-14 - 20 p. - Published in : JHEP 2201 (2022) 069 Fulltext: 2108.07678 - PDF; document - PDF; Related data file(s): ZIP;