# EP Articles

2018-07-16
15:53
 Measurement of $\Upsilon$ production in $pp$ collisions at $\sqrt{s}$= 13 TeV / LHCb Collaboration The production cross-sections of $\Upsilon(1S)$, $\Upsilon(2S)$ and $\Upsilon(3S)$ mesons in proton-proton collisions at $\sqrt{s}$= 13 TeV are measured with a data sample corresponding to an integrated luminosity of $277 \pm 11$ $\rm pb^{-1}$ recorded by the LHCb experiment in 2015. The $\Upsilon$ mesons are reconstructed in the decay mode $\Upsilon\to\mu^{+}\mu^{-}$. [...] LHCB-PAPER-2018-002; CERN-EP-2018-054; arXiv:1804.09214; LHCB-PAPER-2018-002.- 2018-07-20 - 26 p. - Published in : JHEP 07 (2018) 134 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP;

2018-07-06
10:51
 Measurement of the $\Omega_c^0$ baryon lifetime / LHCb Collaboration We report a measurement of the lifetime of the $\Omega_c^0$ baryon using proton-proton collision data at center-of-mass energies of 7 and 8~TeV, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ collected by the LHCb experiment. The sample consists of about 1000 $\Omega_b^-\to\Omega_c^0\mu^-\bar{\nu}_{\mu} X$ signal decays, where the $\Omega_c^0$ baryon is detected in the $pK^-K^-\pi^+$ final state and $X$ represents possible additional undetected particles in the decay. [...] arXiv:1807.02024; LHCb-PAPER-2018-028; CERN-EP-2018-175; LHCB-PAPER-2018-028; LHCB-PAPER-2018-028.- Geneva : CERN, 2018-09-01 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 092003 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-29
15:46
 Measurement of angular and CP asymmetries in $D^0\to\pi^+\pi^-\mu^+\mu^-$ and $D^0\to K^+K^-\mu^+\mu^-$ decays / LHCb Collaboration The first measurements of the forward-backward asymmetry of the dimuon pair ($A_{FB}$), the triple-product asymmetry ($A_{2\phi}$), and the charge-parity-conjugation asymmetry ($A_{CP}$), in $D^0\to\pi^+\pi^-\mu^+\mu^-$ and $D^0\to K^+K^-\mu^+\mu^-$ decays are reported. They are performed using data from proton-proton collisions collected with the LHCb experiment from 2011 to 2016, corresponding to a total integrated luminosity of 5 fb$^{-1}$. [...] arXiv:1806.10793; CERN-EP-2018-162; LHCb-PAPER-2018-020; LHCB-PAPER-2018-020.- Geneva : CERN, 2018-08-31 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 091801 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-28
12:03
 Observation of the decay $\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-$ in the $\phi$ mass region / LHCb Collaboration The $\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-$ decay mode is observed and its branching fraction relative to the corresponding $\chi_{c1}$ decay mode, in a $\pm 15 \textrm{MeV}/c^2$ window around the $\phi$ mass, is found to be $\frac{\mathcal{B}(\overline{B_s^0} \rightarrow \chi_{c2} K^+ K^-) }{ \mathcal{B}(\overline{B_s^0} \rightarrow \chi_{c1} K^+ K^-)} = (17.1 \pm 3.1 \pm 0.4 \pm 0.9)\%,$ where the first uncertainty is statistical, the second systematic and the third due to the knowledge of the branching fractions of radiative $\chi_c$ decays. The decay mode $\overline{B_s^0} \rightarrow \chi_{c1} K^+ K^-$ allows the $B_s^0$ mass to be measured as $m(B_s^0) = 5366.83 \pm 0.25 \pm 0.27 \, \textrm{MeV}/c^2,$ where the first uncertainty is statistical and the second systematic.. LHCb-PAPER-2018-018; CERN-EP-2018-160; arXiv:1806.10576; LHCB-PAPER-2018-018.- Geneva : CERN, 2018-08-29 - 20 p. - Published in : JHEP 08 (2018) 191 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-21
14:15
 Observation of the decay $\Lambda^0_b\rightarrow\psi(2S)p\pi^-$ / LHCb Collaboration The Cabibbo-suppressed decay $\Lambda^0_b\rightarrow\psi(2S)p\pi^-$ is observed for the first time using a data sample collected by the LHCb experiment in proton-proton collisions corresponding to 1.0, 2.0 and 1.9fb$^{-1}$ of integrated luminosity at centre-of-mass energies of 7, 8 and 13TeV, respectively. The branching fraction with respect to that of the $\Lambda^0_b\rightarrow\psi(2S)pK^-$ decay mode is measured to be $$\frac{\mathcal{B}\left(\Lambda^0_b\rightarrow\psi(2S)p\pi^- \right)}{\mathcal{B}\left(\Lambda^0_b\rightarrow\psi(2S)pK^-\right)}=\left(11.4 \pm 1.3 \pm 0.2\right)\!\%\,,$$ where the first uncertainty is statistical and the second is systematic. [...] CERN-EP-2018-156; LHCb-PAPER-2018-022; arXiv:1806.08084; LHCB-PAPER-2018-022; LHCB-PAPER-2018-022.- Geneva : CERN, 2018-08-21 - 16 p. - Published in : JHEP 08 (2018) 131 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-08
09:33
 First measurement of the lifetime of the doubly charmed baryon $\Xi_{cc}^{++}$ / LHCb Collaboration The first measurement of the lifetime of the doubly charmed baryon $\Xi_{cc}^{++}$ is presented, with the signal reconstructed in the final state $\Lambda_c^+ K^- \pi^+ \pi^+$. The data sample used corresponds to an integrated luminosity of $1.7\,\mathrm{fb}^{-1}$, collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of $13\mathrm{\,Te\kern -0.1em V}$. [...] arXiv:1806.02744; LHCb-PAPER-2018-019; CERN-EP-2018-146; LHCB-PAPER-2018-019.- Geneva : CERN, 2018-08-01 - 10 p. - Published in : Phys. Rev. Lett. 121 (2018) 052002 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-05
14:38
 Measurement of the CKM angle $\gamma$ using $B^\pm\to DK^\pm$ with $D\to K_\text{S}^0\pi^+\pi^-$, $K_\text{S}^0K^+K^-$ decays / LHCb Collaboration A binned Dalitz plot analysis of $B^\pm \to D K^\pm$ decays, with $D\to K_\text{S}^0\pi^+\pi^-$ and $D\to K_\text{S}^0K^+K^-$, is used to perform a measurement of the CP-violating observables $x_{\pm}$ and $y_{\pm}$, which are sensitive to the Cabibbo-Kobayashi-Maskawa angle $\gamma$. The analysis is performed without assuming any $D$ decay model, through the use of information on the strong-phase variation over the Dalitz plot from the CLEO collaboration. [...] LHCb-PAPER-2018-017; CERN-EP-2018-135; arXiv:1806.01202; LHCB-PAPER-2018-017.- Geneva : CERN, 2018-08-28 - 36 p. - Published in : JHEP 08 (2018) 176 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-06-01
09:09
 Measurement of $D_s^{\pm}$ production asymmetry in $pp$ collisions at $\sqrt{s} =7$ and 8 TeV / LHCb Collaboration The inclusive $D_s^{\pm}$ production asymmetry is measured in $pp$ collisions collected by the LHCb experiment at centre-of-mass energies of $\sqrt{s} =7$ and 8 TeV. Promptly produced $D_s^{\pm}$ mesons are used, which decay as $D_s^{\pm}\to\phi\pi^{\pm}$, with $\phi\to K^+K^-$ [...] arXiv:1805.09869; LHCb-PAPER-2018-010; CERN-EP-2018-073; LHCB-PAPER-2018-010.- Geneva : CERN, 2018-08-02 - 22 p. - Published in : JHEP 08 (2018) 008 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary Information: ZIP;

2018-05-28
14:55
 Observation of a new $\Xi_b^-$ resonance / LHCb Collaboration From samples of $pp$ collision data collected by the LHCb experiment at $\sqrt{s}=7$, $8$ and $13$ TeV corresponding to integrated luminosities of 1.0, 2.0 and 1.5 fb$^{-1}$, respectively, a peak in both the $\Lambda_b^0K^-$ and $\Xi_b^0\pi^-$ invariant mass spectra is observed. In the quark model, radially and orbitally excited $\Xi_b^-$ resonances with quark content $bds$ are expected. [...] arXiv:1805.09418; LHCb-PAPER-2018-013; CERN-EP-2018-108; LHCB-PAPER-2018-013.- Geneva : CERN, 2018-08-16 - 12 p. - Published in : Phys. Rev. Lett. 121 (2018) 072002 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2018-05-09
13:47
 Measurement of $CP$ violation in $B^{0}\rightarrow D^{\mp}\pi^{\pm}$ decays / LHCb Collaboration A measurement of the $CP$ asymmetries $S_{f}$ and $S_{\bar{f}}$ in $B^0\to D^{\mp}\pi^{\pm}$ decays is reported. The decays are reconstructed in a dataset collected with the LHCb experiment in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV and corresponding to an integrated luminosity of $3.0 \rm{ fb}^{-1}$. [...] LHCb-PAPER-2018-009; CERN-EP-2018-084; LHCB-PAPER-2018-009; arXiv:1805.03448; LHCB-PAPER-2018-009.- Geneva : CERN, 2018-06-18 - 24 p. - Published in : JHEP 06 (2018) 084 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;