CERN Accelerating science

EP Articles

Ultimi arrivi:
2019-07-18
17:03
Precision measurement of the $\Lambda_c^+$, $\Xi_c^+$ and $\Xi_c^0$ baryon lifetimes / LHCb Collaboration
We report measurements of the lifetimes of the $\Lambda_c^+$, $\Xi_c^+$ and $\Xi_c^0$ charm baryons 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 charm baryons are reconstructed through the decays $\Lambda_c^+\to pK^-\pi^+$, $\Xi_c^+\to pK^-\pi^+$ and $\Xi_c^0\to pK^-K^-\pi^+$, and originate from semimuonic decays of beauty baryons. [...]
arXiv:1906.08350; LHCb-PAPER-2019-008; CERN-EP-2019-122; LHCB-PAPER-2019-008.- 2019-08-02 - 12 p. - Published in : Phys. Rev. D 100 (2019) 032001 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-07-02
10:45
Observation of the $\Lambda_b^0\rightarrow \chi_{c1}(3872)pK^-$ decay / LHCb Collaboration
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 $\Lambda_b^0\to \chi_{c1}(3872)pK^-$ with $\chi_{c1}\to J/\psi\pi^+\pi^-$ is observed for the first time. The significance of the observed signal is in excess of seven standard deviations. [...]
arXiv:1907.00954; CERN-EP-2019-131; LHCb-PAPER-2019-023; LHCB-PAPER-2019-023.- 2019-09-03 - 21 p. - Published in : JHEP 1909 (2019) 028 Article from SCOAP3: PDF; Fulltext: LHCb-PAPER-2019-023 - PDF; 1907.00954 - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-06-21
17:31
Updated measurement of time-dependent CP-violating observables in $B^0_s \to J/\psi K^+K^-$ decays / LHCb Collaboration
The decay-time-dependent {\it CP} asymmetry in $B^{0}_{s}\to J/\psi K^{+} K^{-}$ decays is measured using proton-proton collision data, corresponding to an integrated luminosity of $1.9\,\mathrm{fb^{-1}}$, collected with the LHCb detector at a centre-of-mass energy of $13\,\mathrm{TeV}$ in 2015 and 2016. Using a sample of approximately 117\,000 signal decays with an invariant $K^{+} K^{-}$ mass in the vicinity of the $\phi(1020)$ resonance, the {\it CP}-violating phase $\phi_s$ is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the $B^{0}_{s}$-$\overline{B}^{0}_{s}$ system, $\Delta\Gamma_s$. [...]
arXiv:1906.08356; LHCb-PAPER-2019-013; CERN-EP-2019-108; LHCB-PAPER-2019-013.- Geneva : CERN, 2019-08-22 - 42 p. - Published in : Eur. Phys. J. C 79 (2019) 706 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-06-21
17:07
Measurement of $C\!P$ observables in the process $B^0 \to DK^{*0}$ with two- and four-body $D$ decays / LHCb Collaboration
Measurements of $C\!P$ observables in $B^0 \to DK^{*0}$ decays are presented, where $D$ represents a superposition of $D^0$ and $\bar{D}^0$ states. The $D$ meson is reconstructed in the two-body final states $K^+\pi^-$, $\pi^+ K^-$, $K^+K^-$ and $\pi^+\pi^-$, and, for the first time, in the four-body final states $K^+\pi^-\pi^+\pi^-$, $\pi^+ K^-\pi^+\pi^-$ and $\pi^+\pi^-\pi^+\pi^-$. [...]
arXiv:1906.08297; LHCb-PAPER-2019-021; CERN-EP-2019-111.- Geneva : CERN, 2019-08-07 - 30 p. - Published in : JHEP 1908 (2019) 041 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-05-16
14:53
Amplitude analysis of the $B^0_{(s)} \to K^{*0} \overline{K}^{*0}$ decays and measurement of the branching fraction of the $B^0 \to K^{*0} \overline{K}^{*0}$ decay / LHCb Collaboration
The $B^0 \to K^{*0} \overline{K}^{*0}$ and $B^0_s \to K^{*0} \overline{K}^{*0}$ decays are studied using proton-proton collision data corresponding to an integrated luminosity of 3fb$^{-1}$. An untagged and time-integrated amplitude analysis of $B^0_{(s)} \to (K^+\pi^-)(K^-\pi^+) $ decays in two-body invariant mass regions of 150 MeV$/c^2$ around the $K^{*0}$ mass is performed. [...]
arXiv:1905.06662; LHCb-PAPER-2019-004; CERN-EP-2019-063; LHCB-PAPER-2019-004.- Geneva : CERN, 2019-07-05 - 30 p. - Published in : JHEP 1907 (2019) 032 Article from SCOAP3: PDF; Fulltext: LHCb-PAPER-2019-004 - PDF; 1905.06662 - PDF; Related data file(s): ZIP;

Record dettagliato - Record simili
2019-05-16
14:31
Measurement of $CP$-violating and mixing-induced observables in $B_s^0 \to \phi\gamma$ decays / LHCb Collaboration
A time-dependent analysis of the $B_s^0 \to \phi\gamma$ decay rate is performed to determine the $CP$-violating observables $S_{\phi\gamma}$ and $C_{\phi\gamma}$, and the mixing-induced observable $\mathcal{A}^{\Delta}_{\phi\gamma}$. The measurement is based on a sample of $pp$ collision data recorded with the LHCb detector, corresponding to an integrated luminosity of 3 fb$^{-1}$ at center-of-mass energies of 7 and 8 TeV. [...]
arXiv:1905.06284; LHCb-PAPER-2019-015; CERN-EP-2019-077; LHCb-PAPER-2019-015; CERN-EP-2019-077; LHCB-PAPER-2019-015.- 2019-08-28 - 10 p. - Published in : Phys. Rev. Lett. 123 (2019) 081802 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP;

Record dettagliato - Record simili
2019-04-10
11:16
Observation of a narrow pentaquark state, $P_c(4312)^+$, and of two-peak structure of the $P_c(4450)^+$ / LHCb Collaboration
A narrow pentaquark state, $P_c(4312)^+$, decaying to $J/\psi p$ is discovered with a statistical significance of $7.3\sigma$ in a data sample of $\Lambda_b^0\to J/\psi p K^-$ decays which is an order of magnitude larger than that previously analyzed by the LHCb collaboration. The $P_c(4450)^+$ pentaquark structure formerly reported by LHCb is confirmed and observed to consist of two narrow overlapping peaks, $P_c(4440)^+$ and $P_c(4457)^+$, where the statistical significance of this two-peak interpretation is $5.4\sigma$. [...]
arXiv:1904.03947; LHCb-PAPER-2019-014 CERN-EP-2019-058; LHCB-PAPER-2019-014.- Geneva : CERN, 2019-06-06 - 11 p. - Published in : Phys. Rev. Lett. 122 (2019) 222001 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP; External link: SYMMETRY

Record dettagliato - Record simili
2019-04-01
11:42
Observation of an excited $B_c^+$ state / LHCb Collaboration
Using $pp$ collision data corresponding to an integrated luminosity of $8.5\,\mathrm{fb}^{-1}$ recorded by the LHCb experiment at centre-of-mass energies of $\sqrt{s} = 7$, $8$ and $13\mathrm{\,Te\kern -0.1em V}$, the observation of an excited $B_c^+$ state in the $B_c^+\pi^+\pi^-$ invariant-mass spectrum is reported. The state has a mass of $6841.2 \pm 0.6 {\,\rm (stat)\,} \pm 0.1 {\,\rm (syst)\,} \pm 0.8\,(B_c^+) \mathrm{\,MeV}/c^2$, where the last uncertainty is due to the limited knowledge of the $B_c^+$ mass. [...]
arXiv:1904.00081; CERN-EP-2019-050; LHCb-PAPER-2019-007.- Geneva : CERN, 2019-06-11 - 10 p. - Published in : Phys. Rev. Lett. 122 (2019) 232001 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-04-01
09:46
Near-threshold $D\bar{D}$ spectroscopy and observation of a new charmonium state / LHCb Collaboration
Using proton-proton collisiondata, corresponding to an integrated luminosity of 9 fb$^{-1}$, collected with the~LHCb detector between 2011 and 2018, a new narrow charmonium state, the $X(3842)$ resonance, is observed in the decay modes $X(3842)\rightarrow D^0\bar{D}^0$ and $X(3842)\rightarrow D^+D^-$. The mass and the natural width of this state are measured to be \begin{eqnarray*} m_{X(3842)} & = & 3842.71 \pm 0.16 \pm 0.12~ \text {MeV}/c^2\,, \\ \Gamma_{X(3842)} & = & 2.79 \pm 0.51 \pm 0.35 ~ \text {MeV}\,, \end{eqnarray*} where the first uncertainty is statistical and the second is systematic. [...]
arXiv:1903.12240; CERN-EP-2019-047; LHCb-PAPER-2019-005; LHCB-PAPER-2019-005.- Geneva : CERN, 2019-07-08 - 23 p. - Published in : JHEP 1907 (2019) 035 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili
2019-03-22
09:21
Search for lepton-universality violation in $B^+\to K^+\ell^+\ell^-$ decays / LHCb Collaboration
A measurement of the ratio of branching fractions of the decays $B^+\to K^+\mu^+\mu^-$ and $B^+\to K^+e^+e^-$ is presented. The proton-proton collision data used correspond to an integrated luminosity of $5.0$ fb$^{-1}$ recorded with the LHCb experiment at centre-of-mass energies of $7$, $8$ and $13$ TeV. [...]
arXiv:1903.09252; LHCb-PAPER-2019-009; CERN-EP-2019-043; LHCb-PAPER-2019-009 CERN-EP-2019-043.- Geneva : CERN, 2019-05-14 - 13 p. - Published in : Phys. Rev. Lett. 122 (2019) 191801 Article from SCOAP3: PDF; Fulltext: 1903.09252 - PDF; LHCb-PAPER-2019-009 - PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

Record dettagliato - Record simili