# EP Articles

2021-05-06
16:33
 Lattice sites of implanted Na in GaN and AlN in comparison to other light alkalis and alkaline earths / Wahl, Ulrich (Universidade de Lisboa (PT)) ; David Bosne, Eric (Universidade de Lisboa (PT)) ; Amorim, Lígia (KU Leuven) ; Granadeiro Costa, Angelo Rafael (Universidade de Lisboa (PT)) ; De Vries, Bart (KU Leuven) ; Martins Correia, Joao (Universidade de Lisboa (PT)) ; da Silva, Manuel Ribeiro (CICECO Aveiro) ; Da Costa Pereira, Lino Miguel (KU Leuven (BE)) ; Vantomme, André (KU Leuven) /IS634 Collaboration The lattice location of ion implanted radioactive 24Na (t1/2=14.96 h) in GaN and AlN was determined using the emission channeling technique at the ISOLDE/CERN facility. In the room temperature as-implanted state in both GaN and AlN, the majority of the sodium atoms are found on interstitial sites near the octahedral position, with a minority on cation Ga or Al substitutional sites. [...] CERN-ISOLDE-2021-003.- 2021 - 12 p. - Published in : J. Appl. Phys. 128 (2020) 045703 Postprint: PDF; Supplemental Material: PDF;

2021-05-06
16:10
 Direct Structural Identification and Quantification of the Split-Vacancy Configuration for Implanted Sn in Diamond / Wahl, Ulrich (Universidade de Lisboa (PT)) ; Martins Correia, Joao (Universidade de Lisboa (PT)) ; Villarreal, Renan (KU Leuven) ; Bourgeois, Emilie (Hasselt University) ; Gulka, Michal (Hasselt University) ; Nesladek, Milos (Hasselt University) ; Vantomme, André (KU Leuven) ; Da Costa Pereira, Lino Miguel (KU Leuven (BE)) /EC-SLI Collaboration ; IS368 Collaboration We demonstrate formation of the ideal split-vacancy configuration of the Sn-vacancy center upon implantation into natural diamond. Using beta-emission channeling following low fluence 121Sn implantation (2E12 atoms/cm2, 60 keV) at the ISOLDE facility at CERN, we directly identified and quantified the atomic configurations of the Sn-related centers. [...] CERN-ISOLDE-2021-002.- 2021 - 7 p. - Published in : Phys. Rev. Lett. 125 (2020) 045301 Postprint: PDF; Supplemental material: PDF;

2021-03-22
11:02
 Search for $CP$ violation in $D_{(s)}^{+}\rightarrow h^{+}\pi^{0}$ and $D_{(s)}^{+}\rightarrow h^{+}\eta$ decays / LHCb Collaboration Searches for $CP$ violation in the two-body decays $D_{(s)}^{+}\rightarrow h^{+}\pi^{0}$ and $D_{(s)}^{+} \rightarrow h^{+}\eta$ (where $h^{+}$ denotes a $\pi^{+}$ or $K^{+}$ meson) are performed using $pp$ collision data collected by the LHCb experiment corresponding to either 9 fb$^{-1}$ or 6 fb$^{-1}$ of integrated luminosity. The $\pi^{0}$ and $\eta$ mesons are reconstructed using the $e^{+}e^{-}\gamma$ final state, which can proceed as three-body decays $\pi^{0}\rightarrow e^{+}e^{-}\gamma$ and $\eta \rightarrow e^{+}e^{-}\gamma$, or via the two-body decays $\pi^{0}\rightarrow \gamma\gamma$ and $\eta\rightarrow\gamma\gamma$ followed by a photon conversion. [...] arXiv:2103.11058; LHCb-PAPER-2021-001; CERN-EP-2021-036; LHCB-PAPER-2021-001.- Geneva : CERN, 2021 - 25 p. - Published in : JHEP 2106 (2021) 019 Article from SCOAP3: PDF; Fulltext: PDF; Preprint: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-03-18
20:11
 Study of an Air Curtain in the Context of Individual Protection from Exposure to Coronavirus (SARS-CoV-2) Contained in Cough-Generated Fluid Particles / Sakharov, Alexandre (Manhattan College (US) ; CERN) ; Zhukov, Konstantin (Russian Academy of Sciences (RU) ; CERN) The ongoing respiratory COVID-19 pandemic has heavily impacted the social and private lives of the majority of the global population. This infection is primarily transmitted via virus-laden fluid particles (i.e., droplets and aerosols) that are formed in the respiratory tract of infected individuals and expelled from the mouth in the course of breathing, talking, coughing, and sneezing. [...] CERN-OPEN-2021-005.- Geneva : CERN, 2020 - 12 p. - Published in : Physics 2 (2020) 340-351 Article: PDF;

2021-03-15
11:44
 Measurement of prompt-production cross-section ratio $\sigma(\chi_{c2})/\sigma(\chi_{c1})$ in $p$Pb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV / LHCb Collaboration This Letter reports the first measurement of prompt $\chi_{c1}$ and $\chi_{c2}$ charmonium production in nuclear collisions at LHC energies. The cross-section ratio $\sigma(\chi_{c2}) / \sigma(\chi_{c1})$ is measured in $p$Pb collisions at $\sqrt{s_{NN}}$~=~8.16~TeV, collected with the LHCb experiment. [...] arXiv:2103.07349; LHCb-PAPER-2020-048; CERN-EP-2021-024F; LHCB-PAPER-2020-048.- 2021-06-09 - 18 p. - Published in : Phys. Rev. C 103 (2021) 064905 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP;

2021-03-09
15:28
 Observation of the decay $\Lambda_b^0\rightarrow\chi_{c1}p\pi^-$ / LHCb Collaboration The Cabibbo-suppressed decay $\Lambda_b^0\rightarrow\chi_{c1}p\pi^-$ is observed for the first time using data from proton-proton collisions corresponding to an integrated luminosity of 6fb$^{-1}$, collected with the LHCb detector at a centre-of-mass energy of 13TeV. Evidence for the $\Lambda_b^0\rightarrow\chi_{c2}p\pi^-$decay is also found [...] arXiv:2103.04949; CERN-EP-2021-037; LHCb-PAPER-2021-003; LHCB-PAPER-2021-003.- 2021-05-12 - 21 p. - Published in : JHEP 2105 (2021) 095 Article from SCOAP3: PDF; Fulltext: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-01-05
10:04
 Angular Analysis of the $B^{+}\rightarrow K^{\ast+}\mu^{+}\mu^{-}$ Decay / LHCb Collaboration We present an angular analysis of the $B^{+}\rightarrow K^{\ast+}(\rightarrow K_{S}^{0}\pi^{+})\mu^{+}\mu^{-}$ decay using 9$\,\mbox{fb}^{-1}$ 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. [...] arXiv:2012.13241; LHCb-PAPER-2020-041; CERN-EP-2020-239.- 2021-04-23 - 11 p. - Published in : Phys. Rev. Lett. 126 (2021) 161802 Article from SCOAP3: PDF; Fulltext: PDF; Fulltext from Publisher: PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-01-05
09:46
 Observation of the $B_s^0 \rightarrow D^{\ast \pm} D^{\mp}$ decay / LHCb Collaboration A search for the $B^0_s \!\rightarrow D^{*\pm} D^\mp$ decay is performed using proton-proton collision data at centre-of-mass energies of $7$, $8$ and $13\,\text{TeV}$ collected by the LHCb experiment, corresponding to an integrated luminosity of $9\,\text{fb}^{-1}$. The decay is observed with a high significance and its branching fraction relative to the $B^0 \!\rightarrow D^{*\pm} D^\mp$ decay is measured to be \begin{align*} \frac{\mathcal{B}(B_s^0 \rightarrow D^{\ast \pm} D^{\mp}) }{\mathcal{B}(B^0 \rightarrow D^{\ast \pm} D^{\mp}) } = 0.137 \pm 0.017 \pm 0.002 \pm 0.006 \,, \end{align*} where the first uncertainty is statistical, the second systematic and the third is due to the uncertainty on the ratio of the $B_s^0$ and $B^0$ hadronisation fractions.. arXiv:2012.11341; LHCb-PAPER-2020-037; CERN-EP-2020-230.- 2021-03-09 - 19 p. - Published in : JHEP 2103 (2021) 099 Article from SCOAP3: PDF; Fulltext: 2012.11341 - PDF; LHCb-PAPER-2020-037 - PDF; Related data file(s): ZIP; Supplementary information: ZIP;

2021-01-04
13:51
 Measurement of CP violation in the decay $B^{+} \rightarrow K^{+} \pi^{0}$ / LHCb Collaboration A measurement of direct CP violation in the decay $B^{+} \rightarrow K^{+} \pi^{0}$ is reported using a data sample corresponding to an integrated luminosity of 5.4 $\textrm{fb}^{-1}$, collected with the LHCb experiment at a center-of-mass energy of $\sqrt{s}=13$ TeV. The CP asymmetry is measured to be $0.025 \pm 0.015 \pm 0.006 \pm 0.003$, where the uncertainties are statistical, systematic, and due to an external input, respectively. [...] arXiv:2012.12789; LHCb-PAPER-2020-040; CERN-EP-2020-242.- 2021-03-02 - 11 p. - Published in : Phys. Rev. Lett. 126 (2021) 091802 Article from SCOAP3: PDF; Fulltext: 2012.12789 - PDF; LHCb-PAPER-2020-040_arXiv - PDF; Related data file(s): ZIP; supplementary information: ZIP;

2020-12-18
10:36
 Measurement of $C\!P$ observables in $B^\pm \to D^{(*)} K^\pm$ and $B^\pm \to D^{(*)} \pi^\pm$ decays using two-body $D$ final states / LHCb Collaboration Measurements of $C\!P$ observables in $B^\pm \rightarrow D^{(*)} K^\pm$ and $B^\pm \rightarrow D^{(*)} \pi^\pm$ decays are presented, where $D^{(*)}$ indicates a neutral $D$ or $D^*$ meson that is an admixture of meson and anti-meson states. Decays of the $D^*$ meson to the $D\pi^0$ and $D\gamma$ final states are partially reconstructed without inclusion of the neutral pion or photon. [...] arXiv:2012.09903; LHCb-PAPER-2020-036; CERN-EP-2020-225; LHCB-PAPER-2020-036.- 2021-04-09 - 36 p. - Published in : JHEP 2104 (2021) 081 Article from SCOAP3: PDF; Fulltext: 2012.09903 - PDF; LHCb-PAPER-2020-036 - PDF; Related data file(s): ZIP; Supplementary information: ZIP;