Nocturnal position in the Panamanian Golden Frog, Atelopus zeteki (Anura, Bufonidae), with notes on fluorescent pigment tracking

La rana dorada de Panamá, Atelopus zeteki, una especie en peligro de extinción, habita en los ríos de los bosques lluviosos de mediana elevación del istmo panameño. Con el propósito de conocer mejor ésta especie para su conservación, decidimos determinar los sitios de descanso nocturno de estos animales, los cuales se caracterizan por ser activos durante el día. Suponíamos que los machos adultos y los juveniles podrían ocupar micro hábitat distintos durante la noche, basándose en las diferencias en tamaños y patrones de coloración. Los resultados presentados aquí demuestran que, al caer la noche los machos adultos trepan significativamente más alto que los juveniles y que la distancia de estos movimientos desde el punto inicial hasta la posición final de descanso es también significativamente diferente. Estos cambios de posición durante el día y la noche de los machos adultos podrían estar relacionados con una conducta antipredatoria. Finalmente este estudio demuestra que con el uso de pigmentos fluorescentes es posible rastrear anfibios en los bosques lluviosos con habitates húmedos a mojados a través de distancias cortas a moderadas de manera exitosa.The endangered Panamanian golden frog, Atelopus zeteki, is a stream dweller of middle elevation rain forests of the Panamanian isthmus. In order to better understand this species for conservation, we set out to determine the nocturnal whereabouts of this diurnally active animal. It was expected that adult males and juveniles might occupy different nocturnal microhabitats based on differences in size, coloration and patterning. Findings presented here demonstrate that adult males climb significantly higher than juveniles at night and that movement distances to final resting positions also significantly differed. This change in diurnal and nocturnal position in adult males may be related to predator vigilance and avoidance. Lastly, this study demonstrated that individual rain forest amphibians can be successfully tracked over short to moderate distances in humid to wet environments using fluorescent pigments

Nocturnal Position in the Panamanian Golden Frog Atelopus Zeteki (Anura Bufonidae) With Notes on Fluorescent Pigment Tracking

The endangered Panamanian golden frog, Atelopus zeteki, is a stream dweller of middle elevation rain forests of the Panamanian isthmus. In order to better understand this species for conservation, we set out to determine the nocturnal whereabouts of this diurnally active animal. It was expected that adult males and juveniles might occupy different nocturnal microhabitats based on differences in size, coloration and patterning. Findings presented here demonstrate that adult males climb significantly higher than juveniles at night and that movement distances to final resting positions also significantly differed. This change in diurnal and nocturnal position in adult males may be related to predator vigilance and avoidance. Lastly, this study demonstrated that individual rain forest amphibians can be successfully tracked over short to moderate distances in humid to wet environments using fluorescent pigments. © 2007 Departamento de Ciências Biológicas

Evidence of a J/ψΛJ/\psi\Lambda structure and observation of excited Ξ−\Xi^- states in the Ξb−→J/ψΛK−\Xi^-_b \to J/\psi\Lambda K^- decay

First evidence of a structure in the $J/\psi{\Lambda}$ invariant mass distribution is obtained from an amplitude analysis of $\Xi_b^-{\rightarrow}J/\psi{\Lambda}K^-$ decays. The observed structure is consistent with being due to a charmonium pentaquark with strangeness with a significance of $3.1\sigma$ including systematic uncertainties and look-elsewhere effect. Its mass and width are determined to be $4458.8\pm2.9^{+4.7}_{-1.1}$ MeV and $17.3\pm6.5^{+8.0}_{-5.7}$ MeV, respectively, where the quoted uncertainties are statistical and systematic. The structure is also consistent with being due to two resonances. In addition, the narrow excited $\Xi^-$ states, $\Xi(1690)^-$ and $\Xi(1820)^-$, are seen for the first time in a $\Xi^-_b$ decay, and their masses and widths are measured with improved precision. The analysis is performed using $pp$ collision data corresponding to a total integrated luminosity of 9 fb$^{-1}$, collected with the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV

Branching Fraction Measurements of the Rare Bs0→ϕμ+μ−B^0_s\rightarrow\phi\mu^+\mu^- and Bs0→f2′(1525)μ+μ−B^0_s\rightarrow f_2^\prime(1525)\mu^+\mu^- Decays

The branching fraction of the rare $B^0_s\rightarrow\phi\mu^+\mu^-$ decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6 fb$^{-1}$, respectively. The branching fraction is reported in intervals of q$^2$, the square of the dimuon invariant mass. In the q$^2$ region between 1.1 and 6.0 GeV$^2$/c$^4$, the measurement is found to lie 3.6 standard deviations below a standard model prediction based on a combination of light cone sum rule and lattice QCD calculations. In addition, the first observation of the rare $B^0_s\rightarrow f_2^\prime(1525)\mu^+\mu^-$ decay is reported with a statistical significance of 9 standard deviations and its branching fraction is determined

Branching Fraction Measurements of the Rare Bs0→ϕμ+μ−B^0_s\rightarrow\phi\mu^+\mu^- and Bs0→f2′(1525)μ+μ−B^0_s\rightarrow f_2^\prime(1525)\mu^+\mu^-- Decays

International audienceThe branching fraction of the rare Bs0→ϕμ+μ- decay is measured using data collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to integrated luminosities of 1, 2, and 6  fb-1, respectively. The branching fraction is reported in intervals of q2, the square of the dimuon invariant mass. In the q2 region between 1.1 and 6.0  GeV2/c4, the measurement is found to lie 3.6 standard deviations below a standard model prediction based on a combination of light cone sum rule and lattice QCD calculations. In addition, the first observation of the rare Bs0→f2′(1525)μ+μ- decay is reported with a statistical significance of 9 standard deviations and its branching fraction is determined

Observation of excited Ωc0\Omega_c^0 baryons in Ωb−→Ξc+K−π−\Omega_b^- \to \Xi_c^+ K^-\pi^-decays

International audienceThe first observation of the Ωb-→Ξc+K-π- decay is reported using p p collision data at center of mass energies of 7, 8, and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb-1. Four excited Ωc0 baryons are observed in the Ξc+ K- mass projection of the Ωb-→Ξc+K-π- decays with the significance of each exceeding five standard deviations. They coincide with the states previously observed in prompt pp and e+e- production. Relative production rates, masses, and natural widths of the states are measured, and a test of spin hypotheses is performed. Moreover, the branching ratio of Ωb-→Ξc+K-π- is measured relative to the Ωb-→Ωc0π- decay mode and a precise measurement of the Ωb- mass of 6044.3±1.2±1.1-0.22+0.19  MeV is obtained

Observation of excited Ωc0\Omega_c^0 baryons in Ωb−→Ξc+K−π−\Omega_b^- \to \Xi_c^+ K^-\pi^-decays

The first observation of the $Ω_b^- → Ξ_c^+ K^- π^-$ decay is reported using p p collision data at center of mass energies of 7, 8, and 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb$^{-1}$. Four excited $Ω_c^0$ baryons are observed in the $Ξ_c^+ K^-$ mass projection of the $Ω_b^-→ Ξ_c^+ K^- π^-$ decays with the significance of each exceeding five standard deviations. They coincide with the states previously observed in prompt pp and $e^+ e^-$ production. Relative production rates, masses, and natural widths of the states are measured, and a test of spin hypotheses is performed. Moreover, the branching ratio of $Ω_b^- → Ξ_c^+ K^- π^-$ is measured relative to the $Ω_b^- → Ω_c^0 π^-$ decay mode and a precise measurement of the $Ω_b^-$ mass of $6044.3±1.2±1.1_{-0.22}^{+0.19}$ MeV is obtained

Observation of a Λb0−Λ‾b0\Lambda_b^0-\overline{\Lambda}_b^0 production asymmetry in proton-proton collisions at s=7 and 8 TeV\sqrt{s} = 7 \textrm{ and } 8\,\textrm{TeV}

International audienceThis article presents differential measurements of the asymmetry between ${\varLambda}_b^0$ and ${\overline{\varLambda}}_b^0$ baryon production rates in proton-proton collisions at centre-of-mass energies of $\sqrt{s}$ = 7 and 8 TeV collected with the LHCb experiment, corresponding to an integrated luminosity of 3 fb$^{−1}$. The ${\varLambda}_b^0$ baryons are reconstructed through the inclusive semileptonic decay ${\varLambda}_b^0$ → ${\varLambda}_c^{+}$μ$^{−} \overline{\nu} _{μ}$X. The production asymmetry is measured both in intervals of rapidity in the range 2.15 < y < 4.10 and transverse momentum in 2 < p$_{T}$< 27 GeV/c. The results are found to be incompatible with symmetric production with a significance of 5.8 standard deviations for both $\sqrt{s}$ = 7 and 8 TeV data, assuming no CP violation in the decay. There is evidence for a trend as a function of rapidity with a significance of 4 standard deviations. Comparisons to predictions from hadronisation models in Pythia and heavy-quark recombination are provided. This result constitutes the first observation of a particle-antiparticle asymmetry in b-hadron production at LHC energies.[graphic not available: see fulltext

Search for the doubly heavy baryons Ωbc0\Omega^0_{bc} and Ξbc0\Xi^0_{bc} decaying to Λc+π−\Lambda^+_c \pi^- and Ξc+π−\Xi^+_c \pi^-

The first search for the doubly heavy baryon and a search for the baryon are performed using collision data collected via the experiment from 2016 to 2018 at a centre-of-mass energy of , corresponding to an integrated luminosity of 5.2 . The baryons are reconstructed via their decays to and . No significant excess is found for invariant masses between 6700 and 7300 , in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 . Upper limits are set on the ratio of the and production cross-section times the branching fraction to ( ) relative to that of the ( ) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from to for the ( ) decay, and from to for the ( ) decay, depending on the considered mass and lifetime of the ( ) baryon