Observation of an Excited Bc+ State

Using pp collision data corresponding to an integrated luminosity of 8.5 fb-1 recorded by the LHCb experiment at center-of-mass energies of s=7, 8, and 13 TeV, the observation of an excited Bc+ state in the Bc+π+π- invariant-mass spectrum is reported. The observed peak has a mass of 6841.2±0.6(stat)±0.1(syst)±0.8(Bc+) MeV/c2, where the last uncertainty is due to the limited knowledge of the Bc+ mass. It is consistent with expectations of the Bc∗(2S31)+ state reconstructed without the low-energy photon from the Bc∗(1S31)+→Bc+γ decay following Bc∗(2S31)+→Bc∗(1S31)+π+π-. A second state is seen with a global (local) statistical significance of 2.2σ (3.2σ) and a mass of 6872.1±1.3(stat)±0.1(syst)±0.8(Bc+) MeV/c2, and is consistent with the Bc(2S10)+ state. These mass measurements are the most precise to date

El clima laboral y su relación con el desempeño de los colaboradores de la empresa Tai Loy S.A. local El Golf de la ciudad de Trujillo en el I trimestre del año 2017

El objetivo de esta investigación fue determinar la relación entre el clima laboral y el desempeño de los colaboradores de la empresa Tai Loy S.A. local el Golf de la ciudad de Trujillo en el I Trimestre del año 2017, en el cual se evidenció el impacto que este tiene en los colaboradores de dicha empresa. La metodología empleada en la investigación fue la encuesta como técnica y los tests como instrumentos de aplicación de estas, además se realizó una entrevista para obtener datos adicionales que ayudaron con la investigación. La población de estudio estuvo constituida por 15 trabajadores, los mismos que fueron considerados como muestra a tratar, de los cuales nuestra población y muestra uno fueron los 14 colaboradores y nuestra población y muestra dos fueron los jefes inmediatos más el administrador. Mediante la utilización de métodos estadísticos la investigación concluye que no existe dicha relación entre el clima laboral y el desempeño de los colaboradores en esta empresa, salvo en una de las dimensiones que es Remuneración; por lo que inferimos que existe estímulos externos que impulsan el desempeño sin ser consecuencia de un buen clima laboral.The main objective of this research was to determine the relationsip between the working atmosphere and the job performance of the employees of the Tay loy Company, store of El Golf in Trujillo City, in the first trimester of 2017, where it was evident the impact of this factor in the job performance. It was used a survey as research technique and tests were applied as instruments of data collection. Moreover, in this research a deep interview was applied to the manager in order to find out additional and useful data for the research. All the 15 employees were taken as the population for this research, and the same group was considered as the sample for the research. They were divided in two samples: the first one were the 14 employees and the second sample was the immediate boss plus the manager. Using statistical methods, the research concluded that there is not relationship between working atmosphere and the job performance of the employees of this company, unless in one of the dimensions which was remuneration. Because of this it is inferred that there are external stimulus which impel the job performance without being a consequence of the working atmosphere.Tesi

Trabajo remoto y compromiso organizacional de los trabajadores de la universidad nacional Ciro Alegría

La presente tesis tuvo como objetivo, identificar si el trabajo remoto tiene relación o no significativamente en el compromiso organizacional de los trabajadores de la Universidad Nacional Ciro Alegría(UNCA), el tipo de investigación es correlacional y la población fue de 45 trabajadores en modalidad de trabajo remoto. Para recolectar datos se aplicó un cuestionario para cada variable. Del procesamiento y análisis de datos se concluye que, existe una relación directa y altamente significativa por parte del trabajo remoto en el compromiso organizacional de la UNCA, ya que, el coeficiente de correlación de Spearman es Rho = 0.756, con nivel de significancia menor al 1% (p < 0.01), existe relación directa y significativa por parte de los factores de riesgo psicosocial en el compromiso organizacional de los trabajadores de la UNCA, existe relación directa y altamente significativa del T/TICM en el compromiso organizacional de los trabajadores de la UNCA y existe una relación directa y altamente significativa del entorno socio digital en el compromiso organizacional de los trabajadores de la UNCA. Se recomienda monitorear los factores de riesgo psicosocial, implementar una política del derecho a la desconexión de las T/TICM, fortalecer el liderazgo y fomentar actividades que promuevan el equilibrio entre el trabajo y la familia de los trabajadores de la Universidad Nacional Ciro Alegría.Tesi

Nuclear matter distributions in the neutron-rich carbon isotopes 14−17C from intermediate-energy proton elastic scattering in inverse kinematics

The absolute differential cross sections for small-angle proton elastic scattering off the nuclei 12,14−17C have been measured in inverse kinematics at energies near 700 MeV/u at GSI Darmstadt. The hydrogen-filled ionization chamber IKAR served simultaneously as a gas target and a detector for the recoil protons. The projectile scattering angles were measured with multi-wire tracking detectors. The radial nuclear matter density distributions and the root-mean-square nuclear matter radii were deduced from the measured cross sections using the Glauber multiple-scattering theory. A possible neutron halo structure in 15C, 16C and 17C is discussed. The obtained data show evidence for a halo structure in the 15C nucleus

Measurement of the Charm-Mixing Parameter yCP

A measurement of the charm-mixing parameter y_{CP} using D^{0}→K^{+}K^{-}, D^{0}→π^{+}π^{-}, and D^{0}→K^{-}π^{+} decays is reported. The D^{0} mesons are required to originate from semimuonic decays of B^{-} and B[over ¯]^{0} mesons. These decays are partially reconstructed in a data set of proton-proton collisions at center-of-mass energies of 7 and 8 TeV collected with the LHCb experiment and corresponding to an integrated luminosity of 3  fb^{-1}. The y_{CP} parameter is measured to be (0.57±0.13(stat)±0.09(syst))%, in agreement with, and as precise as, the current world-average value

Measurement of the mass and production rate of Ξb− baryons

The first measurement of the production rate of Ξ − b baryons in p p collisions relative to that of Λ 0 b baryons is reported, using data samples collected by the LHCb experiment, and corresponding to integrated luminosities of 1, 2 and 1.6     fb − 1 at √ s = 7 , 8 and 13 TeV, respectively. In the kinematic region 2 &lt; η &lt; 6 and p T &lt; 20     GeV / c , we measure f Ξ − b f Λ 0 b B ( Ξ − b → J / ψ Ξ − ) B ( Λ 0 b → J / ψ Λ ) = ( 10.8 ± 0.9 ± 0.8 ) × 10 − 2 [ √ s = 7 , 8     TeV ], f Ξ − b f Λ 0 b B ( Ξ − b → J / ψ Ξ − ) B ( Λ 0 b → J / ψ Λ ) = ( 13.1 ± 1.1 ± 1.0 ) × 10 − 2 [ √ s = 13     TeV ], where f Ξ − b and f Λ 0 b are the fragmentation fractions of b quarks into Ξ − b and Λ 0 b baryons, respectively; B represents branching fractions; and the uncertainties are due to statistical and experimental systematic sources. The values of f Ξ − b / f Λ 0 b are obtained by invoking SU(3) symmetry in the Ξ − b → J / ψ Ξ − and Λ 0 b → J / ψ Λ decays. Production asymmetries between Ξ − b and ¯ Ξ + b baryons are also reported. The mass of the Ξ − b baryon is also measured relative to that of the Λ 0 b baryon, from which it is found that m ( Ξ − b ) = 5796.70 ± 0.39 ± 0.15 ± 0.17     MeV / c 2 , where the last uncertainty is due to the precision on the known Λ 0 b mass. This result represents the most precise determination of the Ξ − b mass

Search for CP violation through an amplitude analysis of D0 → K+K−π+π− decays

A search for CP violation in the Cabibbo-suppressed D0 → K+K−π +π − decay mode is performed using an amplitude analysis. The measurement uses a sample of pp collisions recorded by the LHCb experiment during 2011 and 2012, corresponding to an integrated luminosity of 3.0 fb−1 . The D0 mesons are reconstructed from semileptonic b-hadron decays into D0µ −X final states. The selected sample contains more than 160 000 signal decays, allowing the most precise amplitude modelling of this D0 decay to date. The obtained amplitude model is used to perform the search for CP violation. The result is compatible with CP symmetry, with a sensitivity ranging from 1% to 15% depending on the amplitude considered

Observation of CP Violation in Charm Decays

A search for charge-parity (CP) violation in D-0 -&gt; K-K+ and D-0 -&gt; pi(-)pi(+) decays is reported, using pp collision data corresponding to an integrated luminosity of 5.9 fb(-1) collected at a center-of-mass energy of 13 TeV with the LHCb detector. The flavor of the charm meson is inferred from the charge of the pion in D* (2010)(+) -&gt; D-0 pi(+) decays or from the charge of the muon in (B) over bar -&gt; D-0 mu(-)(nu) over bar X-mu decays. The difference between the CP asymmetries in D-0 -&gt; K-K+ and D-0 -&gt; pi(-)pi(+) decays is measured to be Delta A(CP) = [-18.2 +/- 3.2(stat) +/- 0.9(syst)] x 10(-4) for pi-tagged and Delta A(CP) = [-9 +/- 8(stat) +/- 5(syst)] x 10(-4) for mu-tagged D-0 mesons. Combining these with previous LHCb results leads to Delta A(CP) = (-15.4 +/- 2.9) x 10(-4), where the uncertainty includes both statistical and systematic contributions. The measured value differs from zero by more than 5 standard deviations. This is the first observation of CP violation in the decay of charm hadrons