34 research outputs found
Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at = 2.76 TeV
The yield of charged particles associated with high- trigger
particles ( GeV/) is measured with the ALICE detector in
Pb-Pb collisions at = 2.76 TeV relative to proton-proton
collisions at the same energy. The conditional per-trigger yields are extracted
from the narrow jet-like correlation peaks in azimuthal di-hadron correlations.
In the 5% most central collisions, we observe that the yield of associated
charged particles with transverse momenta GeV/ on the
away-side drops to about 60% of that observed in pp collisions, while on the
near-side a moderate enhancement of 20-30% is found.Comment: 15 pages, 2 captioned figures, 1 table, authors from page 10,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/350
Trigger and Aperture of the Surface Detector Array of the Pierre Auger Observatory
The surface detector array of the Pierre Auger Observatory consists of 1600
water-Cherenkov detectors, for the study of extensive air showers (EAS)
generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy,
from the identification of candidate showers at the level of a single detector,
amongst a large background (mainly random single cosmic ray muons), up to the
selection of real events and the rejection of random coincidences. Such trigger
makes the surface detector array fully efficient for the detection of EAS with
energy above eV, for all zenith angles between 0 and
60, independently of the position of the impact point and of the mass
of the primary particle. In these range of energies and angles, the exposure of
the surface array can be determined purely on the basis of the geometrical
acceptance.Comment: 29 pages, 12 figure
Ultrahigh energy neutrinos at the Pierre Auger observatory
The observation of ultrahigh energy neutrinos (UHEνs) has become a priority in experimental astroparticle physics. UHEνs can be detected with a variety of techniques. In particular, neutrinos can interact in the atmosphere (downward-going ν) or in the Earth crust (Earth-skimming ν), producing air showers that can be observed with arrays of detectors at the ground. With the surface detector array of the Pierre Auger Observatory we can detect these types of cascades. The distinguishing signature for neutrino events is the presence of very inclined showers produced close to the ground (i.e., after having traversed a large amount of atmosphere). In this work we review the procedure and criteria established to search for UHEνs in the data collected with the ground array of the Pierre Auger Observatory. This includes Earth-skimming as well as downward-going neutrinos. No neutrino candidates have been found, which allows us to place competitive limits to the diffuse flux of UHEνs in the EeV range and above.P. Abreu ... K. B. Barber ... J. A. Bellido ... R. W. Clay ... M. J. Cooper ... B. R. Dawson ... T. A. Harrison ... A. E. Herve ... V. C. Holmes ... J. Sorokin ... P. Wahrlich ... B. J. Whelan ... et al
Evolution of the longitudinal and azimuthal structure of the near-side jet peak in Pb-Pb collisions at 1asNN = 2.76 TeV
In two-particle angular correlation measurements, jets give rise to a near-side peak, formed by particles associated to a higher-pT trigger particle. Measurements of these correlations as a function of pseudorapidity ( \u3b7) and azimuthal ( \u3c6) differences are used to extract the centrality and pT dependence of the shape of the near-side peak in the pT range 1 < pT < 8 GeV/c in Pb-Pb and pp collisions at 1asNN = 2.76 TeV. A combined fit of the near-side peak and long-range correlations is applied to the data and the peak shape is quantified by the variance of the distributions. While the width of the peak in the \u3c6 direction is almost independent of centrality, a significant broadening in the \u3b7 direction is found from peripheral to central collisions. This feature is prominent for the low-pT region and vanishes above 4 GeV/c. The widths measured in peripheral collisions are equal to those in pp collisions in the \u3c6 direction and above 3 GeV/c in the \u3b7 direction. Furthermore, for the 10% most central collisions and 1 < pT,assoc < 2 GeV/c, 1 < pT,trig < 3 GeV/c, a departure from a Gaussian shape is found: a depletion develops around the center of the peak. The results are compared to A Multi-Phase Transport (AMPT) model simulation as well as other theoretical calculations indicating that the broadening and the development of the depletion are connected to the strength of radial and longitudinal flow
Elliptic flow of identified hadrons in Pb-Pb collisions at 1asNN = 2.76 TeV
The elliptic flow coefficient (v2) of identified particles in Pb-Pb collisions at 1asNN = 2.76 TeV was measured with the ALICE detector at the Large Hadron Collider (LHC). The results were obtained with the Scalar Product method, a two-particle corre- lation technique, using a pseudo-rapidity gap of | 06\u3b7| > 0.9 between the identified hadron under study and the reference particles. The v2 is reported for \u3c0\ub1, K\ub1, K0S, p+p, \u3c6, \u39b+\u39b, \u39e 12+\u39e+ and \u3a9 12+\u3a9+ in several collision centralities. In the low transverse momentum (pT) region, pT 3 GeV/c
Centrality dependence of inclusive J/\u3c8 production in p-Pb collisions at 1asNN = 5.02 TeV
We present a measurement of inclusive J/\u3c8 production in p-Pb collisions at 1asNN = 5.02TeV as a function of the centrality of the collision, as estimated from the energy deposited in the Zero Degree Calorimeters. The measurement is performed with the ALICE detector down to zero transverse momentum, pT, in the backward ( 124.46 < ycms < 122.96) and forward (2.03 < ycms < 3.53) rapidity intervals in the dimuon decay channel and in the mid-rapidity region ( 121.37 < ycms < 0.43) in the dielectron decay channel. The backward and forward rapidity intervals correspond to the Pb-going and p-going direction, respectively. The pT-differential J/\u3c8 production cross section at backward and forward rapidity is measured for several centrality classes, together with the corresponding average pT and pT2 values. The nuclear modification factor is presented as a function of centrality for the three rapidity intervals, and as a function of pT for several centrality classes at backward and forward rapidity. At mid- and forward rapidity, the J/\u3c8 yield is suppressed up to 40% compared to that in pp interactions scaled by the number of binary collisions. The degree of suppression increases towards central p-Pb collisions at forward rapidity, and with decreasing pT of the J/\u3c8. At backward rapidity, the nuclear modification factor is compatible with unity within the total uncertainties, with an increasing trend from peripheral to central p-Pb collisions
Centrality dependence of high-pT D meson suppression in Pb-Pb collisions at 1asNN = 2.76 TeV
The nuclear modification factor, RAA, of the prompt charmed mesons D0, D+ and D 17+, and their antiparticles, was measured with the ALICE detector in Pb-Pb collisions at a centre-of-mass energy 1asNN = 2.76 TeV in two transverse momentum intervals, 5 < pT < 8GeV/c and 8 < pT < 16GeV/c, and in six collision centrality classes. The RAA shows a maximum suppression of a factor of 5\u20136 in the 10% most central collisions. The suppression and its centrality dependence are compatible within uncertainties with those of charged pions. A comparison with the RAA of non-prompt J/\u3c8 from B meson decays, measured by the CMS Collaboration, hints at a larger suppression of D mesons in the most central collisions
Impacto del proyecto PERSECC en la productividad de las MYPES de calzado de la ciudad de Trujillo, 2017
RESUMEN
La presente investigación tiene como propósito determinar el impacto del proyecto creado por
la Oficina de Proyectos de Investigación, Desarrollo e Innovación de CITEccal Trujillo, el
“Proyecto de Reactivación del Sector Cuero y Calzado” en la productividad de las MYPES del
sector calzado en relación con la incidencia que tenga este con el comportamiento de las
ventas, producción y demás indicadores de las empresas que aplicaron a PERSECC durante el
año 2017, con la finalidad de demostrar la labor del Estado al tomar medidas orientadas a
elevar los niveles de competitividad de las empresas en estudio en relación a la reactivación de
dicho sector.
Para el desarrollo del presente trabajo de investigación, se utilizaron fuentes de información
primaria debido a que serán documentos directos que se obtendrán de la oficina de
Investigación, Desarrollo e Innovación de CITEccal Trujillo. Para esto, se tuvo en cuenta el
análisis de la documentación de los datos recopilados del registro anual y evolución trimestral
de ventas, producción, capacidad instalada, capacidad productiva, inversión en I+D+i, recurso
humano, plan de acción del programa PERSECC, los cuales fueron facilitados directamente del
área de la oficina de proyectos I+D+i para la realización del proyecto. Luego, se recopilaron los
datos a través del análisis documental para ser procesados en tablas y gráficos, en seguida se
determinaron las medias usando la Prueba T - Student para datos relacionados (muestras
dependientes). Finalmente para medir la relación entre las variables en estudio se calculó el
valor de probabilidad estadístico por el cual se rechaza la hipótesis nula y se acepta la
hipótesis alternativa.
De esta manera, la investigación llega a la conclusión que existen diferencias estadísticamente
significativas entre los valores trimestrales de todos los indicadores analizados de las MYPES
de calzado de la ciudad de Trujillo anteriores y posteriores de la aplicación del proyecto
PERSECC, lo que significa que el proyecto PERSECC incide de manera significativa en la
evolución de los indicadores de la productividad de cada una de las empresas del sector
Calzado que aplicaron al proyecto. La principal recomendación que se hace al área de
Proyectos I+D+i, es que el jefe de Proyectos autorice la continuación de la aplicación anual del
Proyecto PERSECC con la finalidad de ampliar la participación de más MYPES, manteniendo
un continuo control del registro de la data con respecto a la evaluación y seguimiento de
indicadores en la mejora de su productividad y de esta manera, definir mejor el apoyo de la
labor que viene realizando el CITEccal Trujillo para el aumento de la competitividad de las
empresas del sector calzado.
Palabras clave: Proyecto, Soporte Productivo, I+D, Productividad, Mypes (Micro y Pequeñas
Empresas), Sector Calzado, Producción Calzado, Comercio Calzado.ABSTRACT
The purpose of this research is to determine the impact of the project created by the Research,
Development and Innovation Projects Office of CITEccal Trujillo, the "PERSECC" project in the
productivity of the MSEs of the footwear sector in relation to the impact that this has with the
behavior of sales, production and other indicators of the companies that applied to PERSECC
during the year 2017, in order to demonstrate the work of the State to take measures aimed at
raising the levels of competitiveness of companies under study in relation to the reactivation of
this sector.
For the development of this research work, primary information sources were used because
they will be direct documents that will be obtained from the Research, Development and
Innovation office of CITEccal Trujillo. For this, the analysis of the documentation of the annual
record and quarterly evolution of sales, production, installed capacity, productive capacity,
investment in R & D & I, human resources, action plan of the PERSECC program was taken
account, which were provided directly from the area of the R + D + i project office for the
realization of the project. Then, the data was collected through the documentary analysis to be
processed in tables and graphs, consequently sample means were determined using the T -
Student test for related data (dependent samples). Finally, to measure the relationship between
the variables under study, it has been estimated the statistical probability value by which the null
hypothesis is rejected and the alternative hypothesis is accepted.
The main recommendation made to the area of R + D + i Projects, is that the Project Manager
continues to authorize the application of the PERSECC Project in the coming years in order to
expand the participation of more MYPES, maintaining a continuous control of the registry of the
data with respect to the evaluation and monitoring of indicators to improve their productivity and,
in this way, better define the support of the work that CITEccal Trujillo has been doing to
increase the competitiveness of companies in the footwear sector
Energy dependence of exclusive J/\u3c8 photoproduction off protons in ultra-peripheral p\u2013Pb collisions at 1asNN = 5.02 TeV
The ALICE Collaboration has measured the energy dependence of exclusive photoproduction of J/\u3c8 vec- tor mesons off proton targets in ultra\u2013peripheral p\u2013Pb colli- sions at a centre-of-mass energy per nucleon pair 1asNN = 5.02 TeV. The e+ e 12 and \u3bc+ \u3bc 12 decay channels are used to measure the cross section as a function of the rapidity of the J/\u3c8 in the range 122.5 < y < 2.7, correspond- ing to an energy in the \u3b3p centre-of-mass in the interval 40 < W\u3b3 p < 550 GeV. The measurements, which are consis- tent with a power law dependence of the exclusive J/\u3c8 pho- toproduction cross section, are compared to previous results from HERA and the LHC and to several theoretical models. They are found to be compatible with previous measure- ments
Centrality dependence of \u3c0, K, and p production in Pb-Pb collisions at sqrt[s_{NN}]=2.76 TeV
In this paper measurements are presented of \u3c0\ub1, K\ub1, p, and p(bar) production at midrapidity (|y| < 0.5), in Pb-Pb collisions at 1asNN= 2.76 TeV as a function of centrality. The measurement covers the transverse-momentum (pT ) range from 100, 200, and 300 MeV/c up to 3, 3, and 4.6 GeV/c for \u3c0, K, and p, respectively. The measured pT distributions and yields are compared to expectations based on hydrodynamic, thermal and recombination models. The spectral shapes of central collisions show a stronger radial flow than measured at lower energies, which can be described in hydrodynamic models. In peripheral collisions, the pT distributions are not well reproduced by hydrodynamic models. Ratios of integrated particle yields are found to be nearly independent of centrality. The yield of protons normalized to pions is a factor 3c1.5 lower than the expectation from thermal models