Particle-yield modification in jet-like azimuthal di-hadron correlations in Pb-Pb collisions at sNN\sqrt{s_{\rm NN}} = 2.76 TeV

The yield of charged particles associated with high-$p_{\rm T}$ trigger particles ($8 < p_{\rm T} < 15$ GeV/$c$) is measured with the ALICE detector in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 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 $p_{\rm T}> 3$ GeV/$c$ 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 $3\times 10^{18}$ eV, for all zenith angles between 0$^\circ$ and 60$^\circ$, 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

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

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

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

Transverse momentum spectra of charged particles in proton-proton collisions at 1as=900 GeV with ALICE at the LHC

The inclusive charged particle transverse momentum distribution is measured in proton-proton collisions at s=900 GeV at the LHC using the ALICE detector. The measurement is performed in the central pseudorapidity region (|\u3b7|<0.8) over the transverse momentum range 0.15<10 GeV/c. The correlation between transverse momentum and particle multiplicity is also studied. Results are presented for inelastic (INEL) and non-single-diffractive (NSD) events. The average transverse momentum for |\u3b7|<0.8 is \u3008pT\u3009INEL=0.483\ub10.001 (stat.)\ub10.007 (syst.) GeV/c and \u3008pT\u3009NSD=0.489\ub10.001 (stat.)\ub10.007 (syst.) GeV/c, respectively. The data exhibit a slightly larger \u3008pT\u3009 than measurements in wider pseudorapidity intervals. The results are compared to simulations with the Monte Carlo event generators PYTHIA and PHOJET. \ua9 2010

Femtoscopy of pp collisions at sqrt[s]=0.9 and 7\ua0TeV at the LHC with two-pion Bose-Einstein correlations

We report on the high statistics two-pion correlation functions from pp collisions at root s = 0.9 TeV and root s = 7 TeV, measured by the ALICE experiment at the Large Hadron Collider. The correlation functions as well as the extracted source radii scale with event multiplicity and pair momentum. When analyzed in the same multiplicity and pair transverse momentum range, the correlation is similar at the two collision energies. A three-dimensional femtoscopic analysis shows an increase of the emission zone with increasing event multiplicity as well as decreasing homogeneity lengths with increasing transverse momentum. The latter trend gets more pronounced as multiplicity increases. This suggests the development of space-momentum correlations, at least for collisions producing a high multiplicity of particles. We consider these trends in the context of previous femtoscopic studies in high-energy hadron and heavy-ion collisions and discuss possible underlying physics mechanisms. Detailed analysis of the correlation reveals an exponential shape in the outward and longitudinal directions, while the sideward remains a Gaussian. This is interpreted as a result of a significant contribution of strongly decaying resonances to the emission region shape. Significant nonfemtoscopic correlations are observed, and are argued to be the consequence of "mini-jet"-like structures extending to low p(t). They are well reproduced by the Monte-Carlo generators and seen also in pi(+)pi(-) correlations