106 research outputs found

    Performance and characteristics of Piau's carcass

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    Foram estudadas as “performances” e as caracterĂ­sticas da carcaça em uma amostra de um rebanho da raça Piau. O experimento foi feito com 20 suĂ­nos distribuĂ­dos em lotes de 4 animais com cinco repetiçÔes. Os resultados mais importantes obtidos foram: a) 239 dias de idade para alcançar 90 kg; b) ganho diĂĄrio, 0,469 kg; c) peso da carcaça resfriada, 71,348 kg; d) comprimento da carcaça resfriada, 69,48 cm; e) espessura do toucinho, 5,39 cm; f) total dos cortes nobres, 32,82% e 26,93% em relação Ă  carcaça resfriada e ao peso vivo, respectivamente e g) ĂĄrea do olho do lombo entre a 10.ÂȘ e a 11.ÂȘ costelas, 18,12 cm. Os resultados encontrados pelo teste "t" mostram que as caracterĂ­sticas gerais da carcaça e as percentagens dos cortes nobres sobre o peso vivo e sobre a carcaça foram inferiores Ă s do suĂ­no tipo carne, sendo as diferenças altamente significativas (exceção do comprimento da carcaça).The performance and characteristics of carcass were studied in Piau's race. The experiment was carried out with 20 hogs, divided in five treatments, with four repetitions. The most important obtained results were: a) days to reach 90 kg; b) daily gain, 0.469 kg; c) weight of the cooled carcass 71.348 kg; d) length of the cooled carcass 69.48 cm; e) lard thickness 5.39 cm; f) total of prime cuts in relation to the cooled carcass 32.82% and 26.93% with respect to the living weight, and g) loin-oye area between the 10 th and the 11 th ribs 18.12 cm2. The results obtained by the "t" test demonstrate that the general characteristics of the carcass and the percentages of the prime cuts, related to the live weight and to the carcass, were inferior to the pig meat type, with highly significant differences (with exception of the length of the carcass)

    Investigation of K+K− interactions via femtoscopy in Pb-Pb collisions at √sNN = 2.76 TeV at the CERN Large Hadron Collider

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    Femtoscopic correlations of non-identical charged kaons (K+K−) are studied in Pb−Pb collisions at a center-of-mass energy per nucleon−nucleon collision sNN−−−√=2.76 TeV by ALICE at the LHC. One-dimensional K+K− correlation functions are analyzed in three centrality classes and eight intervals of particle-pair transverse momentum. The LednickĂœ and Luboshitz interaction model used in the K+K− analysis includes the final-state Coulomb interactions between kaons and the final-state interaction through a0(980) and f0(980) resonances. The mass of f0(980) and coupling were extracted from the fit to K+K− correlation functions using the femtoscopic technique for the first time. The measured mass and width of the f0(980) resonance are consistent with other published measurements. The height of the ϕ(1020) meson peak present in the K+K− correlation function rapidly decreases with increasing source radius, qualitatively in agreement with an inverse volume dependence. A phenomenological fit to this trend suggests that the ϕ(1020) meson yield is dominated by particles produced directly from the hadronization of the system. The small fraction subsequently produced by FSI could not be precisely quantified with data presented in this paper and will be assessed in future work

    Two-particle transverse momentum correlations in pp and p-Pb collisions at energies available at the CERN Large Hadron Collider

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    Two-particle transverse momentum differential correlators, recently measured in Pb-Pb collisions at LHC energies, provide an additional tool to gain insights into particle production mechanisms and infer transport properties, such as the ratio of shear viscosity to entropy density, of the medium created in Pb-Pb collisions. The longitudinal long-range correlations and the large azimuthal anisotropy measured at low transverse momenta in small collision systems, namely pp and p-Pb, at LHC energies resemble manifestations of collective behaviour. This suggests that locally equilibrated matter may be produced in these small collision systems, similar to what is observed in Pb-Pb collisions. In this work, the same two-particle transverse momentum differential correlators are exploited in pp and p-Pb collisions at s√=7 TeV and sNN−−−√=5.02 TeV, respectively, to seek evidence for viscous effects. Specifically, the strength and shape of the correlators are studied as a function of the produced particle multiplicity to identify evidence for longitudinal broadening that might reveal the presence of viscous effects in these smaller systems. The measured correlators and their evolution from pp and p-Pb to Pb-Pb collisions are additionally compared to predictions from Monte Carlo event generators, and the potential presence of viscous effects is discussed

    Measurement of the lifetime and Λ separation energy of 3ΛH

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    The most precise measurements to date of the 3ΛH lifetime τ and Λ separation energy BΛ are obtained using the data sample of Pb-Pb collisions at √= 5.02 TeV collected by ALICE at the LHC. The 3ΛH is reconsNN structed via its charged two-body mesonic decay channel (3ΛH→ 3He + π− and the charge-conjugate process). The measured values τ=[253±11 (stat.)±6 (syst.)] ps and BΛ=[102±63 (stat.)±67 (syst.)] keV are compatible with predictions from effective field theories and confirm that the 3ΛH structure is consistent with a weakly-bound system

    Inclusive photon production at forward rapidities in pp and p–Pb collisions at sNN=5.02\sqrt{{{s}}_{\textrm{NN}}}={5.02} TeV

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    International audienceA study of multiplicity and pseudorapidity distributions of inclusive photons measured in pp and p–Pb collisions at a center-of-mass energy per nucleon–nucleon collision of sNN = 5.02\sqrt{s_{\textrm{NN}}}~=~5.02 TeV using the ALICE detector in the forward pseudorapidity region 2.3 < ηlab <<~\eta _\textrm{lab} ~< 3.9 is presented. Measurements in p–Pb collisions are reported for two beam configurations in which the directions of the proton and lead ion beam were reversed. The pseudorapidity distributions in p–Pb collisions are obtained for seven centrality classes which are defined based on different event activity estimators, i.e., the charged-particle multiplicity measured at midrapidity as well as the energy deposited in a calorimeter at beam rapidity. The inclusive photon multiplicity distributions for both pp and p–Pb collisions are described by double negative binomial distributions. The pseudorapidity distributions of inclusive photons are compared to those of charged particles at midrapidity in pp collisions and for different centrality classes in p–Pb collisions. The results are compared to predictions from various Monte Carlo event generators. None of the generators considered in this paper reproduces the inclusive photon multiplicity distributions in the reported multiplicity range. The pseudorapidity distributions are, however, better described by the same generators

    Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at s\sqrt{s} = 5.02 and 13 TeV

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    Two-particle transverse momentum correlations in pp and p-Pb collisions at LHC energies

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    Measurement of the radius dependence of charged-particle jet suppression in Pb–Pb collisions at sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV

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    The ALICE Collaboration reports a new differential measurement of inclusive jet suppression using pp and Pb–Pb collision data at center-of-mass energy per nucleon–nucleon collision sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV. Charged-particle jets are reconstructed using the anti-kTk_{\rm T} algorithm with resolution parameters RR = 0.2, 0.3, 0.4, 0.5, and 0.6 in pp collisions and RR = 0.2, 0.4, 0.6 in central (0–10\%), semi-central (30–50\%), and peripheral (60–80\%) Pb–Pb collisions. The analysis uses a novel approach based on machine learning to mitigate the influence of jet background in central heavy-ion collisions, which enables measurements of inclusive jet suppression for jet pT≄40p_{\rm T} \ge 40 GeV/cc in central collisions at a resolution parameter of RR = 0.6. This is the lowest value of jet pTp_{\rm T} achieved for inclusive jet measurements at RR = 0.6 at the LHC, and is an important step for discriminating different models of jet quenching in the quark-gluon plasma. The transverse momentum spectra, nuclear modification factors, and derived cross section and nuclear modification factor ratios for different jet resolution parameters of charged-particle jets are presented and compared to model predictions. A mild dependence of the nuclear modification factor ratios on collision centrality and resolution parameter is observed. The results are compared to a variety of jet quenching models with varying levels of agreement, demonstrating the effectiveness of this observable to discriminate between models.The ALICE Collaboration reports a new differential measurement of inclusive jet suppression using pp and Pb−-Pb collision data at center-of-mass energy per nucleon-nucleon collision sNN=5.02\sqrt{s_{\rm NN}} = 5.02 TeV. Charged-particle jets are reconstructed using the anti-kTk_{\rm T} algorithm with resolution parameters R=R = 0.2, 0.3, 0.4, 0.5, and 0.6 in pp collisions and R=R = 0.2, 0.4, 0.6 in central (0−-10%), semi-central (30−-50%), and peripheral (60−-80%) Pb−-Pb collisions. The analysis uses a novel approach based on machine learning to mitigate the influence of jet background in central heavy-ion collisions, which enables measurements of inclusive jet suppression for jet pT≄40p_{\rm T} \geq 40 GeV/cc in central collisions at a resolution parameter of R=0.6R = 0.6. This is the lowest value of jet pTp_{\rm T} achieved for inclusive jet measurements at R=0.6R=0.6 at the LHC, and is an important step for discriminating different models of jet quenching in the quark-gluon plasma. The transverse momentum spectra, nuclear modification factors, and derived cross section and nuclear modification factor ratios for different jet resolution parameters of charged-particle jets are presented and compared to model predictions. A mild dependence of the nuclear modification factor ratios on collision centrality and resolution parameter is observed. The results are compared to a variety of jet quenching models with varying levels of agreement, demonstrating the effectiveness of this observable to discriminate between models

    Symmetry plane correlations in Pb–Pb collisions at √sNN = 2.76 TeV

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    A newly developed observable for correlations between symmetry planes, which characterize the direction of the anisotropic emission of produced particles, is measured in Pb-Pb collisions at sNN−−−√=2.76 TeV with ALICE. This so-called Gaussian Estimator allows for the first time the study of these quantities without the influence of correlations between different flow amplitudes. The centrality dependence of various correlations between two, three and four symmetry planes is presented. The ordering of magnitude between these symmetry plane correlations is discussed and the results of the Gaussian Estimator are compared with measurements of previously used estimators. The results utilizing the new estimator lead to significantly smaller correlations than reported by studies using the Scalar Product method. Furthermore, the obtained symmetry plane correlations are compared to state-of-the-art hydrodynamic model calculations for the evolution of heavy-ion collisions. While the model predictions provide a qualitative description of the data, quantitative agreement is not always observed, particularly for correlators with significant non-linear response of the medium to initial state anisotropies of the collision system. As these results provide unique and independent information, their usage in future Bayesian analysis can further constrain our knowledge on the properties of the QCD matter produced in ultrarelativistic heavy-ion collisions

    Measurement of the impact-parameter dependent azimuthal anisotropy in coherent ρ0 photoproduction in Pb–Pb collisions at √sNN = 5.02 TeV

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    The first measurement of the impact-parameter dependent angular anisotropy in the decay of coherently photoproduced ρ0 mesons is presented. The ρ0 mesons are reconstructed through their decay into a pion pair. The measured anisotropy corresponds to the amplitude of the cos(2ϕ) modulation, where ϕ is the angle between the two vectors formed by the sum and the difference of the transverse momenta of the pions, respectively. The measurement was performed by the ALICE Collaboration at the LHC using data from ultraperipheral Pb−Pb collisions at a center-of-mass energy of sNN−−−√ = 5.02 TeV per nucleon pair. Different impact-parameter regions are selected by classifying the events in nuclear-breakup classes. The amplitude of the cos(2ϕ) modulation is found to increase by about one order of magnitude from large to small impact parameters. Theoretical calculations, which describe the measurement, explain the cos(2ϕ) anisotropy as the result of a quantum interference effect at the femtometer scale that arises from the ambiguity as to which of the nuclei is the source of the photon in the interaction
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