12 research outputs found

    Study and characterization of global solar radiation and incident UV in the city of Leon, Guanajuato, Mexico

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    Controlled sun exposure can greatly benefit vitamin D synthesis, however, irresponsible sun exposure can cause considerable biological damage. Among the extraterrestrial solar radiation that reaches the earth's surface, UV rays are characterized by having the shortest wavelengths (less than 400 nm) and the highest frequencies, which is why they concentrate a large amount of energy. In particular, radiation with wavelengths less than 300 nm can alter DNA molecules and cause biological damage such as skin changes, cataracts, possible mutations, immunosuppression, photoaging and many other conditions. Therefore, this research estimates the global solar radiation and the incident daily UV radiation, as well as the UV index in order to identify the possible dose of absorbed radiation and consequently identify the relevant protection actions for the local population

    Nuevos enfoques en derechos humanos, irenología y métodos de solución de conflictos

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    El objeto de la presente publicación consiste en ofrecer reflexiones científicas sobre los progresos en nuevos enfoques doctrinarios los cuales sirvan de base para analizar la situación actual, así como diversas perspectivas en los derechos humanos, la irenología y los métodos de solución de conflictos. Los problemas respecto a las temåticas planteadas usualmente abordados desde el dualismo reduccionista de lo que es y lo que debe ser, en la presente obra son extendidos a partir del anålisis científico e interdisciplinario, y sustentado en diversas perspectivas de abordaje a las problemåticas sociales para interpretarlas y darles solución en la mecånica y funcionamiento de nuevas situaciones y realidades emergentes. Esta obra ha sido edificada de forma colectiva y gira en torno a tres ejes temåticos conexos, los cuales son los derechos humanos, la irenología y los métodos de solución de conflictos, cada eje temåtico se encuentra construido por tres capítulos en los que trabajaron diecisiete investigadores adscritos a la Universidad Autónoma de Nuevo León de México, la Universidad Autónoma de Coahuila de México, la Universidad de la Costa de Colombia y la Universidad Rey Juan Carlos de España

    ÎŁ(1385)± resonance production in Pb–Pb collisions at √sNN = 5.02 TeV

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    Hadronic resonances are used to probe the hadron gas produced in the late stage of heavy-ion collisions since they decay on the same timescale, of the order of 1 to 10 fm/c, as the decoupling time of the system. In the hadron gas, (pseudo)elastic scatterings among the products of resonances that decayed before the kinetic freeze-out and regeneration processes counteract each other, the net effect depending on the resonance lifetime, the duration of the hadronic phase, and the hadronic cross sections at play. In this context, the ÎŁ(1385)± particle is of particular interest as models predict that regeneration dominates over rescattering despite its relatively short lifetime of about 5.5 fm/c. The first measurement of the ÎŁ(1385)± resonance production at midrapidity in Pb-Pb collisions at sNN−−−√=5.02 TeV with the ALICE detector is presented in this Letter. The resonances are reconstructed via their hadronic decay channel, Λπ, as a function of the transverse momentum (pT) and the collision centrality. The results are discussed in comparison with the measured yield of pions and with expectations from the statistical hadronization model as well as commonly employed event generators, including PYTHIA8/Angantyr and EPOS3 coupled to the UrQMD hadronic cascade afterburner. None of the models can describe the data. For ÎŁ(1385)±, a similar behaviour as K∗(892)0 is observed in data unlike the predictions of EPOS3 with afterburner

    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

    Measurement of ψ (2S) production as a function of charged-particle pseudorapidity density in pp collisions at √s = 13 TeV and p–Pb collisions at √sNN = 8.16 TeV with ALICE at the LHC

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    Production of inclusive charmonia in pp collisions at center-of-mass energy of √s = 13 TeV and p–Pb collisions at center-of-mass energy per nucleon pair of √sNN = 8.16 TeV is studied as a function of charged-particle pseudorapidity density with ALICE. Ground and excited charmonium states (J/ψ, ψ(2S)) are measured from their dimuon decays in the interval of rapidity in the center-of-mass frame 2.5 < ycms < 4.0 for pp collisions, and 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96 for p–Pb collisions. The charged-particle pseudorapidity density is measured around midrapidity (|η| < 1.0). In pp collisions, the measured charged-particle multiplicity extends to about six times the average value, while in p-Pb collisions at forward (backward) rapidity a multiplicity corresponding to about three (four) times the average is reached. The ψ(2S) yield increases with the charged-particle pseudorapidity density. The ratio of ψ(2S) over J/ψ yield does not show a significant multiplicity dependence in either colliding system, suggesting a similar behavior of J/ψ and ψ(2S) yields with respect to charged-particle pseudorapidity density. Results for the ψ(2S) yield and its ratio with respect to J/ψ agree with available model calculations

    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

    Pseudorapidity densities of charged particles with transverse momentum thresholds in pp collisions at √ s = 5.02 and 13 TeV

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    The pseudorapidity density of charged particles with minimum transverse momentum (pT) thresholds of 0.15, 0.5, 1, and 2 GeV/c is measured in pp collisions at the center of mass energies of √s=5.02 and 13 TeV with the ALICE detector. The study is carried out for inelastic collisions with at least one primary charged particle having a pseudorapidity (η) within 0.8pT larger than the corresponding threshold. In addition, measurements without pT-thresholds are performed for inelastic and nonsingle-diffractive events as well as for inelastic events with at least one charged particle having |η|2GeV/c), highlighting the importance of such measurements for tuning event generators. The new measurements agree within uncertainties with results from the ATLAS and CMS experiments obtained at √s=13TeV.
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