The coherent photoproduction of Formula omitted and Formula omitted mesons was measured in ultra-peripheral Pb-Pb collisions at a center-of-mass energy Formula omitted TeV with the ALICE detector. ...Charmonia are detected in the central rapidity region for events where the hadronic interactions are strongly suppressed. The Formula omitted is reconstructed using the dilepton ( Formula omitted) and proton-antiproton decay channels, while for the Formula omitted the dilepton and the Formula omitted decay channels are studied. The analysis is based on an event sample corresponding to an integrated luminosity of about 233 Formula omitted. The results are compared with theoretical models for coherent Formula omitted and Formula omitted photoproduction. The coherent cross section is found to be in a good agreement with models incorporating moderate nuclear gluon shadowing of about 0.64 at a Bjorken-x of around Formula omitted, such as the EPS09 parametrization, however none of the models is able to fully describe the rapidity dependence of the coherent Formula omitted cross section including ALICE measurements at forward rapidity. The ratio of Formula omitted to Formula omitted coherent photoproduction cross sections was also measured and found to be consistent with the one for photoproduction off protons.
The first measurement of the production of pions, kaons, (anti-)protons and Formula omitted mesons at midrapidity in Xe-Xe collisions at Formula omitted is presented. Transverse momentum ( Formula ...omitted) spectra and Formula omitted-integrated yields are extracted in several centrality intervals bridging from p-Pb to mid-central Pb-Pb collisions in terms of final-state multiplicity. The study of Xe-Xe and Pb-Pb collisions allows systems at similar charged-particle multiplicities but with different initial geometrical eccentricities to be investigated. A detailed comparison of the spectral shapes in the two systems reveals an opposite behaviour for radial and elliptic flow. In particular, this study shows that the radial flow does not depend on the colliding system when compared at similar charged-particle multiplicity. In terms of hadron chemistry, the previously observed smooth evolution of particle ratios with multiplicity from small to large collision systems is also found to hold in Xe-Xe. In addition, our results confirm that two remarkable features of particle production at LHC energies are also valid in the collision of medium-sized nuclei: the lower proton-to-pion ratio with respect to the thermal model expectations and the increase of the Formula omitted-to-pion ratio with increasing final-state multiplicity.
A new generation of high-resolution hypernuclear γ-spectroscopy experiments using high-purity germanium (HPGe) detectors is presently designed for the FINUDA spectrometer at DAΦNE, the Frascati ...Φ-factory, and for PANDA, the p–p¯ hadron spectrometer at the future FAIR facility. In both spectrometers the HPGe detectors have to be operated in strong magnetic fields. In this paper we report on a series of measurements performed on a HPGe detector inserted in a magnetic field of intensity up to 2.5T, the highest ever reached for operations with a HPGe, and with different orientations of the detector's axis with respect to field direction. A significant worsening of the energy resolution was found, but with a moderate loss of the efficiency. The most relevant features of the peak shapes, described by bi-Gaussian functions, are parametrized in terms of field intensity and energy: this allows to correct the spectra measured in magnetic field and to recover the energy resolution almost completely.
The study of (anti-)deuteron production in pp collisions has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. In this ...paper the production of Formula omitted is studied as a function of the charged particle multiplicity in inelastic pp collisions at Formula omitted TeV using the ALICE experiment. Thanks to the large number of accumulated minimum bias events, it has been possible to measure (anti-)deuteron production in pp collisions up to the same charged particle multiplicity ( Formula omitted) as measured in p-Pb collisions at similar centre-of-mass energies. Within the uncertainties, the deuteron yield in pp collisions resembles the one in p-Pb interactions, suggesting a common formation mechanism behind the production of light nuclei in hadronic interactions. In this context the measurements are compared with the expectations of coalescence and statistical hadronisation models (SHM).
This paper presents the measurements of Formula omitted, Formula omitted, Formula omitted and Formula omitted transverse momentum ( Formula omitted) spectra as a function of charged-particle ...multiplicity density in proton-proton (pp) collisions at Formula omitted with the ALICE detector at the LHC. Such study allows us to isolate the center-of-mass energy dependence of light-flavour particle production. The measurements reported here cover a Formula omitted range from 0.1 to 20 Formula omitted and are done in the rapidity interval Formula omitted. The Formula omitted-differential particle ratios exhibit an evolution with multiplicity, similar to that observed in pp collisions at Formula omitted, which is qualitatively described by some of the hydrodynamical and pQCD-inspired models discussed in this paper. Furthermore, the Formula omitted-integrated hadron-to-pion yield ratios measured in pp collisions at two different center-of-mass energies are consistent when compared at similar multiplicities. This also extends to strange and multi-strange hadrons, suggesting that, at LHC energies, particle hadrochemistry scales with particle multiplicity the same way under different collision energies and colliding systems.
Edge effect tests have been used in a number of studies on obliquebanded leafroller, Choristoneura rosaceana (Harris), to test for evidence of mated female immigration into pheromonetreated orchards. ...This type of test compares obliquebanded leafroller presence or activity around the perimeter of an orchard against presence or activity in the interior. Higher numbers detected around the edges of an orchard would indicate higher levels of flight activity at the edge, a pattern that could be generated by high levels of immigration. Recent work has shown that the spatial distribution of recaptured obliquebanded leafroller adults released from a single location can be directionally biased, which could obscure the ability to detect an edge effect. To test this theory, data from an orchard study conducted in 1991 that found no significant edge effect was reanalyzed. When we accounted for the directional bias in the distribution of first-generation mated female moths, we found an edge effect with significantly more mated females captured in the edge traps than in the center or mid-interior traps. No edge effect was found when the directional bias was ignored. In addition, second-generation males and mated females both showed a significant edge effect that had not been detected in the original analysis, which had combined both first- and second-generation data.
The use of High Purity Germanium detectors (HPGe) has been planned in some future experiments of hadronic physics. The crystals will be located close to large spectrometers where the magnetic ...fringing field will not be negligible and their performances might change. Moreover high precision is required in these experiments. The contribution of magnetic field presence and long term measurements is unique. In this paper the results of systematic measurements of the resolution, stability and efficiency of a crystal operating inside a magnetic field of 0.8
T, using radioactive sources in the energy range from 0.08 to 1.33
MeV, are reported. The measurements have been repeated during several months in order to test if any permanent damage occurred. The resolution at 1.117 and 1.332
MeV gamma-rays from a
60Co source has been measured at different magnetic fields in the range of 0–0.8
T and the results are compared with the previous data.
This document corrects two errors in Eur. Phys. J. C77 (2017) no. 8, 56: the incorrect referencing of Fig. 1 labels in three paragraphs in the results section and a missing acknowledgements section.
![Coherent [Formula omitted] ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1434-6044/small "Coherent [Formula omitted] and [Formula omitted] photoproduction at midrapidity in ultra-peripheral Pb-Pb collisions at [Formula omitted] TeV")
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