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1.
Phys Rev Lett ; 125(26): 262301, 2020 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-33449792

RESUMO

Flow coefficients v_{n} of the orders n=1-6 are measured with the High-Acceptance DiElectron Spectrometer (HADES) at GSI for protons, deuterons, and tritons as a function of centrality, transverse momentum, and rapidity in Au+Au collisions at sqrt[s_{NN}]=2.4 GeV. Combining the information from the flow coefficients of all orders allows us to construct for the first time, at collision energies of a few GeV, a multidifferential picture of the angular emission pattern of these particles. It reflects the complicated interplay between the effect of the central fireball pressure on the emission of particles and their subsequent interaction with spectator matter. The high precision information on higher order flow coefficients is a major step forward in constraining the equation of state of dense baryonic matter.

2.
Phys Rev Lett ; 123(2): 022002, 2019 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386541

RESUMO

We present the first observation of K^{-} and ϕ absorption within nuclear matter by means of π^{-}-induced reactions on C and W targets at an incident beam momentum of 1.7 GeV/c studied with HADES at SIS18/GSI. The double ratio (K^{-}/K^{+})_{W}/(K^{-}/K^{+})_{C} is found to be 0.319±0.009(stat)_{-0.012}^{+0.014}(syst) indicating a larger absorption of K^{-} in heavier targets as compared to lighter ones. The measured ϕ/K^{-} ratios in π^{-}+C and π^{-}+W reactions within the HADES acceptance are found to be equal to 0.55±0.04(stat)_{-0.07}^{+0.06}(syst) and to 0.63±0.06(stat)_{-0.11}^{+0.11}(syst), respectively. The similar ratios measured in the two different reactions demonstrate for the first time experimentally that the dynamics of the ϕ meson in nuclear medium is strongly coupled to the K^{-} dynamics. The large difference in the ϕ production off C and W nuclei is discussed in terms of a strong ϕN in-medium coupling. These results are relevant for the description of heavy-ion collisions and the structure of neutron stars.

3.
Phys Rev Lett ; 114(21): 212301, 2015 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-26066429

RESUMO

Results on the production of the double strange cascade hyperon Ξ^{-} are reported for collisions of p(3.5 GeV)+Nb, studied with the High Acceptance Di-Electron Spectrometer (HADES) at SIS18 at GSI Helmholtzzentrum for Heavy-Ion Research, Darmstadt. For the first time, subthreshold Ξ^{-} production is observed in proton-nucleus interactions. Assuming a Ξ^{-} phase-space distribution similar to that of Λ hyperons, the production probability amounts to P_{Ξ^{-}}=[2.0±0.4(stat)±0.3(norm)±0.6(syst)]×10^{-4} resulting in a Ξ^{-}/(Λ+Σ^{0}) ratio of P_{Ξ^{-}}/P_{Λ+Σ^{0}}=[1.2±0.3(stat)±0.4(syst)]×10^{-2}. Available model predictions are significantly lower than the measured Ξ^{-} yield.

5.
Phys Rev Lett ; 103(13): 132301, 2009 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-19905504

RESUMO

We report first results on a deep subthreshold production of the doubly strange hyperon Xi;{-} in a heavy-ion reaction. At a beam energy of 1.76A GeV the reaction Ar + KCl was studied with the High Acceptance Di-Electron Spectrometer at SIS18/GSI. A high-statistics and high-purity Lambda sample was collected, allowing for the investigation of the decay channel Xi;{-} --> Lambdapi;{-}. The deduced Xi;{-}/(Lambda + Sigma;{0}) production ratio of (5.6 +/- 1.2_{-1.7};{+1.8}) x 10;{-3} is significantly larger than available model predictions.

6.
Eur Arch Paediatr Dent ; 9(2): 84-9, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18534176

RESUMO

AIM: To assess the influence of dentofacial appearance of 10-year-old children on interpersonal attractiveness. STUDY DESIGN: Survey. METHODS: Four sets of photographs were prepared, having as their initial models facial portraits of four boys and four girls. In each set facial portraits were presented in four situations: the original, harmonic face and three versions produced by a graphic computing program, classified as the class II, class III and long face syndromes. These photographs were shown to 802 schoolchildren so that they could choose which one they would most and which one they would least, want to have as a friend. Also they were asked which one they considered the most and the least aggressive, the most and least intelligent and the most and the least good-looking. RESULTS: The harmonic face was the predominant choice in the friendship dimension (68.9%), as for intelligence (46.8%), and regarding attractiveness for males (55.4%) and females (61.7%); as regards aggressiveness, class III was the predominant choice (57.9%). CONCLUSIONS: There is an association between harmonic and unharmonic facial appearances and interpersonal attractiveness in 10-year-old Brazilian children.


Assuntos
Estética Dentária , Estética , Face , Relações Interpessoais , Comportamento Social , Agressão , Criança , Face/anormalidades , Feminino , Amigos , Humanos , Inteligência , Masculino , Má Oclusão Classe II de Angle/psicologia , Má Oclusão Classe III de Angle/psicologia , Psicologia da Criança , Desejabilidade Social , Síndrome
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