231 research outputs found
Građa nukleona iz mjerenja elektrotvorbe piona u MAMIju
Recent pion electro-production experiments of the A1 Collaboration at MAMI are presented. The threshold data in the p(e,e′p)π 0 and d(e,e′d)π 0 channels reveal the chiral dynamics of the pion-nucleon system at low energies. Measurements of the neutral channel in the ∆ region address the issue of the pion cloud, while the p(e,e′π +)n channel gives access to the axial structure of the nucleon.Predstavljamo nedavna mjerenja elektrotvorbe piona Suradnje A1 u MAMIju. Podaci oko pragova kanala p(e, e′ p)π 0 i d(e, e′ d)π 0 otkrivaju kiralnu dinamiku sustava pion-nukleon na niskim energijama. Mjerenja neutralnog kanala u području ∆ rezonancije daju uvid u strukturu pionskog oblaka, a kanal p(e, e′π +)n u aksijalnu građu nukleona
Građa nukleona iz mjerenja elektrotvorbe piona u MAMIju
Recent pion electro-production experiments of the A1 Collaboration at MAMI are presented. The threshold data in the p(e,e′p)π 0 and d(e,e′d)π 0 channels reveal the chiral dynamics of the pion-nucleon system at low energies. Measurements of the neutral channel in the ∆ region address the issue of the pion cloud, while the p(e,e′π +)n channel gives access to the axial structure of the nucleon.Predstavljamo nedavna mjerenja elektrotvorbe piona Suradnje A1 u MAMIju. Podaci oko pragova kanala p(e, e′ p)π 0 i d(e, e′ d)π 0 otkrivaju kiralnu dinamiku sustava pion-nukleon na niskim energijama. Mjerenja neutralnog kanala u području ∆ rezonancije daju uvid u strukturu pionskog oblaka, a kanal p(e, e′π +)n u aksijalnu građu nukleona
Uloga pionskog oblaka u nukleonskim faktorima oblika
In the linear sigma model and in the chromodielectric model, it is shown how the pion cloud enhances the electric polarizability, the electroexcitation of the ∆ and the axial form factor, and how it reduces the magnetic polarizability.U linearnom sigma modelu i u kromodielektričnom modelu se pokazuje kako pionski oblak povećava električnu polarizivnost, elektrouzbudu ∆ i aksijalni faktor oblika, te kako smanjuje magnetsku polarizivnost
Uloga pionskog oblaka u nukleonskim faktorima oblika
In the linear sigma model and in the chromodielectric model, it is shown how the pion cloud enhances the electric polarizability, the electroexcitation of the ∆ and the axial form factor, and how it reduces the magnetic polarizability.U linearnom sigma modelu i u kromodielektričnom modelu se pokazuje kako pionski oblak povećava električnu polarizivnost, elektrouzbudu ∆ i aksijalni faktor oblika, te kako smanjuje magnetsku polarizivnost
Modelling of potential spread of pine wood nematode by natural means in Slovenia at present climate conditions and in light of predicted climate changes
Recoil polarization and beam-recoil double polarization measurement of \eta electroproduction on the proton in the region of the S_{11}(1535) resonance
The beam-recoil double polarization P_{x'}^h and P_{z'}^h and the recoil
polarization P_{y'} were measured for the first time for the
p(\vec{e},e'\vec{p})\eta reaction at a four-momentum transfer of Q^2=0.1
GeV^2/c^2 and a center of mass production angle of \theta = 120^\circ at MAMI
C. With a center of mass energy range of 1500 MeV < W < 1550 MeV the region of
the S_{11}(1535) and D_{13}(1520) resonance was covered. The results are
discussed in the framework of a phenomenological isobar model (Eta-MAID). While
P_{x'}^h and P_{z'}^h are in good agreement with the model, P_{y'} shows a
significant deviation, consistent with existing photoproduction data on the
polarized-target asymmetry.Comment: 4 pages, 1 figur
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