Analysing powers and spin correlations in deuteron–proton charge exchange at 726 MeV

Magnetic resonance at 41 meV and charge dynamics in YBa

Comment on “ πNN Coupling from High Precision np Charge Exchange at 162 MeV ”

In this updated and expanded version of our delayed Comment we show that the np backward cross section, as presented by the Uppsala group[1], is seriously flawed (more than 25 sd.). The main reason is the incorrect normalization of the data. We also show that their extrapolation method, used to determine the charged πNN coupling constant, is a factor of about 10 less accurate than claimed by Er...

Differential cross sections for pion charge exchange on the proton at 27 . 5 MeV

We have measured pion single charge exchange differential cross sections on the proton at 27.5 MeV incident π kinetic energy in the center of momentum angular range between 0 and 55. The extracted cross sections are compared with predictions of the standard pion-nucleon partial wave analysis and found to be in excellent agreement. Typeset using REVTEX

Interplay of charge and spin correlations in nickel perovskites

Analyzing the motion of low–spin (s = 1/2) holes in a high–spin (S = 1) background, we derive a sort of generalized t–J Hamiltonian for the NiO2 planes of Sr–doped nickelates. In addition to the rather complex carrier–spin and spin–spin couplings we take into account the coupling of the doped holes to in–plane oxygen breathing modes by a Holstein–type interaction term. Because of strong magneti...

Charge stripes and spin correlations in copper-oxide superconductors

To obtain superconductivity in a layered copper-oxide compound, it is necessary to introduce charge carriers into the antiferromagnetic CuO2 planes. Recent neutron diffraction studies of the system La1.6−xNd0.4SrxCuO4 [1,2] provide evidence that the dopant-induced holes choose to segregate into periodically-spaced stripes which separate antiferromagnetic domains, in a manner similar to that fou...