A cluster glass magnetic state in R5Pd2 R Ho, Tb compounds evidenced by AC susceptibility and neutron scattering measurements

AC and DC susceptibility, high field magnetization and neutron diffraction measurements have been performed in order to study the magnetic state of R5Pd2 R Ho, Tb compounds. The results show that both compounds undergo cluster glass freezing upon cooling below T f. According to the neutron diffraction a long range magnetic order is absent down to 2 K and magnetic clusters with short range incommensurate antiferromagnetic correlations exist not only below Tf but also in a wide temperature range above the freezing temperature at least up to 2T f . A complex cluster glass magnetic state existing in Ho5Pd2 and Tb5Pd2 down to low temperatures results in rather complicated magnetization behavior in DC and AC magnetic fields. Such an unusual magnetic state in compounds with a high rare earth concentration may be associated with the layered type of their crystal structure and with substantial atomic disorder, which results in frustrations in the magnetic subsyste

CMS Physics Technical Design Report: Addendum on High Density QCD with Heavy Ions

This report presents the capabilities of the CMS experiment to explore the rich heavy-ion physics programme offered by the CERN Large Hadron Collider (LHC). The collisions of lead nuclei at energies $\sqrt{s_{NN}}= 5.5\,{\rm TeV}$ , will probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research is to study the fundamental theory of the strong interaction \u2014 Quantum Chromodynamics (QCD) \u2014 in extreme conditions of temperature, density and parton momentum fraction (low- x ). This report covers in detail the potential of CMS to carry out a series of representative Pb-Pb measurements. These include "bulk" observables, (charged hadron multiplicity, low p T inclusive hadron identified spectra and elliptic flow) which provide information on the collective properties of the system, as well as perturbative probes such as quarkonia, heavy-quarks, jets and high p T hadrons which yield "tomographic" information of the hottest and densest phases of the reaction