Observation of recoil-induced resonances and electromagnetically induced absorption of cold atoms in diffuse light

In this paper we report an experiment on the observation of the recoil-induced resonances (RIR) and electromagnetically induced absorption (EIA) of cold Rb87 atoms in diffuse light. The pump light of the RIR and the EIA comes from the diffuse light in an integrating sphere, which also serves the cooling light. The probe light beam is a weak laser split from the cooling laser in order to keep the cooling and probe lasers correlated. We measured the RIR and the EIA signal varying with the detuning of the diffuse laser light, and also measured the temperature of the cold atoms at the different detunings. The mechanism of RIR and EIA in the configuration with diffuse-light pumping and laser probing is discussed, and the difference of nonlinear spectra of cold atoms between in diffuse-light cooling system and in optical molasses as well as in a magneto-optical trap (MOT) are studied.Comment: 9 pages, 6 figure

catena-Poly[[diaqua­bis­(2-ethyl-1H-imidazole-κN 3)cadmium]-μ-sulfato-κ2 O:O′]

In the title one-dimensional coordination polymer, [Cd(SO4)(C5H8N2)2(H2O)2]n, the CdII atom (site symmetry 2) is coordinated by two sulfate O atoms, two water mol­ecules and two 2-ethyl­imidazole ligands in a distorted cis-CdN2O4 octa­hedral geometry. The water mol­ecules have a cis disposition. The bridging sulfate ions (site symmetry 2) link the CdII ions into a polymeric chain extending along [001]. The chains are linked by N—H⋯O and O—H⋯O hydrogen bonds. The terminal –CH3 group of the ligand is disordered over two orientations in a 0.61 (5):0.39 (5) ratio

1H-Pyrazol-2-ium hydrogen oxalate

In the title compound, C3H5N2 +·C2HO4 −, the anions form centrosymmetric dimers through cyclic O—H⋯O hydrogen-bonding associations [graph set R 2 2(10)]. These dimers are then linked through a cyclic R 4 2(10) N—H⋯O hydrogen-bonding association involving two cations and the carboxyl O-atom acceptors of separate anions, giving chain structures extending across the (111) plane

Precise QCD predictions on top quark pair production mediated by massive color octet vector boson at hadron colliders

We present a theoretical framework for systematically calculating next-to-leading order (NLO) QCD effects to various experimental observables in models with massive COVB in a model independent way at hadron colliders. Specifically, we show the numerical results for the NLO QCD corrections to total cross sections, invariant mass distribution and AFB of top quark pairs production mediated by a massive COVB in both the fixed scale (top quark mass) scheme and the dynamical scale (top pair invariant mass) scheme. Our results show that the NLO QCD calculations in the dynamical scale scheme is more reasonable than the fixed scheme and the naive estimate of the NLO effects by simple rescaling of the LO results with the SM NLO K-factor is not appropriate.Comment: 6 pages, 5 figures, 2 tables; version published in EPJ