Related Experiment Video
Updated: Aug 1, 2026

Setting Limits on Supersymmetry Using Simplified Models
Published on: November 16, 2013
Evidence for the color-octet mechanism from CERN LEP2 gamma gamma --> J/psi + X Data
Michael Klasen1, Bernd A Kniehl, Luminiţa N Mihaila
1II. Institut für Theoretische Physik, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
Abstract:
We present theoretical predictions for the transverse-momentum distribution of J/psi mesons promptly produced in gammagamma collisions within the factorization formalism of nonrelativistic quantum chromodynamics, including the contributions from both direct and resolved photons, and we perform a conservative error analysis. The fraction of J/psi mesons from decays of bottom-flavored hadrons is estimated to be negligibly small. New data taken by the DELPHI Collaboration at LEP2 nicely confirm these predictions, while they disfavor those obtained within the traditional color-singlet model.
More Related Videos
08:40Separation of Spinach Thylakoid Protein Complexes by Native Green Gel Electrophoresis and Band Characterization using Time-Correlated Single Photon Counting
Published on: February 14, 2019
05:51Isotopic Effect in Double Proton Transfer Process of Porphycene Investigated by Enhanced QM/MM Method
Published on: July 19, 2019
Related Concept Videos
Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human eye.
¹H NMR: Complex Splitting
Splitting diagrams or splitting tree diagrams are routinely used to depict such complex couplings. While drawing splitting diagrams, the splitting with the larger coupling constant is usually applied first.
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
π Electron Effects on Chemical Shift: Overview
Interpreting ¹H NMR Signal Splitting: The (n + 1) Rule