“After much experimental work, we now believe that neutrinos also possess this property of "oscillation", and by looking at exactly how they oscillate, we can make precise measurements of neutrino phenomenology.”

The field of neutrino physics is very active and exciting at this time. The results in our paper directly influence the interpretation of other experimental results, the design parameters for future experiments, and theoretical research in neutrinos. This, combined with the fact that KamLAND is the only experiment probing neutrino oscillations in the way described in the paper, and that future results will be even more revealing, are probably the reasons that it is cited frequently.

Yes, the paper describes the observation of reactor antineutrinos disappearing as they travel over a hundred miles. This is the first time this has been observed directly. This is, in effect, probing the physics seen by the solar neutrino experiments, but in a controlled terrestrial environment, and using methods which are independent from those used in solar experiments. The KamLAND experiment continues to run, and the results in the first paper also show that additional data will really help pin down the parameters of the neutrino sector.

Our current understanding of the world in terms of quantum mechanics bestows some "wave-like" qualities on fundamental particles. One of the stranger consequences of this is that some types of particle can change from one to another and back again as they propagate. After much experimental work, we now believe that neutrinos also possess this property of "oscillation," and by looking at exactly how they oscillate, we can make precise measurements of neutrino phenomenology. Theories of the structure of the universe differ in the fine details of the neutrino sector, so these experiments can help elucidate what is going on. We have performed a study of oscillations in a very direct way; to put an antineutrino detector, called KamLAND—Kamioka Liquid-scintillator Anti-Neutrino Detector—a hundred miles away from some of the largest nuclear power plants in the world, where antineutrinos are produced. This paper presents unambiguous evidence that these particles do disappear as they travel, and the most likely explanation is that they do so because they are oscillating. Over the last decade or so, our understanding of neutrinos has been getting more and more advanced, and this is set to continue with further measurements from KamLAND and other neutrino experiments.