The neutron and its role in cosmology and particle physics

Experiments with cold and ultracold neutrons have reached a level of precision such that problems far beyond the scale of the present Standard Model of particle physics become accessible to experimental investigation. Due to the close links between particle physics and cosmology, these studies also permit a deep look into the very first instances of our universe. First addressed in this article, both in theory and experiment, is the problem of baryogenesis ... The question how baryogenesis could have happened is open to experimental tests, and it turns out that this problem can be curbed by the very stringent limits on an electric dipole moment of the neutron, a quantity that also has deep implications for particle physics. Then we discuss the recent spectacular observation of neutron quantization in the earth's gravitational field and of resonance transitions between such gravitational energy states. These measurements, together with new evaluations of neutron scattering data, set new constraints on deviations from Newton's gravitational law at the picometer scale. Such deviations are predicted in modern theories with extra-dimensions that propose unification of the Planck scale with the scale of the Standard Model ... Another main topic is the weak-interaction parameters in various fields of physics and astrophysics that must all be derived from measured neutron decay data. Up to now, about 10 different neutron decay observables have been measured, much more than needed in the electroweak Standard Model. This allows various precise tests for new physics beyond the Standard Model, competing with or surpassing similar tests at high-energy. The review ends with a discussion of neutron and nuclear data required in the synthesis of the elements during the "first three minutes" and later on in stellar nucleosynthesis.Comment: 91 pages, 30 figures, accepted by Reviews of Modern Physic

Observation of Charge-Dependent Azimuthal Correlations in p-Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect

Peer reviewe

Search for two Higgs bosons in final states containing two photons and two bottom quarks in proton-proton collisions at 8 TeV

Peer reviewe

EYE: Using Location-based Filtering for a Shopping Agent in the Physical World

Agents of all types rely on easily computed features that are suggestive of a user's preferences and goals to define and constrain their tasks. Although a person's location is usually suggestive of their current activity, agents have not relied upon a user's location to constrain their task. This is because users have typically used their computers only from home or work, and because location has not been easily computable. However the explosive growth in the use personal digital assistants (PDAs), laptop computers, and global positioning system (GPS) receivers is enabling people to use computers in the most remote of locations, and to have their location accessed by software. This paper introduces Shopper's Eye, a PDAbased, GPS-enabled agent prototype that relies on knowledge of a shopper's physical location to support the shopping task while shopping at a mall. Shoppers indicate their shopping goals to Shopper's Eye. Then, as shoppers stroll through a mall, Shopper's Eye informs them..