Summary of spin physics sessions

The list of topics in the many talks given during the Spin Physics sessions of this Intersections conference is nearly as long as the one of this conference: P and T Violation NN Interaction πp and πd Elastic Scattering Nuclear Matter Spin Effects Muon (g−2) Polarized Proton Beams Polarized Gas Targets This points to the almost trivial fact that spin is fundamental to our understanding of nuclear and particle physics. I will discuss in some detail only four of these topics. Needless to say this choice is very much personally biased and I apologize to all the speakers whose excellent contributions I did not include.  (AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87664/2/266_1.pd

Siberian snakes and future polarized beams

Horizontal magnetic fields in accelerators induce depolarizing resonances, 180° spin rotators, commonly called Siberian snakes, eliminate the resonances by reversing the effect of the horizontal field every revolution.(AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87536/2/197_1.pd

Polarized protons at the AGS and high P2⟂ spin effects

At the AGS an intense polarized proton beam was for the first time successfully accelerated to 22 GeV/c, preserving a polarization of ∼45%. Using this polarized beam a surprisingly strong energy dependence of the spin‐spin correlation parameter Ann in high p2⟂ elastic proton‐proton scattering was discovered.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87395/2/1148_1.pd

Properties of partially excited Siberian Snakes

The properties of the insertion of a general spin rotator into a circular accelerator are examined. It is shown that even for a small rotation angle depolarization from weak imperfection resonances is avoided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87385/2/1442_1.pd

Workshop on Siberian Snakes and depolarizing resonances correcting techniques

Discussions during the Workshop on Siberian Snakes and Depolarizing Resonances Correcting Techniques are summarized. It has been firmly established theoretically depolarization can be avoided by means of Siberian Snakes. The results from the first experimental test are eagerly awaited.(AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87384/2/1428_1.pd

Experimental test of the Siberian Snake Concept

The Siberian Snake Concept was experimentally tested at the IUCF Cooler Ring. We showed that the spin tune, which is the number of spin rotations per particle revolution, can be manipulated in a predictable way using local spin rotators (Siberian Snakes). Local spin rotators can then be used to avoid depolarization from intrinsic and imperfection depolarizing resonances.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87486/2/1033_1.pd

Engineering Topological Phases Guided by Statistical and Machine Learning Methods

The search for materials with topological properties is an ongoing effort. In this article we propose a systematic statistical method supported by machine learning techniques that is capable of constructing topological models for a generic lattice without prior knowledge of the phase diagram. By sampling tight-binding parameter vectors from a random distribution we obtain data sets that we label with the corresponding topological index. This labeled data is then analyzed to extract those parameters most relevant for the topological classification and to find their most likely values. We find that the marginal distributions of the parameters already define a topological model. Additional information is hidden in correlations between parameters. Here we present as a proof of concept the prediction of the Haldane model as the prototypical topological insulator for the honeycomb lattice in Altland-Zirnbauer (AZ) class A. The algorithm is straightforwardly applicable to any other AZ class or lattice and could be generalized to interacting systems