Vossen Group

Happy to announce our comprehensive review on transverse spin physics in semi-inclusive processes:

http://inspirehep.net/record/1775754

journal reference:

Phys. Rev. D 100, 092008

Frank Meier started as a postdoctoral research associate in our group in October. His research focuses on flavor physics at the Belle II experiment.

He brings rich experience from his previous experience at the University of Sydney and he also serves as the analysis tools convener for the Belle II experiment.

This paper is based on the thesis of  Hairong Li

From the abstract:

This work reports the first observation of azimuthal asymmetries around the thrust axis in

Thanks for a successful workshop!

Our group is organizing an international workshop on hadronization phenomena at Duke, March 14-16, 2019.

All interested are welcome to attend:

https://ff2019.phy.duke.edu/

Chris explored the spin structure of the proton in p+p collisions at RHIC and is now using novel probes to study quark-gluon correlations with the CLAS12 detector

https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.122.042001

I just came back from the Division of Nuclear Physics meeting of the APS where I could show our first data on beam spin asymmetries from hadron pairs:

This plot shows the asymmetry vs. x Bjorken (roughly the momentum that the struck quark carries of the parent nucleon). There is a very suggestive rise of the measurement that can be interpreted as the force that the gluons exert on a transversely polarized quark as it moves through the proton after being struck.

This is quite interesting since it open up a window to quark-gluon interactions inside the proton and because our understanding is that quarks can only have transverse polarization in an unpolarized nucleon if they also carry transverse momentum (Boer-Mulders effect).

More background can be found in my recent write-up here:

https://arxiv.org/pdf/1810.02435.pdf

…well we already knew that, but it made the list of the three experiments which might revamp the standard model in this article here:

https://www.sciencenews.org/article/new-particle-physics-experiments-revamp-standard-model