Anselm G. Vossen

Anselm G. Vossen

Assistant Professor of Physics

Office Location: 
Physics Building Room 1885, Box 90305, Durham, NC 27007
Front Office Address: 
Physics Building Room 188, PO Box 90305, Durham, NC 27708
Office Hours: 
by appointment

Overview

In Quantum Chromodynamics (QCD), the theory of the strong interactions, the nucleon emerges as a strongly interacting, relativistic bound state of almost massless quarks and gluons.
Fifty years of experimental investigations into the nucleon's internal structure have provided remarkable insight into quark and gluon dynamics. However, many outstanding questions remain.
For example, the origin of the spin of the proton is still eludes us and many other properties of the nucleon cannot yet be derived from first order calculations. Even fundamental aspects like a quantitative understanding of the  origin of the mass of the nuclei (and thus most of the visible mass in the universe) as well as the confinement of quarks into hadrons remain outside our current understanding.

My research approaches these questions from two sides. At the newly upgraded Jefferson Lab facility, we use electron proton scattering data to map out the 3D dynamics of the nucleon. We are in particular interested in polarized probes that are sensitive to spin-orbit coupling in the proton wavefunction.
And at the newly constructed Belle II experiment, we use electron-positron annihilation data, to study how hadrons emergy from initial quarks. We are in particular interested how the quantum numbers of the inital quark, like spin, are expressed in the final state hadrons.

Education & Training

  • D.R., Albert Ludwigs University of Freiburg (Germany) 2008

  • M.S., Albert Ludwigs University of Freiburg (Germany) 2004

Adam, J., et al. “Longitudinal double-spin asymmetries for p0s in the forward direction for 510 GeV polarized pp collisions.” Physical Review D, vol. 98, no. 3, Aug. 2018. Scopus, doi:10.1103/PhysRevD.98.032013. Full Text

Yelton, J., et al. “Observation of an Excited Ω^{-} Baryon..” Physical Review Letters, vol. 121, no. 5, Aug. 2018. Epmc, doi:10.1103/physrevlett.121.052003. Full Text

Adare, A., et al. “Cross section and longitudinal single-spin asymmetry AL for forward W± →μ±ν production in polarized p+p collisions at s =510 GeV.” Physical Review D, vol. 98, no. 3, Aug. 2018. Scopus, doi:10.1103/PhysRevD.98.032007. Full Text

Tamponi, U., et al. “Inclusive study of bottomonium production in association with an η meson in e+e- annihilations near Υ(5 S) : Belle Collaboration.” European Physical Journal C, vol. 78, no. 8, Aug. 2018. Scopus, doi:10.1140/epjc/s10052-018-6086-4. Full Text

Adamczyk, L., et al. “Azimuthal anisotropy in Cu+Au collisions at s NN =200 GeV.” Physical Review C, vol. 98, no. 1, July 2018. Scopus, doi:10.1103/PhysRevC.98.014915. Full Text

Adam, J., et al. “Global polarization of Λ hyperons in Au + Au collisions at sNN =200 GeV.” Physical Review C, vol. 98, no. 1, July 2018. Scopus, doi:10.1103/PhysRevC.98.014910. Full Text

Vossen, A., et al. “Measurement of the branching fraction of B →d (∗)πν at Belle using hadronic tagging in fully reconstructed events.” Physical Review D, vol. 98, no. 1, July 2018. Scopus, doi:10.1103/PhysRevD.98.012005. Full Text

Adamczyk, L., et al. “Beam Energy Dependence of Jet-Quenching Effects in Au+Au Collisions at sqrt[s_{NN}]=7.7, 11.5, 14.5, 19.6, 27, 39, and 62.4 GeV..” Physical Review Letters, vol. 121, no. 3, July 2018. Epmc, doi:10.1103/physrevlett.121.032301. Full Text

Adare, A., et al. “Lévy-stable two-pion Bose-Einstein correlations in s NN =200 GeV Au+Au collisions.” Physical Review C, vol. 97, no. 6, June 2018. Scopus, doi:10.1103/PhysRevC.97.064911. Full Text

Jia, S., et al. “Search for ϒ(1S,2S)→Zc+Zc(′)− and e+e−→Zc+Zc(′)− at s=10.52 , 10.58, and 10.867 GeV.” Physical Review D, vol. 97, no. 11, June 2018. Scopus, doi:10.1103/PhysRevD.97.112004. Full Text

Pages

Vossen, A. “Forward transverse single spin asymmetries at PHENIX.” Journal of Physics: Conference Series, vol. 316, no. 1, 2011. Scopus, doi:10.1088/1742-6596/316/1/012004. Full Text

Dharmawardane, V., and A. Vossen. “Transverse spin results from PHENIX.” Proceedings of Science, 2010.

Vossen, A. “Future PHENIX calorimetry and trigger upgrades.” Proceedings of Science, 2010.

Vossen, A., et al. “Measurement of transverse spin dependent fragmentation functions at Belle.” Aip Conference Proceedings, vol. 1149, 2009, pp. 433–38. Scopus, doi:10.1063/1.3215683. Full Text

Vossen, A. “Basics of feature selection and statistical learning for high-energy physics.” Inverted Cern School of Computing, Icsc 2005 and Icsc 2006  Proceedings, 2008, pp. 1–12.

Vossen, A. “Support vector machines in high-energy physics.” Inverted Cern School of Computing, Icsc 2005 and Icsc 2006  Proceedings, 2008, pp. 23–33.

Haasdonk, B., et al. “Invariance in kernel methods by haar-integration kernels.” Lecture Notes in Computer Science, vol. 3540, 2005, pp. 841–51.

Pages