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

Alekseev, M., et al. “Flavour separation of helicity distributions from deep inelastic muon-deuteron scattering.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 680, no. 3, Sept. 2009, pp. 217–24. Scopus, doi:10.1016/j.physletb.2009.08.065. Full Text

Alekseev, M., et al. “Gluon polarisation in the nucleon and longitudinal double spin asymmetries from open charm muoproduction.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 676, no. 1–3, June 2009, pp. 31–38. Scopus, doi:10.1016/j.physletb.2009.04.059. Full Text

Alekseev, M., et al. “Collins and Sivers asymmetries for pions and kaons in muon-deuteron DIS.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 673, no. 2, Mar. 2009, pp. 127–35. Scopus, doi:10.1016/j.physletb.2009.01.060. Full Text

Alekseev, M., et al. “Measurement of the longitudinal spin transfer to Λ and barΛ hyperons in polarised muon DIS.” European Physical Journal C, vol. 64, no. 2, Jan. 2009, pp. 171–79. Scopus, doi:10.1140/epjc/s10052-009-1143-7. Full Text

Alekseev, M., et al. “The polarised valence quark distribution from semi-inclusive DIS.” Physics Letters, Section B: Nuclear, Elementary Particle and High Energy Physics, vol. 660, no. 5, Mar. 2008, pp. 458–65. Scopus, doi:10.1016/j.physletb.2007.12.056. Full Text

Alekseev, M., et al. “Double spin asymmetry in exclusive ρ0 muoproduction at COMPASS.” European Physical Journal C, vol. 52, no. 2, Oct. 2007, pp. 255–65. Scopus, doi:10.1140/epjc/s10052-007-0376-6. Full Text

Abbon, P., et al. “The COMPASS experiment at CERN.” Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, vol. 577, no. 3, July 2007, pp. 455–518. Scopus, doi:10.1016/j.nima.2007.03.026. Full Text

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