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Anselm G. Vossen

Assistant Professor of Physics
Physics
Physics Building Room 188, PO Box 90305, Durham, NC 27708
Physics Building Room 188, Box 90305, Durham, NC 27708-0305
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.

My group also works on precision tests of the flavor sector of the standard model at the intensity frontier. To this end we study the properties of B meson detected with the Belle II experiment.

Current Appointments & Affiliations


Assistant Professor of Physics · 2018 - Present Physics, Trinity College of Arts & Sciences

Recent Publications


Measurement of the inclusive branching fractions for $${B}_{s}^{0}$$ decays into D mesons via hadronic tagging

Journal Article Journal of High Energy Physics · April 15, 2025 AbstractWe report measurements of the absolute branching fractions $$\mathcal{B}\left({B}_{s}^{0}\to {D}_{s}^{\pm }X\right)$$ Full text Cite

Measurement of the branching fraction and CP -violating asymmetry of the decay B0 →π0π0 using 387 million ϒ (4S) decays in Belle II data

Journal Article Physical Review D · April 1, 2025 We measure the branching fraction and CP-violating flavor-dependent rate asymmetry of B0→π0π0 decays reconstructed using the Belle II detector in an electron-positron collision sample containing 387×106 ϒ(4S) mesons. Using an optimized event selection, we ... Full text Cite
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Recent Grants


REU Site: Undergraduate Research in Nuclear Particle Physics at TUNL and Duke

ResearchSenior Investigator · Awarded by National Science Foundation · 2022 - 2027

Novel Experimental Probes of QCD in SIDIS and e+e- Annihilation

ResearchPrincipal Investigator · Awarded by Department of Energy · 2023 - 2026

Jefferson National Laboratory - Support for Anselm Vossen

ResearchPrincipal Investigator · Awarded by Thomas Jefferson National Accelerator Facility · 2018 - 2026

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Education, Training & Certifications


Albert Ludwigs University of Freiburg (Germany) · 2008 D.R.
Albert Ludwigs University of Freiburg (Germany) · 2004 M.S.

External Links


Group Website