The ExoHad Collaboration

The Exo(tic) Had(ron) Collaboration started in 2023 to explore all aspects of exotic hadron physics, from predictions within lattice QCD, through reliable extraction of their existence and properties from experimental data, to descriptions of their structure within phenomenological models.

ExoHad patchwork

A Constituent Model of Light Hybrid Meson Decays

The discovery of hybrid mesons will be greatly simplified if their couplings to decay channels are understood. To this end, Christian Farina (Pitt graduate student) and
Eric Swanson (Pitt, co-PI), have modeled hybrid decay in terms of gluon dissociation as specified by the Hamiltonian of QCD in Coulomb gauge. The results indicate that direct observation of the light vector hybrid will be difficult, that the hybrid $\pi(1800)$ has distinct decay characteristics, and that a hybrid $\eta_1(1750)$ Read more

Three particles with coupled channels

The extension of the three-particles formalism to multiple three-particle channels has been carried out by ExoHad members
Zack Draper (UW graduate student) and Steve Sharpe (UW, co-PI), in a paper submitted to the arXiv. This is done in the context of the $\pi\pi\eta$ and $K \bar K \pi$ system in isosymmetric QCD, where, if one enforces positive G parity, as well as conservation of $J^P$, there is no mixing with the $2\pi$ or $3\pi$ systems. This two-channel system is suitable for studying the Read more

Extension of finite-volume three-body formalism to scattering of particles with spin

The extension to include spin in the three-particle formalism was carried out in the context of the three-neutron system in a paper by ExoHad members
Zack Draper (UW graduate student) and Steve Sharpe (UW, co-PI) in collaboration with Max Hansen (Edinburgh) and Fernando Romero-Lopez (MIT). The inclusion of spin is more complicated for three-particle systems than for two-particles, because of the need to consider several reference frames: the overall center-of-mass frame (CMF), and the three Read more

New hires working on ExoHad

The Collaboration is happy to announce that two members, Andrew Jackura and Arkaitz Rodas, were hired on tenure-track positions to continue developing the ExoHad program. Moreover, Vanamali Shastry has joined a postdoctoral researcher position.

Andrew Jackura is an Assistant Professor of Physics in the Nuclear Theory group at William & Mary. Andrew joined William & Mary in August 2023 as part of the ExoHad initiative.
Andrew’s research focuses on few-body nuclear and particle reactions, using Read more