Baryons at BESIII
Baryons are the basic building blocks of our world. Since baryons represent
the simplest system in which the three colors of QCD neutralize into
colorless objects and the essential non-Abelian character of QCD is
manifest, understanding the baryon structure is absolutely necessary before
we claim that we really understand QCD. Given many recent processes, our
present baryon spectroscopy is still in its infancy. Many fundamental issues
in baryon spectroscopy are still not well understood. The possibility of
new, as yet unappreciated, symmetries could be addressed with accumulation
of more data. In addition to baryons made of u and d quarks, the search for
hyperon resonances remains an important challenge. Some of the lowest
excitation resonances are even missing, which are necessary to establish the
spectral pattern of hyperon resonances.
Charmonium decays provide an excellent place for studying excited nucleons
and hyperons -- $N^*$, $\Lambda^*$, $\Sigma^*$ and $\Xi^*$ resonances.
Complementary to other facilities, the baryon program at BES3 has several
advantages~\cite{Zou:2001uc}. For instance, $\pi N$ and $\pi\pi N$ systems
from $J/\psi\to\bar NN\pi$ and $\bar NN\pi\pi$ processes have an isospin of
1/2 due to isospin conservation; $\psi$ mesons decay to baryon-antibaryon
pairs through three or more gluons, where is a favorable place for producing
hybrid (qqqg) baryons, and for searching some "missing" $N^*$ resonances
which have weak coupling to both $\pi N$ and $\gamma N$, but stronger
coupling to $g^3N$. Recent results in baryon spectroscopy at BESIII will be
presented. Physics Synergies between BESIII and PANDA will be also
discussed. The cross section of charmonium(-like) states production
$p\bar{p}\to X_{c\bar{c}} + Meson(s)$ at PANDA can be inferred from high
precision studies of $ X_{c\bar{c}} \to p\bar{p} M$ at BESIII. There're
further potentials for cooperation in the studies of hyperons and the
development of PWA tools.