The LHCb collaboration has observed a pentaquark system, $udsc\bar{c}$, with
$J^{\pi} = 1/2^{-}$, whose mass is $4338.2$ MeV with $\Gamma = 7$ MeV [1].
To describe this state, I use a constituent quark model, and the employed
Hamiltonian is based on Semay and Silvestre-Brac [2]. This Hamiltonian
reproduces all of the meson and baryon states which appear in the open channels
of this...
We investigate the three-body $PPV$ and $PVV$ systems, where $P$ denotes a pseudoscalar meson and $V$ denotes a vector meson. The Faddeev equations are solved within the fixed-center approximation, while the underlying two-body $PP$, $PV$ and $VV$ interactions are determined from the chiral unitary approach. Strong interactions among these mesons produce obvious resonance structures in the...
Interactions between a nucleon and a meson containing a heavy antiquark, in which quark-antiquark annihilation is absent, have been predicted to be attractive and to form genuine pentaquark states. With realistic lattice QCD simulations for such systems now feasible, first-principles determination of these interactions can provide theoretical prediction for the existence of the pentaquarks....
Recent advances in lattice QCD have enabled increasingly precise first-principles calculations of nucleon structure observables. In this talk, I will present recent progress on nucleon electromagnetic and axial form factors, together with flavor-diagonal nucleon charges, with particular emphasis on controlling excited-state contamination. I will discuss data-driven analyses guided by the...
The tensor form factors of the nucleon carry essential information for understanding its internal spin structure. The monopole tensor form factor at $Q^2=0$ is identified as the nucleon tensor charge, which corresponds to the first moment of the leading-twist transversity distribution $h_1(x)$. While transversity has been studied extensively both in theory and in experiment, the other tensor...
