Related papers: Four-quark stability
We propose a four-quark structure for some of the excited states of heavy mesons containing a single charm or bottom quark. The four-quark wave functions are constructed based on a diquark-antidiquark form under the constraint that they…
The relativistic four-quark equations are found in the framework of coupled-channel formalism. The dynamical mixing of the meson-meson states with the four-quark states is considered. The approximate solutions of these equations using the…
The quark spin and flavor structure of the nucleon is discussed in the SU(4) symmetry breaking chiral quark model. The spin and flavor contents for charm quarks and anti-charm quarks are predicted and compared with the results given by…
Exotic mesons with hidden strange ($s\bar s$) and heavy quark pairs ($Q\bar Q$), where $Q=c,b$, are considered as diquark-antidiquark systems, $(Qs)(\bar Q\bar s)$. Taking into account that these states can recombinate into two-meson ones,…
We present recent results on charm physics at the Belle and Belle II experiments, covering measurements of charm lifetimes, branching fractions of the decays of charmed mesons and baryons and the decay asymmetry parameters of two-body…
We discuss the spectrum and the internal composition of ground and excited four-quark states in the charm and bottom energy region. To this end we extend previous calculations within the framework of the relativistic four-body…
Over the past few years, there has been a lot of progress in the areas of charm and charmonium spectroscopy, in large part due to the very large data samples being accumulated at the e+e- B-Factories. In this presentation I will focus on…
This paper gives an overview of charm physics. It is a lecture write-up aimed at students with a minimum of prior knowledge in particle physics, but at the same time provides a state-of-the art review of the field. The main focus is on…
We use a constituent model to analyze the stability of pentaquark $\bar Q qqqq$ configurations with a heavy antiquark $\bar c$ or $\bar b$, and four light quarks $uuds$, $ddsu$ or $ssud$. The interplay between chromoelectric and…
Some features and predictions of a recently proposed model based on diquark-antidiquark bound states are illustrated. Its ability in accomodating newly discovered charmed resonances around 4 GeV is discussed.
We study the stability of hexaquark systems containing two heavy quarks and four light quarks within a simple quark model. No bound or metastable state is found. The reason stems on a delicate interplay between chromoelectric and…
Over the past $\sim\!\! 10$ years, the topic of the nucleon's nonperturbative or $\textit{intrinsic}$ charm (IC) content has enjoyed something of a renaissance, largely motivated by theoretical developments involving quark modelers and PDF…
We systematically investigate the electromagnetic properties of exotic states whose internal structures remain uncertain and for which different models have been proposed. In this work, we focus on the magnetic dipole moments of…
We develop an extension of the usual three flavor quark model to four flavors (u, d, s and c), and discuss the classification of pentaquark states with hidden charm. We fit our model to the known baryon spectrum and we predict the double…
A brief review on some recent progresses in our understanding of multi-quark components in baryons is presented. The multi-quark components in baryons seem to be mainly in colored quark cluster configurations rather than in ``meson cloud''…
It is possible that the low-energy effects of physics beyond the standard model can be parametrized mainly by anomalous couplings of quarks to the W boson. Such couplings can generate potentially significant contributions to various…
We review the current status of flavor-changing neutral currents in the charm sector. We focus on the standard-model predictions and identify the main sources of theoretical uncertainties in both charm mixing and rare charm decays. The…
I review the properties of mesons with one heavy quark. I start by examining the predicted masses and widths in the context of the quark model and heavy quark effective theory. Some recent experimental results are described and I conclude…
Recent years have brought a dense sequence of experimental discoveries in heavy-flavor hadron spectroscopy. Heavy-flavor spectroscopy has entered a period in which new hadronic structures are no longer isolated surprises but recurring…
Singly, doubly and fully charmed tetraquark candidates, \emph{e.g.}, $T_{c\bar{s}}(2900)$, $T^+_{cc}(3875)$ and $X(6900)$ have been recently reported by the LHCb collaboration. Therefore, it is timely to implement a theoretical…