Related papers: Theory Overview on Spectroscopy
The Belle II experiment at the SuperKEKB asymmetric $e^+e^-$ collider at KEK, Tsukuba, Japan, is recording data since 2018. The expected high luminosity of $\mathcal{L}=8\cdot 10^{35}~$cm$^{-2}$s$^{-1}$ enables searches for yet unobserved…
Despite the apparent simplicity of meson spectroscopy there are some states which cannot be accommodated in the usual $q\bar q$ structure. Among them there are either exotic states as the X(1600), or the recently measured charmed states…
Some recent discoveries in the spectroscopy of hadrons containing heavy quarks, and some of their theoretical interpretations, are reviewed.
The recently discovered tetraquark, $T_{cc}^+$, has quark content $cc\bar{u}\bar{d}$ and a mass that lies just below open charm thresholds. Hence it is reasonable to expect the state to have a significant molecular component. We calculate…
In the framework of the color-magnetic interaction, we systematically investigate the mass spectrum of the tetraquark states composed of four heavy quarks with the $QQ\bar Q\bar Q$ configuration in this work. We also show their strong decay…
We summarize the main features of the spectroscopy, production and decays of the $J^{PC}=1^{--}$ tetraquarks in the $b\bar{b}$ sector, concentrating on the lowest state called $Y_b(10890)$. The tetraquark framework is used to analyze the…
There have been great advances in charm physics at the B-factories in recent years, including the observation of D0-D0bar mixing and the discovery of many new hidden-charm states, some of them presumably exotic in structure. This talk…
Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also…
Supersymmetric Light Front Holographic QCD is a holographic theory, which not only describes the spectroscopy of mesons and baryons, but also predicts the existence and spectroscopy of tetraquarks. A discussion of the limitations of the…
For very heavy quarks, relations derived from heavy-quark symmetry imply novel narrow doubly heavy tetraquark states containing two heavy quarks and two light antiquarks. We predict that double-beauty states will be stable against strong…
Many newly discovered mesons behave like $\ccbar$ charmonium states in that they preferentially decay into final states that contain a $c$- and a $\bar{c}$-quark, but do not fit expectations for any of the unfilled levels of the…
The physics of charm has become one of the best laboratories exposing the limitations of the naive constituent quark model and also giving hints into a more mature description of meson spectroscopy, beyond the simple quark--antiquark…
Many new results on hadron spectra have been appearing in the past few years thanks to improved experimental techniques and searches in new channels. New theoretical techniques including refined methods of lattice QCD have kept pace with…
We search for the strange pentaquark $\Theta^+$ using kaon interactions in the material of the Belle detector. No signal is observed in the $p K_S$ final state, while in the $p K^-$ final state we observe $\sim 1.6 \cdot 10^4$…
Beauty tetraquark states $X(\bar b q'q'' \bar q )$ composed of $ \bar b s u \bar d$, $\bar b d s \bar u$, and $\bar b u d \bar s$, are unique that all the four valence quarks are different. Although the claim of existence of the first two…
We investigate on exotic tetraquark hadrons of the kind [cs][cbar sbar] by computing their spectrum and decay modes within a constituent diquark-antidiquark model. We also compare these predictions with the present experimental knowledge.
Since 2003 many charmonium-like states were observed experimentally. Especially those charged charmonium-like $Z_c$ states and bottomonium-like $Z_b$ states cannot be accommodated within the naive quark model, which are good candidates of…
We discuss recent theoretical developments in the context of charmed exotics with special emphasis on hadronic molecules. Especially we discuss, how these could be identified from experimental as well as lattice QCD observables.
The Belle collaboration operates a general-purpose detector at the KEKB asymmetric energy e+ e- collider, performing a wide range of measurements in beauty, charm, tau and 2-photon physics. In this paper, the treatment of statistical…
The masses of tetraquark states of all $qc\bar q \bar c$ and $cc\bar c \bar c$ quark configurations are evaluated in a constituent quark model, where the Cornell-like potential and one-gluon exchange spin-spin coupling are employed. All…