Related papers: Understanding open-charm mesons
We discuss three possible scenarios for the interpretation of mesons containing a heavy quark and its antiquark near and above the first threshold for a decay into a pair of heavy mesons in a relative $S$--wave. View I assumes that these…
Mesons with masses below their lowest OZI-allowed strong-decay thresholds have very small widths. Thus, it is usually believed that they can be safely treated as pure quark-antiquark bound states in spectroscopy models. However, unitarised…
Opportunities to observe new hadrons with very narrow widths are discussed. Two areas of focus are the lowest P-states of heavy-light mesons and doubly heavy baryons.
Recent CMS observations in the di-$J/\psi$ invariant mass spectrum reveal new structures at 6638 MeV ($X(6600)$)) and 7134 MeV, and confirm the $X(6900)$ at 6847 MeV. These findings provide crucial insights into four-charm-quark matter. The…
A number of resonances comparable with a hypothesis of hidden-charm pentaquark is observed by the LHCb Collaboration. We interpret these narrow resonances as compact hidden-charm diquark-diquark-antiquark systems. Within this assumption, an…
The ${q}\bar{q}$ spectrum is studied within a chiral constituent quark model. It provides with a good fit of the available experimental data from light (vector and pseudoscalar) to heavy mesons. The new $D$ states measured at different…
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 charm states…
Recently, the LHCb Collaboration reported three $P_c$ states in the ${J/\psi}p$ channel. We systematically study the mass spectrum of the hidden charm pentaquark in the framework of an extended chromomagnetic model. For the $nnnc\bar{c}$…
We use diquark-antidiquark currents to investigate the masses and partial decay widths of the recently observed mesons $D_{sJ}^{+}(2317)$, $D_0^{*0}(2308)$ and X(3872), considered as four-quark states, in a QCD sum rule approach. In…
The bottom-charmed ($B_c$) mesons are more stable than their charmonium ($c\bar c$) and bottomium ($b\bar b$) partners because they cannot annihilate into gluons. However, the low production cross-sections and signal-to-background ratios…
An effective Lagrangian approach based on the heavy quark and chiral symmetry is introduced to analyse the spectroscopy of open charm mesons. Strong two-body decay widths and ratios of branching fractions are computed, and this piece of…
In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the $S$-wave tetraquark states $Qq\bar{Q}\bar{q}$ ($Q=c,b$, and $q=u,d,s$) with different quantum numbers, $J^{PC}=0^{+(+)}$, $1^{+(\pm)}$,…
Weak decays of charm mesons has been used for studies of light quark spectroscopy, with particular emphasis on the J^{PC}=0^{++} states. Recent results on light scalars are summarized and some conceptual issues are discussed, especially the…
The past four years has witnessed the renaissance of the hadron spectroscopy. Many interesting new hadron states were discovered experimentally, some of which do not fit into the quark model easily. I will give a concise overview of these…
Using a constituent quark model we study the mass and decay channels of meson meson and meson baryon structures in the charm sector. We show that the $X(3872)$ and $X(3940)$ resonances can be described as mixed charmonium-molecular states…
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…
Inspired by the recent findings of $Z_{cs}$ and $P_{cs}$ states, we investigate the strong interactions of the systems with open strangeness(es) from the light sector to the heavy sector (no beauty quark), where the interaction potential is…
Using an effective Lagrangian approach based on heavy quark symmetry and chiral dynamics, we explore the strong decay widths and branching ratios of various resonances and suggest their JP find the coupling constants involved in the strong…
Stimulated by the newly observed charged hidden-charm state $Z_{cs}(3985)^-$ by BESIII Collaboration, $Z_{cs}(4000)^+$, $Z_{cs}(4220)^+$ and the excited $B_s^0$ states by LHCb Collaboration, a full calculation including masses and decay…
The full-heavy tetraquarks $cc\bar{c}\bar{b}$ and $bb\bar{b}\bar{c}$ are systematically investigated within the chiral quark model. The meson-meson structure, diquark-antidiquark structure and K-structure are considered in this work. There…