Conveners
Hadron spectroscopy
- Nils Hรผsken (JGU Mainz)
Hadron spectroscopy
- Igor Danilkin
Hadron spectroscopy
- Alessandro Pilloni (Messina U. and INFN Catania)
Hadron spectroscopy
- Igor Danilkin
Hadron spectroscopy
- Annalisa D'Angelo
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Annika Thiel (HISKP, Uni Bonn)16/10/2023, 14:00
The exact dynamics of the quarks and gluons inside the nucleon are a long-standing question in hadron physics. To shed more light on this topic, the excitation spectrum of the nucleons needs to be measured and compared to theoretical models like constituent quark models or lattice QCD calculations. Until now, several predicted resonances - especially at high masses - have not been found by...
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Philipp Krรถnert (University Bonn)16/10/2023, 14:30Talk
Within the strong interaction, the emergence of so-called baryon resonances, such as the nucleon resonance N(1535)1/2-, can be observed. These states can be predicted by the theory of quantum chromodynamics, for example by quark models. However, more resonances are theoretically predicted than have been experimentally found, which is known under the name of the missing-resonance problem....
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Bing-Song Zou (ITP, CAS)16/10/2023, 14:50Talk
The three narrow $P_c$ states decaying to J/ฯp observed by the LHCb experiment are consistent with earlier predictions for one $\bar D\Sigma_c$ and two $\bar D^*\Sigma_c$ bound states. Their strange partners are expected to exist. Here we present evidence for the production of these $N^*$ resonances with hidden strangeness in various reactions, such as ฮณp โ ฯp, ฮณp โ K$\Lambda$, ฮณp โ Kฮฃ, ฮณp...
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Dr Yu-Fei Wang (Institute for Advanced Simulation, Forschungszentrum Jรผlich)16/10/2023, 15:10Talk
This talk focuses on a recent work aiming at determining the composition of certain $N^*$ and $\Delta$ resonances, i.e. whether they are compact states formed directly by quarks and gluons, or hadronic molecules generated from the meson-baryon interaction. The information of the resonance poles is provided by a comprehensive coupled-channel approach, the J\"{u}lich-Bonn model. $13$ states that...
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Satoshi Nakamura (Shandong University)16/10/2023, 15:30Talk
First hidden-charm pentaquark candidate with strangeness, $P_{\psi s}^\Lambda(4338)$, was recently discovered in $B^-\to J/\psi\Lambda\bar{p}$ by the LHCb Collaboration. $P_{\psi s}^\Lambda(4338)$ shows up as a bump at the $\Xi_c\bar{D}$ threshold in the $J/\psi\Lambda$ invariant mass ($M_{J/\psi\Lambda}$) distribution. The $M_{J/\psi\Lambda}$ distribution also shows a large fluctuation at the...
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David Wilson (University of Cambridge)16/10/2023, 16:20Talk
I will discuss scalar and tensor charmonium resonances determined using lattice QCD. Working at $m_\pi\approx 391$ MeV, more than 200 finite-volume energy levels are computed and these are used in extensions of the Lรผscher formalism to determine infinite volume scattering amplitudes. Working in the approximation where charm-annihilation is forbidden, the ground state $\chi_{c0}(1P)$ and...
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Bรกrbara Cid-Mora (GSI Helmholtzzentrum fรผr Schwerionenforschung)16/10/2023, 16:50Talk
The PDG lists the $\Lambda(1405)$ state, a baryon with quantum numbers $I(J^{P}) = 0 (\frac{1}{2}^{-})$ and strangeness $S = -1$, an object of interest given the difficulties encountered in obtaining this state from quark models. There are discrepancies in the literature whether experimental data is compatible with one or two nearby poles in this region, and what the position of those poles in...
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Xiu-Lei Ren (Helmholtz-Institut Mainz)16/10/2023, 17:10Talk
We investigated the meson-baryon scattering using time-order perturbation theory (TOPT) based on the covariant chiral effective field theory. Renormalized scattering amplitudes are obtained by solving the integral equations with the full off-shell dependence of effective potentials and applying subtractive renormalization. Our formalism has been successfully applied to the pion-nucleon...
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Dominik Stamen (Bonn University)16/10/2023, 17:30Talk
Decays into three particles are often described in terms of two-body resonances and a non-interacting spectator particle. To go beyond this simplest isobar model, crossed-channel rescattering effects need to be accounted for. We quantify the importance of these rescattering effects in three-pion systems for different decay masses and angular-momentum quantum numbers. We provide amplitude...
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Jia-Jun Wu (UCAS, School of Physical Sciences)16/10/2023, 17:50Talk
The recent BESIII data on Jpsi-> gamma eta(1405/1475) -> gamma KKbar pi
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, which is significantly more precise than earlier eta(1405/1475)-related data, enables quantitative discussions on eta(1405/1475) at the previously unreachable level. We conduct a three-body unitary coupled-channel analysis of experimental Monte Carlo outputs for Jpsi-> gamma eta(1405/1475) -> gamma KKbar pi. The KKbar... -
Anja Brรผggemann (University of Mรผnster)17/10/2023, 11:00Talk
In electron-positron annihilation, the process of e+e- -> chi_c1 can occur via the
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production of two virtual photons or through neutral current, therefore being suppressed with
respect to the normal annihilation process via one virtual photon. Using a dedicated scan sample
around the chi_c1 mass, the direct production of chi_c1 has been established for the first time
in experiments.... -
Marian Stahl (CERN)17/10/2023, 11:30Talk
Latest LHCb results on beauty decays to two open charm hadrons are presented.
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Those decays probe QCD factorization, are dominant sources of
backgrounds in beauty to charm lepton universality measurements
involving taus, and are crucial inputs to the spectroscopy of exotic
states like penta- or tetra-quarks. Results shown include first
observations and branching fraction measurements using... -
Hugo Garcia Tecocoatzi (INFN Genova)17/10/2023, 11:50Talk
We present a study of the spectra and strong decay widths of heavy baryons. The masses of single heavy baryons up to the D-wave are calculated within a constituent quark model, employing both the three-quark and quark-diquark schemes. We calculated the decay widths of the ground and excited single heavy baryons into the charmed baryon-(vector/pseudoscalar) meson pairs and the (octet/...
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Suxian Li (Fudan University)17/10/2023, 12:10
Charmed baryon spectroscopy can provide unique insights into QCD at low energies. The large data sample accumulated by the Belle experiment at the KEKB asymmetric-energy e^{+}e^{-} collider enables new opportunities to study charmed baryons. We present recent measurements of charmed baryons at Belle, including studies of Omega_c -> Xi pi, Xi K and Omega K, Lambda_c -> p Ks Ks and p Ks eta,...
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Prof. Li-Sheng Geng (Beihang University)17/10/2023, 12:30Talk
In the past two decades, one of the most puzzling phenomena discovered in hadron physics is that a nominal hadronic state can actually correspond to two poles on the complex energy plane. This phenomenon was first noticed for the ฮ(1405), then for K1(1270), and to a lesser extent for Dโ0(2300). In this talk, I show explicitly how the two-pole structures emerge from the underlying universal...
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Raquel Molina Peralta (Raquel.Molina@ific.uv.es)19/10/2023, 14:00Talk
In recent years, a plethora of exotic states have been observed in the experimental facilities. Some of these states, of tetraquark and pentaquark types, were predicted previously in approaches based on Effective Field Theories, unitarity of the S-matrix, and chiral and heavy quark spin symmetries. In this talk, I will review some of the predictions made in the local hidden gauge approach on...
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Frederik Weidner19/10/2023, 14:30Talk
In this talk, several searches for charmonium-like states will be presented. They are i) using data samples at CMS energies from threshold to 4.95 GeV collected with the BESIII detector, the cross-sections of process e+eโโD+sDโs are measured, and three structures with masses around 4.19, 4.41, and 4.79 GeV are found; ii) using a data sample corresponding to 2.93/fb collected at a CMS energy...
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Francesco Giacosa (Institute of Physics, Jan Kochanowski University, Kielce, poland)19/10/2023, 14:50Talk
We revisit the present status of the lightest nonet of hybrid mesons with quantum numbers J^{PC} = 1^{-+}, that includes the resonance \Pi_1(1600) as well as the recently discovered \eta_1(1855). In the framework of an hadronic approach, predictions for not-yet measured decay rates of the two resonances listed above as well as for the not yet found members of the nonet (an isoscalar with a...
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William Imoehl (Carnegie Mellon University)19/10/2023, 15:10Talk
Recent lattice QCD calculations predict the existence of hybrid mesons, which are mesons with gluonic degrees of freedom. By mapping out the hybrid meson spectrum, we can gain insight into how the gluon contributes to the properties of bound states in QCD. The $\pi_1(1600)$ is a candidate for the lightest hybrid meson. This state has exotic quantum numbers of $J^{PC}=1^{-+}$, which are...
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Tong Chen (Institute of High Energy Physics, CAS)19/10/2023, 15:30Talk
Using the worldโs largest samples of J/\psi and \psi(3686) events produced in e^+e^- annihilation, BESIII is uniquely positioned to study light hadrons in radiative and hadronic charmonium decays. In particular, exotic hadron candidates including multiquark states, hybrid mesons and glueballs can be studied in high detail. Recent highlights from the light hadron spectroscopy program, including...
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Alessandra Filippi (INFN Torino)19/10/2023, 16:20Talk
The nature and identification of N and ๐ฅ excitations and the search for missing baryonic resonances are still open issues in the present hadron spectroscopy scenario.
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In photon-induced interactions some couplings with the nucleons could be enhanced, as well as the chance of observing signatures of these poorly known resonances. However, the integrated information available from unpolarized... -
Thomas Jude (Bonn University)19/10/2023, 16:50Talk
The discoveries of the pentaquark states and $XYZ$ mesons in the charmed quark sector initiated a new epoch in hadron physics, where exotic multi-quark states beyond the conventional valence three quark and quark-antiquark systems has been unambiguously observed. Similar structure may be evidenced in the light, $uds$ sector in meson photoproduction, where access to a low momentum exchange and...
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Prof. Fei Huang (School of Nuclear Science and Technology, University of Chinese Academy of Sciences)19/10/2023, 17:10Talk
We analyze all the available data on differential cross sections, total cross sections, and $K^*$ spin density matrix elements for $K^{*+}\Sigma^0$ and $K^{*0}\Sigma^+$ photoproduction off proton in an effective Lagrangian approach. The data are well reproduced, and the contributions from the $s$-channel nucleon resonance and $t$-channel $\kappa$ meson exchange diagrams are discussed.
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Dr Farah Afzal (University of Bonn)19/10/2023, 17:30Talk
The light meson spectrum is explored with the GlueX experiment at Jefferson Lab using a real photon beam with energies of up to 12 GeV that is incident on a liquid hydrogen target. At these high energies, the dominant meson photoproduction mechanism in forward direction is the exchange of Reggeons. Understanding the production mechanism is essential for ongoing searches of exotic hybrid mesons...
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Nadine Hammoud (Institute of Nuclear Physics-PAS), Nadine Hammoud19/10/2023, 17:50Talk
In the domain of hadron spectroscopy, the investigation of meson resonances plays a pivotal role. This study focuses on the significance of two-pion photoproduction as a prominent avenue for studying meson resonances in the $\pi\pi$ system. By employing the Regge formalism, our model incorporates the background contribution from the well-known ``Deck Mechanism" and emphasizes the significant...
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