Physics of Heavy Baryons



Bruno Bennich (Southern Cross University), Elena Santopinto (University of Genoa), Laura Tolos (ICE (IEEC/CSIC)), Marco Pappagallo (University of Bari), Mikhail Barabanov, Mikhail Mikhasenko (ORIGINS Excellence Cluster), Stephan Paul (TUM)

The study of heavy baryons, which are hadrons composed of three quarks including one or more b or c quarks, is an important area of research in hadron physics. Heavy baryons offer a unique laboratory for studying the strong interaction due to the effects related to spin and flavor being suppressed by the mass of the heavy quark. Additionally, the diversity of families of heavy baryons, such as $\Lambda_Q$, $\Sigma_Q$, $\Xi_Q$, and $\Omega_Q,$ provides vast opportunities for testing models and approaches. The Topical Workshop on "Physics of Heavy Baryons" aims to bring together experts in the field to discuss recent developments and future directions in the study of these particles.

The two-day workshop will cover a range of topics related to heavy baryons, including the properties of the ground states (masses, lifetimes, decay parameters), the excitation pattern of heavy baryons (mass splitting and multiplicities),and identification of hadronic molecules in the vicinity of meson-baryon and baryon-baryon thresholds. The workshop will also address recent experimental methods and results, as well as developments in theoretical tools such as lattice QCD, constituent quark models, effective unitarized theories, and QCD sum rules. Through presentations and discussions, the workshop will provide a platform for experts to exchange ideas and collaborate on current and future research in heavy baryon physics.

The workshop aims to deepen our understanding of the properties and behavior of heavy baryons, identify future challenges and opportunities, and promote collaboration in this field of hadron physics.

Zoom information

1/06/2023 Meeting ID: 652 7675 5082

2/06/2023 Meeting ID: 670 3692 8649

Password: 454599

MIAPbP coordination team
  • Thursday, June 1
    • Excitation pattern: Plenary
      • 1
        Speaker: Mikhail Mikhasenko (ORIGINS Excellence Cluster)
      • 2
        Heavy baryon spectroscopy and interactions using lattice QCD
        Speaker: Padmanath Madanagopalan (The Institute of Mathematical Sciences, Chennai)
      • 3
        New heavy baryons from LHCb
        Speaker: Paolo Gandini (Milano)
      • 4
        Heavy baryons in QM
        Speaker: Hugo Garcia Tecocoatzi (University of Genoa)
    • 12:30 PM
    • Ground states: Plenary
      • 5
        Heavy baryon spectroscopy in a quark-diquark approach

        We report progress on calculations of the heavy-light baryons $\Sigma_c$ and $\Lambda_c$ and their excitations with $J^P=1/2^+$ and $3/2^+$ using functional methods. The three-quark Faddeev equations are reduced to two-body equations by employing a covariant quark-diquark approach. The interaction amounts to a quark exchange between quarks and effective diquarks, and the ingredients are determined via a rainbow-ladder truncation. A partial-wave analysis reveals the presence of orbital angular momentum components in terms of p waves, which are non-relativistically suppressed. A diquark contribution analysis reveals the distribution of scalar and axialvector diquarks, of equal and unequal flavors, in the heavy-light baryon spectrum.

        Speaker: André Torcato (LIP/IST Lisbon)
      • 6
        Doubly heavy baryons in and beyond the Born-Oppenhaimer approximation

        We provide general formulas for the potentials at next-to-leading order in the Born-Oppenheimer effective field theory. We apply them to douby heavy baryons and obtain model independent formulas for the hyperfine splittings. Using available lattice data for the static potentials we obtain the spin average spectrum for doubly charmed and doubly bottomed baryons. We also obtain detailed results for the hyperfine splittings by modeling the spin-dependent potentials. The modeled potentials interpolate between a short distance form calculated in pNRQCD and a long distance form obtained from an effective string theory.

        Speaker: Joan Soto (Universitat de Barcelona)
    • 7
      Discussion and Networking - BBQ
    • Approaches and techniques: Plenary
      • 8
        Studying the interactions of charm hadrons with femtoscopy

        In the last years, several unconventional hadrons were observed in the charm sector. As such hadrons cannot be explained as 2- or 3-quark states, they are considered to be quark bags or hadron molecules. To unveil their nature it is necessary to constrain the strong nuclear force that governs the interactions of charm hadrons. An excellent tool to achieve this is the femtoscopy technique, namely the study of phase-space correlations between pairs of particles. In fact, by analyzing its main observable, the correlation function, the scattering parameters can be extracted and the formation of bound states can be tested.

        In this contribution, the measurement of the strong final-state interaction between open-charm and light-flavor mesons is presented. The analysis is performed using high-multiplicity proton-proton collisions at $\sqrt{s}=13~\mathrm{TeV}$, collected by the ALICE collaboration during the Run 2 data-taking period (2016-2018). In addition, the upgrade projections for the next-generation experiment ALICE 3 are shown, focusing on the $\mathrm{DD}^*$ and $\mathrm{D\overline{D}}{}^*$ interactions.

        Speaker: Daniel Battistini (TUM)
      • 9
        Accessing the strong interaction between Λ baryons and strange hadrons with femtoscopy at LHC

        Traditional experimental approaches, such as scattering and hypernuclei measurements, are insufficient to provide stringent constraints to
        the theoretical modeling of the interaction between strange hadrons and hence questions on the existence and nature of predicted exotic bound states or resonances are still open.
        In the baryon-baryon interaction, this is indeed the case for the H-dibaryon, predicted to be a bound state of two Λ baryons, but currently its experimental observation is not confirmed.
        Of particular interest in the meson-baryon sector is the Λ-antiK interaction, where the presence of the Ξ(1620) close to the threshold should play a significant role in the underlying interaction. The πΞ decay channel of the Ξ(1620) resonance has been recently observed by the Belle collaboration, providing the first experimental values for its mass and width.
        However, no measurements are available for the Λ-antiK channel. Delivering high-precision data on the Λ-antiK system can help to shed light into the nature of the Ξ(1620) state and its formation. Experimental data on Λ-antiK are currently rather scarce, leading to large uncertainties and tensions between the available theoretical predictions.
        Recently, measurements of two-particle correlations in small colliding systems such as pp and p-Pb collisions at the LHC provided a significant improvement in the knowledge of several hadron-hadron interactions, in particular when strange baryons and mesons are involved.
        In this talk, we present the results on the Λ-Λ and Λ-K- femtoscopic correlations measured by ALICE in pp collisions and p-Pb collisions. The measurements provides more precise upper limits on the H-dibaryon binding energy and show an attractive interaction for Λ-K-. In particular, we will show the first experimental evidence of the Ξ(1620) decaying into Λ-K- pairs. We will discuss the extracted properties of the Ξ(1620) state based on recent comparison of these data with state-of-the-art chiral calculations for the Λ-antiK interaction.

        Speaker: Valentina Mantovani Sarti (TUM)
      • 10
        Nucleon and Delta resonances with hidden charm and a three-body nature
        Speaker: Brenda Malabarba (Universidade de Sao Paulo)