Heavy Quark Symmetry and Fine Structure of the Spectrum of Hadronic Dark Matter

We analyze the structure of excited states of new heavy hadrons in the scenario with hadronic dark matter. Fine mass-splitting in a doublet of new mesons stipulates the existence of charged metastable heavy mesons. We describe the structure of new meson excited states in the framework of the heavy quark effective theory. Phenomenological consequences of fine and hyperfine splitting are considered in the hadronic dark matter scenario and beyond.

Distribution amplitudes of heavy mesons and quarkonia on the light front

The ladder kernel of the Bethe–Salpeter equation is amended by introducing a different flavor dependence of the dressing functions in the heavy-quark sector. Compared with earlier work this allows for the simultaneous calculation of the mass spectrum and leptonic decay constants of light pseudoscalar mesons, the $$D_u$$ D u , $$D_s$$ D s , $$B_u$$ B u , $$B_s$$ B s and $$B_c$$ B c mesons and the heavy quarkonia $$\eta _c$$ η c and $$\eta _b$$ η b within the same framework at a physical pion mass. The corresponding Bethe–Salpeter amplitudes are projected onto the light front and we reconstruct the distribution amplitudes of the mesons in the full theory. A comparison with the first inverse moment of the heavy meson distribution amplitude in heavy quark effective theory is made.

Identifying the Λb(6146)0 and Λb(6152)0 as D-Wave Bottom Baryons

We study the Λ b ( 6146 ) 0 and Λ b ( 6152 ) 0 recently observed by LHCb using the method of Quantum Chromodynamics (QCD) sum rules within the framework of heavy quark effective theory. Our results suggest that they can be interpreted as D-wave bottom baryons of J P = 3 / 2 + and 5 / 2 + respectively, both of which contain two λ -mode excitations. We also investigate other possible assignments containing ρ -mode excitations. We extract all the parameters that are necessary to study their decay properties when using the method of light-cone sum rules. We predict masses of their strangeness partners to be m Ξ b ( 3 / 2 + ) = 6.26 − 0.14 + 0.11 GeV and m Ξ b ( 5 / 2 + ) = 6.26 − 0.14 + 0.11 GeV with the mass splitting Δ M = m Ξ b ( 5 / 2 + ) − m Ξ b ( 3 / 2 + ) = 4.5 − 1.5 + 1.9 MeV, and propose to search for them in future CMS, EIC, and LHCb experiments.

Effective Field Theories for Heavy Quarks: Heavy Quark Effective Theory and Heavy Quark Expansion

The heavy quark effective theory (HQET) and the heavy quark expansion (HQE) have developed into the standard tools in heavy-flavour physics. The lectures in this chapter introduce the basics of the approach and illustrates the methods by discussing some of their phenomenological applications. The chapter covers construction of the HQET Lagrangian, symmetries of HQET, HQET at one loop, and HQET applications to phenomenology. It also discusses HQE inclusive decays, operator product expansion (OPE), tree-level results, HQE parameters, QCD corrections, and end-point regions. It concludes by reiterating the enormous impact that both HQET and the HQE have had on particle physics phenomenology.

Heavy Quark Effective Theory: A Predictive EFT on the Lattice

The lattice formulation is a complete and unambiguous formulation of QCD. In principle it thus needs no tools beyond efficient Monte Carlo techniques. In practice various limits have to be taken where large-scale ratios occur. It is then advantageous to make use of effective field theories (EFTs). This chapter discusses the case of HQET, where the EFT itself is non-perturbative. It goes on to explain that retaining the full predictivity of QCD then requires to non-perturbatively formulate the theory and its matching to QCD, and to perform both steps by Monte Carlo simulations. Finally, it emphasizes conceptual points that appear when an EFT is treated beyond perturbation theory.