We investigate the effects of the kaon cloud on the electromagnetic and axial-vector form factors of the $Omega^-$ baryon within the framework of the chiral quark-soliton model. We first derive the profile function of the chiral soliton in such a way that the kaon Yukawa tail is properly produced self-consistently. Then, we compute the electromagnetic form factors of the $Omega^-$ baryon. The results for the electromagnetic form factors are compared with the lattice data. We find that the results with kaon tail employed are in far better agreement with the lattice data. We also study the axial-vector form factors of the $Omega^-$ baryon, examining the effects of the kaon cloud.
There are two mass generating mechanisms in the standard model of particle physics (SM). One is related to the Higgs boson and fairly well understood. The other is embedded in quantum chromodynamics (QCD), the SMs strong interaction piece; and although responsible for emergence of the roughly 1 GeV mass scale that characterises the proton and hence all observable matter, the source and impacts of this emergent hadronic mass (EHM) remain puzzling. As bound states seeded by a valence-quark and -antiquark, pseudoscalar mesons present a simpler problem in quantum field theory than that associated with the nucleon. Consequently, there is a large array of robust predictions for pion and kaon properties whose empirical validation will provide a clear window onto many effects of both mass generating mechanisms and the constructive interference between them. This has now become significant because new-era experimental facilities, in operation, construction, or planning, are capable of conducting such tests and thereby contributing greatly to resolving the puzzles of EHM. These aspects of experiment, phenomenology, and theory, along with contemporary successes and challenges, are sketched herein, simultaneously highlighting the potential gains that can accrue from a coherent effort aimed at finally reaching an understanding of the character and structure of Natures Nambu-Goldstone modes.
Kaon flavour physics has played in the 1960s and 1970s a very important role in the construction of the Standard Model (SM) and in the 1980s and 1990s in SM tests with the help of CP violation in $K_Ltopipi$ decays represented by $varepsilon_K$ and the ratio $varepsilon/varepsilon$. In this millennium this role has been taken over by $B_{s,d}$ and $D$ mesons. However there is no doubt that in the coming years we will witness the return of kaon flavour physics with the highlights being the measurements of the theoretically clean branching ratios for the rare decays $K^+rightarrow pi^+ ubar u$ and $K_{L}rightarrowpi^0 ubar u$ and the improved SM predictions for the ratio $varepsilon/varepsilon$, for $varepsilon_K$ and the $K^0-bar K^0$ mixing mass difference $Delta M_K$. Theoretical progress on the decays $K_{L,S}tomu^+mu^-$ and $K_Ltopi^0ell^+ell^-$ is also expected. They all are very sensitive to new physics (NP) contributions and the correlations between them should help us to identify new dynamics at very short distance scales. These studies will be enriched when theory on the $Ktopipi$ isospin amplitudes ${rm Re} A_0$ and ${rm Re} A_2$ improves. This talk summarizes several aspects of this exciting field. In particular we emphasize the role of the Dual QCD approach in getting the insight into the numerical Lattice QCD results on $K^0-bar K^0$ mixing and $Ktopipi$ decays.
Understanding the origin and dynamics of hadron structure and in turn that of atomic nuclei is a central goal of nuclear physics. This challenge entails the questions of how does the roughly 1 GeV mass-scale that characterizes atomic nuclei appear; why does it have the observed value; and, enigmatically, why are the composite Nambu-Goldstone (NG) bosons in quantum chromodynamics (QCD) abnormally light in comparison? In this perspective, we provide an analysis of the mass budget of the pion and proton in QCD; discuss the special role of the kaon, which lies near the boundary between dominance of strong and Higgs mass-generation mechanisms; and explain the need for a coherent effort in QCD phenomenology and continuum calculations, in exa-scale computing as provided by lattice QCD, and in experiments to make progress in understanding the origins of hadron masses and the distribution of that mass within them. We compare the unique capabilities foreseen at the electron-ion collider (EIC) with those at the hadron-electron ring accelerator (HERA), the only previous electron-proton collider; and describe five key experimental measurements, enabled by the EIC and aimed at delivering fundamental insights that will generate concrete answers to the questions of how mass and structure arise in the pion and kaon, the Standard Models NG modes, whose surprisingly low mass is critical to the evolution of our Universe.
We investigate the strong force fields and stabilities of the nucleon and the singly heavy baryon $Sigma_c$ within the framework of the chiral quark-soliton model. Having constructed the pion mean fields in the presence of the $N_c-1$ level quarks self-consistently, we are able to examine the gravitational form factors of $Sigma_c$. We mainly focus in the present work on the stability conditions for both the nucleon and $Sigma_c$ and discuss the strong force fields and their physical implications. We also present the results for the gravitational form factors and relevant observables, emphasising the difference between the nucleon and $Sigma_c$.
In this short presentation I emphasize the increased importance of kaon flavour physics in the search for new physics (NP) that we should witness in the rest of this decade and in the next decade. The main actors will be the branching ratios for the rare decays $K^+rightarrowpi^+ ubar u$ and $K_{L}rightarrowpi^0 ubar u$, to be measured by NA62 and KOTO, and their correlations with the ratio $varepsilon/varepsilon$ on which recently progress by lattice QCD and large $N$ dual QCD approach has been made implying a new flavour anomaly. Further correlations of $K^+rightarrowpi^+ ubar u$, $K_{L}rightarrowpi^0 ubar u$ and $varepsilon/varepsilon$ with $varepsilon_K$, $Delta M_K$, $K_Ltomu^+mu^-$ and $K_Ltopi^0ell^+ell^-$ will help us to identify indirectly possible NP at short distance scales. This talk summarizes the present highlights of this fascinating field including some results from concrete NP scenarios.