相关论文: Paradoxes in Strange Quark Contributions to Hypero…
The significant global spin alignment observed for $\phi$ mesons in heavy-ion collisions has sparked intense discussions about its origin and implications. One explanation suggests that fluctuations in the strong force field may introduce…
Prompted by the recent surprising results in QCD spectroscopy, we extend the treatment of the constituent quark model showing that mass differences and ratios have the same values when obtained from mesons and baryons. We obtain several new…
Using the known experimental data for the hyperon semileptonic decay constants, we calculate integrated quark densities $\Delta q_\Lambda$ and $% \Delta \Sigma_\Lambda$ for the hyperon $\Lambda$ with flavor SU(3) symmetry breaking taken…
We investigate the hyperon semileptonic decays and the quark spin content of the proton $\Delta \Sigma$ taking into account flavor SU(3) symmetry breaking. Symmetry breaking is implemented with the help of the chiral quark-soliton model in…
The simple independent quark models have difficulties explaining simultaneously the totality of the known hyperon magnetic moments and hyperon semi-leptonic decay rates. We show that both the Goldstone boson loop contributions and the…
The recent progress in the investigations on the quark structure of the $\Lambda$ and $\Sigma$ baryons are reviewed. It is shown that the quark structure of $\Lambda$ and $\Sigma$ hyperons can provide a new domain to test various theories…
We have calculated the strangeness contribution to the magnetic moments of the nucleon and $\Delta$ decuplet baryons in the chiral constituent quark model with configuration mixing ($\chi$CQM$_{{\rm config}}$) which is known to provide a…
A review of recent precision measurements of the electromagnetic form factors of the mesons, pion and kaon, and the hyperons, $\Lambda^0$, $\Sigma^0$, $\Sigma^+$, $\Xi^-$, $\Xi^0$, $\Omega^-$, at large timelike momentum transfers is…
We present a simple explanation of the underlying physics in the use of hyperon decay data to obtain information about proton spin structure. We also present an alternative input using nucleon magnetic moment data and show that the results…
Heavy quark spin symmetry is discussed in the context of single and doubly heavy baryons. A special attention is paid to the constraints/simplifications that this symmetry imposes on the non-relativistic constituent quark model wave…
Spin-1/2 baryons are considered as a composite system made out of a "core" of three quarks surrounded by a "sea" (of gluons and $q\bar{q}$-pairs) which is specified by its total quantum numbers. Specifically, we assume this sea to be a…
Measurements from the LHCb experiment and $B$ factories have revealed several discrepancies in angular observables of rare semileptonic $B$ decays involving the quark-level transition $b \to s \ell^+ \ell^-$. In this work, we conduct a…
Recent experimental data show an unexpectedly large spin alignment of $\phi$ mesons in high-energy heavy-ion collisions, which can be explained by short-distance fluctuations of strong-force fields (vector $\phi$ fields) within the…
A brief review of the current state of observed deviations of theoretical predictions from experimental data in semileptonic decays of $B$ and $B_c$ mesons is given. A theoretical analysis of these decays is carried out, taking into account…
The anomalously large like-sign dimuon charge asymmetry in semileptonic b-hadron decays recently measured by the D0 Collaboration may be hinting at the presence of CP-violating new physics in the mixing of B_s mesons. It has been suggested…
Spin-flavor fractions of quarks in the proton and several hyperons are obtained from their lowest order chiral fluctuations involving Goldstone bosons. SU(3) flavor breaking, relativistic effects and the axial anomaly are included. The…
We show how heavy quark symmetry constraints on doubly heavy baryon semileptonic decay widths can be used to test the validity of different quark model calculations. The large discrepancies in the results observed between different quark…
In the large $N_c$ limit, all hyperon decays involving the same quark diagram $Q\to Q'$ are described by a single weak form factor $\eta_{QQ'}(w)$. No assumption on the mass of $Q$ or $Q'$ is necessary, making our results applicable to both…
A survey of the experimental data on the charge and strong hadronic radii is given. A new, however preliminary value of the \Sigma^- charge radius allows to include also hyperons in the systematics. The presented data on the hadronic radii…
The current experimental values of anomalous magnetic moments of muon and electron deviate from the Standard Model predictions by few standard deviations, which might be a hint of new physics. The sizes and signs of these deviations are…