相关论文: Baryon sigma terms in SU(3) BChPT x 1/Nc

We consider the baryon octet and decuplet magnetic moments in a simultaneous expansion in $m_s$ and $1/N$ taking $N_F / N \sim 1$, where $N$ is the number of QCD colors and $N_F$ is the number of light quark flavors. At leading order in…

We consider the chiral Lagrangian for baryon fields with J^P =\frac{1}{2}^+ or J^P =\frac{3}{2}^+ quantum numbers as constructed from QCD with up, down and strange quarks. The specific class of counter terms that are of chiral order Q^3 and…

We establish a connection between the quark model and the 1/N_c expansion mass formulas used in the description of baryon resonances. We show that a remarkable compatibility exists between the two methods in the light and heavy baryon…

A previous work establishing a connection between a quark model, with relativistic kinematics and a $Y$-confinement plus one gluon exchange, and the $1/N_c$ expansion mass formula is extended to strange baryons. Both methods predict values…

We explore the electromagnetic contribution to the charge symmetry breaking in the octet baryon masses using a subtracted dispersion relation based on the Cottingham formula. For the proton-neutron mass splitting we report a minor revision…

Studies of the baryon-baryon interaction involving hyperons within chiral effective field theory, so far performed up to next-to-leading order (NLO) in the chiral expansion, have shown that for the strangeness $S=-1$ ($\Lambda N$, $\Sigma…

Predictions of unknown heavy baryon masses based on an expansion in $1/m_Q$, $1/N_c$ and $SU(3)$ breaking are updated to take into account a recent measurement of the $\Sigma_c^*$ mass. Values are given for the two remaining unknown charm…

The 1/N expansion for exotic baryons is developed, and applied to the masses, meson couplings and decay widths. Masses and widths of the 27 and 35 pentaquark states in the same tower as the Theta+ are related by spin-flavor symmetry. The 27…

Recent discoveries of the Xi_b, Sigma_b and Sigma_b^* baryons at the Tevatron are in good agreement with model-independent mass predictions made a decade ago based on a combined expansion in 1/N_c, 1/m_Q and SU(3) flavor symmetry breaking.…

We calculate the $m_d-m_u$ contribution to the mass splittings in baryonic isospin multiplets using SU(3) chiral perturbation theory and lattice QCD. Fitting isospin-averaged perturbation theory functions to PACS-CS and QCDSF-UKQCD…

The standard method for determining matrix elements in lattice QCD requires the computation of three-point correlation functions. This has the disadvantage of requiring two large time separations: one between the hadron source and operator…

We consider the chiral expansion of the octet baryon magnetic moments in heavy baryon chiral perturbation theory including all terms which are of order $q^4$. These terms are formally of quadratic order in the quark masses. We show that…

We report on a recent chiral extrapolation, based on an SU(3) framework, of octet baryon masses calculated in 2+1-flavour lattice QCD. Here we further clarify the form of the extrapolation, the estimation of the infinite-volume limit, the…

We describe our recent lattice study of SU(4) gauge theory with fermions in the fundamental and sextet representations. In this theory, a new type of baryon consists of quarks in both representations. The spectrum of these "chimera baryons"…

Recent studies have presented evidence for tension between the constraints on Omega_m and sigma_8 from the cosmic microwave background (CMB) and measurements of large-scale structure (LSS). This tension can potentially be resolved by…

Three independent searches for new physics using data collected at BABAR are presented. Firstly, two searches for dark matter and baryogenesis: $B^{0}\rightarrow \Lambda + \psi_{D}$ and $B^{+} \rightarrow p + \psi_{D}$ are detailed, where…

We compute the finite temperature pole mass shifts of the octet and decuplet baryons using heavy baryon chiral perturbation theory and the 1/N_c expansion, where N_c is the number of QCD colors. We consider temperatures of the order of the…

Meson-Baryon Interactions can be successfully described using both Chiral Symmetry and Unitarity. The $s-$wave meson-baryon scattering amplitude is analyzed in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry in the…

Using recent results on higher order cumulants of conserved charge fluctuations from lattice QCD, we construct mean, variance, skewness, kurtosis, hyper-skewness and hyper-kurtosis of net-baryon number distributions for small baryon…

An expression of partial wave expansion of three-baryon interactions in chiral effective field theory is presented. The derivation follows the method by Hebeler et al. [Phys. Rev. C{\bf 91}, 044001 (2015)], but the final expression is more…