Narrow Results

Exploiting the SU(2) Skyrmion Lagrangian with second-class constraints associated with Lagrange multiplier and collective coordinates, we convert the second-class system into the first-class one in the Batalin–Fradkin–Tyutin embedding through the introduction of Stückelberg coordinates. In the enlarged phase space possessing the Stückelberg coordinates, we perform the "canonical" quantization to describe the Schrödinger representation of the SU(2) Skyrmion, so that we can assign via the homotopy class π₄(SU(2))=Z₂ half integers to the isospin quantum number for the solitons. The symplectic embedding and the Becchi–Rouet–Stora–Tyutin symmetries involved in the SU(2) Skyrmion are also investigated.

We study the mixing of excited states of a hydrogen atom in a cavity with de-excited states plus a confined photon as a model for the coupling of quark–antiquark and quark–antiquark–gluon hybrid states in QCD. For an interesting range of parameters, the results are analytic. We find a case for which wave functions (and hence decay patterns) may be at odds with mass with respect to identification of a state as hybrid or not.

We perform the first study of baryons in holographic QCD with multi-D-brane system in type IIA superstring theory. The baryon is described as a chiral soliton solution in the four-dimensional meson effective action derived from holographic QCD. We also present a brief review of the holographic model from the viewpoints of recent hadron physics and QCD phenomenologies.

We study the chiral transformation properties of all possible local (non-derivative) interpolating field operators for baryons consisting of three quarks with two flavors, assuming good isospin symmetry. We derive and use the relations/identities among the baryon operators with identical quantum numbers that follow from the combined color, Dirac and isospin Fierz transformations. These relations reduce the number of independent baryon operators with any given spin and isospin. The Fierz identities also effectively restrict allowed baryon chiral multiplets. It turns out that the chiral multiplets of the baryons are equivalent to their Lorentz representation.

Confinement and spontaneous breaking of chiral symmetry are assumed to generate the governing degrees of freedom of low-energy quantum chromodynamics. On this basis a relativistic constituent-quark model is constructed and formulated along an invariant mass operator within Poincaré-invariant quantum mechanics. The model is effectively applied to the spectroscopy of all known baryons of flavors u, d, s, c and b. The mass-operator eigenstates are furthermore tested with regard to the baryon electromagnetic and axial form factors. Through using the point form of relativistic quantum mechanics, these observables are obtained in a manifestly covariant manner. For all light and strange baryon ground states the electroweak structures are reproduced either in good agreement with phenomenology or, if no experimental data exist, in consistency with results available from lattice quantum chromodynamics. It is concluded that the relativistic constituent-quark model, relying on {QQQ} Fock states only, provides a universal framework for the description of low-energy baryons. The most important ingredients are spontaneous chiral-symmetry breaking and strict relativistic invariance.

We study the free energy per baryon using canonical formalism in the Polyakov loop Nambu–Jona-Lasinio model with imaginary chemical potential. We find that the free energy decreases rapidly with temperature around the transition temperature. This result coupled with the heavy-ion collision geometry leads to the creation of a free energy well for the baryons. We study the time evolution of this free energy well using hydrodynamic simulations and discuss the implications of this free energy well on the dynamics of the baryons.

In a particle theory model whose most readily discovered new particle is the $\sim 1$ TeV bilepton resonance in same-sign leptons, currently being sought at CERN’s LHC, there exist three quarks ${𝒟}$, ${𝒮}$, ${𝒯}$ which will be bound by QCD into baryons and mesons. We consider the decays of these additional baryons and mesons whose detailed experimental study will be beyond the reach of the 14 TeV CERN collider and accessible only at an O(100 TeV) collider.

Recently the H1 Collaboration observed a narrow peak in D*^-p invariant mass spectrum from what is believed to be an anti-charmed pentaquark baryon state with quark content, produced in deep inelastic scattering in ep collisions at HERA. This new state was tentatively named as being an anti-charmed analog of Θ⁺ pentaquark discovered in 2003 by LEPS Collaboration. The upgraded CDF detector is sensitive to production of charmed pentaquark states in central rapidity region due to ability to trigger on displaced tracks from weakly decaying daughter hadrons. At this conference we report results of searches for anti-charmed pentaquark and its charged isospin partner in collisions at at Tevatron.

The status of hybrids and glueballs is critically reviewed with special emphasis on the η(1440) and the ground state scalar glueball. The spectrum of baryon resonances is discussed.

Some past and ongoing explorations of the spectrum of QCD using Monte Carlo simulations on a space-time lattice are described. Glueball masses in the pure-gauge theory are reviewed, and the energies of gluonic excitations in the presence of a static quark-antiquark pair are discussed. Current efforts to compute the baryon spectrum using extended three-quark operators are also presented, emphasizing the need to use irreducible representations of the cubic point group to identify spin quantum numbers in the continuum limit.

Recent results relating to charm baryon and meson decays from the Belle and BABAR experiments are presented. In addition to recent observations for charm hyperons, evidence for a new charm baryon state, the Λ_c(2940), observed in its decay to D⁰p is also reported. No evidence for doubly charmed baryons is seen in e⁺e^- interactions. A measurement of the spin of the Ω^- hyperon is made using decays of the and baryons. On the assumption that the spin of the parent baryons are J = 1/2, the assignment J = 3/2 is confirmed and both J = 1/2 and also higher spins are excluded. New results on rare, Cabibbo-suppressed decays of charm mesons are also presented.

At the laser electron photon facility at SPring-8 (LEPS), meson photoproduction reactions have been studied by using highly polarized photon beams produced by the Compton backscattering of the laser off the high energy electrons. The recent activities at the LEPS experiment are overviewed. From the recent results, the meson photo-production reactions at the backward angles, and the photoproduction of Λ(1405) are discussed. In order to extend our study to wider kinematical range, construction of the new beamline and the large acceptance detector has been started.

We report on investigations of B-meson decays into baryons with the BABAR detector. The comparison of different decay channels reveals that higher multiplicities are preferred for these decays. Furthermore, an enhancement in the invariant baryon-antibaryon mass distribution can be observed in several baryonic decay modes. In addition, the study of baryon resonances seen in baryonic B-meson decays is presented.

We present a review of heavy flavor physics results from the CDF and DØ Collaborations operating at the Fermilab Tevatron Collider. A summary of results from Run 1 is included, but we concentrate on legacy results of charm and b physics from Run 2, including results up to Summer 2014.

Vertex operators for photo- and electro-production of baryon states with arbitrary spin-parity, $\gamma +N\to B(J^P)$, are constructed. The operators obey gauge invariance and analyticity constraints. Analyticity is realized as a requirement of the generalized Siegert theorem for vertex form factors.

The strong coupling constants not only are important to understand the strong interactions of the heavy baryons, but can also help us reveal the nature and structure of these baryons. Additionally, researchers indeed have made great efforts to calculate some of the strong coupling constants, $g_{{\mathrm{\Omega }}_c^{\ast }{\mathrm{\Omega }}_c^{\ast }\varphi }$, $g_{{\mathrm{\Omega }}_c^{\ast }{\mathrm{\Xi }}_c^{\ast }{K}^{\ast }}$, $g_{{\mathrm{\Xi }}_c^{\ast }{\mathrm{\Sigma }}_c^{\ast }{K}^{\ast }}$, $g_{{\mathrm{\Omega }}_b^{\ast }{\mathrm{\Omega }}_b^{\ast }\varphi }$, $g_{{\mathrm{\Xi }}_b^{\ast }{\mathrm{\Sigma }}_b^{\ast }{K}^{\ast }}$, $g_{{\mathrm{\Xi }}_b^{\ast }{\mathrm{\Xi }}_b\pi }$, $g_{{\mathrm{\Xi }}_c^{\ast }{\mathrm{\Xi }}_c\pi }$, $g_{{\mathrm{\Lambda }}_{b}N{B}^{\ast }}$, $g_{{\mathrm{\Lambda }}_b{N}^{\ast }{B}^{\ast }}$, $g_{{\mathrm{\Lambda }}_{c}N{D}^{\ast }}$, $g_{{\mathrm{\Lambda }}_c{N}^{\ast }{D}^{\ast }}$, $g_{{\mathrm{\Sigma }}_{c}N{D}^{\ast }}$, $g_{{\mathrm{\Sigma }}_b{N}^{\ast }{B}^{\ast }}$, $g_{{\mathrm{\Sigma }}_{b}N{B}^{\ast }}$, $g_{{\mathrm{\Sigma }}_c{N}^{\ast }{D}^{\ast }}$, etc. In this paper, we analyze the strong vertices ${\mathrm{\Sigma }}_c^{\ast }ND$ and ${\mathrm{\Sigma }}_b^{\ast }NB$ using the three-point QCD sum rules under the Dirac structure of $q/p//{\gamma }_{\mu }$. We perform our analysis by considering the contributions of the perturbative part and the condensate terms of $〈\bar{q}q〉$ and $〈\frac{{\alpha }_s}{\pi }GG〉$. After the form factors are calculated, they are then fitted into analytical functions which are used to get the strong coupling constants for these two vertices. The final results are $g_{{\mathrm{\Sigma }}_c^{\ast }ND}=7.19_{-3.11}^{+8.49}\pm 1.76$ and $g_{{\mathrm{\Sigma }}_b^{\ast }NB}=10.54_{-5.23}^{+15.59}\pm 1.82$.

The strong coupling constant is an important parameter that can help us understand the strong decay behaviors of baryons. In our previous work, we have analyzed the strong vertices ${\mathrm{\Sigma }}_c^{\ast }ND$, ${\mathrm{\Sigma }}_b^{\ast }NB$, ${\mathrm{\Sigma }}_{c}ND$ and ${\mathrm{\Sigma }}_{b}NB$ in QCD sum rules. Following these works, we further analyze the strong vertices ${\mathrm{\Sigma }}_{c}N{D}^{\ast }$ and ${\mathrm{\Sigma }}_{b}N{B}^{\ast }$ using the three-point QCD sum rules under Dirac structures $q/p/{\gamma }_{\alpha }$ and $q/p/p_{\alpha }$. In this work, we first calculate strong form-factors considering contributions of the perturbative part and the condensate terms $〈\bar{q}q〉$, $〈\frac{{\alpha }_s}{\pi }GG〉$ and $〈\bar{q}{g}_s\sigma Gq〉$. Then, these form-factors are used to fit into analytical functions. According to these functions, we finally determine the values of the strong coupling constants for these two vertices ${\mathrm{\Sigma }}_{c}N{D}^{\ast }$ and ${\mathrm{\Sigma }}_{b}N{B}^{\ast }$.

This paper discusses various aspects of the physical program Super Tau-Charm facility — a future flavor super-factory, whose construction is currently being discussed in China and Russia. Particular attention is paid to the study of charmed baryons, where record statistics Super Tau-Charm facility can provide significant progress.

The evolution of the baryon distribution in different phases, derived from cosmological simulations, are here reported. These computations indicate that presently most of baryons are in a warm-hot intergalactic (WHIM) medium (about 43%) while at z = 2.5 most of baryons constitute the diffuse medium (about 74%). Stars and the cold gas in galaxies represent only 14% of the baryons at z = 0. For z < 4 about a half of the metals are locked into stars while the fraction present in the WHIM and in the diffuse medium increases with a decreasing redshift. In the redshift range 0 ≤ z ≤ 2.5, the amount of metals in the WHIM increases from 4% to 22% while in the diffuse medium it increases from 0.6% to 4%. This enrichment process is due essentially to a turbulent diffusion mechanism associated to mass motions driven by supernova explosions. At z = 0, simulated blue (late type) galaxies show a correlation of the oxygen abundance present in the cold gas with the luminosity of the considered galaxy that agrees quite well with data derived from HII regions.

In this paper, we calculate the light and strange baryons spectrum using a new baryon mass formula. For this purpose we have exactly solved the radial Schrödinger equation in six-dimensional Hilbert space under the decatic potential by power series method via a suitable ansatz to the wave function with parameters those existing in the potential function, possibly for the first time. By applying our model, we find a good agreement for the even and odd parity resonances, the excited multiplets up to 3 GeV and the position of the Roper resonances of the nucleon with the spectrum of the particle data group.