Instanton-induced charm contribution to polarized deep-inelastic scattering

Recent data on B decays involving $\eta'$ may be explained if the singlet axial current of charmed quarks has large matrix element to $\eta'$, and instantons were shown to be able to generate this effect. We study the magnitude of charm contributions to nucleon polarized structure functions generated in a similar way. Comparing the charm contribution, which is related to a dim(6) gluonic operator, to that of light quarks, which are related by the anomaly equation to $G\tilde G$, we found that $\Delta c/\Delta\Sigma$ = -(0.2-0.08). Future experiments like COMPASS at CERN identifying charm production in DIS can measure this ``intrinsic polarized charm'' component of the nucleon.Comment: 12 pages, LaTeX, RevTex, epsfig.sty, 3 figures, one sign in Euclidean definitions correcte

Magnetic Moments of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model

We investigate the magnetic moments of the SU(3) octet baryons in the framework of the $SU(3)$ semibosonized Nambu--Jona--Lasinio model. The rotational $1/N_c$ corrections and strange quark mass in linear order are taken into account. We derive general relations between magnetic moments of the SU(3) octet baryons, based on the symmetry of our model. These relations indicate that higher order corrections such as $O(m_s/N_c)$ and $O(m^{2}_{s})$ are relatively small. The magnetic moments of the octet baryons predicted by our model are quantitatively in a good agreement with experimental results within about 15$\%$.Comment: 17 pages, RevTex, 1 postscript figur

Electromagnetic Form Factors of the SU(3) Octet Baryons in the semibosonized SU(3) Nambu-Jona-Lasinio Model

The electromagnetic form factors of the SU(3) octet baryons are investigated in the semibosonized SU(3) Nambu--Jona-Lasinio model (chiral quark-soliton model). The rotational $1/N_c$ and strange quark mass corrections in linear order are taken into account. The electromagnetic charge radii of the nucleon and magnetic moments are also evaluated. It turns out that the model is in a remarkable good agreement with the experimental data.Comment: RevTex is used. 37 pages. The final version to appear in Phys. Rev. D. 13 figures are include

Strangeness in the Scalar Form Factor of the Nucleon

The scalar form factor of the nucleon and related physical quantities are investigated in the framework of the semibosonized SU(3) Nambu-Jona-Lasinio soliton model. We take into account the rotational $1/N_c$ corrections and linear $m_s$ corrections. The strangeness content of the nucleon in the scalar form factor is discussed in detail. In particular, it is found that the $m_s$ corrections play an essential role of reducing the $\langle N | \bar{s} s | N \rangle$ arising from the leading order and rotational $1/N_c$ contributions. We obtain the \sigma_{\pi N} (0)=40.80\;\mbox{MeV}, \Delta \sigma = \sigma_{\pi N} (2m^{2}_{\pi})-\sigma_{\pi N} (0) = 18.18\;\mbox{MeV} and \langle r^2\rangle^{S}_{N} = 1.50\;\mbox{fm}^2. The results are in a remarkable agreement with empirical data analyzed by Gasser, Leutwyler, and Sainio~\cite{gls}.Comment: 13 pages, RevTex is used. 3 figures as uufiles are include

Rotational Corrections to Axial Currents in Semibosonized SU(3) Nambu--Jona-Lasinio Model

We examine O(1/\Ne) rotational corrections to axial couplings \gt~ and \go~ in the framework of the semibosonized SU(3) Nambu--Jona-Lasinio model. A novelty is due to the observation that the rotational (cranking) velocity and the rotation matrix itself do not commute within semiclassical quantization scheme. If time ordering in the quark loop is maintained new contributions, which have no analogue in the Skyrme model, appear. They substantially improve numerical results for the axial couplings which without the present corrections are badly underestimated.Comment: RUP-TPII-54/93, in LaTeX, 6pages, no figures, in revised version two references have been update

Pentaquark Θ∗\Theta^* States in {27} Baryon Multiplet from Chiral Soliton Model

We estimate the mass and the width of pentaquark $\Theta^*$ states in the 27-plet from chiral soliton models. The calculations show that the mass of $\Theta^*$ is about 1.60 GeV and the width for the process $\Theta^*\to {KN}$ is less than 43 MeV. We also discuss the search for the existence of $\Theta^*$ states in physical processes.Comment: 10 latex pages, 1 figure. Revised version to appear in PL

The Constituent Quark Limit and the Skyrmion Limit of the Chiral Quark Soliton Model

We calculate $g_A^3$ and $g_A^0$ in the Chiral Quark-Soliton Model (or equivalently in semibosonized Nambu--Jona-Lasinio model) in the limit of small and large soliton size. In small soliton limit we recover the results of the Constituent Quark Model. The agreement between the two models is achieved due to the recently calculated 1/\Nc contributions to $g_A^3$ and to $g_A^0$. In the case of $g_A^3$ these terms arise from the {\it time-ordering} of the collective operators. For large solitons simple scaling arguments show that the 1/\Nc contributions vanish with the inverse power of the soliton size.Comment: One additional reference, 14 pages, latex, revtex, picte

The width of Θ+\Theta^{+} for large NcN_{c} in chiral quark soliton model

In the chiral quark soliton model the smallness of $\Theta^+$ width is due to the cancellation of the coupling constants which are of different order in $N_c$. We show that taking properly into account the flavor structure of relevant SU(3) representations for arbitrary number of colors enahnces the nonleading term by an additional factor of $N_c$, making the cancellation consistent with the $N_c$ counting. Moreover, we show that, for the same reason, $\Theta^+$ width is suppressed by a group-theoretical factor ${\cal O}(1/N_c)$ with respect to $\Delta$ and discuss the $N_c$ dependence of the phase space factors for these two decays.Comment: 9 pages, 3 eps figures, in v2 reference added, minor typos correcte