arXiv subjects
Publications and source records attributed to Toshiyuki Morii.
Simple formulas on $Δ\bar d(x)-Δ\bar u(x)$ are proposed for extracting their values from polarized deep-inelastic semi-inclusive data. The present SMC and HERMES data suggest that $Δ\bar d(x)-Δ\bar u(x)$ is slightly negative, though the precision of the data is not enough for confirming it.
We studied the photoproduction of $ψ^{\prime}$ in the forward regions in polarized $γp$ collisions at relevant HERA energies. We found that this reaction is very effective to test the color-octet mechanism which is based on the NRQCD factorization formalism. Furthermore we found that the value of the NRQCD matrix elements can be severely constrained by measuring the two-spin asymmetry, though the process depends on the polarized gluon distribution $Δg(x)$.
We study the possibility to constrain the hidden strangeness content of the nucleon by means of the polarization observables in phi meson electroproduction. We consider the OZI evading direct knockout mechanism that arises from the non-vanishing s\bar{s} sea quark admixture of the nucleon as well as the background of the dominant diffractive and the one-boson-exchange processes. Large sensitivity on the nucleon strangeness are found in several beam-target and beam-recoil double polarization observables. The small \sqrt{s} and W region, which is accesible at some of the current high-energy electron facilities, is found to be the optimal energy region for extracting out the OZI evasion process.
Operating just once with the naive Foldy-Wouthuysen-Tani transformation on the relativistic Fermi-Yang equation for $Q\bar q$ bound states described by the semi-relativistic Hamiltonian which includes Coulomb-like as well as confining scalar potentials, we have calculated heavy meson mass spectra of D and B together with higher spin states. Based on the formulation recently proposed, their masses and wave functions are expanded up to the second order in $1/m_Q$ with a heavy quark mass $m_Q$ and the lowest order equation is examined carefully to obtain a complete set of eigenfunctions for the Schrödinger equation. Heavy quark effective theory parameters, $\barΛ$, $λ_1$, and $λ_2$, are also determined at the first and second order in $1/m_Q$.
Assuming Coulomb-like as well as confining scalar potential, we have solved Shrödinger equation perturbatively in $1/m_Q$ with a heavy quark mass $m_Q$. The lowest order equation is examined carefully. Mass levels are fitted with experimental data for $D/B$ mesons at each level of perturbation. Meson wave functions obtained thereby can be used to calculate ordinary form factors as well as Isgur-Wise functions for semileptonic weak decays and other physical quantities. All the above calculations are expanded in $1/m_Q$ order by order to determine parameters as well as to compare with results of Heavy Quark Effective Theory.
Based on a simple model which is compatible with the idea of the static quark model and the parton model, the polarized structure functions of proton and deuteron, two-spin asymmetries of $π^0$ in polarized $pp$ reactions and inelastic $J/ψ$ productions in polarized lepton-proton collisions are analyzed. In particular, an important role of polarized gluon distributions is pointed out.