The solar LMA neutrino oscillation solution in the Zee model

We examine the neutrino mass matrix in the version of Zee model where both Higgs doublets couple to the leptons. We show that in this case one can accommodate the large mixing angle (LMA) MSW solution of the solar neutrino problem, while avoiding maximal solar mixing and conflicts with constraints on lepton family number-violating interactions. In the simplified scenario we consider, we have the neutrino mass spectrum characterized by $m_1 \simeq m_2 \simeq \sqrt{\Delta m^2_\mathrm{atm}}/\sin 2\theta$ and $m_3/m_1 \simeq \cos 2\theta$, where $\theta$ is the solar mixing angle.Comment: 13 pages, LaTeX, no figures; misprints in Eq. (39) correcte

Non-universal gauge bosons Z′Z^{\prime} and lepton flavor-violation tau decays

There are many models beyond the standard model predicting the existence of non-universal gauge bosons $Z^{\prime}$, which can give rise to very rich phenomena. We calculate the contributions of the non-universal gauge bosons $Z^{\prime}$, predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, to the lepton flavor-violation tau decays $\tau\to l_{i}\gamma$ and $\tau\to l_{i}l_{j}l_{k}$. We find that the branching ratio $B_{r}(\tau\longrightarrow l_{i}l_{j}l_{k})$ is larger than that of the process $\tau\longrightarrow l_{i}\gamma$ in all of the parameter space. Over a sizable region of the parameter space, we have $B_{r}(\tau\longrightarrow l_{i}l_{j}l_{k})\sim 10^{-8}$, which may be detected in the future experiments.Comment: Final version to appear in Phys. Lett. B. References added and typos correcte

クマモト ダイガク ニ オケル アンゼン エイセイ ニ ツイテ

九州地区総合技術研究会in熊本大学, 第21回情報処理センター等担当者技術研究会(2009年9月3.4日開催)　口頭発表

Duodenal gangliocytic paraganglioma showing lymph node metastasis: A rare case report

<p>Abstract</p> <p>We describe a case of duodenal gangliocytic paraganglioma showing lymph node metastasis. A 61-year-old Japanese man underwent pylorus preserving pancreaticoduodenectomy to remove a tumor at the papilla of Vater. The section of the tumor extending from the mucosa to submucosa of the duodenum was sharply demarcated, solid, and white-yellowish. Neither necrosis nor hemorrhage was present. Histological examination confirmed the immunohistochemical identification of three components comprising epithelioid cells, spindle-shaped cells, and ganglion-like cells. Epithelioid cells showed positive reactivity for synaptophysin, somatostatin, and CD56. In contrast, spindle-shaped cells showed positive reactivity for S-100 protein, but not for synaptophysin, somatostatin or CD56. Furthermore, we found lymph node metastasis despite lack of bcl-2 and p53 expression. In addition to the rarity of the tumor, we are describing here the present case suggests the malignant potency of the tumor despite lack of acceptable prognostic indicators for neuroendocrine tumor.</p