Contribution of Instanton Induced Interaction for Penta-quarks in MIT Bag Model

Roles of instanton induced interactions (III) in the masses of pentaquark baryons, Theta^+ (J=1/2 and 3/2) and Xi^{--}, and a dibaryon, H, are discussed using the MIT bag model. It is shown that the two-body terms in III give a strong attraction mainly due to the increase of the number of pairs in multi-quark systems. In contrast, the three-body $u$-$d$-$s$ interaction is repulsive. It is found that III lowers the mass of negative-parity Theta^+ as much as 100 MeV from the mass predicted by the bag model without III.Comment: 4 pages, 2 figures, Talk given at International Workshop PENTAQUARK04 at SPring-8, Japan, July 20-23, 200

P-wave Pentaquark and its Decay in the Quark Model with Instanton Induced Interaction

P-wave pentaquarks with strangeness +1, I=0 and J^P=1/2^+ are studied in the non-relativistic quark model with instanton induced interaction (III). We present their mass splittings and orbital-spin-isospin-color structures. It is found that decompositions of the wave functions are sensitive to III, while the mass splittings are insensitive. The decay of the lowest energy pentaquark, \Theta^+, is found to be suppressed when the contribution of III is increased. Its wave function is dominated by Jaffe-Wilczek-type configuration at large III.Comment: 9 pages, 5 figure

Coupling of ultrathin tapered fibers with high-Q microsphere resonators at cryogenic temperatures and observation of phase-shift transition from undercoupling to overcoupling

We cooled ultrathin tapered fibers to cryogenic temperatures and controllably coupled them with high-Q microsphere resonators at a wavelength close to the optical transition of diamond nitrogen vacancy centers. The 310-nm-diameter tapered fibers were stably nanopositioned close to the microspheres with a positioning stability of approximately 10 nm over a temperature range of 7-28 K. A cavity-induced phase shift was observed in this temperature range, demonstrating a discrete transition from undercoupling to overcoupling

Epidermal Growth Factor and Transforming Growth Factor-α Stimulate the Proliferation of Mouse Uterine Stromal Cells

Growth factors produced in the uterine endometrium are considered to be involved in the proliferation of the mouse uterine stromal cells induced by estradiol-17beta (E-2) and progesterone (P). The effect of epidermal growth factor (EGF) and transforming growth factor-alpha (TGF-alpha), one of EGF-related growth factors, on the proliferation of mouse uterine stromal cells was studied in a serum-free culture. The growth of the uterine stromal cells was measured by MTT assay. EGF was found to increase the number of uterine stromal cells in a dose-dependent manner. The DNA-replicating cells were investigated using the immunocytochemical detection of bromodeoxyuridine (BrdU)-labeled cells. EGF and TGF-alpha increased the percentage of BrdU-Iabeled cells in a dose-dependent manner. Administration of the combination of E-2 (10(-9) M) and P (10(-7) M) for 2 days increased the percentage of BrdU-Iabeled cells 2.3-fold. The stimulatory effect of EGF, TGF-a and the combination of E2 and P on DNA replication in the uterine stromal cells was repressed by RG-13022 (10(-5) M, the inhibitor of the EGF receptor tyrosine kinase). RT-PCR analysis of EGF-receptor-, TGF-alpha, and EGF-mRNA was carried,out in the cultured uterine stromal cells, and revealed the expression of those mRNAs. These data supported the hypothesis that uterine endometrial stromal growth induced by sex steroids required the EGF family of ligands such as EGF and TGF-alpha, both produced in the stromal cells, acting for DNA synthesis through EGF receptors