Formulation of n-d Elastic and Breakup Reactions in Terms of the Faddeev Equation with a Local Potential

We present a heuristic description of a practical theory of n-d elastic and breakup reactions. This is a new version of our three-body theory based on the Faddeev equation with a local potential in coordinate space. We reformulate our previous treatment as legible as possible, and made the following revisions: (i) The structure of the theory is centered on the elastic part of the Faddeev wave function. The breakup components are deduced as necessary ingredients of the elastic part. (ii) Since elastic channel must contain all possible spectator partial waves, it is treated in terms of a multi-channel coupled equation. (iii) Breakup processes to two-body partial waves other than ^lS_O are treated as the perturbation. (iv) The logarithmic singularities in the Faddeev Kernel in the breakup channel are studied in detail, and a practical method of solving our key equation is suggested based on the knowledge of the singularity structure of the solution. The presentation is detailed enough so that the formulas can immediately be transcribed to suit actual coding of a computational program

Central and tensor components of three-nucleon forces in low-energy proton-deuteron scattering

Contributions of three-nucleon forces (3NF) to proton-deuteron scattering observables at energies below the deuteron breakup threshold are studied by solving the Faddeev equation that includes the Coulomb interaction. At E_p=3.0 MeV, we find that the central part of a two-pion exchange 3NF removes the discrepancy between measured cross sections and the calculated ones by two-nucleon forces, and improves the agreement with T_{22} experimental data. However, the tensor part of the 3NF fails in reproducing data of the analyzing power T_{21} by giving worse agreement between the measured and the calculated. Detailed examinations of scattering amplitudes suggest that a P-wave contribution in spin quartet tensor amplitudes has unsuitable sign for reproducing the T_{21} data.Comment: 6 pages, 6 figure

Pressure effects on the phase transitions and energy gap in CeRhAs

We report on the electrical resistivity, thermal expansion, and x-ray diffraction measurements of single-crystalline sample of the so-called Kondo semiconductor CeRhAs under pressures up to 3 GPa. This compound undergoes successive structural phase transitions at T1 = 360, T2 = 235, and T3 = 165 K at ambient pressure. On cooling below T1, the crystal structure changes from the hexagonal LiGaGe-type to the orthorhombic epsilon-TiNiSi-type with a 2b×2c superlattice. By applying pressure up to 1.5 GPa, T1 increases with a ratio of 270 K/GPa, whereas both T2 and T3 decrease with –100 K/GPa. The concurrent decrease of both the a parameter and the energy gap along the a axis with increasing pressure contradict the c-f hybridization gap model in which the gap is enlarged by the enhancement of hybridization between the 4f electrons and conduction band. Instead, a sort of charge-density-wave transition at T1 is proposed for the origin of gap formation of this compound. The semiconducting behavior in the resistivity vanishes when the phase with the 2b×2c superlattice decomposes into two orthorhombic phases below 100 K and above 1.5 GPa

Relativistic Effect on Low-Energy Nucleon-Deuteron Scattering

The relativistic effect on differential cross sections, nucleon-to-nucleon and nucleon-to-deuteron polarization transfer coefficients, and the spin correlation function, of nucleon-deuteron elastic scattering is investigated employing several three-dimensional relativistic three-body equations and several nucleon-nucleon potentials. The polarization transfer coefficients are found to be sensitive to the details of the nucleon-nucleon potentials and the relativistic dynamics employed, and prefer trinucleon models with the correct triton binding energy. (To appear in Phys. Rev. C)Comment: pages: 21, LaTex text + 7 ps-figures at the en

A Bacterial Effector Targets Mad2L2, an APC Inhibitor, to Modulate Host Cell Cycling

SummaryThe gut epithelium self-renews every several days, providing an important innate defense system that limits bacterial colonization. Nevertheless, many bacterial pathogens, including Shigella, efficiently colonize the intestinal epithelium. Here, we show that the Shigella effector IpaB, when delivered into epithelial cells, causes cell-cycle arrest by targeting Mad2L2, an anaphase-promoting complex/cyclosome (APC) inhibitor. Cyclin B1 ubiquitination assays revealed that APC undergoes unscheduled activation due to IpaB interaction with the APC inhibitor Mad2L2. Synchronized HeLa cells infected with Shigella failed to accumulate Cyclin B1, Cdc20, and Plk1, causing cell-cycle arrest at the G2/M phase in an IpaB/Mad2L2-dependent manner. IpaB/Mad2L2-dependent cell-cycle arrest by Shigella infection was also demonstrated in rabbit intestinal crypt progenitors, and the IpaB-mediated arrest contributed to efficient colonization of the host cells. These results strongly indicate that Shigella employ special tactics to influence epithelial renewal in order to promote bacterial colonization of intestinal epithelium

X-Ray Photoelectron Spectral Analysis for Carbon Allotropes,

金沢大学大学院自然科学研究科物質情報解

proton-deuteron elastic scattering above the deuteron breakup

The complex Kohn variational principle and the (correlated) hyperspherical harmonics method are applied to study the proton-deuteron elastic scattering at energies above the deuteron breakup threshold. Results for the elastic cross section and various elastic polarization observables have been obtained by fully taking into account the long-range effect of the Coulomb interaction and using a realistic nucleon-nucleon interaction model. Detailed comparison between the theoretical predictions and the accurate and abundant proton-deuteron experimental data can now be performed.Comment: 6 pages, 2 figure

Reaction mechanism and characteristics of T_{20} in d + ^3He backward elastic scattering at intermediate energies

For backward elastic scattering of deuterons by ^3He, cross sections \sigma and tensor analyzing power T_{20} are measured at E_d=140-270 MeV. The data are analyzed by the PWIA and by the general formula which includes virtual excitations of other channels, with the assumption of the proton transfer from ^3He to the deuteron. Using ^3He wave functions calculated by the Faddeev equation, the PWIA describes global features of the experimental data, while the virtual excitation effects are important for quantitative fits to the T_{20} data. Theoretical predictions on T_{20}, K_y^y (polarization transfer coefficient) and C_{yy} (spin correlation coefficient) are provided up to GeV energies.Comment: REVTEX+epsfig, 17 pages including 6 eps figs, to be published in Phys. Rev.