A new method of determining ∣Vub∣|V_{ub}| by the processes Bˉ→ρlνˉ\bar{B} \to \rho l \bar{\nu} and \bar{B} \to K^* l \lbar

The differential decay width of the process $\bar{B} \rightarrow \rho l \bar{\nu}$ is related to that of the process \bar{B} \rightarrow K^* l \lbar by using $SU(3)$-flavor symmetry and the heavy quark symmetry. The ratio of the Kobayashi-Maskawa matrix elements is obtained in the zero recoil limit of $\rho$ and $K^*$, allowing a determination of $|V_{ub}|$.Comment: Latex file 9 pag

Interplay of Kondo and superconducting correlations in the nonequilibrium Andreev transport through a quantum dot

Using the modified perturbation theory, we theoretically study the nonequilibrium Andreev transport through a quantum dot coupled to normal and superconducting leads (N-QD-S), which is strongly influenced by the Kondo and superconducting correlations. From the numerical calculation, we find that the renormalized couplings between the leads and the dot in the equilibrium states characterize the peak formation in the nonequilibrium differential conductance. In particular, in the Kondo regime, the enhancement of the Andreev transport via a Kondo resonance occurs in the differential conductance at a finite bias voltage, leading to an anomalous peak whose position is given by the renormalized parameters. In addition to the peak, we show that the energy levels of the Andreev bound states give rise to other peaks in the differential conductance in the strongly correlated N-QD-S system. All these features of the nonequilibrium transport are consistent with those in the recent experimental results [R. S. Deacon {\it et al.}, Phys. Rev. Lett. {\bf 104}, 076805 (2010); Phys. Rev. B {\bf 81}, 12308 (2010)]. We also find that the interplay of the Kondo and superconducting correlations induces an intriguing pinning effect of the Andreev resonances to the Fermi level and its counter position.Comment: 22 pages, 23 figure

Studies on Regioselective Binding Mode of Steroid Molecules in Homology Modeled Cytochrome P450-2C11

In this study, we investigated the regioselective binding mode of steroid molecules and structure requirements for steroid molecules for 16[alpha]-hydroxylation by Cytochrome P450-2C11. Docking study by using the homology Cytochrome P450-2C11 indicated that 16[alpha]-hydroxylation is favored with steroidal molecules possessing the following components, 1) a bent A-B ring configuration (5[beta]-reduced), 2) C-3[alpha]-hydroxyl group, 3) C-17[beta]-acetyl group, and 4) methyl group at both the C-18 and C-19. These respective steroid components requirements such as A-B ring configuration and functional groups at C-3 and C-17 were defined as the inhibitory contribution factor. Overall results by rat CYP2C11 revealed that steroidal structure requirements resulted in causing an effective inhibition of [^3^H]progesterone 16[alpha]-hydroxylation by the adult male rat liver microsome. As far as docking of homology modeled CYP2C11 against investigated steroids is concerned, they are docked at the active site superimposed with flurbiprofen. It was also found that the distance between heme iron and C16[alpha]-H was between 4 to 6 Å and that the related angle was in the range of 180±45°

Cu NQR and NMR Studies of Optimally Doped Ca2-xNaxCuO2Cl2

We report on Cu nuclear quadrupole resonance (NQR) and NMR studies of an optimally hole-doped superconductor Ca2-xNaxCuO2Cl2 (Tc ~ 28 K for x ~ 0.2). In spite of robust oxygen composition, we observed a multiple broad NQR frequency spectrum and nonexponential Cu nuclear spin-lattice relaxation, being similar to those of La2-xSrxCuO4-d.Comment: 2 pages, 3 figures; to appear in J. Phys. Soc. Jpn (short note

Running coupling constant of ten-flavor QCD with the Schr\"odinger functional method

Walking technicolor theory attempts to realize electroweak symmetry breaking as the spontaneous chiral symmetry breakdown caused by the gauge dynamics with slowly varying gauge coupling constant and large mass anomalous dimension. Many-flavor QCD is one of the candidates owning these features. We focus on the SU(3) gauge theory with ten flavors of massless fermions in the fundamental representation, and compute the gauge coupling constant in the Schr\"odinger functional scheme. Numerical simulation is performed with $O(a)$-unimproved lattice action, and the continuum limit is taken in linear in lattice spacing. We observe evidence that this theory possesses an infrared fixed point.Comment: 28 pages, 6 figures. v2) remarks on the continuum limit added, analysis simplified and done with more statistics, conclusion unchanged, version accepted for publication in PR

Isoscalar monopole excitations in 16^{16}O: α\alpha-cluster states at low energy and mean-field-type states at higher energy

Isoscalar monopole strength function in $^{16}$O up to $E_{x}\simeq40$ MeV is discussed. We found that the fine structures at the low energy region up to $E_{x} \simeq 16$ MeV in the experimental monopole strength function obtained by the $^{16}$O$(\alpha,\alpha^{\prime})$ reaction can be rather satisfactorily reproduced within the framework of the $4\alpha$ cluster model, while the gross three bump structures observed at the higher energy region ($16 \lesssim E_{x} \lesssim 40$ MeV) look likely to be approximately reconciled by the mean-field calculations such as RPA and QRPA. In this paper, it is emphasized that two different types of monopole excitations exist in $^{16}$O; one is the monopole excitation to cluster states which is dominant in the lower energy part ($E_{x} \lesssim 16$ MeV), and the other is the monopole excitation of the mean-field type such as one-particle one-hole ($1p1h$) which {is attributed} mainly to the higher energy part ($16 \lesssim E_{x} \lesssim 40$ MeV). It is found that this character of the monopole excitations originates from the fact that the ground state of $^{16}$O with the dominant doubly closed shell structure has a duality of the mean-field-type {as well as} $\alpha$-clustering {character}. This dual nature of the ground state seems to be a common feature in light nuclei.Comment: 35 pages, 5 figure

General Connectivity Distribution Functions for Growing Networks with Preferential Attachment of Fractional Power

We study the general connectivity distribution functions for growing networks with preferential attachment of fractional power, $\Pi_{i} \propto k^{\alpha}$, using the Simon's method. We first show that the heart of the previously known methods of the rate equations for the connectivity distribution functions is nothing but the Simon's method for word problem. Secondly, we show that the case of fractional $\alpha$ the $Z$-transformation of the rate equation provides a fractional differential equation of new type, which coincides with that for PA with linear power, when $\alpha = 1$. We show that to solve such a fractional differential equation we need define a transidental function $\Upsilon (a,s,c;z)$ that we call {\it upsilon function}. Most of all previously known results are obtained consistently in the frame work of a unified theory.Comment: 10 page