Radiative CP Phases in Supergravity Theories

In this letter, we point out that possible sources of CP violation originate from radiative corrections to soft terms which are ubiquitous in supergravity theories and also in other high-energy frameworks of supersymmetry breaking. With these radiative phases of gaugino masses and scalar couplings, a complex phase of Higgs holomorphic mass parameter is generated via renormalization-group running down to low energy. It is found that its phase value is mainly controlled by wino as well as gluino, which generally receive different radiative corrections to their complex phases, even if the leading part of mass parameters follow from the universality hypothesis. The radiatively generated phases are constrained by the existing experimental bounds on electric dipole moments, and may be detectable in future measurements. They are also found to be available for the cancellation mechanism to be worked.Comment: 14 pages, 5 figures, references adde

Phenomenology of Minimal Supergravity with Vanishing A and B Soft Supersymmetry-Breaking Parameters

The ansatz of vanishing A and B parameters eliminates CP violating complex phases in soft supersymmetry-breaking parameters of the minimal supersymmetric standard model, and thus provides a simple solution to the supersymmetry CP problem. Phenomenological implications of this ansatz are investigated in the framework of minimal supergravity. We show that electroweak symmetry breakdown occurs, predicting relatively large \tan \beta. The ansatz survives the Higgs mass bound as well as the b \to s \gamma constraint if the universal gaugino mass is larger than 300 GeV. We also find that the supersymmetric contribution to the anomalous magnetic moment of muon lies in an experimentally interesting region of order 10^{-9} in a large portion of the parameter space.Comment: 6 pages, 3 figure

Iridium complex, a phosphorescent light-emitting diode material, serves as a novel chemical probe for imaging hypoxic tumor tissues

Iridium complex, a promising organic light-emitting diode for next generation television displays, emits phosphorescence. Phosphorescence is quenched by oxygen. We used this oxygen-quenching feature for imaging tumor hypoxia. Red light-emitting iridium complex Ir(btp)~2~(acac) (BTP) presented hypoxia-dependent light emission in culture cell lines, whose intensity was in parallel with HIF-1[alpha] expression. BTP was further applied to imaging five tumors (four from human origin and one from mouse origin) transplanted in athymic mice. All tumors presented a bright BTP-emitting image even 5 min after the injection. The BTP-dependent tumor image peaked at 1 to 2 h after the injection, and was then cleared from tumors within 24 h. The minimal BTP image recognition size was 3 to 4 mm in diameter. Compared with ^18^F-FDG/PET images, BTP delineated a clearer image for a tumor profile. We suggest that iridium complex has a vast potential for imaging hypoxic lesions such as tumor tissues

Antioxidant Activity of Intramolecularly Hydrogen Bonded 2-Aminophenol

The antioxidant activities of five classes of 2-aminophenol (model compound) and 2-aminophenols with substituent at the phenyl ring were studied in the oxidation of tetralin induced by an azo-initiator at 61℃. 2-Aminophenols with electron-donating groups at the 4-position exhibited higher antioxidant activity than that of the model compound. However, introduction of the methoxy group at the 4-position reduced the antioxidant activity by 8 % that of the model compound. 2-Aminophenols with electron-donating groups at the 5-position have little effect on the antioxidant activity. 2-Aminophenols with electron-donating groups at both the 4- and 6-positions showed remarkable antioxidant activity. These results were discussed in terms of the hydrogen bonding effect and bond dissociation energies of the O-H and NH-H bonds

Pseudoelastic Behavior and Aging Effect in Thermoelastic In-Tl Martensite

In this paper, the authors report the interesting stress-strain results and an aging behavior found in single crystals of In-21, 22, 23, 24, 25 and 26 at. % Tl alloys. The stress-strain curves can be classified into three groups according to their shapes. In a high temperature region above martensitic temperature, Mₛ, while at a considerably low temperature region, superelastic loops are obtained. While at an intermediate temperature below Mₛ, the residual strain remains after removal of the applied stress, and this strain returns to zero when the specimen is heated up to above the reverse transformation temperature. That is the so-called shape memory effect. The twin boundaries migrated by the external stress were stabilized by strain aging under stress, and the activation energy for the aging process was found to be O.51±O.O3eV. The strain rate dependence of pseudo-elastic behavior is observed in the martensite phase and is explained by the dynamic aging between the moving twin boundaries and Tlatoms

Bottom-Up Approach to Moduli Dynamics in Heavy Gravitino Scenario : Superpotential, Soft Terms and Sparticle Mass Spectrum

The physics of moduli fields is examined in the scenario where the gravitino is relatively heavy with mass of order 10 TeV, which is favored in view of the severe gravitino problem. The form of the moduli superpotential is shown to be determined, if one imposes a phenomenological requirement that no physical CP phase arise in gaugino masses from conformal anomaly mediation. This bottom-up approach allows only two types of superpotential, each of which can have its origins in a fundamental underlying theory such as superstring. One superpotential is the sum of an exponential and a constant, which is identical to that obtained by Kachru et al (KKLT), and the other is the racetrack superpotential with two exponentials. The general form of soft supersymmetry breaking masses is derived, and the pattern of the superparticle mass spectrum in the minimal supersymmetric standard model is discussed with the KKLT-type superpotential. It is shown that the moduli mediation and the anomaly mediation make comparable contributions to the soft masses. At the weak scale, the gaugino masses are rather degenerate compared to the minimal supergravity, which bring characteristic features on the superparticle masses. In particular, the lightest neutralino, which often constitutes the lightest superparticle and thus a dark matter candidate, is a considerable admixture of gauginos and higgsinos. We also find a small mass hierarchy among the moduli, gravitino, and superpartners of the standard-model fields. Cosmological implications of the scenario are briefly described.Comment: 45 pages, 10 figures, typos correcte

The Regulation of Chloroplast Synthesis by a Light Mediated Phosphoinositide System

This work was aided by grants from the Ministry of Education, Science, Sports and culture in Japan (No. 09640795) and the Kazato Research Foundation (2000)

Light energy allocation at PSII under field light conditions: How much energy is lost in NPQ-associated dissipation?

In the field, plants are exposed to fluctuating light, where photosynthesis occurs under conditions far from a steady state. Excess energy dissipation associated with energy quenching of chlorophyll fluorescence (qE) functions as an efficient photo-protection mechanism in photosystem II. PsbS is an important regulator of qE, especially for the induction phase of qE. Beside the regulatory energy dissipation, some part of energy is lost through relaxation of excited chlorophyll molecules. To date, several models to quantify energy loss through these dissipative pathways in PSII have been proposed. In this short review, we compare and evaluate these models for PSII energy allocation when they are applied to non-steady state photosynthesis. As a case study, an investigation on energy allocation to qE-associated dissipation at PSII under non-steady state photosynthesis using PsbS-deficient rice transformants is introduced. Diurnal and seasonal changes in PSII energy allocation in rice under natural light are also presented. Future perspective of studies on PSII energy allocation is discussed