Anomaly Mediation and Radius Stabilization by a Boundary Constant Superpotential in a Warped Space

We present a very simple model of the radius stabilization in a supersymmetric (SUSY) Randall-Sundrum model with a hypermultiplet and a boundary constant superpotential. A wide range of parameters where the anomaly mediation of SUSY breaking is dominated is found although there are many problematic bulk effects of SUSY breaking. A negative cosmological constant in the radius stabilized vacuum can be cancelled by a localized SUSY breaking. Making use of this localized SUSY breaking also solves the \mu-problem by Giudice-Masiero mechanism.Comment: 3 pages, 1 figures, To appear in the proceedings of 16th International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY08), Seoul, Korea, June 16-21 200

Higgsino mass matrix ansatz for MSSM

An ansatz, Det. $M_{\tilde H}=0,$ for the Higgsino mass matrix in string orbifold trinification is suggested toward the minimal supersymmetric standard model(MSSM). Small instanton solutions effective around the GUT scale can fulfil this condition. An argument that the couplings contain a moduli field is given for a dynamical realization of this Higgsino mass matrix ansatz.Comment: 15 pages of LaTeX fil

Holographic aspects of three dimensional QCD from string theory

We study two aspects of 3D QCD with massless fermions in a holographic set-up from string theory, based on D3/D7 branes; parity anomaly and baryons as baby Skyrmions. We first give a novel account of parity anomaly of 3D QCD with odd number of flavors from the IR holographic viewpoint by observing a subtle point in D7 brane embeddings with a given fixed UV theory. We also discuss its UV origin in terms of weakly coupled D-brane pictures. We then focus on the parity-symmetric case of even number of N_F flavors, and study baryons in the holographic model. We identify the monopoles of U(N_F) gauge theory dynamically broken down to U(N_F/2)x U(N_F/2) in the holographic 4 dimensional bulk as a holographic counter-part of 3D baby-Skyrmions for baryons in large N limit, and work out some details how the mapping goes. In particular, we show that the correct baryon charges emerge from the Witten effect with a space-varying theta angle.Comment: 33 pages, 10 figures; v2: references added with comments, typos corrected; v3: more references added; v4: holographic baryon profile and the analysis of its baryon charge is significantly revised, correcting errors in the previous discussio

The cometary composition of a protoplanetary disk as revealed by complex cyanides

Observations of comets and asteroids show that the Solar Nebula that spawned our planetary system was rich in water and organic molecules. Bombardment brought these organics to the young Earth's surface, seeding its early chemistry. Unlike asteroids, comets preserve a nearly pristine record of the Solar Nebula composition. The presence of cyanides in comets, including 0.01% of methyl cyanide (CH3CN) with respect to water, is of special interest because of the importance of C-N bonds for abiotic amino acid synthesis. Comet-like compositions of simple and complex volatiles are found in protostars, and can be readily explained by a combination of gas-phase chemistry to form e.g. HCN and an active ice-phase chemistry on grain surfaces that advances complexity[3]. Simple volatiles, including water and HCN, have been detected previously in Solar Nebula analogues - protoplanetary disks around young stars - indicating that they survive disk formation or are reformed in situ. It has been hitherto unclear whether the same holds for more complex organic molecules outside of the Solar Nebula, since recent observations show a dramatic change in the chemistry at the boundary between nascent envelopes and young disks due to accretion shocks[8]. Here we report the detection of CH3CN (and HCN and HC3N) in the protoplanetary disk around the young star MWC 480. We find abundance ratios of these N-bearing organics in the gas-phase similar to comets, which suggests an even higher relative abundance of complex cyanides in the disk ice. This implies that complex organics accompany simpler volatiles in protoplanetary disks, and that the rich organic chemistry of the Solar Nebula was not unique.Comment: Definitive version of the manuscript is published in Nature, 520, 7546, 198, 2015. This is the author's versio

A Triple Protostar System Formed via Fragmentation of a Gravitationally Unstable Disk

Binary and multiple star systems are a frequent outcome of the star formation process, and as a result, almost half of all sun-like stars have at least one companion star. Theoretical studies indicate that there are two main pathways that can operate concurrently to form binary/multiple star systems: large scale fragmentation of turbulent gas cores and filaments or smaller scale fragmentation of a massive protostellar disk due to gravitational instability. Observational evidence for turbulent fragmentation on scales of $>$1000~AU has recently emerged. Previous evidence for disk fragmentation was limited to inferences based on the separations of more-evolved pre-main sequence and protostellar multiple systems. The triple protostar system L1448 IRS3B is an ideal candidate to search for evidence of disk fragmentation. L1448 IRS3B is in an early phase of the star formation process, likely less than 150,000 years in age, and all protostars in the system are separated by $<$200~AU. Here we report observations of dust and molecular gas emission that reveal a disk with spiral structure surrounding the three protostars. Two protostars near the center of the disk are separated by 61 AU, and a tertiary protostar is coincident with a spiral arm in the outer disk at a 183 AU separation. The inferred mass of the central pair of protostellar objects is $\sim$1 M$_{sun}$, while the disk surrounding the three protostars has a total mass of $\sim$0.30 M_{\sun}. The tertiary protostar itself has a minimum mass of $\sim$0.085 M$_{sun}$. We demonstrate that the disk around L1448 IRS3B appears susceptible to disk fragmentation at radii between 150~AU and 320~AU, overlapping with the location of the tertiary protostar. This is consistent with models for a protostellar disk that has recently undergone gravitational instability, spawning one or two companion stars.Comment: Published in Nature on Oct. 27th. 24 pages, 8 figure

(Extra)Ordinary Gauge/Anomaly Mediation

We study anomaly mediation models with gauge mediation effects from messengers which have a general renormalizable mass matrix with a supersymmetry-breaking spurion. Our models lead to a rich structure of supersymmetry breaking terms in the visible sector. We derive sum rules among the soft scalar masses for each generation. Our sum rules for the first and second generations are the same as those in general gauge mediation, but the sum rule for the third generation is different because of the top Yukawa coupling. We find the parameter space where the tachyonic slepton problem is solved. We also explore the case in which gauge mediation causes the anomalously small gaugino masses. Since anomaly mediation effects on the gaugino masses exist, we can obtain viable mass spectrum of the visible sector fields.Comment: 24 pages, 10 figure

Prior Mating Experience Modulates the Dispersal of Drosophila in Males More Than in Females

Cues from both an animal’s internal physiological state and its local environment may influence its decision to disperse. However, identifying and quantifying the causative factors underlying the initiation of dispersal is difficult in uncontrolled natural settings. In this study, we automatically monitored the movement of fruit flies and examined the influence of food availability, sex, and reproductive status on their dispersal between laboratory environments. In general, flies with mating experience behave as if they are hungrier than virgin flies, leaving at a greater rate when food is unavailable and staying longer when it is available. Males dispersed at a higher rate and were more active than females when food was unavailable, but tended to stay longer in environments containing food than did females. We found no significant relationship between weight and activity, suggesting the behavioral differences between males and females are caused by an intrinsic factor relating to the sex of a fly and not simply its body size. Finally, we observed a significant difference between the dispersal of the natural isolate used throughout this study and the widely-used laboratory strain, Canton-S, and show that the difference cannot be explained by allelic differences in the foraging gene

Pseudo scalar contributions to light-by-light correction of muon g-2 in AdS/QCD

We have performed a holographic calculation of the hadronic contributions to the anomalous magnetic moment of the muon, using the gauge/gravity duality. We study a model of holographic QCD in the five dimensional AdS background with a hard-wall cutoff. Both 5D SU(2) and U(3) flavor gauge symmetries are considered for the neutral pion, eta and eta' contributions to the hadronic corrections. We find the total light-by-light contributions of pseudo scalars to the muon anomalous magnetic moment, a_mu=10.7 x 10^(-10), which is consistent with previous estimates, based on other approaches.Comment: v3. 13 pages, 6 figures, slightly expanded and reorganized for clarit

Improved Outcome of Central Nervous System Germ Cell Tumors: Implications for the Role of Risk-adapted Intensive Chemotherapy

To determine the impact of treatment protocols on the outcome of central nervous system germ cell tumors (CNS-GCTs), we reviewed the medical records of 53 patients who received front-line chemotherapy from September 1997 to September 2006. Pure germinoma, normal alpha-fetoprotein level and beta-human chorionic gonadotropin level <50 mIU/mL were regarded as low-risk features and the others as high-risk. Patients from different time periods were divided into 3 groups according to the chemotherapy protocols. Group 1 (n=19) received 4 cycles of chemotherapy comprising cisplatin, etoposide and bleomycin. Group 2 (n=16) and group 3 (n=18) received 4 cycles of chemotherapy with cisplatin, etoposide, cyclophosphamide and vincristine in the former and with carboplatin, etoposide, cyclophosphamide and bleomycin in the latter. In group 2 and group 3, high-risk patients received double doses of cisplatin, carboplatin and cyclophosphamide. Radiotherapy was given after chemotherapy according to the clinical requirements. The event-free survivals of groups 1, 2, and 3 were 67.0%, 93.8%, and 100%, respectively (group 1 vs. 2, P=0.06; group 2 vs. 3, P=0.29; group 1 vs. 3, P=0.02). Our data suggest that risk-adapted intensive chemotherapy may improve the outcome of patients with malignant CNS-GCTs