The decay rate of ψ(2S)\psi(2S) to Λc+Σ+ˉ\Lambda_c+\bar{\Sigma^+} in SM and beyond

With rapid growth of the database of the BES III and the proposed super flavor factory, measurement on the rare $\psi(2S)$ decays may be feasible, especially the weak decays into baryon final states. In this work we study the decay rate of $\psi(2S)$ to $\Lambda_c+\overline{\Sigma^+}$ in the SM and physics beyond the SM (here we use the unparticle model as an example). The QPC model is employed to describe the creation of a pair of $q\bar q$ from vacuum. We find that the rate of $\psi(2S)\rightarrow \Lambda_c+\overline{\Sigma^+}$ is at order of $10^{-10}$ in the SM, whereas the contribution of the unparticle is too small to be substantial. Therefore if a large branching ratio is observed, it must be due to new physics beyond SM, but by no means the unparticle.Comment: 9 pages, 1 figure

Study on the effects of the light CP-odd Higgs via the leptonic decays of pseudoscalar mesons

To explain the anomalously large decay rate of $\Sigma^+\to p+\mu^+\mu^-$, it was proposed that a new mechanism where a light CP-odd pseudoscalar boson of $m_{A_1^0}=214.3$ MeV makes a crucial contribution. Later, some authors have studied the transition $\pi^0\to e^+e^-$ and $\Upsilon\to \gamma A_1^0$ in terms of the same mechanism and their result indicates that with the suggested mass one cannot fit the data. This discrepancy might be caused by experimental error of $\Sigma^+\to p+\mu^+\mu^-$ because there were only a few events. Whether the mechanism is a reasonable one motivates us to investigate the transitions $\pi^0\to e^+e^-; \eta (\eta^\prime)\to \mu^+\mu^-; \eta_c\to \mu^+\mu^-; \eta_b\to\tau^+\tau^-$ within the same framework. It is noted that for $\pi^0\to e^+e^-$, the standard model (SM) prediction is smaller than the data, whereas the experimental central value of $\eta \to \mu^+\mu^-$ is also above the SM prediction. It means that there should be extra contributions from other mechanisms and the contribution of $A_1^0$ may be a possible one. Theoretically calculating the branching ratios of the concerned modes, we would check if we can obtain a universal mass for $A_1^0$ which reconcile the theoretical predictions and data for all the modes. Unfortunately, we find that it is impossible to have such a mass with the same coupling $|g_\ell|$. Therefore we conclude that the phenomenology does not favor such a light $A_1^0$, even though a small window is still open.Comment: 17 pages, 7 figures, 2 table

Search for lepton flavor violation in supersymmetric models via meson decays

Considering the constraints from the experimental data on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion etc., we analyze the Lepton Flavor Violating decays $\phi(J/\Psi,\Upsilon(1S)) \rightarrow e^+\mu^-(\mu^+\tau^-)$ in the scenarios of the minimal supersymmetric extensions of Standard Model with seesaw Mechanism. Numerically, there is parameter space that the LFV processes of $J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ can reach the upper experimental bounds, meanwhile the theoretical predictions on $\mu\rightarrow e\gamma$, $\mu\rightarrow3e$, $\mu-e$ conversion satisfy the present experimental bounds. For searching of new physics, Lepton Flavor Violating processes $J/\Psi(\Upsilon)\rightarrow\mu^+\tau^-$ may be more promising and effective channels.Comment: 30 pages, 13 figure

The Origin of OB Clusters: From 10 pc to 0.1 pc

We observe the 1.2 mm continuum emission around the OB cluster forming region G10.6-0.4, using the IRAM 30m telescope MAMBO-2 bolometer array and the Submillimeter array. Comparison of the Spitzer 24 $\mu$m and 8 $\mu$m images with our 1.2 mm continuum maps reveals the ionization front of an HII region, the photon-dominated layer, and several 5 pc scale filaments following the outer edge of the photon-dominated layer. The filaments, which are resolved in the MAMBO-2 observations, show regularly spaced parsec-scale molecular clumps, embedded with a cluster of submillimeter molecular cores as shown in the SMA 0.87 mm observations. Toward the center of the G10.6-0.4 region, the combined SMA+IRAM 30m continuum image reveals several, parsec-scale protrusions. They may continue down to within 0.1 pc of the geometric center of a dense 3 pc size structure, where a 200 M$_{\odot}$ OB cluster resides. The observed filaments may facilitate mass accretion onto the central cluster--forming region in the presence of strong radiative and mechanical stellar feedbacks. Their filamentary geometry may also facilitate fragmentation. We did not detect any significant polarized emission at 0.87 mm in the inner 1 pc region with the SMA.Comment: 32 pages, 10 figures, Accepted by ApJ on 2011.October

Characterization of the Enhancing Effect of Protamine on the Proliferative Activity of Hepatocyte Growth Factor in Rat Hepatocytes

金沢大学医薬保健研究域薬学系Purpose: The aim of the present study was to characterize the mechanism of the stimulatory effect of protamine on HGF activity. Methods: The enhancing effects of protamine on the proliferative activity of HGF were investigated in vivo, in primary cultured rat hepatocytes, and in perfused rat liver. Results: In α-naphthylisothiocyanate-intoxicated rats, pretreatment with protamine increased HGF-induced autophosphorylation of the HGF receptor in liver. The maximum enhancing effect of protamine on HGF-induced DNA synthesis of hepatocytes required a 10 min-pretreatment period both in vivo and in vitro, and the stimulatory effect of protamine was not observed when it was administered simultaneously with HGF. Preperfusion of the liver with protamine for 10 min decreased the non-saturable portion of hepatic clearance for 125I-HGF, which is mainly mediated by cell-surface heparan-sulfate proteoglycan (HSPG). Inhibition of HGF binding to heparin by protamine was confirmed using heparin-coated sepharose. This inhibition also required 10 min of pretreatment, for protamine to bind heparin. Conclusion: The enhancing effect of protamine on the mitogenic activity of HGF on hepatocytes requires pretreatment with protamine for a short period presumably required for its binding to cell-surface heparin, implying possible regulation of c-met autophosphorylation by HSPG. © 2008 Springer Science+Business Media, LLC

Measurement of finite-frequency current statistics in a single-electron transistor

Electron transport in nano-scale structures is strongly influenced by the Coulomb interaction which gives rise to correlations in the stream of charges and leaves clear fingerprints in the fluctuations of the electrical current. A complete understanding of the underlying physical processes requires measurements of the electrical fluctuations on all time and frequency scales, but experiments have so far been restricted to fixed frequency ranges as broadband detection of current fluctuations is an inherently difficult experimental procedure. Here we demonstrate that the electrical fluctuations in a single electron transistor (SET) can be accurately measured on all relevant frequencies using a nearby quantum point contact for on-chip real-time detection of the current pulses in the SET. We have directly measured the frequency-dependent current statistics and hereby fully characterized the fundamental tunneling processes in the SET. Our experiment paves the way for future investigations of interaction and coherence induced correlation effects in quantum transport.Comment: 7 pages, 3 figures, published in Nature Communications (open access

Microprocessor, Setx, Xrn2, and Rrp6 Co-operate to Induce Premature Termination of Transcription by RNAPII

SummaryTranscription elongation is increasingly recognized as an important mechanism of gene regulation. Here, we show that microprocessor controls gene expression in an RNAi-independent manner. Microprocessor orchestrates the recruitment of termination factors Setx and Xrn2, and the 3′–5′ exoribonuclease, Rrp6, to initiate RNAPII pausing and premature termination at the HIV-1 promoter through cleavage of the stem-loop RNA, TAR. Rrp6 further processes the cleavage product, which generates a small RNA that is required to mediate potent transcriptional repression and chromatin remodeling at the HIV-1 promoter. Using chromatin immunoprecipitation coupled to high-throughput sequencing (ChIP-seq), we identified cellular gene targets whose transcription is modulated by microprocessor. Our study reveals RNAPII pausing and premature termination mediated by the co-operative activity of ribonucleases, Drosha/Dgcr8, Xrn2, and Rrp6, as a regulatory mechanism of RNAPII-dependent transcription elongation

The Cyprinodon variegatus genome reveals gene expression changes underlying differences in skull morphology among closely related species

Genes in durophage intersection set at 15 dpf. This is a comma separated table of the genes in the 15 dpf durophage intersection set. Given are edgeR results for each pairwise comparison. Columns indicating whether a gene is included in the intersection set at a threshold of 1.5 or 2 fold are provided. (CSV 13 kb