Heavy-to-light transition form factors and their relations in light-cone QCD sum rules

The improved light-cone QCD sum rules by using chiral current correlator is systematically reviewed and applied to the calculation of all the heavy-to-light form factors, including all the semileptonic and penguin ones. By choosing suitable chiral currents, the light-cone sum rules for all the form factors are greatly simplified and depend mainly on one leading twist distribution amplitude of the light meson. As a result, relations between these form factors arise naturally. At the considered accuracy these relations reproduce the results obtained in the literature. Moreover, since the explicit dependence on the leading twist distribution amplitudes is preserved, these relations may be more useful to simulate the experimental data and extract the information on the distribution amplitude.Comment: 1+16 pages, no figure

Cross-species RNA-seq study comparing transcriptomes of enriched osteocyte populations in the tibia and skull

Local site-specific differences between bones in different regions of the skeleton account for their different properties and functions. To identify mechanisms behind these differences, we have performed a cross-species study comparing RNA transcriptomes of cranial and tibial osteocytes, from bones with very different primary functions and physiological responses, collected from the same individual mouse, rat, and rhesus macaque. Bioinformatic analysis was performed to identify 32 genes changed in the same direction between sites and shared across all three species. Several well-established key genes in bone growth and remodeling were upregulated in the tibias of all three species (BMP7, DKK1, FGF1, FRZB, SOST). Many of them associate or crosstalk with the Wnt signaling pathway. These results suggest Wnt signaling-related candidates for different control of regulatory mechanisms in bone homeostasis in the skull and tibia and indicate a different balance between genetically determined structure and feedback mechanisms to strains induced by mechanical loading at the different sites

Distinct binding interactions of α5β1-integrin and proteoglycans with fibronectin

Dynamic single molecule force spectroscopy was performed to monitor the unbinding of fibronectin with the proteoglycans syndecan-4 and decorin, and to compare this with the unbinding characteristics of α5β1-integrin. A single energy barrier was sufficient to describe the unbinding of both syndecan-4 and decorin from fibronectin, while two barriers were observed for the dissociation of α5β1-integrin from fibronectin. The outer (high affinity) barrier in the interactions of fibronectin with α5β1-integrin and syndecan-4 are characterized by larger barrier heights and widths, and slower dissociation rates than those of the inner (low affinity) barrier in the interactions of fibronectin with α5β1-integrin and decorin. These results indicate that syndecan-4 and (ultimately) α5β1-integrin have the ability to withstand deformation in their interactions with fibronectin, while the decorin-fibronectin interaction is considerably more brittle

SL(2,Z) Multiplets in N=4 SYM Theory

We discuss the action of SL(2,Z) on local operators in D=4, N=4 SYM theory in the superconformal phase. The modular property of the operator's scaling dimension determines whether the operator transforms as a singlet, or covariantly, as part of a finite or infinite dimensional multiplet under the SL(2,Z) action. As an example, we argue that operators in the Konishi multiplet transform as part of a (p,q) PSL(2,Z) multiplet. We also comment on the non-perturbative local operators dual to the Konishi multiplet.Comment: 14 pages, harvmac; v2: published version with minor change

A region segmentation method to measure multiple features using a tactile scanning probe

Coordinate measuring machines (CMMs) have been widely used in industry to precisely measure parts for inspection or quality control. One of the main barriers to using a CMM touch-trigger probe is the cumbersome programming work required to identify the probing points and for scan path planning. In this paper, we propose a practical data-segmentation method to continuously measure multiple features of the workpiece using a scanning probe. This approach takes advantage of the fast data-capture capability of the scanning probe and, subsequently, the point dataset is segmented using the information extracted from the CAD model of the part. This methodology does not require tedious programming and all desired measurement results can be obtained from a single scan. The principle of the method is presented, and the feasibility of the method is experimentally verified on a bridge-type Hexagon DEA Global CMM equipped with a Leitz LSP-X1 probe. The proposed method avoids manual operation errors and generates more sampling points than traditional methods; therefore, theoretically providing lower measurement uncertainty. The test results also indicate that the new method using a scanning probe is easy to implement and can save more than 90% measurement time in comparison with a conventional touch-trigger method

Unparticle Physics in the Moller Scattering

We investigate the virtual effects of vector unparticles in the Moller scattering. We derive the analytic expression for scattering amplitudes with unpolarized beams. We obtain 95% confidence level limits on the unparticle couplings $\lambda_{V}$ and $\lambda_{A}$ with integrated luminosity of $L_{int}=50, 500 fb^{-1}$ and $\sqrt{s}=100, 300$ and 500 GeV energies. We show that limits on $\lambda_{V}$ are more sensitive than $\lambda_{A}$.Comment: 10 pages, 5 figures, 4 table

Lambda_b -> Lambda l+ l- decay within family non-universal Z' model

We perform a comprehensive analysis of the rare "Lambda_b -> Lambda l+ l-" decay in the framework of family non-universal Z' model. It is shown that Z' gives considerable contribution to the decay width. Zero positions of the forward-backward asymmetry and alpha_theta parameter are shifted to the left compared to the Standard Model result. The obtained results could be tested in near future at LHC-b.Comment: 14 pages, 4 postscript figures, LaTeX formatte

Study of Bs-> \phi l^+ l^-$ Decay in a Single Universal Extra Dimension

Utilizing form factors calculated within the light-cone sum rules, we have evaluated the decay branching ratios of $B_s\to \phi\gamma$ and $B_s\to \phi \ell^+\ell^-$ in a single universal extra dimension model (UED), which is viewed as one of the alternative theories beyond the standard model (SM). For the decay $B_s \to \phi \ell^+\ell^-$, the dilepton invariant mass spectra, the forward-backward asymmetry, and double lepton polarization are also calculated. For each case, we compared the obtained results with predictions of the SM. In lower values of the compactification factor 1/R, the only parameter in this model, we see the considerable discrepancy between the UED and SM models. However, when 1/R increases, the results of UED tend to diminish and at $1/R = 1000 \mathrm{GeV}$, two models have approximately the same predictions. Compared with data from CDF of $B_s \to \phi \mu^+ \mu^-$, the 1/R tends to be larger than $350 \mathrm{GeV}$. We also note that the zero crossing point of the forward-backward asymmetry is become smaller, which will be an important plat to prob the contribution from the extra dimension model. The results obtained in this work will be very useful in searching new physics beyond SM. Moreover, the order of magnitude for branching ratios shows a possibility to study these channels at the Large Hadron Collider (LHC), CDF and the future super-B factory.Comment: 13 pages, 16 figure

Multiband study of RX J0838-2827 and XMM J083850.4-282759: A new asynchronous magnetic cataclysmic variable and a candidate transitional millisecond pulsar

Indexación: Scopus.In a search for the counterpart to the Fermi-LAT source 3FGL J0838.8-2829, we performed a multiwavelength campaign: in the X-ray band with Swift and XMM-Newton; in the infrared and optical with OAGH, ESO-NTT and IAC80; and in the radio with ATCA observations. We also used archival hard X-ray data obtained by INTEGRAL. We report on three X-ray sources consistent with the position of the Fermi-LAT source.We confirm the identification of the brightest object, RX J0838-2827, as a magnetic cataclysmic variable that we recognize as an asynchronous system (not associated with the Fermi-LAT source). RX J0838-2827 is extremely variable in the X-ray and optical bands, and timing analysis reveals the presence of several periodicities modulating its X-ray and optical emission. The most evident modulations are interpreted as being caused by the binary system orbital period of ~1.64 h and the white dwarf spin period of ~1.47 h. A strong flux modulation at ~15 h is observed at all energy bands, consistent with the beat frequency between spin and orbital periods. Optical spectra show prominent Hß, He I and He II emission lines that are Doppler-modulated at the orbital period and at the beat period. Therefore, RX J0838-2827 accretes through a disc-less configuration and could be either a strongly asynchronous polar or a rare example of a pre-polar system on its way to reaching synchronism. Regarding the other two X-ray sources, XMM J083850.4-282759 showed a variable X-ray emission, with a powerful flare lasting for ~600 s, similar to what is observed in transitional millisecond pulsars during the subluminous disc state: this observation possibly means that this source can be associated with the Fermi-LAT source. © 2017 The Authors.https://academic.oup.com/mnras/article/471/3/2902/408195

Structural Routability of n-Pairs Information Networks

Information does not generally behave like a conservative fluid flow in communication networks with multiple sources and sinks. However, it is often conceptually and practically useful to be able to associate separate data streams with each source-sink pair, with only routing and no coding performed at the network nodes. This raises the question of whether there is a nontrivial class of network topologies for which achievability is always equivalent to routability, for any combination of source signals and positive channel capacities. This chapter considers possibly cyclic, directed, errorless networks with n source-sink pairs and mutually independent source signals. The concept of downward dominance is introduced and it is shown that, if the network topology is downward dominated, then the achievability of a given combination of source signals and channel capacities implies the existence of a feasible multicommodity flow.Comment: The final publication is available at link.springer.com http://link.springer.com/chapter/10.1007/978-3-319-02150-8_