14512709
The present day mass function in the central region of the Arches cluster
We study the evolution of the mass function in young and dense star clusters by means of direct N-body simulations. Our main aim is to explain the recent observations of the relatively flat mass function observed near the centre of the Arches star cluster. In this region, the power-law index of the mass function for stars more massive than about 5–6 M⊙ is larger than the Salpeter value by about unity, whereas further out, and for the lower mass stars, the mass function resembles the Salpeter distribution. We show that the peculiarities in the Arches mass function can be explained satisfactorily without primordial mass segregation. We draw two conclusions from our simulations: (i) the Arches initial mass function is consistent with a Salpeter slope down to ∼1 M⊙, and (ii) the cluster is about half-way towards core collapse. The cores of other star clusters with characteristics similar to those of the Arches are expected to show similar flattening in the mass functions for the high-mass (≳5 M⊙) stars.
17280430
Survivability of a star cluster in a dispersing molecular cloud
Star clusters are formed in molecular clouds which are believed to be the birth places of most stars. From recent observational data, Lada & Lada 2003 estimated that only 4% to 7% of the clusters embedded inside molecular clouds have survived. An important mechanism for the disruption of embedded (bound)-clusters is the dispersion of the parent cloud by UV radiation, stellar winds and/or supernova explosions. In this work we study the effect of this mechanism by N-body simulations. We find that most embedded-clusters survive for more than 30 Myr even when different initial conditions of the cluster may introduce some minor variations, but the general result is rather robust.
55556108
Extracting interstellar diffuse absorption bands from cool star spectra - Application to bulge clump giants in Baade’s window
Interstellar diffuse bands are usually extracted from hot star spectra because they are characterized by smooth continua. It introduces a strong limitation on the number of available targets, and reduces potential studies of the IS matter and the use of absorptions for cloud mapping. We have developed a new automatic fitting method appropriate to interstellar absorptions in spectra of cool stars that possess stellar atmospheric parameters. We applied this method to the extraction of three DIBs in high resolution VLT FLAMES/GIRAFFE spectra of red clump stars from the bulge. By combining all stellar synthetic spectra, HITRAN-LBLRTM atmospheric transmission spectra and diffuse band empirical absorption profiles, we determine the 6196, 6204, and 6284 A DIB strength toward the 219 target stars and discuss the sources of uncertainties. In order to test the sensitivity of the DIB extraction, we intercompare the three results and compare the DIB equivalent widths with the reddening derived from an independent extinction map based on OGLE photometric data. Most stellar spectra could be well reproduced by the composite stellar, atmospheric and interstellar models. Measurement uncertainties on the EWs are smaller for the broad and strong 6284 A DIB, and are of the order of 10-15%. Uncertainties on the two narrow and weaker DIBs are larger, as expected, and found to be highly variable from one target to the other. They strongly depend on the radial velocity of the star . DIB-DIB correlations among the three bands demonstrate that a meaningful signal is extracted. For the 6284 and 6204 A DIBs, the star-to-star variability of the equivalent width (EW) also reflects features of the OGLE extinction map...
17286551
Indicators for cluster survivability in a dispersing cloud
We use N-body simulations to survey the response of embedded star clusters to the dispersal of their parent molecular cloud. The final stages of the clusters can be divided into three classes: the cluster (1) is destroyed, (2) has a loose structure, and (3) has a compact core. We are interested in three of the governing parameters of the parent cloud: (1) the mass, (2) the size, and (3) the dispersing rate. It is known that the final stage of the cluster is well correlated with the star formation efficiency (SFE) for systems with the same cluster and cloud profile. We deem that the SFE alone is not enough to address systems with clouds of different sizes. Our result shows that the initial cluster-cloud mass ratio at a certain Lagrangian radius and the initial kinetic energy are better indicators for the survivability of embedded clusters.
119432484
Open clusters in a dispersing molecular cloud
Star clusters are formed in molecular clouds which are believed to be the birth places of most stars. From recent observational data, Lada & Lada (2003) estimated that only 4 to 7% of the proto-clusters have survived. A possible reason is the dispersion of molecular clouds by UV radiation, stellar winds or supernova explosions. We study the cloud dispersion in the embedded clusters by N-body simulations. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
53378344
On integrable structure and geometric transition in supersymmetric gauge theories
A bstractWe generalize the exact field theoretic correspondence proposed in [1] and embed it into the context of refined topological string. The correspondence originally proposed from the common integrable structures in different field theories can be recast as a special limit of the refined geometric transition relating open and closed topological string partition functions. We realize the simplest examples of the correspondence explicitly in terms of open-closed geometric transition.
17016333
Quantum scattering of giant magnons
We perform a first-principles semi-classical computation of the one-loop corrections to the dispersion relation and S-matrix of Giant Magnons in AdS5 × S5 string theory. The results agree exactly with expectations based on the strong coupling expansion of the exact Asymptotic Bethe Ansatz equations. In particular we reproduce the Hernandez-Lopez term in the dressing phase.
120528491
Tau-Charm factory project at Beijing
Abstract The Tau-Charm Factory (TCF) is a proposed high luminosity e + e − collider at the threshold region of the production of τ and charm. It could provide many precision measurements and search for new phenomena in the flavor physics. IHEP, Beijing, is an ideal cite to build a TCF. The status of the feasibility study of Beijing Tau-Charm Factory (BTCF) is reported.
28336224
Search for physics beyond the standard model in events with two leptons, jets, and missing transverse momentum in pp collisions at s$$ \sqrt{s} $$ = 8 TeV
A bstractA search is presented for physics beyond the standard model in final states with two opposite-sign same-flavor leptons, jets, and missing transverse momentum. The data sample corresponds to an integrated luminosity of 19.4 fb−1 of proton-proton collisions at s$$ \sqrt{s} $$ = 8 TeV collected with the CMS detector at the CERN LHC in 2012. The analysis focuses on searches for a kinematic edge in the invariant mass distribution of the oppositesign same-flavor lepton pair and for final states with an on-shell Z boson. The observations are consistent with expectations from standard model processes and are interpreted in terms of upper limits on the production of supersymmetric particles.

118457882
Towards a warped inflationary brane scanning
We present a detailed systematics for comparing warped brane inflation with the observations, incorporating the effects of both moduli stabilization and ultraviolet bulk physics. We explicitly construct an example of the inflaton potential governing the motion of a mobile D3 brane in the entire warped deformed conifold. This allows us to precisely identify the corresponding scales of the cosmic microwave background. The effects due to bulk fluxes or localized sources are parametrized using gauge/string duality. We next perform some sample scannings to explore the parameter space of the complete potential, and first demonstrate that without the bulk effects there can be large degenerate sets of parameters with observationally consistent predictions. When the bulk perturbations are included, however, the observational predictions are generally spoiled. For them to remain consistent, the magnitudes of the additional bulk effects need to be highly suppressed.