119100218
Confirming the 115.5-day periodicity in the X-ray light curve of ULX NGC 5408 X-1
The Swift/XRT light curve of the ultraluminous X-ray source NGC 5408 X-1 was re-analyzed with two new numerical approaches, the Weighted Wavelet Z-transform and CLEANest, and the results are different from previous studies. Both techniques detected a prominent periodicity with a time scale of 115.5 +/- 1.5 days, in excellent agreement with the detection of the same periodicity first reported by Strohmayer. Monte Carlo simulations were employed to test the statisitical confidence of the 115.5-day periodicity, yielding a statistical significance of >99.98% (or > 3.8 sigma). The robust detection of the 115.5-day quasi-periodic oscillations, if they are due to the orbital motion of the binary, would infer a mass of a few thousand M-circle dot for the central black hole, implying there is an intermediate-mass black hole in NGC 5408 X-1.
119116496
Multiple periodic oscillations in the radio light curves of NRAO 530
In this paper, the time series analysis method CLEANest is employed to search for characteristic periodicities in the radio light curves of the blazar NRAO 530 at 4.8, 8.0 and 14.5 GHz over a time baseline of three decades. Two prominent periodicities on time scales of ∼6.3 and ∼9.5 a are identified at all three frequencies, in agreement with previous results derived from different numerical techniques, confirming the multiplicity of the periodicities in NRAO 530. In addition to these two significant periods, there is also evidence of shorter-timescale periodicities of ∼5.0, ∼4.2, ∼3.4 and ∼2.8 a showing lower amplitude in the periodograms. The physical mechanisms responsible for the radio quasi-periodic oscillations and the multiplicity of the periods are discussed.
990161
Searches for electroweak production of charginos, neutralinos, and sleptons decaying to leptons and W, Z, and Higgs bosons in pp collisions at 8 TeV
Searches for the direct electroweak production of supersymmetric charginos, neutralinos, and sleptons in a variety of signatures with leptons and $$\mathrm{W}$$W, $$\mathrm{Z}$$Z, and Higgs bosons are presented. Results are based on a sample of proton-proton collision data collected at center-of-mass energy $$\sqrt{s}=8\,\mathrm{TeV}$$s=8TeV with the CMS detector in 2012, corresponding to an integrated luminosity of 19.5 $$\,\text {fb}^\text {-1}$$fb-1. The observed event rates are in agreement with expectations from the standard model. These results probe charginos and neutralinos with masses up to 720 $$\,\text {GeV}$$GeV, and sleptons up to 260 $$\,\text {GeV}$$GeV, depending on the model details.
122925118
Monte Carlo simulation of the response of Si(Li) detectors to monoenergetic X-rays
Abstract We present a Monte Carlo simulation of X-ray interaction with a Si(Li) detector which includes for the first time both a detailed description of the atomic excitation and de-excitation and also a physically realistic model of the frontal region of incomplete charge collection. Simulated lineshapes are in good agreement with those measured by us using monoenergetic X-rays of energy 1–10 keV and by varying the two parameters of the model we can generate lineshapes very similar to those reported in the literature for other Si(Li) detectors.
54703955
Summary of the NLC Accelerator Working Group
The NLC (Next Linear Collider) accelerator working group was concerned with a presentation and thorough discussion of the prospects for achieving a 0.5 TeV linear collider and an examination of issues related to energy upgrades to attain 1.0 to 1.5 TeV in the center-of-mass. The contents of the talks and subsequent discussions are summarized in this paper. Highlights of R&D efforts toward the NLC that were underway during the Snowmass workshop are described. Finally, some of the recent results and issues from the Stanford Linear Collider (SLC), relevant to the design of a future linear collider, are also described. Further detail on most subjects can be found in the recently published “Zeroth-Order Design Report for a Next Linear Collider” (ZDR).
15510685
X-ray properties of the quasar He 0450-2958
We present an XMM-Newton EPIC observation of HE 0450-2958, which may be a "naked" quasar as suggested by Magain and coworkers. The XMM-Newton EPIC spectra show a substantial soft X-ray excess and a steep photon index, as well as marginal evidence for a weak Fe K alpha line. The X-ray absorption is consistent with the Galactic level. The 0.3-10 keV EPIC spectra can be fitted by a power-law plus blackbody model; however, the fit by a relativistically blurred photoionized disk reflection model is better. We estimate a black hole mass of 2(-1.3)(+7) x 10(7) M-circle dot from the X-ray variability. This broadly agrees with the value derived from the optical H beta line width. These results support a high-state Seyfert galaxy as the source. HE 0450-2958 shares properties with transitionary objects from ultraluminous infrared galaxies to quasars. We suggest that HE 0450-2958 is just in the beginning of an optical quasar window.
13580118
Opposite-side flavour tagging of B mesons at the LHCb experiment
The calibration and performance of the opposite-side flavour tagging algorithms used for the measurements of time-dependent asymmetries at the LHCb experiment are described. The algorithms have been developed using simulated events and optimized and calibrated with B+→J/ψK+, B0→J/ψK∗0 and B0→D∗−μ+νμ decay modes with 0.37 fb−1 of data collected in pp collisions at $\sqrt{s} = 7\mbox{~TeV}$ during the 2011 physics run. The opposite-side tagging power is determined in the B+→J/ψK+ channel to be (2.10±0.08±0.24) %, where the first uncertainty is statistical and the second is systematic.