Search for Anomalous Couplings in Top Decay at Hadron Colliders

We present a quantitative study on sensitivities to the top-decay anomalous couplings, taking into account realistic experimental conditions expected at Tevatron and LHC. A double angular distribution of W and charged lepton in the top decay is analyzed, using ttbar events in the lepton+jets channel. In order to improve sensitivities to the anomalous couplings, we apply two techniques: (1) We use a likelihood fitting method for full kinematical reconstruction of each top event. (2) We develop a new effective spin reconstruction method for leptonically-decayed top quarks; this method does not require spin information of the antitop side. For simplicity, we neglect couplings of right-handed bottom quark as well as CP violating couplings. The 95% C.L. estimated bound on a ratio of anomalous couplings reads -0.81 < f_2/f_1 < -0.70, -0.12<f_2/f_1<0.14 using 1000 reconstructed top events at Tevatron, while -0.74<f_2/f_1<-0.72, -0.01<f_2/f_1<0.01 is expected with 100k reconstructed top events at LHC, where only statistical errors are taken into account. A two-fold ambiguity in the allowed range remains when the number of events exceeds a few hundred.Comment: 21 pages, 15 figure

A Start-Timing Detector for the Collider Experiment PHENIX at RHIC-BNL

We describe a start-timing detector for the PHENIX experiment at the relativistic heavy-ion collider RHIC. The role of the detector is to detect a nuclear collision, provide precise time information with an accuracy of 50ps, and determine the collision point along the beam direction with a resolution of a few cm. Technical challenges are that the detector must be operational in a wide particle-multiplicity range in a high radiation environment and a strong magnetic field. We present the performance of the prototype and discuss the final design of the detector.Comment: 12 pages, LaTeX, 9 gif and 4 ps figures. Submitted to NIM

Measurement of the electron transmission rate of the gating foil for the TPC of the ILC experiment

We have developed a gating foil for the time projection chamber envisaged as a central tracker for the international linear collider experiment. It has a structure similar to the Gas Electron Multiplier (GEM) with a higher optical aperture ratio and functions as an ion gate without gas amplification. The transmission rate for electrons was measured in a counting mode for a wide range of the voltages applied across the foil using an $^{55}$Fe source and a laser in the absence of a magnetic field. The blocking power of the foil against positive ions was estimated from the electron transmissions.Comment: 25 pages containing 14 figures and 1 tabl

Cosmic ray tests of a GEM-based TPC prototype operated in Ar-CF4-isobutane gas mixtures

Argon with an admixture of CF4 is expected to be a good candidate for the gas mixture to be used for a time projection chamber (TPC) in the future linear collider experiment because of its small transverse diffusion of drift electrons especially under a strong magnetic field. In order to confirm the superiority of this gas mixture over conventional TPC gases we carried out cosmic ray tests using a GEM-based TPC operated mostly in Ar-CF4-isobutane mixtures under 0 - 1 T axial magnetic fields. The measured gas properties such as gas gain and transverse diffusion constant as well as the observed spatial resolution are presented.Comment: 22 pages, 18 figures. Published in Nuclear Instruments and Methods in Physics Research A. Fig. 3 in the introduction was corrected since it had not been properly normalized. Minor corrections and no changes in the conclusio

Serum midkine levels are increased in patients with various types of carcinomas

The level of expression of midkine (MK), a heparin-binding growth factor, is increased in many types of human carcinomas. An enzyme-linked immunoassay, which utilizes a combination of rabbit and chicken antibodies revealed that serum MK level in the controls (n= 135) was 0.154 ± 0.076 (mean ± SD) ng ml–1with an apparent cut-off value as 0.5 ng ml–1. Serum MK level was significantly elevated in the cancer patients (n= 150) (P< 0.001); 87% of the patients showed levels of more than 0.5 ng ml–1. All ten types of cancer examined showed a similar profile of serum MK level. There was no or weak correlation between C-reactive protein level, a marker of inflammation, and serum MK level. Furthermore, in case of gastric carcinoma and lung carcinoma, patients with stage I carcinoma already showed elevated serum MK levels. The present results indicated that serum MK could serve as a general tumour marker with a good potential for clinical application. © 2000 Cancer Research Campaig

Super-Resolution Scanning Transmission X-Ray Imaging Using Single Biconcave Parabolic Refractive Lens Array

A new super resolution imaging technique which potentially enables sub-µm spatial resolution, using a detector of pixels much larger than the spatial resolution, is proposed. The method utilizes sample scanning through a large number of identical X-ray microprobes periodically spaced (the period corresponds to a multiple of the pixel size), which reduces drastically the scanning time. The information about the sample illuminated by the microprobes is stored by large detector pixels. Using these data and sample position information, a super-resolution image reconstruction is performed. With a one-dimensional (1D) high aspect ratio nickel single lens array designed for theoretically expected sub-µm microprobes at 17 keV and fabricated by deep X-ray lithography and electroforming technique, 2 µm X-ray microprobes with a period of 10 µm were achieved. We performed a first experiment at KARA synchrotron facility, and it was demonstrated that the smallest structure of a test pattern with a size of 1.5 µm could be easily resolved by using images generated from a detector having a pixel size of 10.4 µm. This new approach has a great potential for providing a new microscopic imaging modality with a large field of view and short scan time

Right-Sided Location Not Associated With Missed Colorectal Adenomas in an Individual-Level Reanalysis of Tandem Colonoscopy Studies

Background & Aims Interval cancers occur more frequently in the right colon. One reason could be that right-sided adenomas are frequently missed in colonoscopy examinations. We reanalyzed data from tandem colonoscopies to assess adenoma miss rates in relation to location and other factors. Methods We pooled data from 8 randomized tandem trials comprising 2218 patients who had diagnostic or screening colonoscopies (adenomas detected in 49.8% of patients). We performed a mixed-effects logistic regression with patients as cluster effects with different independent parameters. Factors analyzed included location (left vs right, splenic flexure as cutoff), adenoma size, form, and histologic features. Analyses were controlled for potential confounding factors such as patient sex and age, colonoscopy indication, and bowel cleanliness. Results Right-side location was not an independent risk factor for missed adenomas (odds ratio [OR] compared with the left side, 0.94; 95% CI, 0.75–1.17). However, compared with adenomas ≤5 mm, the OR for missing adenomas of 6–9 mm was 0.62 (95% CI, 0.44–0.87), and the OR for missing adenomas of ≥10 mm was 0.51 (95% CI, 0.33–0.77). Compared with pedunculated adenomas, sessile (OR, 1.82; 95% CI, 1.16–2.85) and flat adenomas (OR, 2.47; 95% CI, 1.49–4.10) were more likely to be missed. Histologic features were not significant risk factors for missed adenomas (OR for adenomas with high-grade intraepithelial neoplasia, 0.68; 95% CI, 0.34–1.37 and OR for sessile serrated adenomas, 0.87; 95% CI, 0.47–1.64 compared with low-grade adenomas). Men had a higher number of adenomas per colonoscopy (1.27; 95% CI, 1.21–1.33) than women (0.86; 95% CI, 0.80–0.93). Men were less likely to have missed adenomas than women (OR for missed adenomas in men, 0.73; 95% CI, 0.57–0.94). Conclusions In an analysis of data from 8 randomized trials, we found that right-side location of an adenoma does not increase its odds for being missed during colonoscopy but that adenoma size and histologic features do increase risk. Further studies are needed to determine why adenomas are more frequently missed during colonoscopies in women than men