The Large-Angle Photon Veto System for the NA62 Experiment at CERN

The branching ratio (BR) for the decay K^+ \rightarrow \pi^+ \nu \bar{\nu} is a sensitive probe for new physics. The NA62 experiment at the CERN SPS will measure this BR to within about 10%. To reject the dominant background from channels with final state photons, the large-angle vetoes (LAVs) must detect photons of energy as low as 200 MeV with an inefficiency of less than 10^-4, as well as provide energy and time measurements with resolutions of 10% and 1 ns for 1 GeV photons. The LAV detectors make creative reuse of lead glass blocks recycled from the OPAL electromagnetic calorimeter barrel. We describe the mechanical design and challenges faced during construction, the characterization of the lead glass blocks and solutions adopted for monitoring their performance, and the development of front-end electronics to allow simultaneous time and energy measurements over an extended dynamic range using the time-over-threshold technique. Our results are based on test-beam data and are reproduced by a detailed Monte Carlo simulation that includes the readout chain.Comment: 8 pages, 13 figures. Prepared for the Conference Record of the IEEE Nuclear Science Symposium, Valencia, Spain, October 201

Measurement of the mass difference m(D-s(+))-m(D+) at CDF II

We present a measurement of the mass difference m(D-s(+))-m(D+), where both the D-s(+) and D+ are reconstructed in the phipi(+) decay channel. This measurement uses 11.6 pb(-1) of data collected by CDF II using the new displaced-track trigger. The mass difference is found to be m(D-s(+))-m(D+)=99.41+/-0.38(stat)+/-0.21(syst) MeV/c(2)

The NA62 Large Angle Veto database

The NA62 experiment at CERN will study the very rare decay, K+ π+ ννbar. To reject the K+ π+ πo background, the detector must be hermetic to photons with a single-photon inefficiency of 10-5 for energies above 1 GeV. Three detectors will cover the experiment acceptance: the Liquid Krypton calorimeter from the NA48 experiment, the Large Angle Veto (LAV), and the Small Angle Calorimeter (SAC). The LAV is composed of 12 ring-shaped veto stations positioned along the NA62 vacuum decay tank. Each ring consists of 160 to 256 lead glass blocks, for a total of nearly 2500 blocks, each weighing ∼22 Kg. The construction of the LAV rings started in 2009 and is still ongoing. During the assembly process, each block undergoes a preparation phase which includes the measurement of all properties related to the block's light yield and to the read-out electronics. To regulate and monitor the entire assembly line, we have developed a MySQL-based DB system where all data produced during the assembly process are stored. A web-based user interface offers several functions such as input of block-related data, monitoring of the assembly status of each block, verification of the measurement process, and visualization of the overall status of the LAV production. Data stored in the DB are used both during the assembly process and to configure the LAV DAQ system. This paper will describe the criteria used to create this DB and will provide details about its technical implementation. © 2013 IEEE

Transabdominal laparoscopic approach for adrenalectomy: Experience in 169 consecutive cases

Background: Several techniques have been proposed to remove the adrenal glands laparoscopically. There is still some debate about the respective advantages and inconveniences of the transperitoneal and retroperitoneal approaches. In this study the authors report their experience with the transperitoneal flank approach. Methods: Between June 1994 and January 1999, 217 adrenalectomies were performed in our department. There were 169 laparoscopic adrenalectomies (LA) \u2014 (78 %): 61 Conn\u2019s syndrome, 41 Cushing\u2019s syndrome, 29 pheochromocytomas, 1 androgen producing tumor and 37 non functioning tumors. An open approach was used in 48 patients (22 %). Large and/or malignant or suspected malignant tumors (26 cases) multiple and/or extra adrenal pheochromocytomas (12 cases), previous surgery in the adrenal area (10 cases). Results: LA was unilateral in 149 patients and bilateral in 10 patients. Mean tumor size was 32 mm (7\u2013110). Eight tumors were malignant (4.7 %). Four out of these 8 malignant tumors were completely removed laparoscopically. Conversion to open surgery was required in 8 patients (5 %). Twelve patients (7.5 %) had significant complications. There was no mortality. Mean operative time was 126 minutes (48\u2013300) for unilateral LA and 228 minutes (175\u2013275) for bilateral LA. The average length of hospital stay was 5.4 days (3\u201315). The endocrinopathy was successfully cured in all patients with functioning tumors. Conclusions: There are few absolute contraindications for LA. LA is the procedure of choice for small benign and functioning tumors. Invasive adrenal carcinoma is an absolute contraindication for LA. Nevertheless, depending on the experience of the operator, LA can be also proposed for large tumors or tumors at risk for malignancy. If local invasion is observed at the start of the procedure, LA should be immediately converted to open surgery