Data handling, reconstruction, and simulation for the KLOE experiment Ambrosino, F.; Antonelli, A.; Antonelli, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
12/2004, Volume:
534, Issue:
3
Journal Article
Peer reviewed
Open access
The broad physics program of the KLOE experiment is based on the high event rate at the Frascati φ
factory, and calls for an up-to-date system for data acquisition and processing. In this review of ...the KLOE offline environment, the architecture of the data-processing system and the programs developed for data reconstruction and Monte Carlo simulation are described, as well as the various procedures used for data handling and transfer between the different components of the system.
We present a precise measurement of the ratio RK=Γ(K→eν(γ))/Γ(K→μν(γ)) and a study of the radiative process K→eνγ, performed with the KLOE detector. The results are based on data collected at the ...Frascati e+e− collider DAΦNE for an integrated luminosity of 2.2 fb−1. We find RK=(2.493±0.025stat±0.019syst)×10−5, in agreement with the Standard Model expectation. This result is used to improve constraints on parameters of the Minimal Supersymmetric Standard Model with lepton flavor violation. We also measured the differential decay rate dΓ(K→eνγ)/dEγ for photon energies 10<Eγ< 250 MeV. Results are compared with predictions from theory.
We report the construction and the tests of a small prototype of the lead-scintillating fiber calorimeter of the KLOE experiment, instrumented with multianode photomultipliers to obtain a 16 times ...finer readout granularity. The prototype is 15 cm wide, 15 radiation lengths deep and is made of 200 layers of fibers 50 cm long. On one side it is read out with an array of 3×5 multianode photomultipliers Hamamatsu type R8900-M16, each segmented with 4×4 anodes, the read out granularity being 240 pixels of 11 × 11 mm2 corresponding to about 64 scintillating fibers each. These are interfaced to the 6 × 6 mm2 pixeled photocathode with truncated pyramid light guides made of Bicron BC-800 plastic to partially transmit the UV light. Each photomultiplier provides also an OR of the 16 last dynodes that is used for trigger. The response of the individual anodes, their relative gain and cross-talk has been measured with the light (440 nm) of a laser illuminating only few fibers on the side opposite to the readout. We finally present the first results of the calorimeter response to cosmic rays in auto-trigger mode.
Using a large sample of pure, slow, short lived K0 mesons collected with KLOE detector at DAΦNE, we have measured the KS lifetime. From a fit to the proper time distribution we find ...τ(KS)=(89.562±0.029stat±0.043syst) ps. This is the most precise measurement to date of the short lived K0 meson lifetime, in good agreement with the world average derived from previous measurements. We observe no dependence of the lifetime on the direction of the KS in galactic coordinates.
The neutron detection efficiency of a sampling calorimeter made of 1
mm diameter scintillating fibers embedded in a lead/bismuth structure has been measured at the neutron beam of The Svedberg ...Laboratory at Uppsala. A significant enhancement of the detection efficiency with respect to a bulk organic scintillator detector with the same thickness is observed.
We describe the realization and performance of a prototype high granularity calorimeter built with lead and scintillating fibers. We describe the calorimeter construction and show cosmic ray and ...electron test beam results obtained with a custom-designed trigger.
We have measured the overall detection efficiency to neutrons of a small prototype of the KLOE Pb-scintillating fiber calorimeter in the kinetic energy range 5-175 MeV using the neutron beam facility ...of The Svedberg Laboratory, TSL, Uppsala. The measurement of the neutron detection efficiency of a NE110 scintillator provided a reference calibration. At the lowest trigger threshold, the overall calorimeter efficiency ranges from 28% to 33%. This value largely exceeds the estimated ~8% expected if the response were proportional only to the scintillator equivalent thickness. A detailed simulation of the calorimeter and of TSL beamline has been performed with the FLUKA Monte Carlo code. The simulated response of the detector to neutrons is presented together with first data to Monte Carlo comparison. The results show an overall neutron efficiency of about 35%. The reasons for such an efficiency enhancement, in comparison with the typical scintillator-based neutron counters, are explained, opening the road to a novel neutron detector.
Background. Cancer is one of the most common acquired causes of venous thromboembolism.
Aim. To evaluate haemostasis disorders in patients with non-metastatic gastric cancer.
Patients and methods. We ...studied 11 patients with non-metastatic gastric cancer (9 males and 2 females, median age 54 years) and 20 healthy subjects (15 males and 5 females, median age 48 years) control. We measured prothrombin time, activated partial thromboplastin time, coagulation time, clot lysis time, fibrinogen, clotting factors (II, VII, VIII, IX, X), C protein, S protein, AT Ill, activated protein C resistance, prothrombin 1+2 fragment, tissue plasminogen activator, and D-Dimer in all subjects.
Results. Fibrinogen plasma levels were significantly higher in patients with non-metastatic gastric cancer than in control group (505±24 mg/dl vs 336±30 mg/dl, p<0.001). We also found a significant increase in prothrombin 1+2 fragment plasma concentration compared with controls (3. 8±0. 6 nM vs O. 83±0. 09 nM, p<O. 001). Plasma D-dimer levels were 20-fold higher in patients with non-metastatic gastric cancer compared with controls (9.5±0.4 ng/dl vs 0.4±0.05 ng/dl, p<0.001). Also tissue plasminogen activator was significantly higher in gastric cancer patients than in controls (20.8±2.32 nglml vs 9.1±1.37 ng/ml, p<0.011. Finally clot lysis time was significantly accelerated in gastric cancer patients compared with control subjects (81±t37 min vs 233±74 min, p<0.01).
Conclusions. Patients with non-metastatic gastric cancer are at risk for thrombotic events due to the combined increase in fibrinogen plasma levels and thrombin formation.