The MOSCAB experiment (Materia OSCura A Bolle) uses the “geyser technique”, a variant of the superheated liquid technique of extreme simplicity. Operating principles of the new dark matter detector ...and technical solutions of the device are reported in detail. First results obtained in a series of test runs taken in laboratory demonstrate that we have successfully built and tested a geyser-concept bubble chamber that can be used in particle physics, especially in dark matter searches, and that we are ready to move underground for extensive data taking.
This paper uses a dynamic quantile model to estimate the elasticity of intertemporal substitution (EIS) and risk attitude using large disaggregated data from the NielsenIQ Consumer Panel. This data ...is transactional at the consumption purchase level, which minimizes measurement error, and the final sample contains more than two million observations. In the quantile model, the risk attitude is captured by the quantile and is, therefore, separable from the EIS. To estimate the parameters of interest we use the Euler equation along with instrumental variables quantile regression. First, we estimate the model across different levels of risk attitude. Empirical results document evidence of monotonically decreasing EIS along quantiles. For large risk aversion, the EIS is greater than one, whereas for small risk aversion it descends into negative values. Subsequently, we estimate the risk attitude and the EIS simultaneously. The results substantiate a risk attitude close to the median, with EIS consistently positive and smaller than one.
A sample of more than one million K +/- ? p + p - e +/- ? (K e 4) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in ...2003-2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of K e 4 gamma decays, is measured to be BR (K e 4) = (4.257 +/- 0.016 exp +/- 0.031 ext) X 10 - 5 with a total relative error of 0.8 % . This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the pp scattering lengths conducted on the same data sample. The overall form factor normalization f s = 5.705 +/- 0.017 exp +/- 0.031 ext is obtained with a total relative precision of 0.6 % .
A new technique for direct investigation of dark matter Bertoni, R; Chignoli, F; Chiesa, D ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2014, Volume:
744
Journal Article
Peer reviewed
Open access
The MOSCAB experiment (Materia OSCura A Bolle) uses a new technique for dark matter search. The Geyser technique is applied to the construction of a prototype detector with a mass of 0.5 kg and the ...encouraging results are reported here; an accent is placed on a big detector of 40 kg in construction at the Milano-Bicocca University and INFN.
Impurities are still among the primary concerns regarding the realization of many fixed points of the International Temperature Scale (ITS-90). Several methods have been suggested to correct for ...these effects. The most promising strategy, with regard to the achievable uncertainty level, is the ‘sum of the individual estimates’ (SIE) method. It involves a chemical analysis of the material and a calculation of each of the detected chemical species’ effect on the phase-transition temperature of the fixed-point substance. This correction can be accurate only if all the detected impurities are completely dissolved. Given the recent evidence for insoluble impurities in metal fixed points, this strategy needs to be modified; otherwise, it may lead to an inaccurate estimation of the impurity-related effect on the fixed-point temperature. In this article, a correction method is set out that reflects the crucial distinction between soluble, insoluble, and partially soluble impurities. This ‘sum of the individual estimates for the dissolved species’ (SIEDS) method starts from a chemical analysis but takes into account only the dissolved particles. For this purpose, different types of substances are considered as possible dissolved impurities and are discussed from a chemical point of view. For those impurities where data are insufficient, only an uncertainty estimation is possible. For this purpose, the ‘overall maximum estimate of the dissolved species’ (OMEDS) method is derived from the SIEDS method as the new counterpart to the well-known ‘overall maximum estimate’ (OME) method.
The NA48/2 experiment at CERN collected a large sample of charged kaon decays to final states with multiple charged particles in 2003–2004. A new upper limit on the rate of the lepton number ...violating decay K±→π∓μ±μ± is reported: B(K±→π∓μ±μ±)<8.6×10−11 at 90% CL. Searches for two-body resonances X in K±→πμμ decays (such as heavy neutral leptons N4 and inflatons χ) are also presented. In the absence of signals, upper limits are set on the products of branching fractions B(K±→μ±N4)B(N4→πμ) and B(K±→π±X)B(X→μ+μ−) for ranges of assumed resonance masses and lifetimes. The limits are in the (10−11,10−9) range for resonance lifetimes below 100 ps.
A
bstract
The NA48/2 experiment at CERN reports the first observation of the
K
±
→
π
0
π
0
μ
±
ν
decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV
2
/
c
4
is measured to be (0.65 ± 0.03) × 10
−
6
. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10
−
6
, in agreement with chiral perturbation theory predictions.
The NA48/2 experiment at CERN reports the first observation of the $K^± → π^0π^0μ^±$ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. The decay ...branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c4 is measured to be (0.65 ± 0.03) × 10–6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10–6, in agreement with chiral perturbation theory predictions.
PDF
