scholarly journals Direct measurement of the branching fraction for the decay of D+→K¯0e+νe and determination of Γ(D0→K−e+νe)/Γ(D+→K¯0e+νe)

2005 ◽  
Vol 608 (1-2) ◽  
pp. 24-30 ◽  
Author(s):  
M. Ablikim ◽  
J.Z. Bai ◽  
Y. Ban ◽  
J.G. Bian ◽  
X. Cai ◽  
...  
2020 ◽  
Vol 235 ◽  
pp. 04001
Author(s):  
J. William Gary

The BABAR Collaboration at SLAC continues to produce a wide variety of publications on interesting and unique topics despite having ceased data-collection operations more than 10 years ago. Presented here are the results of three recent studies. The first is on the direct measurement of the B± → K± X(3872) branching fraction, allowing the first determination of the branching fractions of the exotic X(3872) charmonium state. The second is a publication on the first observation of the D0 → K−π+e+e− branching fraction. The third is on searches for lepton flavor and lepton number violating decays in D0 meson decays, resulting in improvements over existing limits by factors that vary from 20 to almost 800 depending on the D0 decay channel.


2007 ◽  
Vol 644 (1) ◽  
pp. 20-24 ◽  
Author(s):  
M. Ablikim ◽  
J.Z. Bai ◽  
Y. Ban ◽  
X. Cai ◽  
H.F. Chen ◽  
...  

1997 ◽  
Vol 14 (4) ◽  
pp. 202-206 ◽  
Author(s):  
John C. Rennie ◽  
Jack D. Leake

Abstract Girard form class is widely used to describe tree form. Tree volume estimates change about 3% per unit change of Girard form class (Mesavage and Girard 1946). Hardwoods growing in close proximity have been observed to have a wide range in Girard form class. Accurate determination of Girard form class can therefore be important in getting accurate estimates of hardwood timber volume. However, the cost of estimating Girard form class for every tree being measured in the stand would be prohibitively expensive. Thus, estimation of average Girard form class for a stand is considered here. Three instruments used to estimate Girard form class—a Wheeler pentaprism optical caliper, a wedge prism, and a Spiegel relaskop—were compared to direct measurement. Number of sample trees to achieve desired half-widths of the confidence interval of ±1 and ±1 1/2 units of Girard form class was calculated for each method. Direct measurement requires the fewest trees to achieve the desired results. However, it requires considerably more time per tree than any of the instruments tested. The Wheeler pentaprism requires only a few more trees than direct measurement, and considerably fewer trees than either the wedge prism or the Spiegel relaskop. Use of all three instruments is hindered when understory vegetation obscures the top of the first log. North. J. Appl. For. 14(4):202-206.


2006 ◽  
Vol 31 (4) ◽  
pp. 392-397 ◽  
Author(s):  
Rae S. Gordon ◽  
Kathryn L. Franklin ◽  
Julien S. Baker ◽  
Bruce Davies

The purpose of this study was to compare the power and work outputs of a cycle ergometer using the manufacturer’s guidelines, with calculations using direct flywheel velocity and brake torque. A further aim was to compare the values obtained with those supplied by the manufacturer. A group of 10 male participants were asked to pedal a Monark 824E ergometer at a constant cadence of 60 r/min for a period of 3 min against a resistive mass of 3 kg. The flywheel velocity was measured using a tachometer. The brake force was determined by measuring the tension in the rope on either side of the flywheel. The calculated mean power was 147.45 ± 6.5 W compared with the Monark value of 183 ± 3.7 W. The difference between the methods for power estimation was 18% and was statistically significant (p < 0.01). The mean work done by the participants during the 3 min period was found to be 26 460 ± 1145 J compared with the Monark value of 33 067 ± 648 J (p < 0.01). The Monark formulae currently used to determine the power and work done by a participant overestimates the actual values required to overcome the resistance. There findings have far-reaching implications in the physiological assessment of athletic, sedentary, and diseased populations.


Geophysics ◽  
1953 ◽  
Vol 18 (2) ◽  
pp. 271-288 ◽  
Author(s):  
L. Y. Faust

Assuming velocity (V) a function of depth (Z), geologic time (T), and lithology (L) the resistivity log is an approach to the determination of L. Since general knowledge of water resistivity values [Formula: see text] is lacking, the values of true resistivity [Formula: see text] against [Formula: see text] were compared for 670,000 feet of section widely distributed geographically. Variations in [Formula: see text] were presumably averaged out thereby, and the results indicate that statistically [Formula: see text] and [Formula: see text] This formula was applied to an additional 270,000 feet of section more localized geographically to observe its accuracy in predicting vertical travel time. If a correction map for [Formula: see text] variations is applied the results are encouraging but less accurate than good velocity surveys. Examination of an inconclusively small amount of data with more careful measurements of [Formula: see text] suggests that accuracy comparable to direct measurement may be attainable. The cooperation of other investigators and of the electric‐logging specialists is desired.


1957 ◽  
Vol 30 (2) ◽  
pp. 449-459
Author(s):  
J. E. McKinney ◽  
S. Edelman ◽  
R. S. Marvin

Abstract An apparatus has been developed for the direct measurement of the real and imaginary parts of the dynamic bulk modulus of solid and liquid materials over the frequency range of 50 to 10,000 cps. Piezoelectric crystals serving as driver and detector, together with the sample and a confining liquid, are contained in a cavity small compared with the wavelength of sound at these frequencies. Static pressure is superposed to eliminate the effect of small air bubbles. The complex compliances of the sample, confining liquid, and the cavity, are additive in this region, where the compliance is pure dilatation. The dynamic compliances of several natural rubber-sulfur mixtures were obtained in a preliminary evaluation of the behavior of the apparatus.


1959 ◽  
Vol 37 (1) ◽  
pp. 20-28 ◽  
Author(s):  
G. L. Smithson ◽  
R. L. Eager ◽  
A. B. VanCleave

X-Ray fluorescence has been applied to the analysis of flotation concentrates obtained from pegmatitic uranium ores occurring in Northern Saskatchewan. Approximate uranium analyses can be obtained by direct measurement on flotation concentrates but more accurate results are obtained by using an internal standard such as strontium or yttrium. The time required for an analysis, as compared to that of conventional chemical or fluorimetric methods, is considerably reduced and flotation pilot plant operations can therefore be more effectively controlled. The method has been extended to include the analysis of sulphate leach liquors obtained from the leaching of pegmatitic ores and their flotation concentrates. Organic phases obtained in liquid – liquid extraction studies can also be rapidly analyzed for uranium by X-ray fluorescence.


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