decay constant


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decay constant

[di′kā ‚kän·stənt]
(physics)
The constant c in the equation I = I0 e -ct , for the time dependence of rate of decay of a radioactive species; here, I is the number of disintegrations per unit time. Also known as decay coefficient; disintegration constant; radioactive decay constant; transformation constant.
References in periodicals archive ?
Decay Constants and Half-Lives Geologically Important Radioactive Isotopes Radioactive Decay Constant Half-Life Isotope ([years.sup.-1]) (years) [sup.14]C 0.1209 x [10.sup.-3] 5730 [sup.40]K 0.581 x [10.sup.-10] 1.19 x [10.sup.10] [sup.87]Rb 1.42 x [10.sup.-11] 48.8 x [10.sup.9] [sup.147]Sm 0.654 x [10.sup.-12] 1.06 x [10.sup.11] [sup.232]Th 4.9475 x [10.sup.-11] 14.01 x [10.sup.9] [sup.235]U 9.8485 x [10.sup.-10] 0.7038 x [10.sup.9] [sup.238]U 1.55125 x [10.sup.-10] 4.468 x [10.sup.9]
In addition, the decay constants, leptonic decay widths, and branching fractions of the HLM are calculated.
In phenomenological or physical approach, it can be evaluated in terms of hadronic parameters such as masses, decay constants, and form factors.
Before giving the matrix elements for the B [right arrow] J/[psi][eta]K decay, we discuss the parametrization of the decay constants and form factors which appear in the factorized form of the hadronic matrix elements.
Moreover, the leptonic decay constants of the vertices are [mathematical expression not reproducible], and [mathematical expression not reproducible] [27]
Evidence Against Solar Influence on Nuclear Decay Constants. Physics Letters, 2016, v.
This removes slow moving wave modes and increases the decay constant from 2.2 to 4.2.
The parameter c'3 accounted for the difference in time decay constants between 0 cm and well away from CWD.
Where E is exhalation rate Ceq is equilibrium radon concentration is decay constant of radon Veff is volume of RTC and S is surface area of sample.
in which [I.sub.L] is the long term intensity at time t, [[alpha].sub.L] is the last time-invariant constant corresponding to the slowest decay component (i.e., [[alpha].sub.2] in (3) or [[alpha].sub.3] in (4)), and [[tau].sub.L] is the corresponding decay constant.
The decay constant range, k = 2.14-0.88 in dry season and k = 2.34-0.94 in wet season, was found for this study while k = 3.46-2.35 was found for three tropical agroforestry tree species (Mangifera indica, Artocarpus heterophyllus, and Anacardium occidentale) as reported by Isaac and Nair but higher range of decay constant, k = 6.67-3.91, was found for the other three tropical agroforestry tree species (Melia azadirachta, Azadirachta indica, and Dalbergia sissoo) as reported by Isaac and Nair [41] and Hossain et al.
Using Equation 1 with values from experimentation for X, [V.sub.0], [V.sub.X] and [A.sub.0], gave a decay constant, K, of around 1.8.