اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدFirst measurement of the partial widths of $^{209}$Bi decay to the ground and to the first excited states
225
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
$^{209}$Bi alpha decay to the ground and to the first excited state have been contemporary observed for the first time with a large BGO scintillating bolometer. The half-life of $^{209}$Bi is determined to be $tau_{1/2}$=(2.01$pm$0.08)$cdot10^{19}$ years while the branching ratio for the ground-state to ground-state transition is (98.8$pm$0.3)%.
قيم البحث
اقرأ أيضاً
The resonance parameters of the excited psi-family resonances, namely the psi(4040), psi(4160), and psi(4415), were determined by fitting the R-values measured by experiments. It is found that the previously reported leptonic partial widths of these
states were merely one possible solutions among a four-fold ambiguity. By fitting the most precise experimental data on the R-values measured by the BES collaboration, this work presents all four sets of solutions. These results may affect the interpretation of the charmonium and charmonium-like states above 4GeV/c^2.
The alpha decays of naturally occurring platinum isotopes, which are accompanied by the emission of gamma quanta, have been searched for deep underground (3600 m w.e.) in the Gran Sasso National Laboratories of the INFN (Italy). A sample of Pt with m
ass of 42.5 g and a natural isotopic composition has been measured with a low background HP Ge detector (468 cm^3) during 1815 h. The alpha decay of 190-Pt to the first excited level of 186-Os (J^pi = 2^+, E_{exc}=137.2 keV) has been observed for the first time, with the half-life determined as: T_{1/2} = 2.6_{-0.3}^{+0.4} (stat.) pm 0.6 (syst.) times 10^{14} yr. The T_{1/2} limits for the alpha decays of other Pt isotopes have been determined at level of T_{1/2} simeq 10^{16}-10^{20} yr. These limits have been set for the first time or they are better than those known from earlier experiments.
The CUORICINO experiment was an array of 62 TeO$_{2}$ single-crystal bolometers with a total $^{130}$Te mass of $11.3,$kg. The experiment finished in 2008 after more than 3 years of active operating time. Searches for both $0 u$ and $2 u$ double-beta
decay to the first excited $0^{+}$ state in $^{130}$Xe were performed by studying different coincidence scenarios. The analysis was based on data representing a total exposure of N($^{130}$Te)$cdot$t=$9.5times10^{25},$y. No evidence for a signal was found. The resulting lower limits on the half lives are $T^{2 u}_{1/2}(^{130} Terightarrow^{130} Xe^{*})>1.3times10^{23},$y (90% C.L.), and $T^{0 u}_{1/2}(^{130} Terightarrow^{130} Xe^{*})>9.4times10^{23},$y (90% C.L.).
The double beta decay of $^{150}$Nd to the first excited 0$^+$ level of $^{150}$Sm ($E_{exc}$ = 740.5 keV) has been investigated with the help of the ultra-low-background setup consisting of four HP Ge (high-purity germanium) detectors (${approx}$ 22
5 cm$^3$ volume each one) at the Gran Sasso underground laboratory of INFN (Italy). A highly purified 2.381-kg sample of neodymium oxide (Nd$_2$O$_3$) was used as a source of ${gamma}$ quanta expected in the decays. Gamma quanta with energies 334.0 keV and 406.5 keV emitted after deexcitation of the $0_1^+$ 740.5 keV level of $^{150}$Sm are observed in the coincidence spectra accumulated over 16375 h. The half-life relatively to the two neutrino double beta decay $^{150}$Nd $rightarrow$ $^{150}$Sm(0$_1^+$) is measured as $T_{1/2} = [4.7_{-1.9}^{+4.1}text{(stat)} {pm} 0.5text{(syst)}] {times} 10^{19} y$, in agreement with results of previous experiments.
Two-proton decay of the $^{17}$Ne low-lying states populated in the $^1$H($^{18}$Ne,$d$)$^{17}$Ne transfer reaction was studied. The two-proton width $Gamma_{2p}$ of the $^{17}$Ne first excited $3/2^-$ state at $E^*=1.288$ MeV is of importance for th
e two-proton radioactivity theory and nuclear-astrophysics applications. A dedicated search for the two-proton emission of this state was performed leading to the new upper limit obtained for the width ratio $Gamma_{2p}/Gamma_{gamma} < 1.6(3) times 10^{-4}$. A novel, combined mass method is suggested and tested capable to improve the resolution of the experiment which is a prime significance for the study of nuclear states with extremely small particle-to-gamma width ratios $Gamma_{mathrm{part}}/Gamma_{gamma}$. The condition $Gamma_{mathrm{part}} ll Gamma_{gamma}$ is quite common for the states of astrophysical interest which makes the proposed approach promising in this field.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
