Lifetime of the 6793-keV state in 15O.
Lifetime of the 6793-keV state in 15O.
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6793-keV态的寿命为15O。
DOI：
10.1103/physrevlett.87.152501
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发表时间：
2001
影响因子：
8.6
通讯作者：
V. Hansper
中科院分区：
文献类型：
--
作者：
P. Bertone;A. Champagne;D. C. Powell;C. Iliadis;S. Hale;V. Hansper
在低恒星温度下，CN循环产生的能量由14 N（p，gamma）15 O反应调节。以前的直接测量这个反应已被解释为显示的亚阈值共振，使在低温下的反应速率的主要贡献的证据。这种共振，在E（c.m.）= -504 keV将对应于15 O中已知的Ex = 6793-keV状态。我们测得的平均寿命为1.60（+0.75）（-0.72）fs（90% C.L.）使用多普勒频移衰减方法。这个寿命比从（p，伽马）数据推断的寿命长15倍，这意味着亚阈值共振的贡献可以忽略不计。
The energy derived from the CN cycle at low stellar temperatures is regulated by the 14N(p,gamma)15O reaction. A previous direct measurement of this reaction has been interpreted as showing evidence for a subthreshold resonance which makes a major contribution to the reaction rate at low temperatures. This resonance, at E(c.m.) = -504 keV would correspond to the known Ex = 6793-keV state in 15O. We have measured a mean lifetime of 1.60(+0.75)(-0.72) fs (90% C.L.) for this state using the Doppler-shift attenuation method. This lifetime is a factor of 15 longer than that inferred from the (p,gamma) data and implies that the contribution of the subthreshold resonance is negligible.