A free proton cannot decay into `(n+e^(+)+v)`, because such decay is not energetically allowed. Yet we observe in nature beta decay with positron emission. How do we understand the emission of positrons form nuclei?
A free proton cannot decay into `(n+e^(+)+v)`, because such decay is not energetically allowed. Yet we observe in nature beta decay with positron emission. How do we understand the emission of positrons form nuclei?
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To understand why a free proton cannot decay into a neutron, a positron, and a neutrino, while we do observe positron emission from certain nuclei (beta plus decay), we can break down the explanation into several steps:
### Step-by-Step Solution:
1. **Understanding Free Proton Decay**:
- A free proton (p) cannot decay into a neutron (n), a positron (e+), and a neutrino (ν) because this reaction is not energetically favorable. The mass-energy of the products (n + e+ + ν) is greater than that of the initial proton.
2. **Energy Considerations**:
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