In the book of The First Three Minutes by Weinberg, on pages 106-107, it is stated that

SECOND FRAME. The temperature of the universe is 30,000 million degrees Kelvin [...] The nuclear particle balance has conse- quently shifted to 38 per cent neutrons and 62 per cent protons.

 

[...]

 

THIRD FRAME. The temperature of the universe is 10,000 million degrees Kelvin. [...] The decreasing temperature has now allowed the proton-neutron balance to shift to 24 per cent neutrons and 76 per cent protons.

What is the reason for this balance shift between neutrons and protons? And what determines the rate of change of the neutron/proton ratio?

In the book of The First Three Minutes by Weinberg, on pages 106-107, it is stated that

SECOND FRAME. The temperature of the universe is 30,000 million degrees Kelvin [...] The nuclear particle balance has conse- quently shifted to 38 per cent neutrons and 62 per cent protons.

[...]

THIRD FRAME. The temperature of the universe is 10,000 million degrees Kelvin. [...] The decreasing temperature has now allowed the proton-neutron balance to shift to 24 per cent neutrons and 76 per cent protons.

What is the reason for this balance shift between neutrons and protons? And what determines the rate of change of the neutron/proton ratio?

In the book of The First Three Minutes by Weinberg, at page 106-107, it is stated that

SECOND FRAME. The temperature of the universe is 30,000 million degrees Kelvin [...] The nuclear particle balance has conse- quently shifted to 38 per cent neutrons and 62 per cent protons.

[...]

THIRD FRAME. The temperature of the universe is 10,000 million degrees Kelvin. [...] The decreasing temperature has now allowed the proton-neutron balance to shift to 24 per cent neutrons and 76 per cent protons.

What is the reason for this balance shift between neutrons and protons exaclty ? and what does determine this rate of the change this shift ?

In the book of The First Three Minutes by Weinberg, on pages 106-107, it is stated that

SECOND FRAME. The temperature of the universe is 30,000 million degrees Kelvin [...] The nuclear particle balance has conse- quently shifted to 38 per cent neutrons and 62 per cent protons.

[...]

THIRD FRAME. The temperature of the universe is 10,000 million degrees Kelvin. [...] The decreasing temperature has now allowed the proton-neutron balance to shift to 24 per cent neutrons and 76 per cent protons.

What is the reason for this balance shift between neutrons and protons? And what determines the rate of change of the neutron/proton ratio?