{"action":"opened","issue":{"url":"https://api.github.com/repos/CRPropa/CRPropa3/issues/20","labels_url":"https://api.github.com/repos/CRPropa/CRPropa3/issues/20/labels{/name}","comments_url":"https://api.github.com/repos/CRPropa/CRPropa3/issues/20/comments","events_url":"https://api.github.com/repos/CRPropa/CRPropa3/issues/20/events","html_url":"https://github.com/CRPropa/CRPropa3/issues/20","id":56036848,"number":20,"title":"Nuclear decay: correct beta energy spectrum","user":{"login":"DavidWalz","id":2913236,"avatar_url":"https://avatars.githubusercontent.com/u/2913236?v=3","gravatar_id":"","url":"https://api.github.com/users/DavidWalz","html_url":"https://github.com/DavidWalz","followers_url":"https://api.github.com/users/DavidWalz/followers","following_url":"https://api.github.com/users/DavidWalz/following{/other_user}","gists_url":"https://api.github.com/users/DavidWalz/gists{/gist_id}","starred_url":"https://api.github.com/users/DavidWalz/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/DavidWalz/subscriptions","organizations_url":"https://api.github.com/users/DavidWalz/orgs","repos_url":"https://api.github.com/users/DavidWalz/repos","events_url":"https://api.github.com/users/DavidWalz/events{/privacy}","received_events_url":"https://api.github.com/users/DavidWalz/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/CRPropa/CRPropa3/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-01-30T14:04:50Z","updated_at":"2015-01-30T14:04:50Z","closed_at":null,"body":"The energy distribution of electrons from beta decay is given by (Basdevant, eq 4.92)\r\np(E_e) ~ F(Z',E_e) E_e \\sqrt{E_e^2 - m_e^2 c^4} (\\Delta m c^2 - E_e)^2\r\n\r\nCurrently beta energies are generated according to the free neutron decay (Delta m = m_n - m_p, F=1) and then approximatively scaled to the given nuclear decay.\r\nImplementing the correct treatment would be straightforward however."}}