Radiative corrections for semileptonic decays of hyperons: ‘‘Model-independent’’ part

Abstract

The "model independent" part of the order a radiative correction due to virtual photon exchanges and inner bremsstrahlung is studied for semileptonic decays of hyperons. Numerical results of high accuracy are given for the rela tive correction to the branching ratio, the electron energy spectrum and the (Ee ,Ef) Dalitz distribution in case of four different decays: I" •> n e v , l~-* ■ Aev,-* • Aev and Л-* • pev. АННОТАЦИЯ Изучена "независимая от модели" часть радиационных поправок в порядке а, которая соответствует обмену виртуальных фотонов и тормозного излучения. Для распадов Е-*nev, £-* ■ Aev, = Aev и Л-* • pev получены точные численные резуль таты для поправок к "branching ratio", спектру энергии электронов и диаграмме Далица (Е£ , E f). KIVONAT A virtuális foton csere és fékezési sugárzás következtében fellépő a ren di! sugárzási korrekciók "modell független" részét tanulmányozzuk hyperonok szemileptonos bomlásaiban. Nagy pontosságú numerikus eredményeket adunk a l~-* ■ nev, l~ ■ * Aev, =" ■ + r^eV és A ■ + pev bomlások esetén az elágazási arány, az elektron energia spektrum és az (Ee ,Ef) Dalitz eloszlás relativ korrekci óira .

Influence of the recoil-order and radiative correction on the beta decay correlation coefficients in mirror decays

“…As Glück and collaborators [44,47,49,62] have shown, former calculations of the radiative correction to correlations coefficients involving the (anti-)neutrino momentum, such as the beta-neutrino correlation a βν or the neutrino asymmetry B ν [40][41][42][43], are incorrect to use in an experimental analysis. Measurements determine the correlation between the beta particle and the recoiling nucleus to avoid the challenging detection of the neutrino.…”

Radiative corrections to neutron and nuclear $β$-decays: a serious kinematics problem in the literature

“…In the case of the presence of bremsstrahlung photons we have 4-body kinematics with 12 momentum parameters, but the same number of conservation equations and Euler angles as above, therefore 12-4-3=5 parameters determine the unpolarized decay kinematics; e.g. these could be the electron and recoil particle energy, the third side of the decay triangle Q = |Q|, the photon energy K = |k|, and the azimuthal angle φ k of the photon momentum vector k around the vector Q [23,29]. The kinematical limits of these 4-body decay parameters can be determined by the energy and momentum conservation equations:…”

“…(see Refs. [3,23,27,29]). Q 1 and Q 2 are connected with the geometrical decay triangle limits for (anti)parallel p 2 and p f momentum vectors, while the K min and K max limits originate from the geometrical properties of the rotational ellipsoid in Fig.…”

“…[26,27,29,64] about the 3-dimensional analytical integration method used in our publications. The 3-dimensional integral can also be performed completely numerically [23][24][25]. Semianalytical integration methods for the non-infrared divergent integrals, with analytical integrals over the parameters φ k and K and numerical integrations over Q, are described in Refs.…”

“…The radiative corrections to the electron and recoil energy Dalitz distributions for neutron and several hyperon semileptonic decays were computed in Refs. [23][24][25] by numerical integrations over the bremsstrahlung photon phase space. Afterwards rather elaborate analytical methods of the 3-dimensional bremsstrahlung integrations were developed in Refs.…”