Regular Article - Theoretical Physics
Bremsstrahlung simulation in K→πl ± ν l (γ) decays
Department of Physics, Hangzhou Normal University, Hangzhou, 310036, China
2 Institute of Nuclear Physics, PAN, ul. Radzikowskiego 152, Kraków, Poland
3 Theory Group, Physics Department, CERN, 1211, Geneva 23, Switzerland
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Revised: 28 August 2012
Published online: 25 September 2012
In physics simulation chains, the PHOTOS Monte Carlo program is often used to simulate QED effects in decays of intermediate particles and resonances.
The program is based on an exact multiphoton phase space. In general, the matrix element is obtained from iterations of a universal kernel and approximations are involved. To evaluate the program’s precision, it is necessary to formulate and implement within the generator the exact matrix element, which depends on the decay channel. Then, all terms necessary for non-leading logarithms are taken into account. In the present letter we focus on the decay K→πl ± ν l and tests of the PHOTOS Monte Carlo program. We conclude that there is a 0.2 % relative precision in the implementation of the hard photon matrix element into the emission kernel, including the case where approximations are used.
© Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica, 2012