Studies of Spin Effects in Charged Higgs Boson Production with an Iterative Discriminant An.pdf

Eur. Phys. J. C 53 (2008) 311 SHEP-06-36, LPT-ORSAY-07-103 Studies of Spin Effects in Charged Higgs Boson Production with an Iterative Discriminant Analysis at the Tevatron and LHC 8 0 0 2 n a J 1 1,2 3 3∗ S. Hesselbach , S. Moretti , J. Rathsman and A. Sopczak 1 2 ] h 1School of Physics Astronomy, Southampton University, Highfield, p - Southampton SO17 1BJ, UK p 2Laboratoire de Physique Th´eorique, Paris XI, 91405 Orsay, France e 3 h High Energy Physics, Uppsala University, Box 535, S-75121 Uppsala, Sweden [ 2 v 4 9 3 4. Abstract 8 0 We report on detailed Monte Carlo comparisons of selection variables to separate tbH ± signal events from 7 ¯ 0 the Standard Model tt background using an Iterative Discriminant Analysis (IDA) method. While kinematic : v differences exist between the two processes whenever mH ± = mW ± , the exploration of the spin difference i X between the charged Higgs and the W ± gauge boson becomes crucial in the particularly challenging case of r near degeneracy of the charged Higgs boson mass with the W ± mass. The TAUOLA package is used to decay a the tau leptons emerging from the charged Higgs and W ± boson decays taking the spin difference properly into account. We demonstrate that, even if the individual selection variables have limited discriminant power, the IDA method achieves a significant separation between the expected signal and background. For both Tevatron and LHC energies, the