FTUV/14−0423 IFIC/14−05 B 0 s,d → ℓ + ℓ - Decays in the Aligned Two-Higgs-Doublet Model Xin-Qiang Li 1,2∗ , Jie Lu 3† and Antonio Pich 3‡ 1 Institute of Particle Physics and Key Laboratory of Quark & Lepton Physics (MOE), Central China Normal University, Wuhan, Hubei 430079, P. R. China 2 State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China 3 IFIC, Universitat de Val` encia – CSIC, Apt. Correus 22085, E-46071 Val` encia, Spain Abstract The rare decays B 0 s,d → ℓ + ℓ − are analyzed within the general framework of the aligned two-Higgs doublet model. We present a complete one-loop calculation of the relevant short-distance Wilson coefficients, giving a detailed technical summary of our results and comparing them with previous calculations performed in particular limits or approxima- tions. We investigate the impact of various model parameters on the branching ratios and study the phenomenological constraints imposed by present data. ∗ xqli@itp.ac.cn † lu.jie@ific.uv.es ‡ pich@ific.uv.es 1 arXiv:1404.5865v1 [hep-ph] 23 Apr 2014