https://doi.org/10.1140/epjc/s10052-022-10225-z
Regular Article - Theoretical Physics
General one-loop formulas for 
and its applications
1
Institute of Applied Technology, Thu Dau Mot University, 75000, Thu Dau Mot City, Binh Duong, Vietnam
2
University of Science Ho Chi Minh City, 227 Nguyen Van Cu, District 5, Ho Chi Minh City, Vietnam
3
Institute of Fundamental and Applied Sciences, Duy Tan University, 700000, Ho Chi Minh City, Vietnam
4
Faculty of Natural Sciences, Duy Tan University, 550000, Da Nang City, Vietnam
Received:
15
November
2021
Accepted:
18
March
2022
Published online:
31
March
2022
General one-loop contributions to the decay processes and its applications are presented in this paper. We consider all possible contributions of the additional heavy vector gauge bosons, heavy fermions, and charged (also neutral) scalar particles propagating in Feynman loop diagrams. Therefore, analytic results are valid in a wide class of models beyond the Standard Model. Analytic formulas for the form factors are expressed in terms of Passarino-Veltman functions in the standard notations of LoopTools. Hence, the decay rates can be evaluated numerically by using this package. The computations are then applied to the cases of the Standard Model, 
extension of the Standard Model as well as Two Higgs Doublet Model. Phenomenological results for all the above models are studied. We observe that the effects of new physics are sizable contributions and these can be probed at future colliders.
© The Author(s) 2022
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3
