https://doi.org/10.1140/epjp/s13360-020-00341-8
Regular Article
Flavor signatures of complex anomalous tcZ couplings
1
Indian Institute of Technology Bombay, Mumbai, 400076, India
2
Indian Institute of Technology Jodhpur, Jodhpur, 342037, India
* e-mail: saini.1@iitj.ac.in
Received:
18
June
2019
Accepted:
17
March
2020
Published online:
27
March
2020
In this work, we study the effects of anomalous tcZ couplings. Such couplings would potentially affect several neutral current decays of K and B mesons via Z-penguin diagrams. Using constraints from relevant observables in K and B sectors, we find that the 2
upper bound on the branching ratio of 
is 
for real coupling and 
for complex coupling. The current experimental upper bound from ATLAS and CMS collaborations on the branching ratio of 
is 
and 
at 
C.L., respectively. Hence the possibility of observation of decay at the level of 
would imply the anomalous couplings to be complex. Such complex couplings should also show up its presence in other related decays. We find that an order of magnitude enhancement is possible in the branching ratio of 
. Further, the complex tcZ coupling can also provide large enhancements in many CP violating angular observables in 
decay.
© Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature, 2020
