TY  - JOUR
AU  - Mandal, R.
AU  - Pich, A.
PY  - 2019
DA  - 2019//
TI  - Constraints on scalar leptoquarks from lepton and kaon physics
T2  - J. High Energy Phys.
JO  - Journal of High Energy Physics
SP  - 089
EP  - 40pp
VL  - 12
IS  - 12
PB  - Springer
KW  - Beyond Standard Model
KW  - Kaon Physics
AB  - We present a comprehensive analysis of low-energy signals of hypothetical scalar leptoquark interactions in lepton and kaon transitions. We derive the most general effective four-fermion Lagrangian induced by tree-level scalar leptoquark exchange and identify the Wilson coefficients predicted by the five possible types of scalar leptoquarks. The current constraints on the leptoquark Yukawa couplings arising from lepton and kaon processes are worked out, including also loop-induced transitions with only leptons (or quarks) as external states. In the presence of scalar leptoquark interactions, we also derive the differential distributions for flavour-changing neutral-current transitions in semileptonic kaon modes, including all known effects within the Standard Model. Their interference with the new physics contributions could play a significant role in future improvements of those constraints that are currently hampered by poorly-determined non-perturbative parameters.
SN  - 1029-8479
UR  - https://arxiv.org/abs/1908.11155
UR  - https://doi.org/10.1007/JHEP12(2019)089
DO  - 10.1007/JHEP12(2019)089
LA  - English
N1  - WOS:000503847800001
ID  - Mandal+Pich2019
ER  -