Jay Desai,SBU, [HET Seminar] Universal Standard Model Effective Field Theory beyond dimension-six

Thursday 11 Dec 2025, 11:00 → 13:00 US/Eastern

Small Seminar Room

Abstract: The assumption that new physics lies beyond the energy scales of the LHC, leads us towards the Standard Model Effective Field Theory (SMEFT) as a tool for model independent BSM searches. Beyond the leading order, such complete model-independent analysis becomes infeasible as the number of operators increases dramatically. In that case, physically motivated scenarios, such as that of universal physics, reduces the parameter space while still capturing a significant class of BSM theories.

First, I will present the basis of dimension-eight operators associated with universal theories. Without imposing C nor P the universality assumption reduces the number of independent SMEFT operators at dimension eight from 44807 to 175.
I will then focus on the description of Drell-Yan and Electroweak precision observables in this framework.  I will also introduce an extension of the parametrization of universal effects in terms of Oblique parameters obtained by linearly expanding the self-energies of the electroweak gauge bosons to O(q^6).  Finally, I will present the results of the combined analysis of a variety of LHC data on the neutral- and charged-current DY processes as well as electroweak precision W and Z pole observables.  We will see how the DY bounds provide a complementary sensitivity to the EWPO.

 

https://bnl.zoomgov.com/j/16010362754?pwd=Z1l1SS9JUDlyR1hSUHNyaDV1dTZHUT09