MSSM with Dimension-five Operators (MSSM_5)

TL;DR

This paper analyzes the impact of dimension-five operators in the MSSM, identifying a minimal set that introduces new couplings affecting Higgs physics and collider searches, with implications for supersymmetry phenomenology.

Contribution

It presents a method to identify the minimal, irreducible set of dimension-five operators in the MSSM and discusses their phenomenological effects, especially on Higgs and collider physics.

Findings

Redundancy in D=5 operators can be removed via spurion-dependent redefinitions.

The minimal set introduces new couplings like wrong-Higgs Yukawas and contact interactions.

Quantum corrections are still necessary to satisfy experimental Higgs mass bounds.

Abstract

We perform a general analysis of the R-parity conserving dimension-five operators that can be present beyond the Minimal Supersymmetric Standard Model. Not all these operators are actually independent. We present a method which employs spurion-dependent field redefinitions that removes this "redundancy" and establishes the minimal, irreducible set of these dimension-five operators. Their potential effects on the MSSM Higgs sector are discussed to show that the tree level bound $m_h\leq m_Z$ cannot be easily lifted within the approximations used, and quantum corrections are still needed to satisfy the LEPII bound. An ansatz is provided for the structure of the remaining couplings in the irreducible set of D=5 operators, which avoids phenomenological constraints from flavor changing neutral currents. The minimal set of operators brings new couplings in the effective Lagrangian, notably "wrong"-Higgs Yukawa couplings and contact fermion-fermion-scalar-scalar interactions, whose effects are expected to be larger than those generated in the MSSM at loop or even tree level. This has implications in particular for LHC searches for supersymmetry by direct squark production.