OPTIMASS: A Package for the Minimization of Kinematic Mass Functions with Constraints

Understand

Reconstructed mass variables, such as $M_2$, $M_{2C}$, $M_T^\star$, and $M_{T2}^W$, play an essential role in searches for new physics at hadron colliders.

• The calculation of these variables generally involves constrained minimization in a large parameter space, which is numerically challenging.
• We provide a C++ code, OPTIMASS, which interfaces with the MINUIT library to perform this constrained minimization using the Augmented Lagrangian Method.
• The code can be applied to arbitrarily general event topologies and thus allows the user to significantly extend the existing set of kinematic variables.