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

Abstract

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. We describe this code and its physics motivation, and demonstrate its use in the analysis of the fully leptonic decay of pair-produced top quarks using the $M_2$ variables.

39 pages, 12 figures, (1) minor revision in section 3, (2) figure added in section 4.3, (3) reference added and (4) matched with published version

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Cited by in corpus (17)

• Probing the Top-Higgs Yukawa CP Structure in dileptonic $t\bar{t}h$ with $M_2$-Assisted Reconstruction
• Direct Higgs-top CP-phase measurement with $t\bar{t}h$ at the 14 TeV LHC and 100 TeV FCC
• Resolving Combinatorial Ambiguities in Dilepton $t\bar{t}$ Event Topologies with Constrained $M_2$ Variables
• Detecting kinematic boundary surfaces in phase space: particle mass measurements in SUSY-like events
• Testing Invisible Momentum Ansatze in Missing Energy Events at the LHC
• Identifying Phase Space Boundaries with Voronoi Tessellations
• Is the Machine Smarter than the Theorist: Deriving Formulas for Particle Kinematics with Symbolic Regression
• Singularity Variables for Missing Energy Event Kinematics
• YAM2: Yet another library for the $M_2$ variables using sequential quadratic programming
• Measuring Masses in Semi-Invisible Final States at Electron-Positron Colliders
• Estimation of Ru-97 Half-Life Using the Most Frequent Value Method and Bootstrapping Techniques
• Kinematic Focus Point Method for Particle Mass Measurements in Missing Energy Events
• Resolving Combinatorial Ambiguities in Dilepton $t\bar{t}$ Event Topologies with Neural Networks
• Dreaming Awake: Disentangling the Underlying Physics in Case of a SUSY-like Discovery at the LHC
• Identifying the production process of new physics at colliders; symmetric or asymmetric?
• $M_{TN}$ is all you need: production of multiple semi-invisible resonances at hadron colliders
• Could $M_{T2}$ be a singularity variable?