Unraveling flavor & naturalness from RUN II to 100 TeV

TL;DR

This paper discusses the importance of flavor constraints in setting bounds on new physics, emphasizing the potential of future 100 TeV colliders to explore higher mass scales and test naturalness more stringently.

Contribution

It highlights the role of flavor constraints in constraining new physics scales and advocates for a 100 TeV collider to improve bounds and test naturalness beyond LHC capabilities.

Findings

Flavor constraints push new physics scales above 10 TeV.

A 100 TeV collider could directly produce particles over 5-10 TeV.

Naturalness tests could improve by a factor of 50 beyond LHC.

Abstract

The importance of incorporating flavor constraints, when providing bounds on new physics is stressed. As is well known it is very difficult for models of new physics to have scales lighter than about 10 TeV once flavor constraints are built in. Although, in the conventional sense, this higher scale means more tuning, it may well make the underlying theory simpler as illustrated with one example. Direct production of new particles heavier than about 5 TeV becomes very difficult at LHC though indirect signals such as deviations in the Higgs to gamma gamma branching ratio may still be possible. Also of course precision studies at low energy facilities can be useful for detecting new phenomena. For direct production of new particles over 5-10 TeV a new high energy collider perhaps at 100 TeV is highly desirable. Indeed, a very strong physics case can be made for such a machine. It can be used to significantly improve many bounds as well as allow a multitude of direct searches in many channels without relying on specific models. Naturalness can be tested by another factor of about 50 past LHC to O($10^{-4}$), a valuable achievement in itself.