Search Talks

The search for physics beyond the Standard Model at the LHC is largely oriented towards new particles associated with solutions to the electroweak hierarchy problem. While the precise character of these partner states may vary from model to model, they typically possess large QCD production rates favorable for detection at hadron colliders. Null results in searches for partner particles during Run 1 of the LHC have placed the idea of electroweak naturalness under increasing strain. In this talk I'll discuss a broad class of natural theories where the new degrees of freedom relevant for naturalness lie in hidden sectors and are largely unconstrained by LHC data. Rather than rendering electroweak naturalness untestable, they give rise to entirely new signs of naturalness at the LHC, including displaced decays and other exotic signatures. They also furnish a variety of viable dark matter candidates testable at current and future experiments.

I will talk about a novel theory of dark matter superfluidity that matches the success of LCDM model on cosmological scales while simultaneously reproducing the MOND phenomenology on galactic scales.

In this talk I will discuss the most singular point and T^2 compactifications of a 6d N=(1,0) supersymmetric conformal field theory (SCFT) which arises as the worldvolume theory on coincident N of M5 branes probing the singular locus of the ALE orbifold. When N=1, the compactified theory can be describe by a class S theory of three punctured sphere. Generalization to multiple M5s case results in a pair of 4d N=2 SCFTs which are connected by a IR free gauge multiplet. Along the line, we see that the “dynamical version" of class S simple puncture plays a role. Closing one of two flavor groups, we can isolate one of them with manifest SL(2,Z) invariance of T^2 and a non-abelian flavor group, including presumably new N=2 SCFTs.

 I  will first analytically show a simple, yet subtle "invariance" of two-body decay kinematics for the case of a massless  daughter and a mother particle which is unpolarized and has a *generic* boost distribution in the laboratory frame. Namely, the laboratory frame energy distribution of the massless decay product has a peak, whose location is identical to the  (fixed) energy of that particle in the rest frame of the corresponding mother particle. In turn, this value of the energy is a simple function of the other masses involved in the decay.
As a proof of principle of the usefulness of this observation, I will then apply it for measuring  the mass of the top quark at the LHC, using simulated data (including experimental  effects). In fact, CMS collaboration (in CMS-PAS-TOP-15-002) has recently implemented our method for measuring the top quark mass! Finally, I will show how it can be used to measure all the superpartner masses in a cascade decay chain of the gluino.