New Physics Anticipations in Dilepton Angular Distributions
Abstract:Searches for a new resonance in kinematic distributions is an important program at the LHC. Once its mass is discovered from the location of the peak, one typically relegates to angular distributions the role of profiling its spin and chiral couplings. This approach, however, is troublesome if new physics is non-resonant, where the lack of a bump feature gives no indication as to which spectrum to first anticipate signals in. Most likely, both kinematic and angular spectra information may be needed to extract all at once the mass, spin and coupling properties. A good testing ground for this possibility is the Drell-Yan process, due to its well-understood backgrounds and small uncertainties. In this talk, I will use LHC measurements of the dilepton forward-backward asymmetry (AFB) and invariant mass spectra to corner leptoquarks (LQs), which may mediate Drell-Yan in the t-channel and yield no resonant feature. These probes, exploiting the cleanness of dileptons, are often stronger than dedicated searches through direct LQ production. The couplings of first generation LQs are best probed today by low-energy atomic parity violation measurements, but the high luminosity runs of the LHC can deliver enough precision to overtake these experiments, with the dilepton angular spectra leading the way. I will conclude with suggestions on the use of certain angular observables that may provide an unambiguous interface between theory and experiment, and help facilitate prompt interpretations of new physics.
4:10pm-5:10pm calendar page