Abstract
A framework is proposed to describe resonant diphoton phenomenology at hadron colliders in full generality. It can be employed for a comprehensive model-independent interpretation of the experimental data. Within the general framework, few benchmark scenarios are defined as representative of the various phenomenological options and/or of motivated new physics scenarios. Their usage is illustrated by performing a characterization of the 750 GeV excess, based on a recast of available experimental results. We also perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions. These include the spin J of the new particle and its dominant production mode. Partial information on its CP-parity can also be obtained, but only for $J\geq2$. The complete determination of the resonance CP properties requires studying the pattern of the initial state radiation that accompanies the resonant diphoton production.
Highlights
We perform an assessment of which properties of the resonance could be inferred, after discovery, by a careful experimental study of the diphoton distributions
The second reason to neglect the Massive Vector Bosons (MVB) processes is the fact that the photon parton distribution function (PDF), again because of the lack of a hard low-p⊥ cut-off in the photon splitting, is larger than the MVB one
The only model-dependence is encoded in the relative strengths of the various production channels, which can be parametrized through the partonic production cross sections σin
Summary
We stress that the “a” (and “a”) coefficients in table 1 are, in general, complex numbers.6 They become real when the resonance production/decay processes are induced by heavy mediators. The heavy-mediator condition can be equivalently formulated as the hypothesis that the production/decay amplitudes are well described by a contact interaction at Born level, i.e. by the matrix element of a local Hermitian operator, in which case the CPT symmetry, combined with eq (2.2), gives a relation. We classify all the Lorentz-invariant terms, expressed as functions of the 4-momenta of the resonance and in particles and of their polarization vectors or spinor wave functions, which can appear in the polarized amplitudes The coefficients of these Lorentz-invariant terms are found to be in one-to-one correspondence with the parameters, showing that no further restrictions emerge from imposing the full Lorentz symmetry. Complete simulations for J ≥ 3, taking properly into account soft QCD radiation, hadronization and detector effect would require a different approach, based on matrix-element reweighting techniques as discussed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
