Non-Gaussianities in collider energy flux

Abstract

The microscopic dynamics of particle collisions is imprinted into the statistical properties of asymptotic energy flux, much like the dynamics of inflation is imprinted into the cosmic microwave background. This energy flux is characterized by correlation functions $$ \left\langle \mathcal{E}\left({\overrightarrow{n}}_1\right)\cdots \mathcal{E}\left({\overrightarrow{n}}_k\right)\right\rangle $$ E n → 1 ⋯ E n → k of energy flow operators $$ \mathcal{E}\left(\overrightarrow{n}\right) $$ E n → . There has been significant recent progress in studying energy flux, including the calculation of multi-point correlation functions and their direct measurement inside high-energy jets at the Large Hadron Collider (LHC). In this paper, we build on these advances by defining a notion of “celestial non-gaussianity” as a ratio of the three-point function to a product of two-point functions. We show that this celestial non-gaussianity is under perturbative control within jets at the LHC, allowing us to cleanly access the non-gaussian interactions of quarks and gluons. We find good agreement between perturbative calculations of the non-gaussianity and a charged-particle-based analysis using CMS Open Data, and we observe a strong non-gaussianity peaked in the “flattened triangle” regime. The ability to robustly study three-point correlations is a significant step in advancing our understanding of jet substructure at the LHC. We anticipate that the celestial non-gaussianity, and its generalizations, will play an important role in the development of higher-order parton showers simulations and in the hunt for ever more subtle signals of potential new physics within jets.

Modeling hadronization using machine learning

“…Instead, the training will need to be performed on the physically accessible observables constructed from particle flows measured either in e + e − or pp collisions with two, three or more jets in the final state. We anticipate that this is where the machine learning approach to hadronization will prove most useful -capturing the many observables in principle available in the data, such as hadron multiplicities, angular separations and momentum distributions for various hadrons (see [73][74][75][76][77][78] for a selection of potentially useful observables). While many of these observables are not currently available in the literature, open-data efforts by a number of collaborations have or will make access possible.…”

Spinning gluons from the QCD light-ray OPE

“…The two equivalent definitions (1.1) and (1.2), from momentum space and position space perspectives respectively, make EEC an interesting observable which benefits both from scattering amplitude and correlation function techniques. Motivated by these definitions, there are a number of interesting generalizations of the EEC, including the multi-point and projective versions [8,[13][14][15][16][17], track-based EEC [8,[18][19][20][21], Transverse EEC at hadron colliders [22], generalized event shapes [23,24], nuclear EEC [25][26][27][28], the celestial nongaussianities [29], and in various backgrounds like quark-gluon plasma and cold nuclear matter [30][31][32][33]. See also [34] for a review on EEC in the precision QCD.…”

Analytic Computation of Three-point Energy Correlator in QCD

“…Furthermore, standard CFT tools like conformal blocks and Lorentz inversion formula [43,44] are also developed to organize the power correction of triple-collinear EEEC [45,46], opening a new window to studying jet substructure. More recent progress can be found in [47,48]. An outline of this paper is as follows.…”