A high-energy QCD portal to exotic matter: Heavy-light tetraquarks at the HL-LHC

Abstract

By taking advantage of the natural stability of the high-energy resummation, recently discovered in the context of heavy-flavor studies, we investigate the inclusive hadroproduction of a neutral heavy-light, hidden-flavored tetraquark ($X_{cu\bar{c}\bar{u}}$ or $X_{bs\bar{b}\bar{s}}$ state), in association with a heavy (single $c$- or $b$-flavored) hadron or a light jet at the (HL-)LHC. We make use of the JETHAD multi-modular working package to provide predictions for rapidity, azimuthal-angle and transverse-momentum distributions calculated via the hybrid high-energy and collinear factorization, where the Balitsky--Fadin--Kuraev--Lipatov resummation of energy logarithms is supplemented by collinear parton densities and fragmentation functions. We rely upon the single-parton fragmentation mechanism, valid in the large transverse-momentum regime, to describe the tetraquark production. Our study represents a first attempt at bridging the gap between all-order calculations of high-energy QCD and the exotics.

Comments: 11 pages, 5 figures, version published in Physics Letters B. Four novel sets of "TetraQuarks with Heavy and Light Flavors" (TQHL1.0) collinear fragmentation functions released in LHAPDF format and publicly available from https://github.com/FGCeliberto/Collinear_FFs/