High-energy QCD dynamics from bottom flavor fragmentation at the Hi-Lumi LHC

Abstract

We study the inclusive production of hadrons with bottom flavor at the LHC and its luminosity upgrade. We describe the collinear fragmentation of singly b-flavored hadrons, B mesons and $$\Lambda _b$$ Λ b baryons, via the determination of fragmentation functions, while for charmed B mesons, $$B_c(^1S_0)$$ B c ( 1 S 0 ) and $$B_c(^3S_1)$$ B c ( 3 S 1 ) particles, we employ the novel set, built on the basis of state-of-the-art nonrelativistic QCD inputs. We use the Jethad multimodular working environment to analyze rapidity and transverse-momentum distributions for observables sensitive to the associated emission of two hadrons or a hadron-plus-jet system. Our reference formalism is the $$\mathrm{NLL/NLO^+}$$ NLL / NLO + hybrid collinear and high-energy factorization, where the standard collinear description is improved by the inclusions of energy logarithms resummed up to the next-to-leading approximation and beyond. We provide corroborating evidence that b-flavor emissions act as fair stabilizers of the high-energy resummation, thus serving as valuable tools for precision studies of high-energy QCD. As a bonus, we highlight that the predicted production-rate hierarchy between noncharmed b-hadrons and charmed $$B_c(^1S_0)$$ B c ( 1 S 0 ) mesons is in line with recent LHCb estimates. This serves as simultaneous benchmark both for the hybrid factorization and for the single-parton fragmentation mechanism based on initial-scale inputs calculated via the nonrelativistic QCD effective theory.

Forward & Far-Forward Heavy Hadrons with Jethad: A High-Energy Viewpoint

“…These findings mark a significant advancement in our understanding of high-energy QCD processes and offer promising prospects for future precision studies in this area. Subsequent analyses on vector quarkonia [253,254,334,335], B c mesons [314,317], and X Qq Q q tetraquarks [318], confirmed that this remarkable feature, known as natural stability of the BFKL resummation [312], comes out as basic property connected to the inclusive emission of any given heavy-flavored particle.…”

“…Version v0.4.7 [253] introduced quarkonium-sensitive reactions from NRQCD leadingtwist fragmentation. Novel features in v0.5.0 [254] and v0.5.1 [317] encompass an enhanced system for MHOU-related studies, an expanded list of observables with a focus on singly-and doubly-differential transverse-momentum production rates [276,289,317], and support for matching procedures with collinear factorization [324][325][326][327]329]. The most significant update of v0.5.2 is symJETHAD, a MATHEMATICA plugin devoted to symbolical calculations for high-energy QCD and the proton structure.…”

“…Following precedent studies [282,288,309], we set a 10 < |⃗ q T M |/GeV < 20 window for the transverse momentum of the M hadron. In contrast, we select a wider and disjoint transverse momentum range for the b-hadron, specifically 20 < |⃗ q T b |/GeV < 60, as recently suggested in studies of high-energy b-flavored emissions [310,317]. This selection ensures the robustness of our treatment within the VFNS framework, as energy scales consistently exceed the thresholds for DGLAP evolution of heavy-quark FFs (we refer to Section 2.3 for further details).…”

“…By studying such observables, we can gain a more comprehensive view of how BFKL dynamics manifest across various exclusive final states, thereby enriching our understanding of high-energy QCD phenomena. We can mention: light-flavored di-hadron [280][281][282][283][284], hadron-plus-jet [249,[285][286][287][288][289], multi-jet [290][291][292][293][294][295][296][297][298][299][300][301][302] and Drell-Yan [303] angular distributions, Higgs-jet rapidity and transverse-momentum distributions [250,[304][305][306][307], heavy-flavored jet [251,308] and hadron [179][180][181][182]253,[309][310][311][312][313][314][315][316][317][318]…”