2017/03/10 by Rhorry Gauld · 6 citations
Physics and Astronomy · #Consistency (knowledge bases) #Gluon #Hadron #High-Energy Particle Collisions Research #Particle Detector Development and Performance #Particle physics theoretical and experimental studies #Production (economics) #Pseudorapidity #Range (aeronautics) #Rapidity #hep-ex #hep-ph
paper · pdf · doi:10.1007/jhep05(2017)084
published in Journal of High Energy Physics 2017(5) (Springer Nature) · 31 pages
arxiv created 2017/03/10 · openalex created_date 2017/03/23 · openalex publication_date 2017/05/01 · arxiv updated 2017/08/23 · openalex updated_date 2026/08/05
The LHCb collaboration has recently performed a measurement of the production rate of inclusive B hadron production (pp → BX) at both 7 and 13 TeV centre-of-mass (CoM) energies. As part of this measurement, the ratio of these two cross section measurements has been presented differentially in B hadron pseudorapidity within the range of η B ∈ [2.0, 5.0]. A large tension (4σ) is observed for the ratio measurement in the lower pseudorapidity range of η B ∈ [2.0, 3.0], where the data is observed to exceed theoretical predictions, while consistency is found at larger η B values. This behaviour is not expected within perturbative QCD, and can only be achieved by introducing ad-hoc features into the structure of the non-perturbative gluon PDF within the region of x ∈ [10−3 , 10−4]. Specifically, the gluon PDF must grow extremely quickly with decreasing x within this kinematic range, closely followed by a period of decelerated growth. However, such behaviour is highly disfavoured by global fits of proton structure. Further studies of the available LHCb B and D hadron cross section data, available for a range of CoM energies, indicate systematic tension in the (pseudo)rapidity region of [2.0, 2.5].