Paper
Understanding forward $B$ hadron production
Authors
Abstract
The LHCb collaboration has recently performed a measurement of the production rate of inclusive hadron production () 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 hadron pseudorapidity within the range of . A large tension () is observed for the ratio measurement in the lower pseudorapidity range of , where the data is observed to exceed theoretical predictions, while consistency is found at larger 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 . Specifically, the gluon PDF must grow extremely quickly with decreasing within this kinematic range, closely followed by a period of decelerated growth. However, such behaviour is highly disfavoured by global fits to proton structure. Further studies of the available LHCb and hadron cross section data, available for a range of CoM energies, indicate systematic tension in the (pseudo)rapidity region of .