Reweighting NNPDFs : the W lepton asymmetry

By T. Ball, Valerio Bertone, F. Cerutti, Luigi Del Debbio, S. Forte, Alberto Guffanti, José I. Latorre, Juan Rojo, M. Ubiali. 2010

156 citations recorded by the source corpus.

We present a method for incorporating the information contained in new datasets into an existing set of parton distribution functions without the need for refitting. The method involves reweighting the ensemble of parton densities through the computation of the chi-square to the new dataset. We explain how reweighting may be used to assess the impact of any new data or pseudodata on parton densities and thus on their predictions. We show that the method works by considering the addition of inclusive jet data to a DIS+DY fit, and comparing to the refitted distribution. We then use reweighting to determine the impact of recent high statistics lepton asymmetry data from the D0 experiment on the NNPDF2.0 parton set. We find that the D0 inclusive muon and electron data are perfectly compatible with the rest of the data included in the NNPDF2.0 analysis and impose additional constraints on the large-x d/u ratio. The more exclusive D0 electron datasets are however inconsistent both with the other datasets and among themselves, suggesting that here the experimental uncertainties have been underestimated.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/a5bd6731254e2e2b9b79952b0e084b84c9193199

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Nuclear and High Energy Physics

Citations in the corpus

Combined SMEFT interpretation of Higgs, diboson, and top quark data from the LHC (2021, methodology): “In doing so, we also evaluate the uncertainty associated to the input PDFs and their correlations, as discussed in Ref.”
A facility to Search for Hidden Particles (SHiP) at the CERN SPS (2015, unknown): “[226, 227].”
The Structure of the Proton in the LHC Precision Era (2017, methodology): “These two methods go under the name of the Bayesian reweighting of MC replicas [444, 445] and the profiling of Hessian sets [446].”
Parton distribution benchmarking with LHC data (2012, methodology): “[18] it is shown that once the LHC W asymmetry data is included in MSTW08 using PDF reweighting [66, 67], the fit quality improves substantially.”