scholarly journals Correlation of theoretical uncertainties in PDF fits and theoretical uncertainties in predictions

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Richard D. Ball ◽  
Rosalyn L. Pearson
Keyword(s):  
Distribution Function ◽  
Total Cross Section ◽  
Cross Section ◽  
Parton Distribution ◽  
Parton Distribution Function ◽  
Higher Order ◽  
Central Values ◽  
Accuracy And Precision ◽  
Rapidity Distributions

AbstractWe show how to account for correlations between theoretical uncertainties incorporated in parton distribution function (PDF) fits, and the theoretical uncertainties in the predictions made using these PDFs. We demonstrate by explicit calculations, both analytical and numerical, that these correlations can lead to corrections to the central values of the predictions, and reductions in both the PDF uncertainties and the theoretical uncertainties in the prediction. We illustrate our results with predictions for top production rapidity distributions and the Higgs total cross-section at the LHC, using the NLO NNPDF3.1 PDF set which incorporates missing higher order uncertainties. We conclude that the inclusion of correlations can increase both the accuracy and precision of predictions involving PDFs, particularly for processes with data already included in the PDF fit.

scholarly journals Resummed Drell-Yan cross-section at N3LL

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
A. H. Ajjath ◽  
Goutam Das ◽  
M. C. Kumar ◽  
Pooja Mukherjee ◽  
V. Ravindran ◽  
...  
Keyword(s):  
Distribution Function ◽  
Cross Section ◽  
Parton Distribution ◽  
Parton Distribution Function ◽  
Vector Boson ◽  
Inclusive Cross Section ◽  
Leading Order ◽  
Neutral Vector ◽  
Fixed Order ◽  
Standard Techniques

Abstract We present the resummed predictions for inclusive cross-section for Drell-Yan (DY) production as well as onshell Z, W± productions at next-to-next-to-next-to leading logarithmic (N3LL) accuracy. Using the standard techniques, we derive the N-dependent coefficients in the Mellin-N space as well as the N-independent constants and match the resummed result through the minimal prescription procedure with the fixed order results. In addition to the standard ln N exponentiation, we study the numerical impacts of exponentiating N-independent part of the soft function and the complete $$ {\overline{g}}_0 $$ g ¯ 0 that appears in the resummed predictions in N space. All the analytical pieces needed in these different approaches are extracted from the soft-virtual part of the inclusive cross section known to next-to-next-to-next-to leading order (N3LO). We perform a detailed analysis on the scale and parton distribution function (PDF) variations and present predictions for 13 TeV LHC for the neutral Drell-Yan process as well as onshell charged and neutral vector boson productions.

scholarly journals Updating and optimizing error parton distribution function sets in the Hessian approach. II.

2019 ◽  
Vol 100 (11) ◽  
Author(s):  
Tie-Jiun Hou ◽  
Zhite Yu ◽  
Sayipjamal Dulat ◽  
Carl Schmidt ◽  
C.-P. Yuan
Keyword(s):  
Distribution Function ◽  
Parton Distribution ◽  
Parton Distribution Function

scholarly journals Measurement of the W boson mass

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
◽  
R. Aaij ◽  
A. S. W. Abdelmotteleb ◽  
C. Abellán Beteta ◽  
T. Ackernley ◽  
...  
Keyword(s):  
Distribution Function ◽  
Parton Distribution ◽  
W Boson ◽  
Parton Distribution Function ◽  
Boson Mass ◽  
Proton Collision ◽  
Proton Proton ◽  
Lhcb Experiment ◽  
Proton Proton Collision ◽  
Pm 10

Abstract The W boson mass is measured using proton-proton collision data at $$ \sqrt{s} $$ s = 13 TeV corresponding to an integrated luminosity of 1.7 fb−1 recorded during 2016 by the LHCb experiment. With a simultaneous fit of the muon q/pT distribution of a sample of W → μν decays and the ϕ* distribution of a sample of Z → μμ decays the W boson mass is determined to be$$ {m}_w=80354\pm {23}_{\mathrm{stat}}\pm {10}_{\mathrm{exp}}\pm {17}_{\mathrm{theory}}\pm {9}_{\mathrm{PDF}}\mathrm{MeV}, $$ m w = 80354 ± 23 stat ± 10 exp ± 17 theory ± 9 PDF MeV , where uncertainties correspond to contributions from statistical, experimental systematic, theoretical and parton distribution function sources. This is an average of results based on three recent global parton distribution function sets. The measurement agrees well with the prediction of the global electroweak fit and with previous measurements.

scholarly journals Transverse momentum-dependent parton distributions of pion in the light-front holographic model

2021 ◽  
Vol 36 (08n09) ◽  
pp. 2150052
Author(s):  
Navdeep Kaur ◽  
Harleen Dahiya
Keyword(s):  
Experimental Data ◽  
Distribution Function ◽  
Transverse Momentum ◽  
Parton Distribution ◽  
Parton Distribution Function ◽  
Light Front ◽  
Holographic Model ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Mulders Function

Using the light-front holographic model, we study the transverse momentum-dependent parton distributions (TMDs) for the case of pion. At leading twist, the unpolarized parton distribution function [Formula: see text] and the Boer–Mulders function [Formula: see text] are obtained for pion. We calculate both the functions using the light-front holographic model with spin improved wave function and compare the predicted results with available results of other models. In order to provide inputs in predicting future experimental data, an LO evolution is performed from model scale to experimental scale for the case of unpolarized parton distribution function [Formula: see text].

scholarly journals New method for reducing parton distribution function uncertainties in the high-mass Drell-Yan spectrum

2019 ◽  
Vol 99 (5) ◽  
Author(s):  
C. G. Willis ◽  
R. Brock ◽  
D. Hayden ◽  
T.-J. Hou ◽  
J. Isaacson ◽  
...  
Keyword(s):  
Distribution Function ◽  
Parton Distribution ◽  
Parton Distribution Function ◽  
New Method ◽  
High Mass
Sign in / Sign up

Export Citation Format

Share Document