Coarse-grained binning in Drell-Yan transverse momentum spectra

We report a study of the determination of the intrinsic transverse momentum of partons, the intrinsic <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msub><a:mi>k</a:mi><a:mi>T</a:mi></a:msub></a:math>, from the dilepton transverse momentum <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msub><c:mi>p</c:mi><c:mi>T</c:mi></c:msub></c:math> in Drell-Yan (DY) production at hadron colliders. The result shows that a good sensitivity to the intrinsic <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msub><e:mi>k</e:mi><e:mi>T</e:mi></e:msub></e:math> distribution is achieved by measuring relative ratios between the cross sections of suitably defined low-<g:math xmlns:g="http://www.w3.org/1998/Math/MathML" display="inline"><g:msub><g:mi>p</g:mi><g:mi>T</g:mi></g:msub></g:math> and high-<i:math xmlns:i="http://www.w3.org/1998/Math/MathML" display="inline"><i:msub><i:mi>p</i:mi><i:mi>T</i:mi></i:msub></i:math> regions. The study is performed through both a pseudodata test and an extraction from measurements of the DY process by the CMS Collaboration. Since the methodology does not rely on any dedicated partition of bins, this <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"><k:msub><k:mi>p</k:mi><k:mi>T</k:mi></k:msub></k:math>-ratio observable requires less special treatment in very low <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" display="inline"><m:msub><m:mi>p</m:mi><m:mi>T</m:mi></m:msub></m:math> regions and propagates lower systematic uncertainties induced from unfolding or momentum migration, in contrast with previous proposals of using a fine-binning measurement of the differential cross section.