Observation of associated production of a Z boson with a D meson in the forward region

The paper is available here.

arXiv: 1401.3245


A search for associated production of a Z boson with an open charm meson is presented using a data sample, corresponding to an integrated luminosity of 1.0 fb−1 of proton–proton collisions at a centre-of-mass energy of 7 TeV, collected by the LHCb experiment. Seven candidate events for associated production of a Z boson with a D0 meson and four candidate events for a Z boson with a D+ meson are observed with a combined significance of 5.1 standard deviations. The production cross-sections in the forward region are measured to be

σZ→μ+ μ−,D0 = 2.50 ± 1.12 ± 0.22 pb

σZ→μ+ μ−,D+ = 0.44 ± 0.23 ± 0.03 pb,

where the first uncertainty is statistical and the second systematic.


(pdf and eps versions are available under attachments).

Caption Figure
Figure 1: Invariant mass distribution for Z (left) and D (right) candidates for Z + D0 (top) and Z + D+ (bottom) events. The superimposed curves represent the projection of the fit described in Sect. 4. Fig1a.png
Figure 1 top right Fig1b.png
Figure 1 bottom left Fig1c.png
Figure 1 bottom right Fig1d.png
Figure 2: Invariant mass of the Z and D0 (left) and Z and D+ (right) candidates (shown as black dots) compared to the fit (see text) that was used to extract the combinatorial background. The fit shown includes the signal and the background components. The colour scale shows the PDF value at any given point. Fig2a.png Fig2b.png
Supplementary: Graphical comparison to theory predictions. The Ds+and Λc+ states were searched for in the decay channels Ds → φ(→ K K )π and Λc → pK π with no observed candidates. The measured cross-section is expected to be the sum of SPS and DPS. Fig3.png

-- KatharinaMueller - 15 Jan 2014

Topic attachments
I Attachment History Action Size Date Who Comment
Unknown file formateps Fig1a.eps r1 manage 8.5 K 2014-01-15 - 11:26 KatharinaMueller  
PDFpdf Fig1a.pdf r1 manage 14.3 K 2014-01-15 - 11:26 KatharinaMueller  
PNGpng Fig1a.png r1 manage 10.5 K 2014-01-15 - 11:26 KatharinaMueller  
Unknown file formateps Fig1b.eps r1 manage 8.0 K 2014-01-15 - 11:26 KatharinaMueller  
PDFpdf Fig1b.pdf r1 manage 14.1 K 2014-01-15 - 11:26 KatharinaMueller  
PNGpng Fig1b.png r1 manage 10.4 K 2014-01-15 - 11:26 KatharinaMueller  
Unknown file formateps Fig1c.eps r1 manage 8.6 K 2014-01-15 - 11:26 KatharinaMueller  
PNGpng Fig1c.png r1 manage 10.4 K 2014-01-15 - 11:29 KatharinaMueller  
Unknown file formateps Fig1d.eps r1 manage 8.4 K 2014-01-15 - 11:29 KatharinaMueller  
PDFpdf Fig1d.pdf r1 manage 14.1 K 2014-01-15 - 11:29 KatharinaMueller  
PNGpng Fig1d.png r1 manage 10.2 K 2014-01-15 - 11:29 KatharinaMueller  
Unknown file formateps Fig2a.eps r1 manage 467.8 K 2014-01-15 - 11:29 KatharinaMueller  
PDFpdf Fig2a.pdf r1 manage 126.0 K 2014-01-15 - 11:29 KatharinaMueller  
PNGpng Fig2a.png r1 manage 36.2 K 2014-01-15 - 11:29 KatharinaMueller  
Unknown file formateps Fig2b.eps r1 manage 467.3 K 2014-01-15 - 11:29 KatharinaMueller  
PDFpdf Fig2b.pdf r1 manage 128.9 K 2014-01-15 - 11:29 KatharinaMueller  
PNGpng Fig2b.png r1 manage 35.1 K 2014-01-15 - 11:29 KatharinaMueller  
Unknown file formateps Fig3.eps r1 manage 14.6 K 2014-01-15 - 11:31 KatharinaMueller  
PDFpdf Fig3.pdf r1 manage 15.3 K 2014-01-15 - 11:31 KatharinaMueller  
PNGpng Fig3.png r1 manage 8.4 K 2014-01-15 - 11:31 KatharinaMueller  

This topic: LHCb > LHCbQEEPublicResults > ZplusD11
Topic revision: r2 - 2014-01-16 - KatharinaMueller
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