LEP/TEV EW WG Plots for Winter 2012
Latest corrections and/or modifications 02-March-2012.
You can find here the plots that have been updated for the Winter
2012 conferences (March and beyond).
Most results are final, such as the Z-pole
measurements from SLD and at LEP. The LEP-2 results on the mass and
width of the W boson are final but their combination is still
preliminary.
Changes:
All fits on which all plots posted here are based, include the
electroweak precision measurements made by SLD and LEP-1 in
electron-positron collisions at the Z pole, described in the final Z-pole paper. Compared to the final Z-pole paper, the updated input
measurements are:
- hadronic vacuum polarisation (exp. driven, updated for winter 2011)
- mass of the top quark from the Tevatron (updated for summer 2011:
final Run-I results and published and preliminary Run-II results)
- mass and width of the W boson from the Tevatron (updated for
winter 2012: final Run-I results and published and preliminary Run-II
results)
- mass and width of the W boson from LEP-2 (updated for summer
2006: final results from Aleph, Delphi, L3, Opal, but preliminary
combination)
Version 6.43 of ZFITTER is used for SM calculations, fixing a small bug
w.r.t. 6.42 used previously.
Attention:
Since winter 2004, the global SM fits now use only
high-Q2 results from LEP, SLC and the Tevatron (together with the
hadronic vacuum polarisation). This disentangles the numerical
Higgs-mass constraint and limit from the issue of the high chi2 caused
by the low-Q2 NuTeV measurement which, however, has only a small
influence on the fitted Higgs mass. Based on these high-Q2 analyses,
predictions for low-Q2 measurements such as atomic parity violation in
cesium (APV), parity violation in Moller scattering (e-e-), and
neutrino-nucleon scattering (NuTeV) are derived.
Answers to FAQs on plots presented below:
- Only updated plots are collected on this page.
- While the measurements of W mass and W width of all four LEP
experiments are now final and used in the combination, the LEP
combination itself is still preliminary as it uses a preliminary LEP-2
combined estimate for the effect of color reconnection.
- For plots showing generic SM predictions in form of arrows or areas,
the following parametric variations are used:
dal5had = 0.02750(33),
alpha_s = 0.118(3),
MZ = 91187.5(2.1) MeV,
M_top = 173.2(0.9) GeV,
M_Higgs = 300+700-186 GeV (lower limit of 114 GeV as given by the
direct search). The arrows are pointing in the
direction of increasing parameter values!
For plots showing exclusions based on direct searches, the excluded band
corresponds to the July 2011 Tevatron combination (156-177 GeV) and
the December 2011 LHC exclusion (127-600 GeV, CMS).
- Higgs constraint from each measurement:
- For each observable, the corresponding constraint on the
Higgs mass is determined in a full MSM fit to the measurement
result of this observable, constraining
dal5had=0.02750+-0.00033, alpha_s=0.118+-0.003, MZ =
91.1875+-0.0021 GeV and M_top=173.2+-0.9 GeV.
- For Higgs masses larger than about 1 TeV, the MSM and its
formulae used do not make too much sense, so that part of
the Higgs mass regime is cut of as it should not be taken
quantitatively.
- The vertical green band denotes the overall constraint on the
Higgs mass derived from the fit to all data.
- The vertical black line denotes the limit on the Higgs mass
obtained from the direct search at LEP-2.
- The effects of real Higgs-strahlung, Z*+H, is not taken into
account, neither in the experimental analyses (such as
Higgs-mass dependent efficiencies for various Z*H decay
channels) nor in the calculation of MSM predictions (increased
Z decay widths). Thus quantitative conclusions from individual
observables are uncertain in the low Higgs-mass regime.
Enjoy!
Preliminary LEP-2 W mass and width:
Unchanged w.r.t. summer 2006
Input measurements as published:
mw_qqln_pub.eps - mw_qqln_pub.pdf
mw_qqqq_pub.eps - mw_qqqq_pub.pdf
mw_ffff_pub.eps - mw_ffff_pub.pdf
gw_ffff_pub.eps - gw_ffff_pub.pdf
Input measurements with common but preliminary FSI uncertainties:
mw_qqln_com.eps - mw_qqln_com.pdf
mw_qqqq_com.eps - mw_qqqq_com.pdf
mw_ffff_com.eps - mw_ffff_com.pdf
gw_ffff_com.eps - gw_ffff_com.pdf
Preliminary constraints on the Standard Model:
Updated for new results from the Tevatron experiments!
w12_plot_mt.eps - w12_plot_mt.pdf
w12_plot_mw.eps - w12_plot_mw.pdf
w12_plot_gw.eps - w12_plot_gw.pdf
w12_gl_s2_contours.eps - w12_gl_s2_contours.pdf
w12_mh_mt_contours.eps - w12_mh_mt_contours.pdf
w12_mh_mw_contours.eps - w12_mh_mw_contours.pdf
w12_mt_mw_contours.eps - w12_mt_mw_contours.pdf
w12_show_higgs.eps - w12_show_higgs.pdf
w12_show_pull_18.eps - w12_show_pull_18.pdf
w12_blueband.eps - w12_blueband.pdf