Compact Muon Solenoid
LHC, CERN
Visit us: CMS Public Website, CMS Physics ;
Contact us: CMS Publications Committee
| CMS-PAS-EXO-15-005 | ||
| Search for a narrow resonance produced in 13 TeV pp collisions decaying to electron pair or muon pair final states | ||
| CMS Collaboration | ||
| December 2015 | ||
| Abstract: A search for a new narrow resonance decaying to an electron pair or a muon pair is performed using 13 TeV pp collision data collected by the CMS experiment at the CERN LHC. The electron event sample used corresponds to an integrated luminosity of 2.6 fb$^{-1}$ while the muon event sample used corresponds to an integrated luminosity of 2.8 fb$^{-1}$. No evidence for such a resonance is observed and limits are set at the 95\% confidence level on a new massive narrow spin 1 boson decaying into electron or muon pairs. These limits exclude a sequential standard model $\mathrm{ Z}^\prime_\mathrm{SSM}$ resonance with a mass lighter than 3.15 TeV and superstring-inspired $\mathrm{Z}^\prime_{\psi}$ with a mass lighter than 2.60 TeV. | ||
|
Links:
CDS record (PDF) ;
CADI line (restricted) ;
These preliminary results are superseded in this paper, PLB 768 (2017) 57. |
||
| Figures | |
png ; pdf ; |
Figure 1-a:
The invariant mass spectrum of $\mu^+ \mu^- $ (a) and $ \mathrm{ee} $ (b) events. The points with error bars represent the data. The histograms represent the expectations from standard model processes: $\mathrm{Z /\gamma ^*} $, $\mathrm{ t \bar{t} } $ and other sources of prompt leptons ($ \mathrm{ t W } $, diboson production, $\mathrm{ Z \rightarrow \tau \tau } $), and the multijet backgrounds. Multijet backgrounds contain at least one jet that has been misreconstructed as a lepton. The Monte Carlo simulated backgrounds are normalised to the data in the region of 60 $ < m_{\ell \ell } < $ 120 GeV, with the muon channel using events collected using a prescaled lower threshold trigger for this purpose. |
png ; pdf ; |
Figure 1-b:
The invariant mass spectrum of $\mu^+ \mu^- $ (a) and $ \mathrm{ee} $ (b) events. The points with error bars represent the data. The histograms represent the expectations from standard model processes: $\mathrm{Z /\gamma ^*} $, $\mathrm{ t \bar{t} } $ and other sources of prompt leptons ($ \mathrm{ t W } $, diboson production, $\mathrm{ Z \rightarrow \tau \tau } $), and the multijet backgrounds. Multijet backgrounds contain at least one jet that has been misreconstructed as a lepton. The Monte Carlo simulated backgrounds are normalised to the data in the region of 60 $ < m_{\ell \ell } < $ 120 GeV, with the muon channel using events collected using a prescaled lower threshold trigger for this purpose. |
png ; pdf ; |
Figure 2-a:
The invariant mass spectrum for $ \mathrm{ee} $ events split into barrel-barrel (a) and barrel-endcap (b) categories. The points with error bars represent the data. The histograms represent the expectations from standard model processes: $\mathrm{ Z / \gamma ^* }$, $ \mathrm{ t \bar{t} } $ and other sources of prompt leptons ($ \mathrm{ t W} $, diboson production, $\mathrm{ Z \rightarrow \tau \tau } $), and the multijet backgrounds. Multijet backgrounds contain at least one jet that has been misreconstructed as a lepton. The Monte Carlo simulated backgrounds are normalised to the data in the region of 60 $ < m_{\mathrm{ee}}< $ 120 GeV. |
png ; pdf ; |
Figure 2-b:
The invariant mass spectrum for $ \mathrm{ee} $ events split into barrel-barrel (a) and barrel-endcap (b) categories. The points with error bars represent the data. The histograms represent the expectations from standard model processes: $\mathrm{ Z / \gamma ^* }$, $ \mathrm{ t \bar{t} } $ and other sources of prompt leptons ($ \mathrm{ t W} $, diboson production, $\mathrm{ Z \rightarrow \tau \tau } $), and the multijet backgrounds. Multijet backgrounds contain at least one jet that has been misreconstructed as a lepton. The Monte Carlo simulated backgrounds are normalised to the data in the region of 60 $ < m_{\mathrm{ee}}< $ 120 GeV. |
png ; pdf ; |
Figure 3-a:
The observed limits obtained at a 95% confidence level on the cross section for Z's of various widths for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. The cross sections do not include contributions from PDF and interference events. |
png ; pdf ; |
Figure 3-b:
The observed limits obtained at a 95% confidence level on the cross section for Z's of various widths for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. The cross sections do not include contributions from PDF and interference events. |
png ; pdf ; |
Figure 3-c:
The observed limits obtained at a 95% confidence level on the cross section for Z's of various widths for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. The cross sections do not include contributions from PDF and interference events. |
png ; pdf ; |
Figure 4-a:
The observed limits obtained at the 95% confidence level on the on-shell cross section for a narrow Z' modelled by a Breit-Wigner function with width 0.6% for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. |
png ; pdf ; |
Figure 4-b:
The observed limits obtained at the 95% confidence level on the on-shell cross section for a narrow Z' modelled by a Breit-Wigner function with width 0.6% for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. |
png ; pdf ; |
Figure 4-c:
The observed limits obtained at the 95% confidence level on the on-shell cross section for a narrow Z' modelled by a Breit-Wigner function with width 0.6% for the electron channel (a), muon channel (b) and the muon and electron channels combined (c). The expected limits are also shown. |
|
|
Compact Muon Solenoid LHC, CERN |
|
|
|
|
|
|