| 1 |
benhoob |
1.1 |
\section{Introduction}
|
| 2 |
|
|
\label{sec:intro}
|
| 3 |
|
|
|
| 4 |
|
|
Supersymmetry (SUSY) is a popular extension to the standard model (SM) of particle physics, which may explain
|
| 5 |
|
|
the 16 orders of magnitude difference between the electroweak and Planck scales (hierarchy problem), introduce
|
| 6 |
|
|
a natural candidate for the dark matter weakly-interacting massive particle (WIMP), and lead to the unification of
|
| 7 |
benhoob |
1.2 |
gauge couplings.
|
| 8 |
|
|
In order to solve the hierarchy problem without fine-tuning, SUSY must introduce
|
| 9 |
|
|
light top and bottom squarks, the SUSY partners of the top and bottom quarks~\cite{ref:naturalsusy}.
|
| 10 |
benhoob |
1.1 |
If R-parity is conserved, the lightest SUSY particle (LSP),
|
| 11 |
|
|
usually the lightest neutralino \lsp, is a stable WIMP. If produced in pp collisions this
|
| 12 |
|
|
particle carries away undetected energy and leads to large missing transverse energy (\met).
|
| 13 |
benhoob |
1.2 |
In this note we present the results of searches for top and bottom squarks in final states with \met,
|
| 14 |
|
|
using data collected by the Compact Muon Solenoid (CMS)~\cite{ref:CMS} detector at the
|
| 15 |
|
|
Large Hadron Collider (LHC). The data was collected at a center-of-mass energy $\sqrt{s}=8$~TeV in 2012
|
| 16 |
benhoob |
1.1 |
and corresponds to an integrated luminosity of approximately 10~fb$^{-1}$.
|
| 17 |
|
|
|
| 18 |
|
|
\begin{figure*}
|
| 19 |
benhoob |
1.2 |
\begin{center}
|
| 20 |
|
|
\subfloat[] {
|
| 21 |
|
|
\includegraphics[width=0.35\textwidth]{HCPPlots/T2tt.pdf}
|
| 22 |
|
|
}\quad
|
| 23 |
|
|
\subfloat[] {
|
| 24 |
|
|
\includegraphics[width=0.35\textwidth]{HCPPlots/T2bw.pdf}
|
| 25 |
|
|
}\quad
|
| 26 |
|
|
\subfloat[] {
|
| 27 |
|
|
\includegraphics[width=0.35\textwidth]{HCPPlots/T2bb.pdf}
|
| 28 |
|
|
}
|
| 29 |
|
|
\subfloat[] {
|
| 30 |
|
|
\includegraphics[width=0.35\textwidth]{HCPPlots/T2ttww.pdf}
|
| 31 |
|
|
}
|
| 32 |
|
|
\caption{Example topologies with direct pair production of top (a,b) and bottom (b,c) squarks.
|
| 33 |
benhoob |
1.1 |
\label{fig:diagrams}
|
| 34 |
|
|
}
|
| 35 |
benhoob |
1.2 |
\end{center}
|
| 36 |
benhoob |
1.1 |
\end{figure*}
|
| 37 |
|
|
|
| 38 |
|
|
|
| 39 |
|
|
%\begin{figure*}
|
| 40 |
|
|
%\centering
|
| 41 |
|
|
%\includegraphics[width=1cm,clip]{HCPPlots/T2tt.pdf}
|
| 42 |
|
|
%% Use the relevant command for your figure-insertion program
|
| 43 |
|
|
%% to insert the figure file. See example above.
|
| 44 |
|
|
%% If not, use
|
| 45 |
|
|
%\vspace*{5cm} % Give the correct figure height in cm
|
| 46 |
|
|
%\caption{Please write your figure caption here}
|
| 47 |
|
|
%\label{fig:diagrams} % Give a unique label
|
| 48 |
|
|
%\end{figure*}
|
| 49 |
|
|
|
| 50 |
|
|
Top and bottom squarks may either be produced directly in pairs
|
| 51 |
benhoob |
1.2 |
(direct pair production) or in the decays of heavier SUSY particles such as the gluino (gluino-mediated squark production).
|
| 52 |
|
|
In this note we focus on searches for the direct pair production mode.
|
| 53 |
benhoob |
1.1 |
Examples of such processes are indicated in Fig.~\ref{fig:diagrams}.
|
| 54 |
|
|
The production of these particles may lead to excesses above the SM background expectations in several final states,
|
| 55 |
|
|
depending on the mass hierarchy of the SUSY particles.
|
| 56 |
|
|
Here we report the results from three searches which focus on the single lepton final state using the transverse
|
| 57 |
|
|
mass~\cite{ref:stop}, the same-sign dilepton final state~\cite{ref:ss}, and the all-hadronic final state~\cite{ref:alphat}.
|
| 58 |
|
|
|
