= Solution
<supersymmetry> pairs bosonic and fermionic degrees of freedom; broken <supersymmetry> permits partners heavier than known particles. At the <Large Hadron Collider>, strong production of <squarks> and <gluinos> is an important channel. If <R-parity> is conserved, partners are produced in pairs and their cascades end in a stable <lightest supersymmetric particle>. A neutral weakly interacting <lightest supersymmetric particle> escapes, giving <missing transverse momentum> together with jets and possibly <leptons>. Conservation is tested transversely because the initial <parton> longitudinal momenta are unknown.
The experimental observable is
$$
\boldsymbol p_T^{\rm miss}=-\sum_{\rm reconstructed}\boldsymbol p_T.
$$
<neutrinos> produce genuine <missing transverse momentum>, and <calorimeter> mismeasurement or detector defects can imitate it. Searches use jet multiplicity, transverse momenta, missing <momentum>, angular separation cuts and a <collider effective mass> such as $m_{\rm eff}=p_T^{\rm miss}+\sum p_T^{\rm jet}$. Isolated-lepton selections explore complementary cascades. Trigger efficiency, jet <energy> scale, <collision pileup> and event cleaning affect acceptance.
A credible search estimates backgrounds from <particle-physics control regions> before inspecting the <signal region>. Invisible $Z\to\nu\bar\nu$ plus jets can be constrained using photon-plus-jets or visible $Z\to\ell^+\ell^-$ samples with <control-region transfer factors>. Lepton-enriched samples constrain $W$ and top backgrounds with lost <leptons>; multijet samples constrain fake missing <momentum>. A joint <likelihood> includes these observations and <nuisance parameters> for <systematic uncertainties>. Agreement with background gives upper bounds on signal rate and conditional <mass> exclusions. The pre-examination ATLAS 7 TeV analysis is a concrete example of this strategy and reported no significant excess.<Search for squarks and gluinos with the ATLAS detector in final states with jets and missing transverse momentum using 4.7 fb^-1 of sqrt(s) = 7 TeV proton-proton collision data by ATLAS Collaboration>[Sections III, IX and XI, control-region likelihood and background estimates; abstract for the null result]{ref}
Electroweak production motivates multilepton searches; compressed spectra can give soft visible decay products and require special selections such as recoil against <initial-state radiation>. <R-parity> violation can instead remove the stable missing-particle signature, requiring other searches. \b[An exclusion always depends on <masses>, <branching fractions>, production rates and decay assumptions; a null jets-plus-missing-momentum result does not exclude <supersymmetry> as a whole.]
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