Hunting quasidegenerate Higgsinos

By Zhenyu Han, G. Kribs, Adam Martin, A. Menon. 2014

157 citations recorded by the source corpus.

We present a new strategy to uncover light, quasidegenerate Higgsinos, a likely ingredient in a natural supersymmetric model. Our strategy focuses on Higgsinos with interstate splittings of $O(5\ensuremath{-}50)\text{ }\text{ }\mathrm{GeV}$ that are produced in association with a hard, initial-state jet and decay via off-shell gauge bosons to two or more leptons and missing energy, $pp\ensuremath{\rightarrow}j+{\overline{)E}}_{T}+{2}^{+}\ensuremath{\ell}$. The additional jet is used for triggering, allowing us to significantly loosen the lepton requirements and gain sensitivity to small inter-Higgsino splittings. Focusing on the two-lepton signal, we find the seemingly large backgrounds from diboson plus jet, $\overline{t}t$ and $Z/{\ensuremath{\gamma}}^{*}+j$ can be reduced with careful cuts, and that fake backgrounds appear minor. For Higgsino masses ${m}_{\ensuremath{\chi}}$ just above the current LEP II bound ($\ensuremath{\mu}\ensuremath{\simeq}110\text{ }\text{ }\mathrm{GeV}$) we find the significance can be as high as $3\ensuremath{\sigma}$ at the LHC using the existing $20\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of 8 TeV data. Extrapolating to LHC at 14 TeV with $100\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ of data, and as one example ${M}_{1}={M}_{2}=500\text{ }\text{ }\mathrm{GeV}$, we find $5\ensuremath{\sigma}$ evidence for ${m}_{\ensuremath{\chi}}\ensuremath{\lesssim}140\text{ }\text{ }\mathrm{GeV}$ and $2\ensuremath{\sigma}$ evidence for ${m}_{\ensuremath{\chi}}\ensuremath{\lesssim}200\text{ }\text{ }\mathrm{GeV}$. We also present a reinterpretation of ATLAS/CMS monojet bounds in terms of degenerate Higgsino ($\ensuremath{\delta}{m}_{\ensuremath{\chi}}\ensuremath{\ll}5\text{ }\text{ }\mathrm{GeV}$) plus jet production. We find the current monojet bounds on ${m}_{\ensuremath{\chi}}$ are no better than the chargino bounds from LEP II.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/796f04cd9361a7eba2682fd7bddeb0ee9f56d13e

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

  1. Atlas Collaboration

In Nuclear and High Energy Physics

  1. Atlas Collaboration
  2. Cms Collaboration
  3. K. Tobe
  4. Syuhei Iguro
  5. A. Vladimirov
  6. I. Scimemi

Citations in the corpus