# Dark Matter @ LHC 2019 (DM@LHC)

13-16 August 2019
Kane Hall 225
US/Pacific timezone

## [YSF] Search for the compressed SUSY in stau-neutralino coannihilation region with a soft tau lepton and ISR jets

14 Aug 2019, 15:15
10m
Walker-Ames (Kane Hall 225)

### Walker-Ames

#### Kane Hall 225

Young Scientist Forum

### Speaker

Savanna Rae Starko (Vanderbilt University (US))

### Description

A search for compressed supersymmetry in the stau-neutralino ($\tilde{\tau}\tilde{\chi}^{0}_{1}$) coannihilation region is presented. The search targets final states with exactly one low-energy (soft'') hadronically-decaying $\tau$ lepton and large missing transverse momentum ($\vec{E}^{miss}_{T}$) due to the natural kinematic boost from a high transverse momentum jet from initial state radiation (ISR). The data sample corresponds to an integrated luminosity of 77.2 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} = 13$ TeV collected with CMS detector at the CERN LHC in 2016 and 2017. The distribution of the transverse mass between the $\tau_{h}$ and the $\vec{E}^{miss}_{T}$ is found to be consistent with the standard model predictions. Upper limits are set on the cross section for chargino ($\tilde{\chi}^{\pm}_{1}$) and neutralino ($\tilde\chi^{0}_{2}$) production with an associated ISR jet. For a compressed mass spectrum scenario in which the mass difference between the $\tilde{\chi}^{0}_{1}$ and the $\tilde{\chi}^{\pm}_{1}$ is 50 GeV, an upper limit of 290 GeV is set on the mass of the $\tilde\chi^{\pm}_{1}$, which exceeds the sensitivity obtained by other $\tilde{\tau}$ searches to date. Finally, the results are also interpreted considering direct production of $\tilde{\tau}$ pairs with associated ISR jets.

### Primary authors

Alfredo Gurrola (Vanderbilt University (US)) Andrew Malone Melo (Vanderbilt University (US)) Carlos Andres Florez Bustos (Universidad de los Andes (CO)) Klaas Padeken (Vanderbilt University (US)) Manuel Alejandro Segura Delgado (Universidad de los Andes (CO)) Paul Sheldon (Vanderbilt University (US)) Savanna Rae Starko (Vanderbilt University (US)) Teruki Kamon (Texas A & M University (US)) Willard Johns (Vanderbilt University (US))