Search for compressed electroweak SUSY production in final states with two τ-leptons in √s = 13 and $13.6$ TeV pp collisions with the ATLAS detector

@misc{aad2026search,
  title = {{Search for compressed electroweak SUSY production in final states with two $τ$-leptons in $\sqrts = 13$ and $13.6$ TeV $pp$ collisions with the ATLAS detector}},
  author = {Georges Aad and Erlend Aakvaag and Braden Keim Abbott and Sara Abdelhameed and Kira Abeling and Nils Julius Abicht and Haider Abidi and Mohammed Aboelela and Asmaa Aboulhorma and Halina Abramowicz and Bobby Samir Acharya and Anke Ackermann and Jona Ackerschott and Claire Adam Bourdarios and Leszek Adamczyk and Sagar Addepalli and Matt Addison and Jahred Adelman and Habeeb Adenle and Aytul Adiguzel and Tim Adye and Tony Affolder and Yoav Afik and Merve Nazlim Agaras and Anamika Aggarwal and Catalin Agheorghiesei and Ammara Ahmad and Faig Ahmadov and Sonakshi Ahuja and Xiaocong Ai and Giulio Aielli and Arya Aikot and Malak Ait Tamlihat and Torsten Akesson and Daiya Akiyama and Sina Aktas and Gian Luigi Alberghi and Justin Albert and Una Helena Alberti and Pietro Albicocco and Sara Alderweireldt and Zackary Lee Alegria and Martin Aleksa and Igor Alexandrov and Calin Alexa and Theodoros Alexopoulos and Fabrizio Alfonsi and Malte Algren and Muhammad Alhroob and Babar Ali and Hanadi Ali and Shahzad Ali and Samuel William Alibocus and Malik Aliev and Gianluca Alimonti and Corentin Allaire and Benedict Allbrooke and Derrick Allen and Jonny Allen and Camron Stephen Alley},
  howpublished = {HAL},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.37215},
  eprint = {2609.37215},
  archivePrefix = {arXiv},
  url = {https://hal.science/hal-05781936v1},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - Search for compressed electroweak SUSY production in final states with two τ-leptons in √s = 13 and $13.6$ TeV pp collisions with the ATLAS detector
AU  - Georges Aad
AU  - Erlend Aakvaag
AU  - Braden Keim Abbott
AU  - Sara Abdelhameed
AU  - Kira Abeling
AU  - Nils Julius Abicht
AU  - Haider Abidi
AU  - Mohammed Aboelela
AU  - Asmaa Aboulhorma
AU  - Halina Abramowicz
AU  - Bobby Samir Acharya
AU  - Anke Ackermann
AU  - Jona Ackerschott
AU  - Claire Adam Bourdarios
AU  - Leszek Adamczyk
AU  - Sagar Addepalli
AU  - Matt Addison
AU  - Jahred Adelman
AU  - Habeeb Adenle
AU  - Aytul Adiguzel
AU  - Tim Adye
AU  - Tony Affolder
AU  - Yoav Afik
AU  - Merve Nazlim Agaras
AU  - Anamika Aggarwal
AU  - Catalin Agheorghiesei
AU  - Ammara Ahmad
AU  - Faig Ahmadov
AU  - Sonakshi Ahuja
AU  - Xiaocong Ai
AU  - Giulio Aielli
AU  - Arya Aikot
AU  - Malak Ait Tamlihat
AU  - Torsten Akesson
AU  - Daiya Akiyama
AU  - Sina Aktas
AU  - Gian Luigi Alberghi
AU  - Justin Albert
AU  - Una Helena Alberti
AU  - Pietro Albicocco
AU  - Sara Alderweireldt
AU  - Zackary Lee Alegria
AU  - Martin Aleksa
AU  - Igor Alexandrov
AU  - Calin Alexa
AU  - Theodoros Alexopoulos
AU  - Fabrizio Alfonsi
AU  - Malte Algren
AU  - Muhammad Alhroob
AU  - Babar Ali
AU  - Hanadi Ali
AU  - Shahzad Ali
AU  - Samuel William Alibocus
AU  - Malik Aliev
AU  - Gianluca Alimonti
AU  - Corentin Allaire
AU  - Benedict Allbrooke
AU  - Derrick Allen
AU  - Jonny Allen
AU  - Camron Stephen Alley
PY  - 2026
DA  - 2026/09/29
PB  - HAL
DO  - 10.48550/arxiv.2609.37215
UR  - https://hal.science/hal-05781936v1
AB  - Searches for the production of τ-sleptons (τ̃), charginos (χ̃^±_1), and neutralinos (χ̃^0_2) in events with at least one hadronically decaying τ-lepton are presented, targeting compressed mass spectra scenarios. For charginos and neutralinos, the cascade decays producing either a τ-slepton or a τ-sneutrino are considered. Two final selections are studied, requiring either one hadronically decaying τ-lepton and one other charged lepton, or two or more hadronically decaying τ-leptons. To enhance sensitivity to the compressed mass spectra, production modes with initial-state radiation (ISR) jets are considered. The searches use 140 fb^−1 and 53 fb^−1 of proton-proton collision data recorded by the ATLAS detector at the Large Hadron Collider during 2015-2018 at a centre-of-mass energy of √s = 13 TeV and 2022-2023 at a centre-of-mass energy of √s = 13.6 TeV, respectively. The searches provide sensitivity to the compressed mass spectra scenarios with light τ-sleptons. The results are generally consistent with the Standard Model, although several deviations with local significances of $2.1-2.4 σ$ are observed. These deviations weaken the observed exclusion limits. For direct τ-slepton production, in the ISR channel alone the limits are set for Δm(τ̃, χ̃^0_1) = 30 GeV for τ-slepton masses up to $115$ GeV at 95% confidence level. Given the observed data, no exclusion limits are set for direct τ-sleptons production when statistically combining all considered channels. For electroweakino production, limits are set for Δm(χ̃^0_2, χ̃^0_1) = 30 GeV for χ̃^0_2 masses up to $200$ GeV. For pure chargino pair-production, limits are set for chargino masses up to $175$ GeV for the same mass splitting.
ER  -