Search for the pair production of long-lived supersymmetric partners of the tau lepton in proton-proton collisions at √(s)=13 TeV

2026/01/24 by CMS Collaboration, A. Hayrapetyan, В. Макаренко +97 · 2 voices
Physics and Astronomy · Computer Science · #Particle physics theoretical and experimental studies #Neutrino Physics Research #Computational Physics and Python Applications

paper · pdf · doi:10.1007/jhep07(2026)102

Abstract

A bstract Gauge-mediated supersymmetry-breaking models provide a strong motivation to search for a supersymmetric partner of the tau lepton (stau) with a macroscopic lifetime. Long-lived stau decays produce tau leptons that are displaced from the primary proton-proton interaction vertex, leading to an unconventional signature. This paper presents a search for the direct production of long-lived staus decaying within the CMS tracker volume in proton-proton collisions at √(s)=13 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msqrt> <mml:mi>s</mml:mi> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>13</mml:mn> </mml:math> TeV, performed for the first time with an identification algorithm based on a graph neural network dedicated to displaced tau leptons. The data sample, corresponding to an integrated luminosity of 138 fb − 1 , was recorded with the CMS experiment at the CERN LHC between 2016 and 2018. This search excludes, at 95% confidence level, stau masses, m_\overset∼ \uptau <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mover> <mml:mi>τ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:msub> </mml:math> , in the 126–260 (90–425) GeV range for a proper decay length of 50 mm in the maximally mixed (mass-degenerate) scenario, while for m_\overset∼ \uptau=200 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>m</mml:mi> <mml:mover> <mml:mi>τ</mml:mi> <mml:mo>~</mml:mo> </mml:mover> </mml:msub> <mml:mo>=</mml:mo> <mml:mn>200</mml:mn> </mml:math> GeV, stau proper decay lengths are excluded in the range 21–94 (6–333) mm. These results improve the exclusion limits compared to previous searches, and extend the parameter space explored in the context of supersymmetry.

Discussions

• If there are supersymmetry versions of tau leptons (creatively called stau/scalar-tau), they could create signatures where normal taus appear in the middle of the CMS detector. This #CMSPaper looks fo [bsky, 6 points, 1 comments]
• #CMSpaper: Search for the pair production of long-lived supersymmetric partners of the tau lepton in proton-proton collisions at √s = 13 TeV (arXiv:2601.17576) https://arxiv.org/abs/2601.17576 #NewPhy [bsky, 0 points, 0 comments]

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