Abstract
Colored and colorless particles that are stable on collider scales and carry exotic electric charges, so-called Multiply-Charged Heavy Stable Particles (MCHSPs), exist in extensions of the Standard Model, and can include the top partner(s) in solutions of the hierarchy problem. To obtain bounds on color-triplets and color-singlets of charges up to |Q| = 8, we recast searches for signatures of two production channels: the “open” channel — where the particles are pair-produced above threshold, and are detectable in dedicated LHC searches for stable multiply charged leptons, and the “closed” channel — where a particle-antiparticle pair is produced as a bound state, detectable in searches for a diphoton resonance. We recast the open lepton searches by incorporating the relevant strong-interaction effects for color-triplets. In both open and closed production, we provide a careful assessment of photon-induced processes using the accurate LUXqed PDF, resulting in substantially weaker bounds than previously claimed in the literature for the colorless case. Our bounds for colored MCHSPs are shown for the first time, as the LHC experiments have not searched for them directly. Generally, we obtain nearly charge-independent lower mass limits of around 970 GeV (color-triplet scalar), 1200 GeV (color-triplet fermion), and 880-900 GeV (color-singlet fermion) from open production, and strongly charge-dependent limits from closed production. In all cases there is a cross-over between dominance by open and closed searches at some charge. We provide prospective bounds for s=13 TeV LHC searches at integrated luminosities of 39.5 fb −1 , 100 fb −1 , and 300 fb −1 . Moreover, we show that a joint observation in the open and the closed channels allows to determine the mass, spin, color, and electric charge of the particle.
| Original language | English |
|---|---|
| Article number | 041 |
| Number of pages | 38 |
| Journal | Journal of High Energy Physics |
| Volume | 2019 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 4 Apr 2019 |
Funding
We thank Shikma Bressler for her insights and expertise that greatly assisted the research, and for her comments on the manuscript. We also thank Marumi Kado and Yevgeny Kats for the useful discussions. We are grateful to Luke Arpino, Tom Steudtner, Matthias Schlaffer, Sanmay Ganguly and the WIS LCG team for their kind help with different aspects of the project. The work of GP is supported by grants from the BSF, ERC, ISF, the Minerva Foundation, and the Segre Research Award. GP, SJ and SK acknowledge the support through a Weizmann-UK Making Connections grant, including a studentship jointly funded with the School of Mathematical and Physical Sciences at the University of Sussex. The work of SJ was supported by UK STFC Consolidated Grant ST/P000819/1. SJ and SK thank the Weizmann Institute, and IS the University of Sussex, for the hospitality during visits while working on this project. IS and SK are grateful for STSM support from European Cooperation in Science and Technology (COST) action CA15108 “Connecting Insights in Fundamental Physics”. Article funded by SCOAP
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics