Exploiting exotic LHC datasets for long-lived new particle searches

Abstract

Motivated by the expectation that new physics may manifest itself in the form of very heavy new particles, most of the operation time of the LHC is devoted to $pp$ collisions at the highest achievable energies and collision rates. The large collision rates imply tight trigger requirements that include high thresholds on the final-state particles' transverse momenta $p_T$ and an intrinsic background in the form of particle pileup produced by different collisions occurring during the same bunch crossing. This strategy is potentially sub-optimal for several well-motivated new physics models where new particles are not particularly heavy and can escape the online selection criteria of the multi-purpose LHC experiments due to their light mass and small coupling. A solution may be offered by complementary datasets that are routinely collected by the LHC experiments. These include heavy ion collisions, low-pileup runs for precision physics, and the so-called 'parking' and 'scouting' datasets. While some of them are motivated by other physics goals, they all have the usage of mild $p_T$ thresholds at the trigger-level in common. In this study, we assess the relative merits of these datasets for a representative model whose particular clean signature features long-lived resonances yielding displaced dimuon vertices. We compare the reach across those datasets for a simple analysis, simulating LHC data in Run 2 and Run 3 conditions with the Delphes simulation. We show that the scouting and parking datasets, which afford low-$p_T$ trigger thresholds by only using partial detector information and delaying the event reconstruction, respectively, have a reach comparable to the standard $pp$ dataset with conventional thresholds. We also show that heavy ion and low-pileup datasets are far less competitive for this signature.

arXiv commentv2: version accepted by JHEP. 23 pages with tables and figures

References in corpus (32)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• DELPHES 3, A modular framework for fast simulation of a generic collider experiment
• FeynRules 2.0 - A complete toolbox for tree-level phenomenology
• Parton distributions with LHC data
• LHAPDF6: parton density access in the LHC precision era
• New parton distribution functions from a global analysis of quantum chromodynamics
• Tuning PYTHIA 8.1: the Monash 2013 Tune
• Echoes of a Hidden Valley at Hadron Colliders
• The Standard Model as an Effective Field Theory
• EPPS16: Nuclear parton distributions with LHC data
• Feebly-Interacting Particles:FIPs 2020 Workshop Report
• ALPs Effective Field Theory and Collider Signatures
• Searching for long-lived particles beyond the Standard Model at the Large Hadron Collider
• Searching for axion-like particles with ultra-peripheral heavy-ion collisions
• The Angantyr model for Heavy-Ion Collisions in PYTHIA8
• Heavy Neutrinos in displaced vertex searches at the LHC and HL-LHC
• Anomalous electromagnetic moments of $\tau$ lepton in $\gamma \gamma \to {\tau }^{+}{\tau }^{-}$ reaction in Pb+Pb collisions at the LHC
• Magnetic monopole mass bounds from heavy ion collisions and neutron stars
• New physics searches with heavy-ion collisions at the LHC
• Unveiling Hidden Physics at the LHC
• A comprehensive real-time analysis model at the LHCb experiment
• Towards Schwinger production of magnetic monopoles in heavy-ion collisions
• Unleashing the full power of LHCb to probe Stealth New Physics
• Strangelet Search in AuAu Collisions at 200 GeV
• New Long Lived Particles Searches in Heavy Ion Collisions at the LHC
• A Trigger for Displaced Muon Pairs Following the CMS Phase II Upgrades
• Portal Effective Theories: A framework for the model independent description of light hidden sector interactions
• The Electroweak Sphaleron in a strong magnetic field
• Soft displaced leptons at the LHC
• Searching for New Long Lived Particles in Heavy Ion Collisions at the LHC
• Model of Centauro and strangelet production in heavy ion collisions
• Dark photons from pions produced in ultraperipheral $PbPb$ collisions