Related papers: Hidden valley scenario sensitivity in the CMS muon…
We study the potential collider discovery for the right-handed neutrinos (RHNs) in the minimal left-right symmetric model (LRSM). In this model, the RHNs can be either produced from the right-handed gauge boson $W_R^\pm$, or the scalar…
A recent paper by the CDF collaboration suggests (but does not claim) an anomalous event sample containing muons produced with large impact parameter, often with high multiplicity and at small angles from one another. This curious hint of a…
The number of muons in extensive air showers predicted using LHC-tuned hadronic interaction models, such as EPOS-LHC and QGSJetII-04, is smaller than observed in showers recorded by leading cosmic ray experiments. In this paper, we present…
The ongoing perplexing scenario with no hints of new physics at the Large Hadron Collider can be elucidated amicably if the exotic particle spectrum in many of the well-motivated theoretical models possesses degenerate mass. We investigate…
The LHC experiments will perform sensitive tests of physics beyond the Standard Model (BSM). The investigation of decays of beauty hadrons represents an alternative approach in addition to direct BSM searches. The ATLAS and CMS efforts…
A search for long-lived particles decaying into hadrons and at least one muon is presented. The analysis selects events that pass a muon or missing-transverse-momentum trigger and contain a displaced muon track and a displaced vertex. The…
We describe a new code and approach using particle-level information to recast the recent CMS disappearing track searches including all run 2 data. Notably, the simulation relies on knowledge of the detector geometry, and we also include…
We study the potential to probe the origin of neutrino masses, by searching for long-lived right-handed neutrinos (RHNs) $N$ in the $B-L$ model and in the RHN-extended Standard Model (SM) Effective Field Theory (EFT). Despite the small…
Hard scattering events in high-energy collisions produce highly virtual partons that subsequently fragment into collimated hadronic cascades. When such partonic showers evolve in a QCD medium, as in deep-inelastic scattering or heavy-ion…
A search for scalar or pseudoscalar states decaying to a top quark-antiquark pair ($\mathrm{t \bar{t}}$), using $138\,\mathrm{fb}^{-1}$ of pp collision data taken at $\sqrt{s} = 13\,\mathrm{TeV}$ using the CMS detector, is presented. Events…
High-energy cosmic rays are observed indirectly by detecting the extensive air showers initiated in Earth's atmosphere. The interpretation of these observations relies on accurate models of air shower physics, which is a challenge and an…
A search for the production of long-lived particles in proton-proton collisions at a center-of-mass energy of 13 TeV at the CERN LHC is presented. The search is based on data collected by the CMS experiment in 2016-2018, corresponding to a…
The MACRO experiment detected more than 300000 multiple muon events. We analysed these events to measure the distribution of the separation of underground TeV muons (decoherence function), up to a distance of 70 meters. On a subsample of…
We show that in a confining hidden valley model where the lightest hidden particles are dark hadrons that have mass splittings larger than $\mathcal{O}(0.1)$ GeV, if the lightest dark hadron is either stable or decays into Standard Model…
Long-lived particles can manifest themselves at the LHC via "displaced vertices" - several charged tracks originating from a position separated from the proton interaction point by a macroscopic distance. Here we demonstrate a potential of…
In this work, we consider the case of a strongly coupled dark/hidden sector, which extends the Standard Model (SM) by adding an additional non-Abelian gauge group. These extensions generally contain matter fields, much like the SM quarks,…
The most recent searches for long-lived particles at CMS are presented. Searches for displaced jets, displaced leptons, displaced stops, and heavy stable charged particles are among those discussed. A variety of models are constrained by…
Measurements of the muon content of extensive air showers at the highest energies show discrepancies compared to simulations as large as the differences between proton and iron. This so-called muon puzzle is commonly attributed to a lack of…
The event-to-event fluctuations of hadron multiplicities are studied for a quark system undergoing second-order phase transition to hadrons. Emphasis is placed on the search for an observable signature that is realistic for heavy-ion…
A first search is presented for vector-like leptons (VLLs) decaying into a light long-lived pseudoscalar boson and a standard model $\tau$ lepton. The pseudoscalar boson is assumed to have a mass below the $\tau^+\tau^-$ threshold, so that…