Conveners
New ideas: 1
- James Beacham (Duke University (US))
- Carlos Vazquez Sierra (Nikhef National institute for subatomic physics (NL))
New ideas: 2
- James Beacham (Duke University (US))
- Carlos Vazquez Sierra (Nikhef National institute for subatomic physics (NL))
New ideas: 3
- Rebeca Gonzalez Suarez (Uppsala University (SE))
- Katherine Pachal (Duke University (US))
Abstract: Profiling the Higgs boson requires the study of its non-standard decay modes. In this work we discuss the prospects of the Large Hadron electron Collider (LHeC) to detect scalar particles with masses >= 10 GeV produced from decays of the Standard Model (SM) Higgs boson. These scalar particles decay mainly to bottom pairs, and in a vast portion of the allowed parameter space they...
Models where dark matter is a part of an electroweak multiplet feature charged particles with macroscopic lifetimes due to the charged-neutral mass split of the order of pion mass. At the Large Hadron Collider, the ATLAS and CMS experiments will identify these charged particles as disappearing tracks, since they decay into a massive invisible dark matter candidate and a very soft charged...
The search for long-lived particles (LLP) is an exciting physics opportunity in the upcoming runs of the Large Hadron Collider. In this paper, we focus on a new search strategy of using the High Granularity Calorimeter (HGCAL), part of the upgrade of the CMS detector, in such searches. In particular, we demonstrate that the high granularity of the calorimeter allows us to see ``shower tracks"...
Many existing or proposed intensity-frontier search experiments look for decay signatures of light long-lived particles (LLPs), highly displaced from the interaction point. This approach is, however, limited to new particles with decay lengths similar to or larger than the baseline of those experiments. We will discuss how this basic constraint can be overcome in BSM models that go beyond the...
The neutrino oscillation experiment has clearly pointed out that the Standard Model neutrinos have tiny masses and their flavors are mixed. There are a plenty of models which explain the mechanism of the generation of the neutrino mass. In this talk we will discuss about the simple neutrino mass generation process at the TeV scale which is often called the seesaw mechanism and its...
We study the prospects of a displaced-vertex search of sterile neutrinos at the Large Hadron Collider (LHC) in the framework of the neutrino-extended Standard Model Effective Field Theory. The production and decay of sterile neutrinos can proceed via the standard active-sterile neutrino mixing in the weak current, as well as through higher-dimensional operators arising from decoupled new...
Long-lived particles are predicted in many extensions beyond the standard model. They often have unique signatures in the detector. A particularly interesting model considers long-lived particles decaying hadronically just in front of or inside the CMS muon system. These particles are capable of producing large shower of hits in the muon chambers. Due to bandwidth limitations the current muon...
In this talk we will demonstrate that what was previously considered as different mechanisms of baryon asymmetry generation involving two right-handed Majorana neutrinos with masses far below the GUT scale -- leptogenesis via neutrino oscillations and resonant leptogenesis -- are actually united. We show that the observed baryon asymmetry can be generated for all experimentally allowed values...
MATHUSLA is a proposed large-volume displaced vertex (DV) detector, situated on the surface above CMS and designed to search for long-lived particles (LLPs) produced at the HL-LHC. We show that a discovery of LLPs at MATHUSLA would not only prove the existence of BSM physics, it would also uncover the theoretical origin of the LLPs, despite the fact that MATHUSLA gathers no energy or momentum...
Motivated by the Strong CP and the Axion Quality problem, I will consider heavier variants of the QCD axion which has a large and uncharted parameter space where it is long-lived. By focusing on the defining axionic coupling to gluons, I will evaluate the prospect of discovery of GeV-scale axions at the HL-LHC relying on the CMS track trigger upgrade. I will also comment on vetoing possible...
We will discuss multi-lepton signals of LNV that can arise with experimentally interesting rates in certain loop models of neutrino mass generation. Interestingly, in such models the observed smallness of the active neutrino masses, together with the high-multiplicity of the final states, leads in large parts of the viable parameter space to the prediction of long-lived charged particles. We...
Light top quark superpartners are the key ingredients for supersymmetric models to solve the electroweak hierarchy problem. The compressed region of the parameter space that $m_{\tilde t_1} \approx m_{\chi^0_1}$ is notoriously difficult to search. In this region, if the LSP neutralino is pure bino, $\tilde t_1$ can be long-lived, which produces displaced vertices in detectors. We propose to...
We explore the phenomenology of a pseudo-Nambu-Goldstone bosons of a spontaneous broken global U(1) symmetry, axion-like particles (ALPs), with flavour violating couplings to up-quarks and vanishing couplings to down-quarks and leptons. Such a scenario is motivated by a confining ‘dark QCD’ UV completion. For light ALPs the phenomenology is governed by the couplings to charm- and up-quarks....
