Conveners
Particle physics
- Nicole Bell (University of Melbourne)
Particle physics
- Pavel Fileviez Perez (Case Western Reserve University)
Particle physics
- Hai-Bo Yu (University of California, Riverside)
Particle physics
- Asher Berlin (University of Chicago)
I will discuss new signatures in direct detection experiments if part or all of the dark matter particles in nature are in the form of bound states. It will allow the sub-GeV dark matter candidates to be much more visible at dark matter and neutrino detectors.
The spectrum of Weakly-Interacting-Massive-Particle (WIMP) dark matter generically possesses bound states when the WIMP mass becomes sufficiently large relative to the mass of the electroweak gauge bosons. The presence of these bound states enhances the annihilation rate via resonances in the Sommerfeld enhancement, but they can also be produced directly with the emission of a low-energy...
The LHC Dark Matter Working Group (LHC DM WG) brings together theorists and experimentalists to provide the benchmark models, interpretation, and characterisation needed for a robust and broad set of searches for dark matter at the LHC. I will discuss the work of the LHC DM WG, and its predecessor the ATLAS/CMS Dark Matter Forum---the interaction between theory and experiment, the types of...
New particles with long lifetimes are introduced by many extensions to the standard model and would produce striking and non-conventional signatures in collider experiments such as long-lived charged particles, highly displaced jets, and particles that come to a rest within the detector and later decay. We present the results of several recent searches for long-lived particles with the CMS...
We present several complementary searches for low mass dijet resonances using a 35.9 inverse femtobarn data set of proton-proton collisions at 13 TeV collected with the CMS experiment at the LHC in 2016. One search uses the CMS scouting data stream concept to record larger data rates than otherwise possible. Another search uses an initial state radiation jet to overcome trigger thresholds and...
We present the latest results in the search for rare, exotic, and invisible Higgs boson decays in proton-proton collision events collected with the CMS detector at the LHC. The rich experimental program we describe, which includes searches for lepton flavor violation and decays to dark matter and light scalars, provides a wide ranging probe for physics beyond the standard model.
The wide range of probes of physics beyond the standard model (BSM) lead to the need for tools that consistently combine experimental results to make the most robust possible statements about the validity of new physics theories and the preferred regions of their parameter space. In this talk, I will introduce a new publicly released code for such studies: GAMBIT, the Global and Modular BSM...
Recent Fermi-LAT observations of dwarf spheroidal galaxies in the Milky Way have placed strong
limits on the gamma-ray flux from dark matter annihilation. In order to produce the strongest limit
on the dark matter annihilation cross-section, the observations of each dwarf galaxy have typically
been “stacked” in a joint-likelihood analysis, utilizing optical observations to constrain...
I will revisit the production of baryon asymmetries in the minimal type I seesaw model with two heavy Majorana singlets in the GeV range. Beside the tree level top scattering we include scattering processes on gauge bosons as well as $1\rightarrow 2$ processes of Higgs decay and inverse decays, that can contribute significantly to the wash-out effect.
I will show that the region of parameter...
In this talk I will discuss a model in which the matter / anti-matter asymmetry of the universe is generated during a first order cosmological phase transition associated with the spontaneous breaking of lepton-number, which gives rise to the Majorana mass for heavy sterile neutrinos. The dynamics leading to lepton-number generation, namely CP-violating scattering at a bubble wall, are...
I will introduce the MATHUSLA proposal (Massive Timing Hodoscope for Ultra-Stable neutraL pArticles) for a ~200mx200m tracker above ATLAS or CMS at the HL-LHC. Its primary purpose is the search for exotic long-lived particles with lifetimes up to the BBN bound of ~ 0.1 seconds, where it would extend LHC sensitivity by orders of magnitude. In addition, the design and position of MATHUSLA close...
We propose the first viable radiative seesaw model, in which the neutrino masses are induced radiatively via the two-loop Feynman diagram involving Strongly Interacting Massive Particles (SIMP). The stability of SIMP dark matter (DM) is ensured by a Z5 discrete symmetry, through which the DM annihilation rate is dominated by the 3 to 2 self-annihilating processes. The right amount of thermal...
The J-PARC Sterile Neutrino Search at the J-PARC Spallation Neutron Source (JSNS$^2$) will search for neutrino oscillations with $\Delta m^2 \sim$ 1 eV$^2$ at the J-PARC Material and Life Science Experimental Facility (MLF). The experiment will perform a search for $\bar{\nu}_\mu \rightarrow \bar{\nu}_e$ oscillations over a 24 m baseline using muon decay at rest neutrinos originating from 3...
In this talk we will present novel ways in which neutrino oscillation experiments can probe dark matter. In
particular, we focus on interactions between neutrinos and ultra-light (“fuzzy”) dark matter particles
with masses of order $10^{-22}$ eV. It has been shown previously that such dark matter candidates are
phenomenologically successful and might help ameliorate the tension between...
Neutron tagging is a promising experimental technique for separating between signal and background in a wide variety of astroparticle measurement. The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) located along the Booster Neutrino Beam at Fermilab has a goal of measuring the final state neutron multiplicity from charged current neutrino-nucleus interactions within the...
MicroBooNE is a liquid argon TPC neutrino experiment based at Fermilab and situated on the Booster Neutrino Beam. MicroBooNE's primary aim is to investigate the excess of electron neutrino-like events seen by the MiniBooNE experiment, which is potential evidence for new non-Standard physics such as sterile neutrinos. This talk will discuss a search for low-energy electron neutrino interactions...
In this talk, I will present the status and plans of a new dedicated experiment called milliQan that we propose to install at LHC Point 5. It is designed to be sensitive to particles produced in pp collisions that have EM charges ranging from 0.001 e to 0.1 e, as can arise in a variety of beyond-the-standard model scenarios.
One interesting class of models involves dark matter as the lightest state of a strongly interacting hidden sector, similar to the pions of QCD. In this talk, I will examine the possibility that the lightest vector resonances of the hidden sector are nearby in mass and accessible within the current operating energy of fixed-target experiments. These states significantly modify processes in the...
In this talk we discuss the sensitivity of probing light bosons in the Borexino-SOX experiment, and the possibility of detecting heavy leptons in the SHiP and DUNE experiments.
Bringing an external radioactive source close to a large underground detector can significantly advance sensitivity not only to sterile neutrinos but also to "dark" gauge bosons and scalars. Here we address in detail...
Nanosecond precision timing synchronization via the Global Positioning System has become a common technique for a variety of particle physics and astrophysics experiments including, for example, large arrays of detectors for cosmic ray air showers. By using the common time-standard in GPS, time synchronization can be achieved at low cost, even over large areas in remote locations. ...
A direct measurement of the gravitational acceleration of antimatter has never
been performed to date. Recently, such an experiment has been proposed, using antihydrogen with an atom interferometer and an Antihydrogen confinament has been realized at CERN. In alternative we propose an experimental test of the gravitational interaction with antimatter by measuring the branching fraction of the...
In the minimal left-right symmetric model which could accommodate the tiny neutrino masses via TeV seesaw mechanism, the neutral scalar from the right-handed symmetry breaking sector could be much lighter than the electroweak scale. Limited by the meson oscillation and decay data, such a light particle is necessarily long-lived and decays predominantly into two photons, mediated by the heavy...
Despite the recent discovery of the Higgs boson contributing to the success of the Standard Model, the large excess of dark matter in the Universe remains one of the outstanding questions in science. This excess cannot be explained by Standard Model particles. A compelling hypothesis is that dark matter is comprised of particles can be produced at the LHC, called Weakly Interacting Massive...
Dark matter can be sought in complementary experiments: direct detection, indirect detection and colliders all contribute to a comprehensive set of searches for weakly interacting massive particles (WIMPs). This talk underlines the searches for Dark Matter by the ATLAS experiment in the context of this complementarity, using models that include a mediator particle between SM and DM.
Will cover searches for neutralinos and electroweakinos.
Several theories beyond the Standard Model predict the existence of high mass neutral or charged Higgs particles or BSM decay modes of the 125 GeV Higgs boson. In this presentation, the latest ATLAS results on searches for these particles will be discussed.
