Event Category: Particle Seminar

Particle Seminar:
Wednesdays 2:00pm at LBNL

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Abstract: Detecting light dark matter that interacts weakly with electromagnetism has recently become one of the benchmark goals of near-term and futuristic direct detection experiments. In this talk, I will discuss an alternative technique to directly detecting such particles below the GeV-scale. The approach involves distorting the local flow of dark matter with time-varying fields and measuring these distortions with … Read More

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Abstract: Processes in particle physics are often described by a large number of observables that can carry information on the theory parameters of interest. This proves a challenge for traditional analysis methods, which struggle to extract all of this information. However, recently, a family of new inference techniques combining matrix element information and machine learning has been developed. MadMiner, a … Read More

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Collider events, when imbued with a metric which characterizes the ‘distance’ between two events, can be thought of as populating a data manifold in a metric space. The geometric properties of this manifold reflect the physics encoded in the distance metric. I will show how the geometry of collider events can be probed using a class of machine learning architectures … Read More

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Axions may be produced thermally inside the cores of neutron stars (NSs), escape the stars due to their weak interactions with matter, and subsequently convert into X-rays in the magnetic fields surrounding the NSs. I will describe a hard X-ray search from 2 – 8 keV for X-rays arising from this emission mechanism from the nearby Magnificent Seven isolated NSs … Read More

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Abstract: Light dark matter scattering in a crystal or fluid must recoil off a collective excitation (phonon) rather than off individual nuclei. I will set up the appropriate low energy effective theory and show how density functional theory (DFT) methods can be used to calculate the dark matter scattering rate for various dark matter models and target materials.

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ABSTRACT: Halometry—mapping out the spectrum, location, and kinematics of nonluminous structures inside the Galactic halo—can be realized via effects that variable weak gravitational lensing induces on the proper motions of stars and other luminous background sources. Modern astrometric surveys provide unprecedented positional precision along with a leap in the number of cataloged objects. Astrometry thus offers a new and sensitive … Read More

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Abstract: Sensitivity gaps in the search for keV-MeV mass dark matter exist in both direct and indirect detection experiments. For direct detection, this gap can be closed by utilising new and rapidly developing quantum sensing technologies. I will discuss (i) single quantum detection using magnetic avalanches in chemical crystals and its application to the dark matter search, and (ii) novel … Read More

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Abstract: The QCD axion explains why QCD almost preserves the charge-conjugation parity symmetry. The QCD axion is also a dark matter candidate and is under intensive experimental searches. I will introduce new cosmological evolutions of the QCD axion as a result of natural but unexplored initial conditions in the early universe, such as a non-zero Peccei-Quinn charge asymmetry. These evolutions … Read More

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ABSTRACT: I will discuss how black holes can become nature’s laboratories for new ultralight bosons and ongoing observations of gravitational waves can inform beyond the standard model theories. When a particle’s Compton wavelength is comparable to the horizon size of a black hole, energy and angular momentum from the black hole are converted into exponentially growing clouds of bosons. Theories … Read More