Minimal non-thermal dark matter models are an attractive type of model, since they can potentially explain both the existence of dark matter as well as the baryon asymmetry in the universe. In this presentation, I focus on a type of model with two color-triplet iso-singlet scalars at TeV scale masses and a singlet Majorana fermion dark matter candidate at the GeV scale. A phenomenological...
Top quark polarization measurements provide observables that are sensitive to spin correlation measurements and new physics. The down-type fermion from the W decay is the most powerful spin analyzer from top, which is not straight forward to measure in hadronic decays. Most applications measure top quark spin via an optimal hadronic spin analyzer built from kinematics. In this talk, we discuss...
String theory setups can accommodate superheavy dark matter with the correct relic abundance. In addition, they may induce tiny R-parity violating couplings which make dark matter unstable with a lifetime well above the age of the universe. In this talk, I will discuss the high-energy gamma ray and neutrino signals from various three-body decays of superheavy neutralinos. I will then show how...
We investigate the influence of the reheating temperature of the visible sector on the freeze-in dark matter (DM) benchmark model for direct detection experiments, where DM production is mediated by an ultralight dark photon. Here we consider a new regime for this benchmark: we take the initial temperature of the thermal Standard Model (SM) bath to be below the DM mass. Then the production...
I will discuss light dark matter candidates with kinetic coupling. More specifically, a condensate dark matter in a two-field model where the axion is coupled to a second moduli field at the level of its kinetic term. I will discuss cosmological consequences of such a dark matter candidate.
The recent observation of collider neutrinos and BSM searches for ALPs by the FASER collaboration highlights the potential the forward direction at the LHC has for neutrino physics and BSM studies. After briefly reviewing some of the FASER collaboration's recent results, I will present some of my own work on the phenomenological studies of the electromagnetic properties of neutrinos, namely...
There has been a surge of interest in hidden valley models with new, strong forces, sometimes called "dark QCD". These models propose asymmetric, composite dark matter in the form of "dark hadrons" that would evade direct and indirect bounds as well as typical collider DM searches for large missing transverse momentum accompanied by radiation. However, evidence of these models can still be...
Dark matter is thought to make up 25% of the universe. Dark sector particles (DSP) do not interact through the known forces but could be weakly coupled to Standard Model particles through a portal or a mediator. Many searches for dark matter/dark sector particles at an accelerator thus far seem to face a ceiling that the sensitivity reach is greatly limited, beyond statistical effects. DAMSA...
I will discuss measurements of Higgs boson properties with the ATLAS and CMS experiments.
Several theories beyond the Standard Model (BSM) suggest an expanded Higgs sector, prompting investigations for neutral and charged Higgs bosons in addition to the one observed at 125 GeV. The completion of Run 2 of the LHC in 2018 yielded a total of 139 fb^−1 of data, offering an opportunity to delve deeper into the BSM Higgs parameter space. This presentation covers the searches for BSM...
The Standard Model predicts non-resonant production of Higgs boson pairs, which provides a handle to directly measure the shape of the Higgs potential. Numerous BSM models predict new scalar fields with couplings that lead to the simultaneous production of scalar bosons. The ATLAS and CMS Collaborations have active search programs targeting multi-scalar-boson production. This talk provides and...
The most precise determination of the sum of neutrino masses from cosmological data, derived from analysis of the cosmic microwave background and recent baryon acoustic acoustic oscillations data from DESI, favors a value below the minimum inferred from neutrino flavor oscillation experiments. The sum of neutrino mass is determined in cosmology from the suppression of matter clustering in the...
The Belle II experiment has collected 424 fb$^{-1}$ sample of $e^+e^-$ collisions produced by the asymmetric SuperKEKB collider, at a centre-of-mass energy equal to or near the mass of the $\Upsilon(4S)$ resonance. Ninety-percent of the sample is at the $\Upsilon(4S)$ resonance, which decays to $B$-meson pairs. The predecessor experiment, Belle, collected nearly $1~{\rm ab}^{-1}$ of data from...
With the HL-LHC and EIC on the horizon, high-precision measurements are paramount to both SM and BSM studies. As PDF uncertainty is often a limiting factor, our goal is not only to ‘fit’ PDFs but also to better understand the underlying process at the precision level. We describe ongoing projects within both the nCTEQ and BNL-based SURGE project as we explore and characterize the full...
On the example of recent work by the CTEQ-TEA group, I discuss the progress on precision parton distribution functions (PDFs) in the proton. I particularly emphasize new insights on quantification of uncertainties on PDFs that affect key electroweak and Higgs precision studies at the HL-LHC.
Cosmological and astrophysical observations provide a unique opportunity to probe the fundamental properties of dark matter. Dark matter interactions with the Standard Model of particle physics, for example, can alter predictions from the standard cosmological model, permitting robust tests of new dark matter physics. In this talk, I will describe the impact that dark matter interactions have...
Many theories of physics beyond the Standard Model give rise to a unique early-universe cosmology during which the abundances of different energy components such as matter, radiation, and vacuum energy remain constant across extended cosmological eras, even though the universe is expanding. Even more surprisingly, such “stasis” epochs are actually universal attractors, with the universe...
In this talk, we will look at the role of primordial black holes in sourcing the cosmic baryon as well as dark matter abundance.
Future gravitational wave detectors probing the mHz - nHz frequency range will provide a unique opportunity for BSM physicists to study new physics. Neutron star and white dwarf mergers can serve as axion probes, while extreme mass ratio inspirals can constrain dark forces. Gravitational wave detectors will also probe early first order phase transitions. I will discuss some ongoing work and...
The observation of gravitational waves opens a new window for exploring astrophysics and cosmology. These messengers enable the concurrent measurement of their amplitudes and phases, facilitating a precise analysis of wave production and propagation. In this talk, I will demonstrate how gravitational waves can be utilized to study the properties of dark matter. Specifically, I will use wave...
The knowledge of the Higgs potential is crucial for understanding the origin of mass and the thermal history of our Universe. We show how collider measurements and observations of stochastic gravitational wave signals can complement each other to explore the multiform scalar potential in the two Higgs doublet model. In our investigation, we analyze critical elements of the Higgs potential to...
Pre-stellar galactic halos are highly sensitive to soft radiation: the presence of sources of O(10 eV) Lyman-Werner radiation changes the gas chemistry and prevent the standard fragmentation of the gas. Rather than producing Population III stars, this may instead lead to direct collapse black holes. Observations of supermassive black holes at high redshift have long been suspected to be...
I will discuss the LHC search efforts for dark matter and dark-sector particles.
We propose a novel method to determine the mass scale of ambient dark matter that can be generally applied to the (at least effectively) two-dimensional direct detection experiments allowing for directional observables.
In this talk, I will discuss the potential of current/future tau neutrino experiments in probing new physics beyond the Standard Model. A focus will be given to a tau neutrino-philic new particle that can play an important role in the evolution of early Universe.
The sources of the high-energy neutrino events detected by IceCube remain largely unknown. A more precise neutrino flavor ratio measurement in the future will be crucial in resolving this open question. We discuss how the flavor ratio gets modified in presence of matter effects for Active Galactic Nuclei (AGNs) which are currently the most promising astrophysical candidate sources. We show...
Over the past decade the LHC collaborations have developed an extensive program of searches for new, long-lived particles produced in proton-proton collisions. These searches probe phase space where new physics could be hiding. I will review some of the newest results from the LHC collaborations.
Talk on behalf of the ATLAS and CMS Collaborations
We present a comprehensive study on how to distinguish the properties of heavy dijet resonances at hadron colliders. A variety of spins, chiral couplings, charges, and QCD color representations are considered. Distinguishing the different color representations is particularly difficult at hadron colliders. To determine the QCD color structure, we consider a third jet radiated in a resonant...
We derive new constraints on axion-like particles (ALPs) using precision $X$-ray polarization studies of magnetars. Specifically, we use the first detection of polarized $X$-rays from the magnetars 4U 0142+61 and 1RXS J170849.0-400910 by the Imaging $X$-ray Polarimetry Explorer (IXPE) to place bounds on the product of the ALP-photon and ALP-nucleon couplings, $g_{a\gamma}g_{aN}$, with $g_{aN}$...
A cosmological network of axion strings in our Universe today may leave its imprint on the polarization pattern of the cosmic microwave background radiation through the phenomenon of axion-string-induced birefringence. I will explain how this signal arises, discuss how it depends on the properties of the string network and the axion-photon coupling, describe how existing measurements of...
