The neutrino oscillation needs parameters to be measured precisely to provide essential information for a modification of the Standard Model. Accomplishing this novel goal in future neutrino experiments requires high flux neutrino beams and powerful combination of near and far detectors. Fermilab’s PIP-II LINAC is an essential element in providing high flux protons to the Long Baseline...
Neutrino experiments will have leading sensitivity to several dark matter and dark sector models. I discuss signals from a range of different dark sector models, from induced nucleon decay in mesogenesis models to production, scattering, and decay of dark sector states in neutrino beams. I present simulation tools for boosted dark matter and induced nucleon decay signals. I discuss some...
Many new physics scenarios predict multi-photon Higgs resonances. One such scenario is the dark axion portal model. The primary decay chain that we study is the Higgs to dark photon ($\gamma_D$) pairs that subsequently decay into a photon ($\gamma$) and an axion-like particle ($a$). The axion-like particles then decay into photon pairs. Hence, the signal is a six-photon Higgs decay:...
This talk will present the first physics results of the FASER experiment, where we were the first to directly observe neutrino interactions at a particle collider experiment and also probed previously unconstrained phase space of the dark photon with couplings $ϵ∼10^{-5}−10^{-4}$ and masses ∼10 MeV - 100 MeV. FASER is an experiment dedicated to searching for light, extremely weakly-interacting...
Despite the current standard model of particle physics has been highly successful, there are still unanswered questions surrounding dark matter. This suggests that new physics beyond the standard model may be discovered at the Large Hadron Collider. In my talk, I will focus on the search for the dark sector using a novel concept of beam dump experiments at the CMS experiment. While this...
We study charged Higgs boson search via $e^+e^− \to H^+H^− \to c\bar b \bar cb$
at the 500 GeV ILC. In a general two Higgs doublet model without $Z_2$ symmetry,
extra Yukawa couplings $\rho_{tt}$ and $\rho_{tc}$ can drive baryogenesis, but
searches at the HL-LHC may still go empty-handed if the couplings are relatively
weak. Taking $m_{H^+} \simeq m_H \simeq m_A \sim 200$ GeV, with...
In this talk, we present a new interacting dark sector model, Stepped Partially Acoustic Dark Matter (SPartAcous), that can tackle two major issues in current cosmological data, namely the $H_0$ and $S_8$ problems. Similar to Partially Acoustic Dark Matter (PAcDM), this model involves a part of dark matter that interacts with dark radiation at high temperatures, resulting in a decrease in the...
The flux of high energy neutrinos and photons produced in a blazar could get attenuated when they propagate through the dark matter spike around the central black hole and the halo of the host galaxy. Using the observation by IceCube of a few high-energy neutrino events from TXS 0506+056, and their coincident gamma ray events, we obtain new constraints on the dark matter-neutrino and dark...
Whether neutrinos are Majorana or Dirac particles is an open question. Theoretically, it is also possible that neutrinos are pseudo-Dirac, which are fundamentally Majorana fermions, but essentially act like Dirac fermions in most experimental settings, due to extremely small active-sterile mass splitting. Such small values of mass splitting can only be accessed via active-sterile oscillations...
The future high-energy muon colliders, featuring both high energy and low background, could play a critical role in our searches for new physics. The smallness of neutrino mass is a puzzle of particle physics. Broad classes of solutions to the neutrino puzzles can be best tested by seeking the partners of SM light neutrinos, dubbed as heavy neutral leptons (HNLs), at muon colliders.
We can...
Many physics models beyond the Standard Model predict heavy new particles preferentially decaying to at least one top quark. This talk will present searches for Leptoquark/Vector-like quark/new resonances decaying into at least one top quark in pp collision at a center-of-mass energy of 13 TeV at the CMS and ATLAS detectors at the LHC.
The searches use the data set collected with the CMS or...
The Large Hadron Collider provides a unique environment to study quantum entanglement and violation of Bell's inequalities at the highest energy available today. In this talk, we will discuss the possible observation of these quantum correlations with top quark pair production, which represents a system of two-qubits. Our study focus on the semi-leptonic top pair channel. They indicate that...
We describe a new jet clustering algorithm named SIFT (Scale-Invariant Filtered Tree) that maintains the resolution of substructure for collimated decay products at large boosts. The scale-invariant measure combines properties of kT and anti-kT by preferring early association of soft radiation with a resilient hard axis, while avoiding the specification of a fixed cone size. Integrated...
In [1] and [2], my co-authors and I revisit the the field theory of axion model building from two separate perspectives. We first considered [1] the effects of small-size instantons arising from enlarged color gauge groups on the QCD axion mass, reaffirming earlier results that QCD axion masses can be parametrically heavier than vanilla models when the confinement effects of the extended...
Asteroid-mass primordial black holes (PBH) can make up a fraction or all of dark matter. Their Hawking radiation process offers a novel channel to produce new particles, which is especially interesting if these particles are mostly secluded from the Standard Model sector. Future MeV gamma-ray telescopes provide exciting prospects for detecting the Hawking radiation signal from asteroid-mass...
Cosmological observables, from the CMB anisotropy to the census of galaxies in the local universe, offer the most direct and broad tests for the nature of dark matter, including a number of scenarios that are challenging or even impossible to test in a laboratory setting. I will review the status of the recent early-universe and late-universe searches for the identity of dark matter,...
We use multimessenger observations of the neutron star merger event GW170817 to derive the first merger constraints on axion-like particles (ALPs) coupling to photons. ALP production from Primakoff and photon coalescence processes is calculated; then, the region of parameter space where ALPs can escape the remnant and decay back into two photons is considered. This gives rise to an ALP-induced...
We initiate a study of the gravitational wave signatures of a phase transition that occurs as the Universe's temperature increases during reheating. The gravitational wave signatures of a heating phase transition are different from those of a cooling phase transition and observation of them would allow us to probe reheating. In the lucky case that the gravitational wave signatures from both...
In the last few years increased precision of experimental data led to challenges to ΛCDM. The dynamics of the expansion and the statistics of the growth of structure appear to be in tension between local measurements and inference from the CMB. I will discuss the H0 and S8 tensions and discuss new physics solutions in the context of dark matter/energy and quantum gravity.
I discuss the cosmological signals of theories in which the neutrinos decay into invisible dark radiation after becoming nonrelativistic. I show that, in this scenario, near-future large-scale structure measurements from the Euclid satellite, when combined with cosmic microwave background data from Planck, may allow an independent determination of both the lifetime of the neutrinos and the sum...
I will discuss atmospheric neutrino measurements in DUNE and HK. I will discuss sub-GeV atmospheric neutrinos and how they can be used to measure $\delta_{CP}$; Earth tomography measurements, and the impact of solar cycles in the time modulation of atmospheric neutrinos.
Most will be based on 1904.02751, 2110.00003, and 2304.04689.
While the standard 3-flavor neutrino oscillation scenario is well-established, the mechanism behind neutrino mass is not yet pinned down experimentally. In fact, some new physics (related or not related to new physics behind neutrino mass) can modify the standard 3-flavor neutrino oscillation paradigm. We introduce an analytical solution for n-flavor neutrino oscillation in an arbitrary matter...
Coherent elastic neutrino nucleus scattering (CE$\nu$NS) is a standard-model interaction in which the neutrino interacts with the nucleus as a whole. It was first measured by the COHERENT collaboration in 2017 decades after its prediction.
A coherent interaction is only possible at neutrino energies of a few tens of MeV or below, which makes the Spallation Neutron Source (SNS) at Oak Ridge...
A minimal extension of the standard model is presented that includes a long-lived fermion with weak-scale mass and an O(GeV) fermionic dark matter candidate. Decays of a TeV-scale colored scalar in a radiation-dominated phase bring the former to a thermal abundance while also producing dark matter. The long-lived fermion then drives a period of early matter domination and decays to reheat the...
