Related papers: The Lightest Massive Invisible Particles at the LH…
We now know firmly that neutrinos have tiny masses, but in the minimal Standard Model there is no natural sources for such tiny masses. On the other hand, the extra heavy Z^{\prime 0} requires the extra Higgs field, the particle generating…
The identification of the nature of dark matter is one of the most important problems confronting particle physics. Current observational constraints permit the mass of the dark matter to range from $10^{-22}$ eV - $10^{48}$ GeV. Given the…
We consider the Littlest Higgs Model with T-parity (LHT), in the parameter region where a heavy neutrino is the lightest T-odd particle (LTP). Having emphasized that this corresponds to a sizable region in the parameter space of the theory,…
We address the question how light the lightest MSSM neutralino can be as dark matter candidate in a scenario where all supersymmetric scalar particles are heavy. The hypothesis that the neutralino accounts for the observed dark matter…
We propose a new method to detect low-energy neutrinos and low-mass dark matter at or below the MeV scale, through their coherent scatterings from freely falling heavy atoms and the resulting kinematic shifts. We start with a simple…
We examine the case of neutralino dark matter in the focus point region of the MSSM, in which the scalar sparticles are too heavy to be produced at the LHC. Whilst it has been previously asserted that the LHC alone would fail to constrain…
A search for dark matter particles is performed using events with a pair of W bosons and large missing transverse momentum. Candidate events are selected by requiring one or two leptons ($\ell =$ electrons or muons). The analysis is based…
Although various pieces of indirect evidence about the nature of dark matter have been collected, its direct detection has eluded experimental searches despite extensive effort. If the mass of dark matter is below 1 MeV, it is essentially…
The cold dark matter (CDM) cosmological model unambigously predicts that a large number of haloes should survive as subhaloes when they are accreted into a larger halo. The CDM model would be ruled out if such substructures were shown not…
A search for dark matter particles is performed by looking for events with large transverse momentum imbalance and a recoiling Higgs boson decaying to either a pair of photons or a pair of $\tau$ leptons. The search is based on…
We propose a simple testable model with mass generation mechanisms for dark matter and neutrino based on the gauged $U(1)_{B-L}$ symmetry and an exact $Z_2$ parity. The $U(1)_{B-L}$ symmetry is spontaneously broken at the TeV scale, by…
Under the assumption that dark matter is made of new particles, annihilations of those are required to reproduce the correct dark matter abundance in the Universe. This process can occur in dense regions of our Galaxy such as the Galactic…
The search for dark matter has been performed mainly for weakly interacting massive particles and massive compact halo objects, and the intermediate mass region has not been investigated experimentally. A method to search dark matter with…
A search for dark matter is conducted in events with large missing transverse momentum and a hadronically decaying, Lorentz-boosted top quark. This study is performed using proton-proton collisions at a center-of-mass energy of 13 TeV, in…
A long-range ``dark force'' has recently been proposed to mediate the dark matter (DM) annihilation. If DM particles are copiously produced at the Large Hadron Collider (LHC), the light dark force mediator will also be produced through…
Motivated by the recent discovery of the Higgs boson, we investigate the possibility that a missing energy plus Higgs final state is the dominant signal channel for dark matter at the LHC. We consider examples of higher-dimension operators…
Cosmological measurements indicate that a large component of non-visible gravitating matter is present in the universe. A common hypothesis for its origin is a weakly interacting, massive particle. Annihilations or decays of such particles…
Despite being very successful in explaining the wide range of precision experimental results obtained so far, the Standard Model (SM) of elementary particles fails to address two of the greatest observations of the recent decades: tiny but…
Freeze-in mechanism provides robust dark matter production in the early universe. Due to its feeble interactions, freeze-in dark matter leaves signals at colliders which are often involved with long lived particle decays and consequent…
Understanding the fundamental nature and properties of dark matter is a main goal of fundamental physics experiments. The LHC experiments seek to detect processes that could explain how dark matter is produced and how it interacts with…