Dark Matter-Neutrino Interaction in Light of Collider and Neutrino Telescope Data

We study the DM-neutrino interaction in the framework of simplified model. The phenomenology of such an interaction are derived. We also investigate the bound on DM-neutrino interaction from the LHC and neutrino telescopes. We find that for the case of a scalar dark matter, the LHC gives a stronger bound on dark matter annihilation cross-section than the neutrino telescopes. However, for the fermionic dark matter case the neutrino telescopes bounds are more stringent for dark matter mass, $\gtrsim 200$ MeV. In the case of lower DM mass, the neutrino telescopes provide better bounds for a light mediator, while the collider bounds are better for a heavy mediator. Possible UV completions of the simplified model are briefly discussed.Comment: 23 pages, 12 figures. Add discussion on DM-neutrino interaction. References updated. Match JHEP versio

Probing Lepton Flavor Violation at the 13 TeV LHC

We investigate the bounds on tau-mu lepton flavor violation (LFV). Our main focus is on the collider constrains on tau-mu LFV. We use the Type-III Two-Higgs-Doublet-Model (2HDM) as a set up for our study. While the LFV branching fraction of the 125 GeV is well constrained by current LHC searches, the heavier neutral states could have a large branching fraction to tau and muon. We estimate the LHC reach for the 13 TeV center of mass energy with 300 $\text{fb}^{-1}$ luminosity for a neutral boson decaying into a tau and a muon. We identify parts of the LFV parameter space where the searches for heavy scalar and pseudoscalar decaying into a tau and a muon are more sensitive than the similar search for the 125 GeV boson.Comment: 29 + 3 pages, 23 figures. Version 2 expanded discussion of low energy constraints and added more references. Matched the JHEP versio

Dark matter in the heavens and at colliders: Models and constraints

In this dissertation, we investigate various aspects of dark matter detection and model building. Motivated by the cosmic ray positron excess observed by PAMELA, we construct models of decaying dark matter to explain the excess. Specifically we present an explicit, TeV-scale model of decaying dark matter in which the approximate stability of the dark matter candidate is a consequence of a global symmetry that is broken only by instanton-induced operators generated by a non-Abelian dark gauge group. Alternatively, the decaying operator can arise as a Planck suppressed correction in a model with an Abelian discrete symmetry and vector-like states at an intermediate scale that are responsible for generating lepton Yukawa couplings. A flavor-nonconserving dark matter decay is also considered in the case of fermionic dark matter. Assuming a general Dirac structure for the four-fermion contact interactions of interest, the cosmic-ray electron and positron spectra were studied. We show that good fits to the current data can be obtained for both charged-lepton-flavor-conserving and flavor-violating decay channels. Motivated by a possible excess of gamma rays in the galactic center, we constructed a supersymmetric leptophilic higgs model to explain the excess. Finally, we consider an improvement on dark matter collider searches using the Razor analysis, which was originally utilized for supersymmetry searches by the CMS collaboration

KARAKTERISASI INTERAKSI WIMP-QUARKS DI LHC DENGAN MENGGUNAKAN DEEP LEARNING

Materi gelap merupakan salah satu komponen terbesar dari isi alam semesta yang kita tidak ketahui interaksinya. Large Hadron Collider (LHC) merupakan laboratorium yang dapat digunakan untuk mencari materi gelap terutama dalam bentuk Weakly Interacting Massive Particles (WIMP). Untuk mencari sifat interaksi dari materi gelap, jika ditemukan pada LHC, maka channel sepasang lepton dan missing energy dapat diguanakan. Penelitian ini dilakukan untuk mencari cara untuk membedakan interaksi dari WIMP dengan menggunakan deep feedforward networks. Dengan cara ini didapat akurasi 62,41% dalam membedakan jenis interaksi V+A dan V-A

Taking a razor to dark matter parameter space at the LHC

Dark matter (DM) has been searched for at colliders in a largely model-independent fashion by looking for an excess number of events involving a single jet, or photon, and missing energy. We investigate the possibility of looking for excesses in more inclusive jet channels. Events with multiple jets contain more information and thus more handles to increase the signal-to-background ratio. In particular, we adapt the recent CMS razor analysis from a search for supersymmetry (SUSY) to a search for DM and estimate the potential reach. The region of razor variables which are most sensitive to dark matter are not covered by the current SUSY search. We consider simplified models where DM is a Dirac fermion that couples to the quarks of the standard model (SM) through exchange of vector or axial-vector mediators or to gluons through scalar exchange. We consider both light and heavy (leading to effective contact interactions) mediators. Since the razor analysis requires multiple jets in the final state, the data set is complementary to that used for the monojet search and thus the bounds can be combined

The Dark Penguin Shines Light at Colliders

Collider experiments are one of the most promising ways to constrain Dark Matter (DM) interactions. For several types of DM-Standard Model couplings, a meaningful interpretation of the results requires to go beyond effective field theory, considering simplified models with light mediators. This is especially important in the case of loop-mediated interactions. In this paper we perform the first simplified model study of the magnetic dipole interacting DM, by including the one-loop momentum-dependent form factors that mediate the coupling -- given by the Dark Penguin -- in collider processes. We compute bounds from the monojet, monophoton, and diphoton searches at the $8$ and $14$ TeV LHC, and compare the results to those of direct and indirect detection experiments. Future searches at the $100$ TeV hadron collider and at the ILC are also addressed. We find that the optimal search strategy requires loose cuts on the missing transverse energy, to capture the enhancement of the form factors near the threshold for on-shell production of the mediators. We consider both minimal models and models where an additional state beyond the DM is accessible. In the latter case, under the assumption of anarchic flavor structure in the dark sector, the LHC monophoton and diphoton searches will be able to set much stronger bounds than in the minimal scenario. A determination of the mass of the heavier dark fermion might be feasible using the $M_{T2}$ variable. In addition, if the Dark Penguin flavor structure is almost aligned with that of the DM mass, a displaced signal from the decay of the heavier dark fermion into the DM and photon can be observed. This allows us to set constraints on the mixings and couplings of the model from an existing search for non-pointing photons.Comment: 32 pages + appendices and references, 22 figure

From gamma ray line signals of dark matter to the LHC

We explore the relationship between astrophysical gamma-ray signals and LHC signatures for a class of phenomenologically successful secluded dark matter models, motivated by recent evidence for a ~130 GeV gamma-ray line. We consider in detail scenarios in which interactions between the dark sector and the standard model are mediated by a vev-less scalar field \phi, transforming as an N-plet (N > 3) under SU(2)_L. Since some of the component fields of \phi carry large electric charges, loop induced dark matter annihilation to \gamma \gamma and \gamma Z can be enhanced without the need for non-perturbatively large couplings, and without overproduction of continuum gamma-rays from other final states. We discuss prospects for other experimental tests, including dark matter-nucleon scattering and production of \phi at the LHC, where future searches for anomalous charged tracks may be sensitive. The first LHC hints could come from the Higgs sector, where loop corrections involving \phi lead to significantly modified h to \gamma \gamma and h to \gamma Z branching ratios.Comment: 27 pages, 10 figures. v2: added references, fixed import-order issue with cleveref and hyperref. v3: updated to journal version. v4: erratum correction to figs. 7-8 for monojet/monophoton cross-section

Dark Matter Induced Brownian Motion

We discuss a novel approach for directional, light dark matter searches inspired by the high precision position measurements achieved in gravitational wave detectors. If dark matter interacts with ordinary matter, movable masses are subject to an effect similar to Brownian motion induced by the scattering with dark matter particles which exhibits certain characteristics and could be observed. We provide estimates for the sensitivity of a hypothetical experiment looking for that motion. Interestingly, if successful, our approach would allow to constrain the local distribution of dark matter momentum.Comment: 12 pages, 3 figures; version published in EPJ