In this work, we consider an extension of the Standard Model (SM) with an inert Higgs doublet and... more In this work, we consider an extension of the Standard Model (SM) with an inert Higgs doublet and a real scalar singlet, in order to address problems around the origin of dark matter (DM). In this model, the lightest among the CP-odd and CP-even neutral inert components plays the role of a DM candidate, where the model parameters are subject to many theoretical and experimental constraints. These constraints include vacuum stability, perturbativity, LEP negative searches, electroweak precision tests, Higgs di-photon, Higgs invisible and Higgs undetermined decays, DM relic density and DM direct detection bounds. Using these constraints, we find that the allowed parameter space for these models is quite sizeable and could be explored in upcoming collider and astrophysical searches.
In this work, we consider an extension of the Standard Model with an inert Higgs doublet and a re... more In this work, we consider an extension of the Standard Model with an inert Higgs doublet and a real scalar singlet, in order to address problems around the origin of dark matter (DM). In this model, the lightest among the CP-odd and CP-even neutral inert components plays the role of a DM candidate, where the model parameters are subject to many theoretical and experimental constraints. These constraints include vacuum stability, perturbativity, LEP negative searches, electroweak precision tests, Higgs diphoton, Higgs invisible and Higgs undetermined decays, DM relic density, and DM direct detection bounds. Using these constraints, we find that the allowed parameter space for these models is quite sizable and could be explored in upcoming collider and astrophysical searches.
We have addressed this erratum for two reasons: (1) we have detected an error in the code where t... more We have addressed this erratum for two reasons: (1) we have detected an error in the code where the b → s bounds were not properly included; and (2) we realized that the possible parameter space was not fully considered, since we ignored the negative values of the mixing tan β according to the referee's suggestion. Here, we take advantage of this erratum to correct a typo in (4) where it becomes ffiffi ffi 2 p υs β ;
In this work, we investigate the parameter space of the Georgi-Machacek (GM) model, where we cons... more In this work, we investigate the parameter space of the Georgi-Machacek (GM) model, where we consider many theoretical and experimental constraints such as the perturbativity, vacuum stability, unitarity, electroweak precision tests, the Higgs diphoton decay, the Higgs total decay width and the LHC measurements of the signal strengths of the SM-like Higgs boson h in addition to the constraints from doubly charged Higgs bosons and Drell-Yan diphoton production and the indirect constraint from the b → s transition processes. We investigate also the possibility that the electroweak vacuum could be destabilized by unwanted wrong minima that may violate the CP and/or the electric charge symmetries. We found that about 40 % of the parameter space that fulfills the above mentioned constraints are excluded by these unwanted minima. In addition, we found that the negative searches for a heavy resonance could exclude a significant part of the viable parameter space, and future searches could exclude more regions in the parameter space.
Contributions to the 36th International Cosmic Ray Conference (ICRC 2019) of the JEM-EUSO Collaboration
arXiv: High Energy Astrophysical Phenomena, 2019
Compilation of papers presented by the JEM-EUSO Collaboration at the 36th International Cosmic Ra... more Compilation of papers presented by the JEM-EUSO Collaboration at the 36th International Cosmic Ray Conference (ICRC), held July 24 through August 1, 2019 in Madison, Wisconsin.
EUSO-TA is a on-ground telescope, installed at the Telescope Array (TA) site in Black Rock Mesa, ... more EUSO-TA is a on-ground telescope, installed at the Telescope Array (TA) site in Black Rock Mesa, Utah, USA in 2013. The main aim of the project is observation of Ultra High Energy Cosmic Rays (UHECR) through detection of ultraviolet light generated by cosmic-ray showers. EUSO-TA consists of two, 1 m 2 square Fresnel lenses with a field of view of about 10.6 • × 10.6 •. Light is focused on the Photo Detector Module (PDM), identical to the ones that are employed in the other EUSO missions' focal surfaces. The PDM is composed of 36 Hamamatsu multi-anode photomultipliers (64 channels per tube), for a total of 2304 channels. Front-End readout is performed by 36 ASICS, with trigger and readout tasks done by two acquisition boards that send the data to a CPU and storage system. The telescope is housed in a shed located in front of one of the fluorescence detectors of the TA experiment, pointing in the direction of the Electron Light Source and Central Laser Facility. After the installation in February 2013, the performance of the detector has been very good, with little (about one photoelectron) electronic noise and a Point Spread Function of stars compatible with expectations. Several ultra high energy cosmic rays and meteors have been observed. The limiting magnitude of 5.5 on summed frames has been established, with PSF of ∼ 2.5 pixels FWHM. Measurements of the UV background in different darkness conditions and moon phases and positions have been completed. EUSO-TA has been used for development of balloon and space flights within the EUSO framework.
Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese E... more Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25 th of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.
The JEM-EUSO (Joint Experiment Missions for the Extreme Universe Space Observatory) program aims ... more The JEM-EUSO (Joint Experiment Missions for the Extreme Universe Space Observatory) program aims at developing UltraViolet (UV) fluorescence telescopes for efficient detections of Extensive Air Showers (EASs) induced by Ultra-High Energy Cosmic Rays (UHECRs) from satellite orbit. In order to demonstrate key technologies for JEM-EUSO, we constructed the EUSO-Balloon instrument that consists of a 1 m 2 refractive telescope with two Fresnel lenses and an array of multi-anode photo-multiplier tubes at the focus. Distinguishing it from the former balloon-borne experiments, EUSO-Balloon has the capabilities of single photon counting with a gate time of 2.3 µs and of has imaging with a total of 2304 pixels. As a pathfinder mission, the instrument was launched for an 8 hour stratospheric flight on a moonless night in August 2014 over Timmins, Canada. In this work, we analyze the count rates over 2.5 hour intervals. The measurements are of diffuse light, e.g. of airglow emission, back-scattered from the Earth's atmosphere as well as artificial light 166 4 ACCEPTED MANUSCRIPT sources. Count rates from such diffuse light are a background for EAS detections in future missions and relevant factor for the analysis of EAS events. We also obtain the geographical distribution of the count rates over a km 2 area along the balloon trajectory. In developed areas, light sources such a the airport, mines, and factories are clearly identified. This demonstrates the correct location of signals that will be required for the EAS analysis in future missions. Although a precise determination of count rates is relevant for the existing instruments, the absolute intensity of diffuse light is deduced for the limited conditions by assuming spectra models and considering simulations of the instrument response. Based on the study of diffuse light by EUSO-Balloon, we also discuss the implications for coming pathfinders and future space-based UHECR observation missions.
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2017
JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (... more JEM-EUSO is a space mission designed to investigate Ultra-High Energy Cosmic Rays and Neutrinos (E > 5 • 10 19 eV) from the International Space Station (ISS). Looking down from above its wide angle telescope is able to observe their air showers and collect such data from a very wide area. Highly specific trigger algorithms are needed to drastically reduce the data load in the presence of both atmospheric and human activity related background light, yet retain the rare cosmic ray events recorded in the telescope. We report the performance in offline testing of the first level trigger algorithm on data from JEM-EUSO prototypes and laboratory measurements observing different light sources: data taken during a high altitude balloon flight over Canada, laser pulses observed from the ground traversing the real atmosphere, and model landscapes reproducing realistic aspect ratios and light 5 conditions as would be seen from the ISS itself. The first level trigger logic successfully kept the trigger rate within the permissible bounds when challenged with artificially produced as well as naturally encountered night sky background fluctuations and while retaining events with general air-shower characteristics.
We summarize the state of the art of a program of UV observations from space of meteor phenomena,... more We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop dia... more In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop diagrams. The standard model (SM) is extended by three singlet Majorana fermions and two inert scalar doublets instead of one doublet as in the minimal scotogenic model. The model scalar sector includes two CP-even, two CP-odd and two charged scalars in addition to the Higgs. The dark matter (DM) candidate could be either the light Majorana fermion (Majorana DM), or the lightest among the CP-even and the CP-odd scalars (scalar DM). We show that the model accommodates both Majorana and scalar DM within a significant viable parameter space, while considering all the relevant theoretical and experimental constraints such as perturbativity, vacuum stability, unitarity, the di-photon Higgs decay, electroweak precision tests and lepton flavor violating constraints. In addition to the collider signatures predicted by the minimal scotogenic model, our model predicts some novel signatures that can be probed through some final states such as 8 jets + / E T , 1 + 4 jets + / E T and 4b + / E T .
We identify a minimal model achieving one-loop radiative neutrino masses due to couplings with da... more We identify a minimal model achieving one-loop radiative neutrino masses due to couplings with dark matter. Interestingly the model contains both the quintuplet fermion and the septuplet scalar identified as minimal dark matter candidates by Cirelli, Fornengo and Strumia - it gives radiative neutrino mass due to both minimal dark matter candidates. The model is related to those proposed in a recent work (dubbed minimal R$\nu$MDM models). Here we note that one of the latter models, which employs the T1-iii one-loop topology and was studied in detail, is not a viable R$\nu$MDM model (the scalar potential contains a term that explicitly breaks the accidental symmetry, rendering the dark matter unstable). Identifying this issue leads to our new model and a related variant.
In this letter, we show that the electroweak symmetry is restored at high temperature for Little ... more In this letter, we show that the electroweak symmetry is restored at high temperature for Little Higgs (LH), when including dominant higher order thermal corrections, that are consequence of the non-linear nature of the scalar sector. This leads us to suggest that the LH requires a UV completion above the scale Λ f .
Dark matter nature at electron-positron colliders: scalar or fermionic?
Journal of Physics: Conference Series, 2021
In this work, we investigated the possibility of identifying DM nature, at the future electron-po... more In this work, we investigated the possibility of identifying DM nature, at the future electron-positron colliders such as the International Linear Collider (ILC) and Compact Linear Collider (CLIC), at s=500GeV and 1 TeV, using the final state bb¯+ET . For this purpose, we consider two models in which DM could be either a real scalar or a heavy right-handed neutrino (RHN). So we considered two parameter values sets for both models, and we defined and investigated the different recent experimental constraints. After that we define a set of kinematical cuts that suppress the background, and generate different distributions that are useful in identifying the DM nature. The use of polarized beams P(e −, e +) = [+0.8,−0.3] at the ILC makes the signal detection easier and the DM identification more clear, where the statistical significance gets enhanced by twice (five times) for scalar (fermionic) DM.
In a class of neutrino mass models with a lepton flavor violation (LFV) Yukawa interaction term t... more In a class of neutrino mass models with a lepton flavor violation (LFV) Yukawa interaction term that involves a heavy right handed neutrino, a charged scalar and a charged lepton, we investigate at the ILC@500 GeV the possibility of observing news physics. These models can address neutrino mass and dark matter without being in conflict with different LFV constraints. By imposing DM relic density and LFV constraints, we recast the analysis done by L3 collaboration at LEP-II of monophoton searches on our space parameter and look for new physics in such channels like monophoton and $S S(\\gamma)$, where we give different cuts and show the predicted distributions. We show also that using polarized beams could improve the statistical significance.
In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop dia... more In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop diagrams. The standard model (SM) is extended by three singlet Majorana fermions and two inert scalar doublets instead of one doublet as in the minimal scotogenic model. The model scalar sector includes two CP-even, two CP-odd and two charged scalars in addition to the Higgs. The dark matter (DM) candidate could be either the light Majorana fermion (Majorana DM), or the lightest among the CP-even and the CP-odd scalars (scalar DM). We show that the model accommodates both Majorana and scalar DM within a significant viable parameter space, while considering all the relevant theoretical and experimental constraints such as perturbativity, vacuum stability, unitarity, the di-photon Higgs decay, electroweak precision tests and lepton flavor violating constraints. In addition to the collider signatures predicted by the minimal scotogenic model, our model predicts some novel signatures that can b...
We present a minimal model that simultaneously accounts for neutrino masses and the origin of dar... more We present a minimal model that simultaneously accounts for neutrino masses and the origin of dark matter (DM) and where the electroweak phase transition is strong enough to allow for electroweak baryogenesis. The Standard Model is enlarged with a Majorana fermion, three generations of chiral fermion pairs, and a single complex scalar that plays a central role in DM production and phenomenology, neutrino masses, and the strength of the phase transition. All the new fields are singlets under the SM gauge group. Neutrino masses are generated via a new variant of radiative inverse seesaw where the required small mass term is generated via loops involving DM and no large hierarchy is assumed among the mass scales. The model offers all the advantage of low-scale neutrino mass models as well as a viable dark matter candidate that is testable with direct detection experiments.
Uploads
Papers by Amine Ahriche