The Pierre Auger Observatory, located near Malargüe in the Argentinian province of Mendoza, is the world's largest cosmic ray detector ever built. In operation since 2004, the Pierre Auger Collaboration has published more than a hundred scientific papers covering a wide range of topics regarding the detection, origin, and nature of the most energetic particles of the Universe. In this...
A review of open heavy flavor and quarkonia production measured by STAR and PHENIX Collaborations at RHIC.
Heavy flavored mesons produced with high 𝑝𝑇 in heavy ion collisions collisions, reveal several specific features of the production mechanism:
(i) short time of jet formation by a highly virtual heavy quark;
(ii) enhancement of the fragmentation function at large fractional momenta of the heavy meson;
(iii) extremely short time of color neutralization and formation of the heavy flavored...
Conventional semiconductor detectors used for light dark matter detection via ionization signals lose sensitivity for dark matter masses below an MeV, for which the energy deposited in a scattering event falls below the bandgap. We propose to overcome this limitation by introducing dopants in the semiconductor target. Dopants have ionization energies that lie orders of magnitude below typical...
Black hole superradiance is a unique mechanism that allows a large cloud of ultralight bosons to grow around spinning black holes, requiring only gravitational interactions. I will focus on superradiance of vector fields around stellar mass black holes and consider a dark photon that kinetically mixes with the Standard Model photon. The dark photon superradiance cloud sources a rotating...
An overview of selected recent results in heavy-ion collisions from the CMS experiment.
An open problem in the Standard Model relates to the origin of the mass hierarchy among fermions, and its mixing. Different alternatives have been proposed by adding extra symmetries that relate the three generations of fermions and by extending the Higgs sector. In particular, it has been shown that the S3 symmetry has given good results if two extra Higgs doublets are added to the Standard...
Parton distribution functions at high momentum fraction x continue to be of high interest. On the one hand, they can test predictions from models, effective theories and pQCD in the valence region, where most of the nucleon momentum is carried by a single quark. On the other hand, PDFs at high x and moderate Q2 are linked, via DGLAP evolution, to moderate x and high Q2 kinematics relevant for...
I will describe a low scale renormalizable extended left-right symmetric theory where the observed SM fermion mass hierarchy arises from a seesaw-like mechanism and the light active neutrino masses are generated from a radiative inverse seesaw. I will discuss its implications in charged lepton flavour violation, in the lepton and baryon asymmetries of the Universe, in the muon and electron...
The ATLAS experiment has investigated strong force dynamics via searches for exotic hadron states and measurements of production rates. Studies of potential pentaquark and tetraquark candidates will be discussed, as will measurements of charmonium and B hadron differential cross sections.
The distribution of arrival directions of high-energy cosmic rays carries major clues to understanding their origin. The Pierre Auger Observatory, the largest cosmic-ray observatory in the world, collected an unprecedentedly large data set over 17 years of operation. In this work, we describe anisotropy-related results obtained by using such events. These are the large-scale searches in the...
According to SM, the electroweak bosons couple to the three lepton families with the same strength, the only difference in their behaviour being due to the difference in mass. In recent years, some deviations from the SM predictions have been observed in b→cℓνℓ transitions. These measurements have been made by calculating R-values, which represent the ratio of branching fractions for b decays...
An overview of the latest NA62 results and the future prospect of the experiment are presented. The NA62 experiment at CERN collected the world’s largest dataset of charged kaon decays in 2016-2018, leading to the first measurement of the branching ratio of the ultra-rare 𝐾+→𝜋+𝜈𝜈¯ decay, based on 20 candidates.
The radiative kaon decay 𝐾+→𝜋0𝑒+𝜈𝛾 (Ke3g) was studied with a data sample of...
Search for the dark matter (DM) candidates is one of the growing direction of the experimental and theoretical research in heavy-ion physics [1]. The vector 𝑈-bosons, or so called 'dark photons', are one of the possible candidates for the dark matter mediators. They are supposed to interact with the standard matter via a 'vector portal' due to the 𝑈(1)−𝑈(1)′ symmetry group mixing which might...
Leptoquarks are predicted by many new physics theories to describe the similarities between the lepton and quark sectors of the Standard Model and offer an attractive potential explanation for the B-physics anomalies observed at LHCb and flavour factories. The ATLAS experiment has a broad program of direct searches for leptoquarks, coupling to the first-, second- or third-generation particles....
We describe the phenomenology of the scalar and dark matter sectors of an extended 2HDM with Q4 symmetry among the SM fermions. The model features a Higgs portal to a dark sector comprised of heavy right handed neutrinos. We discuss relic abundance as well as direct detection constraints on the DM candidate.
We discuss the behavior of the Jpsi transverse-momentum distribution in the color evaporation model (CEM) at NLO. Our calculations use transverse-momentum-dependent PDFs and include a timelike parton shower. The latter solves the issue of the too-hard spectrum at NLO in the CEM. Finally, we will present the consequence of the present study for the NRQCD's LDME.
The large top quark samples collected with the ATLAS experiment at the LHC have yielded measurements of the production cross section of unprecedented precision and in new kinematic regimes. They have also enabled new measurements of top quark properties that were previously inaccessible, enabled the observation of many rare top quark production processes predicted by the Standard Model and...
The presence of a non-baryonic Dark Matter (DM) component in the Universe is inferred from the observation of its gravitational interaction. If Dark Matter interacts weakly with the Standard Model (SM) it could be produced at the LHC. The ATLAS Collaboration has developed a broad search program for DM candidates in final states with large missing transverse momentum produced in association...
Many new physics models predict the existence of resonances decaying into two bosons (W, Z, photon, or Higgs bosons) making these important signatures in the search for new physics. Searches for Vy, VV, and VH resonances have been performed in various final states. In some of these searches, jet substructure techniques are used to disentangle the hadronic decay products in highly boosted...
In the high-luminosity era of the Large Hadron Collider, the instantaneous luminosity is expected to reach unprecedented values, resulting in up to 200 proton-proton interactions in a typical bunch crossing. To cope with the resulting increase in occupancy, bandwidth and radiation damage, the ATLAS Inner Detector will be replaced by an all-silicon system, the Inner Tracker (ITk). The innermost...
Supersymmetry (SUSY) provides elegant solutions to several problems in the Standard Model, and searches for SUSY particles are an important component of the LHC physics program. This talk will present the latest results from SUSY searches conducted by the ATLAS experiment. The searches target multiple final states and different assumptions about the decay mode of the produced SUSY particles,...
Various theories beyond the Standard Model predict new, long-lived particles with unique signatures which are difficult to reconstruct and for which estimating the background rates is also a challenge. Signatures from displaced and/or delayed decays anywhere from the inner detector to the muon spectrometer, as well as those of new particles with fractional or multiple values of the charge of...
The ATLAS experiment is able to probe potential beyond the Standard Model physics by performing precise measurements of B meson decays. In particular this talk will highlight the branching fractions of rare decays B_s and B -> mu mu and CP violation in B_s -> J/psi phi, which can both be altered by new physics.
I will present two models where light active neutrino masses are radiatively generated. In the first one the light active neutrino masses are generated at one loop level via a radiative seesaw mechanism mediated by the neutral components of the SU(3)L leptonic Octet and electrically neutral scalars. These SU(3)L leptonic Octet is crucial for achieving successful gauge coupling unification. The...
Experimental uncertainties related to hadronic object reconstruction can limit the precision of physics analyses at the LHC, and so improvements in performance have the potential to broadly increase the impact of results. Recent refinements to reconstruction and calibration procedures for ATLAS jets and MET result in reduced uncertainties, improved pileup stability and other performance gains....
A search is reported for low-mass structures in the J/ψJ/ψ mass spectrum produced by proton-proton collisions at s√=13TeV. The data sample corresponds to an integrated luminosity of 135 fb−1 collected by the CMS experiment at the LHC. Modelling signals with relativistic Breit-Wigner shapes, and under the assumption of the absence of interference between signal components, and between signal...
There are many models trying to explain some of the main current questions in physics. The scotogenic model presents both an explanation to neutrino masses and provides a dark matter candidate that can be a scalar or a fermion. In this work we focus on a real scalar as the dark matter candidate which is generated in a thermal freeze-out scenario. We study the parameter space of the model...
SND@LHC is a compact and stand-alone experiment to perform measurements with neutrinos produced at the LHC in a hitherto unexplored pseudo-rapidity region of 7.2 < 𝜂 < 8.6, complementary to all the other experiments at the LHC. The experiment is located 480 m downstream of IP1 in the unused TI18 tunnel. The detector is composed of a hybrid system based on an 800 kg target mass of tungsten...
The wealth of data and an optimized detector configuration has enabled PHENIX to perform an extensive study on the evolution of medium effects from small to large systems. An insight into the properties of Quark-Gluon Plasma (QGP) is obtained through detailed measurements of the direct photons, 𝜋0-hadron correlation, non-photonic electrons, and 𝐽/𝜓 flow with a large statistics of data...
We suggest a new class of models - Fermionic Portal Vector Dark Matter (FPVDM) which extends the Standard Model (SM) with SU(2)D dark gauge sector. While FPVDM does not require kinetic mixing and Higgs portal, It is based on the Vector-Like (VL) fermionic doublet which couples the dark sector with the SM sector through the Yukawa interaction. The FPVDM model provides a vector Dark Matter (DM)...
Abstract:
The Southern Wide-field Gamma-ray Observatory (SWGO) will be a new extensive air shower array in South America for the observation of VHE (very high energy) to UHE (ultra high energy) gamma rays. The SWGO Collaboration is currently engaged in the design work and the site selection towards the construction of this future facility. SWGO will use an array of water Cherenkov-based...
We present a completely general, model-independent formalism to probe the possible nonstandard couplings of (Dirac and Majorana) neutrinos. The proposed methodology is based on the different quantum statistical properties of the Dirac and Majorana neutrinos which, contrary to neutrinomediated processes of lepton number violation, could lead to observable effects not suppressed by the small...
We discuss the phenomenology of neutrino decoupling in the early universe, by summarising the details of the calculation in standard and non-standard scenarios. We present the state-of-the-art calculation of the effective number of neutrino species in the early universe (Neff) in the three-neutrino case, which gives Neff=3.044, and show how the result can change when additional particles (such...
Muon reconstruction performance plays a crucial role in the precision and sensitivity of the Large Hadron Collider (LHC) data analysis of the ATLAS experiment. Using di-muon Resonances we are able to calibrate to per-mil accuracy the detector response for muons. Innovative techniques developed throughout the Run-2 period and during the collider's shut-down significantly improve the measurement...
We will discuss multi-lepton signals of LNV that can arise with experimentally interesting rates in certain loop models of neutrino mass generation. Interestingly, in such models the observed smallness of the active neutrino masses, together with the high-multiplicity of the final states, leads in large parts of the viable parameter space to the prediction of long-lived charged particles. We...
The event rates and kinematics of Higgs boson production and decay processes at the LHC are sensitive probes of possible new phenomena beyond the Standard Model (BSM). This talk presents precise measurements of Higgs boson production and decay rates, obtained using the full Run 2 pp collision dataset collected by the ATLAS experiment at 13 TeV. These include total and fiducial cross-sections...
The requirements for hadron polarimetry at the future Electron Ion Collider (EIC) include measurements of the absolute helion (3He, ℎ) beam polarization with systematic uncertainties better than 𝜎syst𝑃/𝑃≤1%. Here, we consider a possibility to utilize the Polarized Atomic Hydrogen Gas Jet Target (HJET) for precision measurement of polarization of the ∼100\,GeV/n helion beam. HJET, which serves...
In 2003, an experiment with a Double-Target (liquid deuterium and solid target simultaneously exposed to an electron beam) dedicated to better understanding the hadronization process in a nuclear medium was conducted in the CLAS spectrometer in Jefferson Lab's Hall B. To detect a wider variety of higher energy hadrons with higher luminosity at the upgraded CLAS12, a new experiment will be...
The Daya Bay Reactor Neutrino Experiment discovered a non-zero value
for the neutrino mixing angle 𝜃13 in 2012. Since then, Daya Bay
continues to provide leading determination of this small mixing angle. This
is accomplished by comparing the measured rate and energy spectrum of
electron antineutrinos coming from three pairs of reactors between multiple
identical-designed detectors...
This talk presents precise measurement of the properties of the Higgs boson, including its mass, total width, spin, couplings and CP quantum number. The measurements are performed in various Higgs boson production and decay modes, as well as their combinations. Observation of deviations between these measurements and Standard Model (SM) predictions would be a sign of possible new phenomena...
Hadronic object reconstruction is one of the most promising settings for cutting-edge machine learning and artificial intelligence algorithms at the LHC. In this contribution, selected highlights of ML/AI applications by ATLAS to particle and boosted-object identification, MET reconstruction and other tasks will be presented.
The Standard Model (SM) of particle physics has been very successful in explaining a wide range of experimental observations. However, it still can not address certain issues such as the non-zero neutrino masses, existence of dark matter and the baryon asymmetry of the Universe. This motivates studies beyond the SM. Among the various scenarios that have been proposed in the literature, the...
The discovery of the Higgs boson with the mass of 125 GeV confirmed the mass generation mechanism via spontaneous electroweak symmetry breaking and completed the particle content predicted by the Standard Model. Even though this model is well established and consistent with many experimental measurements, it is not capable of solely explaining some observations. Many extensions of the Standard...
In this work, we study the photon spectrum produced by the Hawking radiation from a primordial black hole (PBH). We focus on the last stages before full evaporation. The spectrum is estimated using the black body approach and Hawking's emission formula. The connection between both descriptions is discussed. Furthermore, through analytical approximations for the greybody factors at the high...
We propose a predictive model based on the $SU(3)_C \times SU(3)_L \times U(1)_X \times U(1)_{Lg}~$ gauge symmetry, supplemented by the $S_4$ family symmetry and auxiliary cyclic symmetries whose spontaneous breaking produces the observed SM fermion mass and mixing pattern. The masses of the neutrinos are produced by an inverse seesaw mechanism mediated by the right-handed Majorana neutrinos....
We propose two extended 3HDM theories where the SM gauge symmetry is enlarged by the inclusion of the spontaneously broken $S_4$ discrete symmetry group, supplemented by the preserved $Z_2$ and broken $Z_4$ cyclic symmetries. The first one has an extra inert scalar singlet field, whereas the second one has an inert scalar doublet. Both models yield the same structure of the mass matrices for...
One of the current topics in Particle Physics is the attempt to understand the nature of dark matter, through the predictions of simplified but realistic models. In this case we will focus on the Minimal Vectorial Dark Matter Model [1], where dark matter is the neutral component of a massive spin 1 field that transforms into the adjoint representation of $SU(2)_L$. The model has two free...
The Schwinger mechanism predicts the production of an electron-positron pair through the decay of an extremely strong electric field. The electro-magnetic dual of this process would produce magnetic monopoles (MMs) - if they exist - in sufficiently strong magnetic fields. The 2018 lead ion collisions at the LHC produced the strongest magnetic fields in the known Universe. The MoEDAL detectors...
With large active volume sizes dark matter direct detection experiments are sensitive to solar neutrino fluxes. Nuclear recoil signals are induced by $^{8}B$ neutrinos, while electron recoils are mainly generated by the pp flux. Measurements of both processes offer an opportunity to test neutrino properties at low thresholds with fairly low backgrounds. In this work we study the sensitivity of...
Assumed a test magnetic dipole (MD) moment contains positive magnetic charge on its North Pole. Laws of physics tell that an accelerating object can lose applied (external) energy. In the case of a test MD-moment undergone free fall, its mass keeping constant in allowing to pass through the region B1B1 of a positively diverged magnetic (PDM) field contained 1d box on condition that Δv/Δt =...
A vital issue in making accurate predictions in QCD is establishing the renormalization scale $\mu_r$ to determine the correct running coupling in the perturbative expansion. In conventional scaling, the renormalization scale is set to the typical process scale $Q$, and errors are estimated by scaling over a range of two $[Q/2,2Q]$. This procedure introduces a considerable ambiguity in the...
An overview of selected recent results in heavy-ion collisions from the CMS experiment.
The Tokai-to-Kamioka (T2K) long-baseline neutrino experiment measures neutrino-flavor oscillation parameters using the three-flavor oscillation model parameterized by the PMNS matrix. This measurement is performed by sampling the JPARC (anti)neutrino beam by various detectors: once at a near detector complex before oscillations take place and once at a far detector after oscillations. A...
Machine learning (ML) is becoming more widely used in nuclear physics, often used to complement or replace conventional data analysis, eg for detector calibration, track reconstruction and particle identification, but it is rarely used for detector control. We developed a ML model and incorporated it into software to control the anode voltage of the GlueX Central Drift Chamber in order to...
The IceCube observatory at the South Pole, with its 1km3 of instrumented ice, is one of the largest neutrino detectors worldwide. The observatory has detected the first high-energy astrophysical neutrinos and has shown compelling evidence for the first neutrino point source. The success of IceCube has matured plans for the extension of its energy range of 10GeV to PeV towards both lower and...
We have studied Bose-Einstein correlations for positive pions produced in DIS events with data from experiments carried out during the run period EG2 in Jefferson Lab, Virginia using different targets, such as D2, C, Fe and Pb, exposed to a 5.014 GeV electron beam. By comparing the pairs of π+ from same events to uncorrelated pairs, we can obtain information of the space-time structure and...
Suppression of open heavy flavors and quarkonia in heavy-ion collisions is among the most informative probes of the quark-gluon plasma. Interpreting the full wealth of data obtained from the collision events requires a precise understanding of the evolution of heavy quarks and quarkonia as they propagate through the nearly thermal and strongly coupled plasma. Only in the past few years,...
This talk presents an overview of recent ATLAS measurements in heavy ion collision systems. These include multiple measurements of jet production and structure, which probe the dynamics of the hot, dense Quark-Gluon Plasma formed in relativistic nucleus-nucleus collisions, and measurements of quarkonia and heavy flavor production to probe the QGP medium properties. The final measurement of...
MicroBooNE is a liquid argon time projection chamber (LArTPC) neutrino detector located in Fermilab. Operating from 2015 to 2020 it collected the largest number of neutrino interactions in liquid-argon to date. Its primary physics goal is to clarify the origins of the low-energy excess of electromagnetic activity observed by MiniBooNE; the first set of results on this were released during...
The ATLAS Liquid Argon (LAr) calorimeter measures the energy of particles produced in LHC collisions. This calorimeter has also trigger capabilities to identify interesting events. In order to enhance the ATLAS detector physics discovery potential, in the blurred environment created by the pileup, an excellent resolution of the deposited energy and an accurate detection of the deposited time...
We consider the effects of a noisy magnetic field background over the fermion propagator in QED, as an approximation to the spatial inhomogeneities that would naturally arise in certain physical scenarios, such as heavy ion collisions or the quark gluon plasma in the early stages of the evolution of the universe. We consider a classical, finite and uniform magnetic field background ⟨𝐁(𝐱)⟩=𝐁,...
In this talk I will briefly review the status of neutrino physics and describe symmetry-based approaches to some of the main drawbacks of in particle physics
Long-lived particles are predicted in several beyond the Standard Model theories. Their signatures can be tested at the LHC main detectors (such as ATLAS or CMS), current and proposed far detectors (such as FASER or MATHUSLA), as well as other experimental facilities. I will comment on the phenomenology of displaced signatures and sensitivity reach of models predicting long-lived Heavy Neutral...
The sPHENIX detector at the BNL Relativistic Heavy Ion Collider (RHIC) is currently under construction and on schedule for first data in summer 2023. Built around the excellent BaBar superconducting solenoid, the central detector consists of a silicon pixel vertexer adapted from the ALICE ITS design, a silicon strip detector with single event timing resolution, a compact TPC, novel EM...
MoEDAL is an experiment at the LHC that is dedicated to searches for magnetic monopoles (MM) and other exotic particles. In Run 2, MoEDAL established best current laboratory constraints for point-like MM with magnetic charges ranging from 2 to 5 Dirac charges, surpassing the results of ATLAS in this range. MoEDAL also performed the first search for Dyons, particles with both electric and...
The Liquid Argon Calorimeters are employed by ATLAS for all electromagnetic calorimetry in the pseudo-rapidity region |η| < 3.2, and for hadronic and forward calorimetry in the region from |η| = 1.5 to |η| = 4.9. They also provide inputs to the first level of the ATLAS trigger. After successful period of data taking during the LHC Run-2 between 2015 and 2018 the ATLAS detector entered into the...
A new era of hadron collisions will start around 2029 with the High-Luminosity LHC which will allow to collect ten times more data than what has been collected during 10 years of operation at LHC. This will be achieved by higher instantaneous luminosity at the price of higher number of collisions per bunch crossing.
In order to withstand the high expected radiation doses and the harsher...
The Circular Electron Positron Collider (CEPC) and Future Electron Position Circular Collider (FCCee) were been proposed as a Higgs and high luminosity Z factory in last few years. The detector conceptual design of a updated detector consists of a tracking system, which is a high precision (about 100μm) spatial resolution Time Projection Chamber (TPC) detector as the main track device in very...
With the restart of the proton-proton collision program in 2022 (Run-3) at the Large Hadron Collider (LHC), the ATLAS detector aims to double the integrated luminosity accumulated during the ten previous years of operation. After this data-taking period the LHC will undergo an ambitious upgrade program to be able to deliver an instantaneous luminosity of $7.5\times 10^{34}$ cm$^{-2}$...
A search for supersymmetric particles produced in the Vector Boson Fusion (VBF) topology using LHC Run II data at $\sqrt{s}$ = 13 TeV collected with the CMS detector is performed. The search focuses on the final states involving a single low-pT lepton, large missing transverse momentum, and two widely separated jets having large invariant mass. Such a dijet system is the peculiar signature of...
