The quest for the origin of ultra-high-energy cosmic rays (UHECRs) continues to be an open question in high energy astrophysics. We will give an overview of the current status of the field from an experimental point of view, discussing the most recent results and the information obtained in a multi-messenger approach. The open problems and the perspectives of multi-messenger observatories...
Large High-Altitude Air Shower Observatory (LHAASO) has one square kilometer array of scintillator detectors and muon detectors (KM2A), 18 Wide Field of View Imaging Atmospheric Cherenkov Telescopes (WFCTA) and a 78,000 square meter Water Cherenkov Detector Array (WCDA). LHAASO is located at very high altitude (around 4410 m a.s.l.) in Haizishan mountain, Daocheng, Sichuan, China....
In this talk we will report on the investigation of cosmic rays in the energy range between some 100 TeV and about 1 EeV using the IceCube Neutrino Observatory at the South Pole. The IceCube facility combines the in-ice detector with the 1-km$^2$ surface detector IceTop. The combination offers a unique possibility to study the air shower development at the surface together with the high energy...
Over the past forty years, there have been occasional reports of the observations of ‘bursts’ by small air shower arrays operating at energies of about 1 PeV. These would seem to be of astrophysical origin and related to the thrust of studies pursued to the CREDO program. The bursts are rare and few burst searches have extended past a a time required to record more than a handful of...
In this talk, I will revisit our understanding of the air shower initiated by ultra high energy cosmic rays, focusing on the hadronic core and how macroscopic variables relate with the microscopic variables of the highest energy hadronic interactions therein. Many of those interactions occur at energies and phase-space regions beyond the reach of accelerator experiments. It will be shown how...
Indications of a discrepancy between simulations and data on the number of muons in cosmic ray showers exist over a large span of investigations. The excess of muon bundles has been observed by the ALICE detector at LHC in its dedicated cosmic ray run (confirming similar findings from the LEP era at CERN) as well as the excess in the muon number in general has been reported by the Pierre...
The talk aims to introduce the status of the field, discuss key recent results and instruments, as well as future perspectives.
Very-high-energy (VHE) gamma-ray astroparticle physics is a relatively young field, and observations over the past decade have surprisingly revealed almost two hundred VHE emitters which appear to act as cosmic particle accelerators. These sources are an important component of the Universe, influencing the evolution of stars and galaxies. At the same time, they also act as a probe of physics...
SiPMs are now widely applied for light detection in particle physics and astroparticle. I will focus on Cherenkov light detection from ground and discuss also some space application. Focus will be construction of cameras and challenges for their operation.
The Very Energetic Radiation Imaging Telescope Array System (VERITAS) consists of four atmospheric Cherenkov telescopes fully operating in the northern hemisphere since 2007. It is located at Fred Lawrence Whipple Observatory in southern Arizona, USA and is sensitive to gamma rays from 85 GeV to 30 TeV energy range. One of the major focuses of the broad science topics of the multinational...
In this presentation, I will discuss how the wide field-of-view, high-duty cycle, and excellent sensitivity at energies above 10 TeV make the HAWC Gamma-Ray Observatory a uniquely suited instrument to survey the Northern Hemisphere sky for cosmic-ray acceleration, distribution, and propagation, gamma-ray transients, dark matter signals, and other fundamental physics phenomena. I will present...
The Fermi Large Area Telescope has been surveying the gamma-ray sky for more than 13 years. With more than 5,000 detected gamma-ray sources, LAT observations have been instrumental to improve our understanding of particle acceleration and gamma-ray production in astrophysical sources. In this talk, I will review recent science highlights from the LAT. In particular, I will focus on transient...
In this talk, we will review multi-messenger capabilities of the Pierre Auger Observatory involving searches for high energy neutrinos and photons from transient events as well as searches for temporal and/or directional correlations between different messengers including UHECR. Upper bounds on the flux of up-going air showers - of the type that was reported by ANITA - will be presented and...
Investigations of the energy spectrum as well as the mass composition of cosmic rays in the energy range of PeV to EeV are important for understanding both, the origin of the galactic and the extragalactic cosmic rays. The multi-detector arrangement of KASCADE and its extension KASCADE-Grande was designed for observations of cosmic ray air showers in this energy range. Most important result...
We discuss the acceleration and escape of secondary cosmic-ray (CR) nuclei, such as lithium, beryllium, and boron, produced by spallation of primary CR nuclei like carbon, nitrogen, and oxygen accelerated at the shock in supernova remnants (SNRs) surrounded by the interstellar medium (ISM) or a circumstellar medium (CSM). We take into account the energy-dependent escape of CR particles from...
High Energy Stereoscopic System (H.E.S.S.)$^1$ is a very high energy gamma-ray observatory located in the Khomas Highlands in Namibia. It operates a hybrid set of five imaging atmospheric Cherenkov telescopes, with its one 28 m instrument being the largest in the World. For almost 20 years, since its beginning H.E.S.S. delivers high quality scientific results revolutionizing our understanding...
MAGIC is an array of two 17-m diameter Cherenkov telescopes observing gamma rays in the very-high-energy (VHE; above a few tens of GeV) range. MAGIC is in operation since 2003, leading a successful observational program covering a broad range of scientific topics. Observations of gamma-ray emission from Galactic or extragalactic sources allow us to probe the conditions of acceleration of...
Detection of 1.1 PeV photons from the Crab poses challenges to even classical electrodynamic theory and pure magnetohydrodynamics. Or, an accelerator that boosts protons to at highest energy of 30 PeV may be at the center of the nebula? LHAASO has found the most fascinating object, which was recorded as the first recognized supernova by Chinese in Song dynasty, so attractive that it may hint...
Massive stars with powerful winds represent alternatives to supernova remnants as major contributors to CRs. Currently, based on the spectral and morphological studies of GeV and TeV gamma-rays, the evidence is mounting that young massive stellar clusters are indeed the highest energy CR factories. The colliding stellar winds and SN explosions can drive superbubbles filled by highly turbulent...
The Galaxy hosts sources of cosmic rays up to PeV energies, so called PeVatrons. Gamma-rays at the highest energies turn out to be the most effective tracer of the highest energies cosmic rays in the Galaxy. I will here review current searches for the sources of the highest energy cosmic rays. I will also present prospectives for future gamma-ray observatories.
Although supernova remnants remain the main suspects as sources of Galactic cosmic rays up to the knee, the supernova paradigm still has many loose ends. The weakest point in this construction is the possibility that individual supernova remnants can accelerate particles to the rigidity of the knee, ~ 106 GV. This scenario heavily relies upon the possibility to excite current driven...
There are about 300 supernova remnants (SNRs) observed in our Galaxy. They evolve in interstellar medium which is not uniform. SNRs may be classified into a few morphological classes, based on their surface brightness morphologies in different photon energy ranges: shell-like (both in radio and X-rays), centrally-filled (as in radio as in X-rays), thermal X-ray composites (TXCs). The last...
Below the geographic South Pole, the IceCube project has transformed one cubic kilometer of natural Antarctic ice into a neutrino detector. IceCube detects more than 100,000 neutrinos per year in the GeV to 10 PeV energy range. From those, we have isolated a flux of high-energy neutrinos of cosmic origin, with an energy flux that is comparable to that of high-energy photons. We have also...
ANTARES is a high-energy neutrino telescope running since 2007 below the surface of the Mediterranean Sea with the main aim of identifying the sources of the astrophysical neutrinos. The location of ANTARES allows for an advantageous view of the Southern Sky, in particular for neutrino energies below 100 TeV. This feature, combined with a very good angular resolution, makes the telescope an...
Baikal-GVD is a cubic kilometer neutrino detector currently under construction in Lake Baikal, Russia. We review the current status of Baikal-GVD and first results obtained using data from the partially complete instrument.
The recent detection of potential point sources of astrophysical neutrinos by the IceCube observatory has led to renewed interest in developing next-generation techniques for very to ultra-high-energy neutrino astronomy. The Trinity Observatory, employing an optical technique for detecting tau-air showers induced by Earth-skimming PeV neutrinos, is proposed to fill in the energy gap between...
We present the status of the development of a Cherenkov telescope to be flown on an ultra-long-duration balloon flight, the Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2). EUSO-SPB2 is an approved NASA balloon mission that is planned to fly in 2023 from Wanaka, New Zealand and is a precursor for future space-based missions to detect astrophysical neutrinos. The...
The nonthermal particle acceleration during magnetic reconnection has remained a fundamental topic in many astrophysical phenomena such as solar flares, pulsar wind, and magnetars and so on for more than half a century, and one of the unresolved questions is the efficiency of the nonthermal particle acceleration. Recently, nonthermal particle acceleration mechanisms during reconnection have...
Relativistic magnetized shocks are ubiquitous in the universe. High energy astrophysical objects such as active galactic nuclei, gamma ray burst, and pulsar wind nebula are usually associated with the shocks as a consequence of the interaction between relativistic plasma outflow and interstellar medium. The nonthermal emission from these objects are generally modeled as synchrotron radiation...
The acceleration of high-energy particles is common both in heliophysics and astrophysics. The diffusive shock acceleration (DSA) process has been the standard mechanism for particle acceleration at collisionless shock waves. It is, however, well known that DSA cannot explain the acceleration of low-energy electrons because of the lack of efficient scatterers. We have proposed stochastic shock...
Supernova remnants (SNRs) are believed to produce the most part of the galactic cosmic rays (CRs). SNRs harbor non-relativistic collisionless shocks responsible for acceleration of CRs via diffusive shock acceleration (DSA), in which particles gain their energies in repetitive interactions with the shock front. As the DSA theory involves pre-existing mildly energetic particles, a means of...
Low Mach number shocks with M~2-3 are induced in the hot tenuous intracluster medium (ICM) by mergers of galaxy clusters. Cosmic ray (CR) protons are expected to be accelerated mainly at quasi-parallel shocks, whereas CR electrons are expected to be accelerated preferentially at quasi-perpendicular shocks. Microinstabilities excited by reflected protons and electrons, and the ensuing...
Shock waves in cosmic plasmas are the places of the electromagnetic turbulence generation and acceleration of particles. They can be found in a big number of astrophysical objects on different scales, e.g. Earth's bow shock, solar flares, supernova remnant (SNR) shocks, merger shocks in galaxy clusters. In the latter case, X‑ray and radio observations indicate the efficient electron...
Galaxy clusters are filled with hot, diffuse X-ray emitting plasma, with a stochastically tangled and intermittent magnetic field whose energy is close to equipartition with the energy of the turbulent motions. In the cluster cores, the temperatures remain anomalously high compared to what might be expected considering that the radiative cooling time is short relative to the Hubble time. While...
I will present some recent analytical and numerical results on the current filamentation instability/Weibel instability, with a focus on conditions relevant for planned/future experiments with relativistic beams. Results on the long time behavior of the instability will also be discussed with a focus on observables (such as beam/cloud slowdown) and expected magnetization. Astrophysical...
I will review our current knowledge about jets in accreting X-ray binaries. I will concentrate on three well-studied systems, namely MAXI J1820+070, Cyg X-1, and Cyg X-3. The compact objects in the first two are black holes, while it is likely but not certain in Cyg X-3. Thanks to an extensive multiwavelength campaign during the recent outburst of MAXI J1820+070, the structure of its compact...
I will present an overview of some recent progress in the GRB field. The topics include discovery and implications of TeV emission in GRB afterglows, new events that point to special progenitor channels, as well as theoretical models that help to diagnose the jet composition and central engine of both long and short GRBs.
Relativistic jets of blazars and magnetized coronae of highly accreting black holes routinely display non-thermal emission signatures, including fast and bright flares of high-energy emission. Yet, the “engine” responsible for accelerating the emitting particles to ultra-relativistic energies is still unknown. With fully-kinetic particle-in-cell (PIC) simulations, we will argue that...
Relativistic jets are produced by certain accreting black holes where accumulation of magnetic fields leads to relativistic magnetizations. Magnetic reconnection is one of the most promising mechanisms of energy dissipation and particle acceleration that may operate in the relativistic jets. Magnetic reconnection may be triggered instabilities, in particular the current and pressure driven...
Gamma-Ray Bursts (GRBs) are long-standing cosmic-ray source candidates. It is however unclear how large the fraction of energy transferred to non-thermal protons (often dubbed baryonic loading) can be in order to be still compatible with observed photon spectra. Using the internal shock model for the dynamic evolution of the outflow, we perform self-consistent lepto-hadronic radiation models...
The era of Gravitational Wave (GW) Astronomy started on 2015, with the first observation of GWs from the merger of a binary black hole (BBH) system by Advanced LIGO. Two years later, the detection of GWs from a binary neutron star (BNS) merger by the Advanced LIGO and Advanced Virgo network and of the associated electromagnetic (EM) signals marked the birth of multi-messenger astronomy with...
Recent years have brought us a great development in the gravitational wave astronomy with many new sources discovered by LIGO and Virgo. I will summarize the properties of the objects discovered and listed in the recent GWTC-3 catalog, and provide a summary of the models of their origin. Each of these models has specific predictions. I will review these predictions and confront them with the...
The electromagnetic radiation emerging from jets in gamma rays is modulated on timescales driven by the magnetirotational instability. Shorter, free-fall timescales, are relevant for the state of magnetically arrested accretion, when the interchange instabilities regulate the excess of magnetic flux on the black hole horizon region. On the other hand, the uncollimated outflows accretion disk...
This talk will review recent advances in multi-wavelength observations of blazars as well as indications of associations of very-high-energy neutrino events with blazars. Physics constraints that may be drawn from such associations will be reviewed. Recent work on consistent particle acceleration and time-dependent radiation transfer modeling in mildly relativistic shocks in blazar jets will...
In this talk I will briefly discuss some recent observational constraints on the magnetization of relativistic jets in AGN jets, and the related issue of the energy dissipation and acceleration of the jet particles to ultra-relativistic energies. I will focus predominantly on the structures beyond the jet formation site, i.e. on the large-scale portions of the outflows, the jet termination...
The catalogue of TeV gamma-ray emitting objects includes about 90 extragalactic sources, among which only a few belong to the class of radio galaxies or misaligned blazars. This smaller class includes PKS 0625-354, a source detected as TeV gamma-ray emitter already in 2012. Here, we report H.E.S.S. observations of this active galaxy performed in November 2018. The classification of the object...
We present the results of a preliminary investigation of a potential association of a blazar candidate behind the Large Magellanic Cloud (LMC) and a gamma-ray transient object. The indication of gamma-ray flaring activity in the Fermi-LAT data was detected at the position (RA, decl.) ∼(86.60 deg,-69.02 deg), while the J0545-6846 blazar candidate is located at (RA, decl.) = (86.47 deg, -68.77...
Blazars, a subset of powerful active galactic nuclei, feature relativistic jet which shine in a broadband electromagnetic radiation, e. g. from radio to TeV emission. Here we present the results of the studies that explore gamma-ray and optical variability properties of a sample of gamma-ray bright sources Several methods of time-series analyses are performed on the decade-long optical and...
Active galactic nuclei show in their spectra broad-emission lines that are considered to be created by clouds orbiting close to the central black hole. The motion of these clouds is predominantly Keplerian, consistent with the scenario described by the Failed Radiatively Accelerated Dusty Outflow (FRADO; Czerny & Hryniewicz 2011). In this talk, we discuss the non-thermal signatures that can...
Gamma-ray-emitting narrow-line Seyfert 1 galaxies (NLS1) constitute an intriguing small population of Active Galactic Nuclei (AGN) with debated fundamental properties, unexpected gamma-ray emission and anomalous variability features, possessing properties similar to low power flat-spectrum radio quasars (FSRQ). They are jetted, gamma/radio-loud Seyfert galaxies, with relatively low BH masses,...
Hadronic interactions in cosmic-ray propagation can produce charged and neutral pions. The neutron pion decays into photons, while positrons and electrons are produced due to the decay of charged pions. The basic mechanisms that can produce gamma-ray fluxes associated with jets of cosmic rays are the decay of neutral pions electron/positron bremsstrahlung, and inverse Compton scattering. These...
The recent very-high-energy (VHE) gamma-ray observations of gamma-ray bursts (GRBs) in their afterglow phase motivate a review of the established fireball model in which a relativistic blast wave accelerates electrons in the forward shock, which then radiate via the synchrotron process and inverse Compton scattering on these synchrotron photons (synchrotron self-Compton). We use the rich...
A small fraction of GRBs with available data down to soft X-rays ( ~0.5 keV) have been shown to feature a spectral break in the low energy part of their prompt emission spectrum. The overall spectral shape is consistent with optically thin synchrotron emission from a population of marginally fast cooling particles. In this work we firstly consider that the radiating particles are hadrons and...
Multi-wavelength flux variabilities observed in relativistic jets are most often attributed to the diffusive acceleration of a population of relativistic electrons on internal shocks. The shortest observed variability time scale changes over several orders of magnitude between the radio and X-ray band. We simulate relativistic jets with the SR-HD code AMRVAC. Non-thermal particle distributions...
Ultrahigh energy cosmic rays (UHECRs) are probably originated from extragalactic sources as, e.g., Starburst, Radio Galaxies, and Active Galactic Nuclei (AGNs). In the present work, we obtain the upper limits of the cosmic-rays luminosity of Starburst galaxies. The method described in (Supanitsky 2013 and Anjos 2014) is a productive tool for the obtainment of the upper limits of the...
The properties of relativistic jets, their interaction with the ambient environment, and particle acceleration due to kinetic instabilities are studied self-consistently with Particle-in-Cell simulations. An important key issue is how a toroidal magnetic field affects the evolution of a pair and an electron - proton jet, how kinetic instabilities such as the Weibel instability (WI), the...
The Telescope Array is a hybrid cosmic ray detector consisting both of fluorescence telescopes and an array of scintillator surface detectors. It is the largest cosmic ray detector in the northern hemisphere. It is presently expanding from 700 sq km to 2800 sq km. The status of spectral, composition, and source search measurements will be presented in addition to an update on the...
Digital radio arrays have become an effective tool to measure air showers at energies around and above 100 PeV. Compared to optical techniques, the radio technique is not restricted to clear nights. Thanks to recent progress on computational analysis techniques, radio arrays can provide an equally accurate measurement of the energy and the depth of the shower maximum. Stand-alone radio arrays...
Recent instruments deployed in space or on stratospheric balloons are targeted at the study of a variety of energetic cosmic particles, including protons and nuclei, electrons, antimatter particles, secondary nuclei (including isotopes), ultraheavy nuclei, all complementing gamma-ray studies. Thus a new wealth of data is providing fresh insights on high-energy phenomena in the Galaxy. The...
For many years, high-energy pulsar models were rather uncertain as to the expectations of detectable pulsed TeV spectral components from pulsars. Surprisingly, MAGIC announced the detection of pulsations from the Crab pulsar up to 25 GeV in 2008, followed by the VERITAS pulsed detection up to 400 GeV, and finally MAGIC's detection up to 1.5 TeV. This opened a new window into pulsar science....
Fermi-LAT observations have provided a wealth of data in the GeV band. Moreover, recent observations from ground-based imaging atmospheric Cherenkov telescopes have revealed multi-TeV pulsed emission. The consensus from the latest theoretical modeling is that the high-energy pulsar emission is produced in the equatorial current sheet outside the light cylinder. I will discuss how the...
Over the course of more than six decades numerous and sophisticated models of the interaction of the solar wind (SW) with the Local Interstellar Medium (LISM) have been developed. As a result of this interaction, the heliosphere was formed. Understanding of the heliosphere and surrounding it region is necessary to enable future investigations, aimed for example at exploring the structure and...
Dark matter accounts for 23% of the mass-energy density of the Universe, however, its nature and origins remain the most important open questions in physics. The search for Weakly Interacting Massive Particles (WIMPs), one of the leading dark matter particle candidate, is now in a decisive phase. This talk will present the status of the leading experimental searches and summarize constraints...
In recent years, the ALICE Collaboration carried out dedicated measurement campaigns to advance the understanding of the physics of neutron stars and indirect dark matter searches and provided new input for the nuclear physics underlying these astrophysics phenomena. The study of the internal structure of neutron stars relies on the knowledge of two- and three-body strong interaction for...
Many astronomical observations indicate that the known matter accounts only for a small fraction of the observed gravitational matter of the Universe. The remaining mass, called dark matter, could be explained by weakly interacting particles with properties different from ordinary matter. Direct detection of that dark matter would be a changing discovery in the history of science and would...
The purpose of this talk is discuss the possibility of detection of dark matter through multiple observations of compact stars and related phenomena. Recent scientific and technological developments have allowed for a better study of the nature of these astrophysical objects, in particular of the equation of state (EoS). As we advance on the quest for clarification of the neutron star internal...
Long-baseline neutrino oscillations hold the key to understanding the crucial open questions in neutrino physics: what is the neutrino mass ordering and is the Charge-Parity(CP) symmetry violated in the lepton sector. The Deep Underground Neutrino Experiment (DUNE) is being constructed at the Sanford Underground Research Facility (SURF) in South Dakota to adress these very questions. It will...
T2K is an accelerator neutrino experiment conducted in Japan, which studies of oscillations from muon (anti)neutrinos disappearance and electron (anti)neutrinos appearance at a distance of 295 km between the set of near detectors (at J-PARC) and the far detector SuperKamiokande (SK, at Kamioka). It has already provided world-leading measurements of the two oscillation parameters: θ23 mixing...
The Borexino has recently reported the first experimental evidence of neutrinos from the CNO cycle. Since this process accounts only for about 1% of the total energy production in the Sun, the associated neutrino flux is extremely low as compared with the one from the pp-chain, the dominant process of hydrogen burning. This experimental evidence of the CNO neutrinos was obtained using the...
The GERDA experiment, located in the underground Laboratori Nazionali del Gran Sasso in Italy, has been designed to search for the neutrinoless double-beta (0vbb) decay in 76Ge. It used in different stages of the project up to 44 kg of high purity germanium (HPGe) detectors enriched up to about 86% in the isotope 76Ge. The bare detectors were operated in liquid argon, which served in the first...
We investigate the effect of a dark matter component inside a neutron star using gravitational wave constraints coming from binary neutron star merger. We consider the nuclear matter using the relativistic mean-field model including $\sigma-\omega-\rho$ meson interaction. We study fermionic dark matter interacting with nucleonic matter via the Yukawa interaction inside the neutron star. We...
ICARUS is one of three liquid argon time projection chambers (LArTPCs) of the Short-Baseline Neutrino (SBN) Program at FNAL. SBN’s purpose is to address the observed neutrino measurement anomalies seen by experiments such as LSND and MiniBooNE, and the potential existence of sterile neutrinos. ICARUS underwent an overhaul at CERN and has now been transferred to FNAL where ICARUS will serve as...
Large-scale neutrino telescopes, such as Baikal-GVD or ORCA, require calibration and testing of the optical modules. Calibration methods typically use laser and LED-based systems to not only test the telescope's response to light, but also to monitor optical parameters of water, such as absorption and scattering lengths, which show seasonal changes in natural water bodies. In addition, the...
We have studied the transport process of galactic cosmic rays invading into the heliosphere using test particle simulations embedded in global MHD simulation of the heliosphere. The heliosphere was reproduced by an MHD simulation under the assumptions that the solar wind is steady with northward solar magnetic polarity and zero tilt angle. Motions of a number of test particles (=galactic...
Search for sources of ultra high energy cosmic rays (UHECRs, $E>10^{18}$ eV) remains one of the main unsolved problems in modern astrophysics. Galactic magnetars are potential candidates for the UHECR accelerators due to their ability to generate relativistic plasma flows and shock waves during magnetar giant flares. Favorable conditions for UHECR acceleration also occur during a Supernova...
Supernova remnants are expected to be the main source of Galactic cosmic rays up to energies of about 3 PeV, provided that they transfer a significant fraction of their kinetic energy to the particles. The bilateral supernova remnant SN 1006 shows bright synchrotron X-ray emission from ultrarelativistic electrons accelerated at the shock front in its northeastern and southwestern limbs. If...
Synchrotron X-ray emission in young supernova remnants (SNRs) is a powerful diagnostic tool to study the population of high energy electrons accelerated at the shock front and the acceleration process. We performed a spatially resolved spectral analysis of NuSTAR and XMM-Newton observations of the young Kepler's SNR, aiming to study in detail its non-thermal emission in hard X-rays. We...
Investigation of astrophysical shocks has a major importance in understanding physics of the cosmic rays acceleration. Electrons to be accelerated at shocks must have an injection energy, which implies that they should undergo some pre-acceleration mechanism. Many numerical studies examined possible injection mechanisms, however most of them considered homogenous upstream medium, which is...
X-ray binaries are systems consisting on a massive star and a compact object. If the compact object is a pulsar, both the star and the pulsar will have their own winds. When both winds clash, they produce a contact discontinuity which creates shocked flows that go away from the binary and are affected by the orbital motion of the system. These flows are a plasma made by charged particles and...
Relativistic shocks possess a central role in energetic astrophysical phenomena, with gamma-ray bursts (GRBs) being a prominent example. This has led to the extensive investigation of the properties of shocks propagating in both non-magnetized and magnetized fluids characterized by infinite electrical conductivity. The derivation of the jump conditions for a relativistic shock propagating in a...
Astrophysical jets are considered among the most stable structures throughout the cosmos, as they are able to propagate to distances many times their initial radii. In this context we conduct a linear stability analysis on astrophysical outflows, for which the dynamics are described by the relativistic magnetohydrodynamics. A new peculiar solution emerged, having instabilities' growth...
The first observation of intensity correlation between bosons, namely photons was observed in the field of radio astronomy by Hanbury Brown and Twiss, hence such quantumstatistical correlations usually referred as HBT correlations. Quantumstatistical correlations were also observed in particle physics, firstly by Goldhaber, Goldhaber, Lee and Pais among same charged pions. They could explain...
Abstract: Space-time evolution of spin polarization within the framework of hydrodynamics with spin based on de Groot - van Leeuwen - van Weert forms of energy-momentum and spin tensors is studied. Due to the non-boost invariant flow in the system the spin polarization components couple to each other implying some effects on the spin polarization observables. We study transverse-momentum and...
As a result of hadronization, the partons (quarks and gluons) are being observed via objects called jets which represent energy deposits in clustered calorimeters with associated jet reconstruction algorithm. This study investigates the determination of the initial parton from which the jet evolved based on five variables called angularities. Having a discriminant on an event-by-event basis...
High energy proton-proton and proton-lead collisions may proceed via double-parton scattering. In addition, soft interactions accompany any hard process. To describe these processes, Pythia parameters are revised and constantly tuned to match Run 2 LHC data and to make better predictions that would fit the astrophysics data. In this presentation, the recent LHCb results on double-parton...
Analyses of D meson yields as functions of decay time provide access to fundamental standard model parameters and probe natural non-SM scales at 10-100 TeV energies. Outstanding vertexing performances are key enablers of this program. We prove the capabilities of the Belle II detector by measuring the lifetimes of the D0 and D+ mesons. The results are the most precise to date, owing to a...
Large Hadron Collider- beauty (LHCb) is one of the four large experiments operating currently at Large Hadron Collider(LHC) it is designed to study New Physics phenomena in the heavy flavor quarks sector and perform precise measurements of CP symmetry violation in beauty and charm quarks sector. At present, the detector is undergoing a major upgrade with respect to its original design. In...
The MUonE experiment planned to be operating at the SPS accelerator in 2021-2022 (pilot run) and 2023-26 provides a great potential to search for New Physics in the sector o of the anomalous muon magnetic moment a_μ. The discrepancy between the most accurate determination of a_μ and the Standard Model predictions is about 4 standard deviations, and an analogous improvement is required in...
At extremely high temperatures and densities, hadronic matter undergoes a phase transition to a state of deconfined quarks and gluons known as quark-gluon plasma (QGP). It is believed that our universe had been in such deconfined state just after the big bang when the temperature was of the order of several thousand billion degrees. Such state of matter might be also present in the inner...
DAMPE (DArk Matter Particle Explorer) is a satellite-born experiment smoothly taking data since its launch in december 2015. The detector features (good resolutions, large geometric factor, etc.) allow measuring the energy spectra of galactic cosmic rays (electrons/positrons , protons and single nuclear species) up to hundreds of TeV (few TeV in case of electrons/positrons). A first direct...
