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info:eu-repo/semantics/published

info:eu-repo/semantics/published

In 1995, Glendenning et al. postulated the existence of some exotic kinds of compact stars ressembling white dwarfs but containing a very dense core made of strange quark matter. The surrounding layers consisting of a crystal lattice of nuclei in a sea of free electrons were described by the same equation of state as for the outer crust of a neutron star. In this work, we revisit the structure of these stars and compute their tidal deformability using more realistic models taking into account different possible compositions., info:eu-repo/semantics/published

Primordial black holes (PBHs) with a wide mass distribution imprinted by the thermal history of the Universe, which naturally produces a high peak at the solar mass scale, could explain the gravitational-wave events seen by LIGO/Virgo and up to the totality of the dark matter. We show that compared to monochromatic or log-normal mass functions, the gravitational wave backgrounds (GWBs) from early PBH binaries and from late binaries in clusters are strongly enhanced at low frequency and could even explain the NANOGrav observations. This enhancement comes from binaries with very low mass ratios, involving solar-mass and intermediate-mass PBHs at low frequency, solar-mass and subsolar-mass at high frequency. LISA could distinguish the various models, while in the frequency band of ground-based detectors, we find that the GWB from early binaries is just below the current LIGO/Virgo limits and above the astrophysical background, if they also explain black hole mergers. The GWB from binaries in clusters is less boosted but has a different spectral index than for neutron stars, astrophysical black holes or early PBH binaries. It is detectable with Einstein Telescope or even with the LIGO/Virgo design sensitivity., SCOPUS: ar.j, info:eu-repo/semantics/published

As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15% with in situ measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on 12C nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve. This talk gives an overview of physics potential of CCSN neutrino detection in JUNO., 0, info:eu-repo/semantics/published

Over the last two decades, various experiments have measured muon densities in extensive air showers over several orders of magnitude in primary energy. While some experiments observed differences in the muon densities between simulated and experimentally measured air showers, others reported no discrepancies. We will present an update of the meta-analysis of muon measurements from nine air shower experiments, covering shower energies between a few PeV and tens of EeV and muon threshold energies from a few 100 MeV to about 10GeV. In order to compare measurements from different experiments, their energy scale was cross-calibrated and the experimental data has been compared using a universal reference scale based on air shower simulations. Above 10 PeV, we find a muon excess with respect to simulations for all hadronic interaction models, which is increasing with shower energy. For EPOS-LHC and QGSJet-II.04 the significance of the slope of the increase is analyzed in detail under different assumptions of the individual experimental uncertainties., 0, info:eu-repo/semantics/published

The Astrophysical Multimessenger Observatory Network (AMON), has developed a real-time multi-messenger alert system. The system performs coincidence analyses of datasets from gamma-ray and neutrino detectors, making the Neutrino-Electromagnetic (NuEM) alert channel. For these analyses, AMON takes advantage of sub-threshold events, i.e. events that by themselves are not significant in the individual detectors. The main purpose of this channel is to search for gamma-ray counterparts of neutrino events. We will describe the different analyses that make-up this channel and present a selection of recent results., 0, info:eu-repo/semantics/published

The measurement of the energy spectrum of ultra-high-energy cosmic rays (UHECRs) is of crucial importance to clarify their origin and acceleration mechanisms. The Pierre Auger Observatory in Argentina and the Telescope Array (TA) in the US have reported their measurements of UHECR energy spectra observed in the southern and northern hemisphere, respectively. The region of the sky accessible to both Observatories ([-15, +24] degrees in declination) can be used to cross-calibrate the two spectra. The Auger-TA energy spectrum working group was organized in 2012 and has been working to understand the uncertainties in energy scale in both experiments, their systematic differences, and differences in the shape of the spectra. In previous works, we reported that there was an overall agreement of the energy spectra measured by the two observatories below 10 EeV while at higher energies, a remaining significant difference was observed in the common declination band. We revisit this issue to understand its origin by examining the systematic uncertainties, statistical effects, and other possibilities. We will also discuss the differences in the spectra in different declination bands and a new feature in the spectrum recently reported by the Auger Collaboration., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

Production cross sections of [Formula presented], [Formula presented], and [Formula presented] states decaying into [Formula presented] in proton-lead (pPb) collisions are reported using data collected by the CMS experiment at sNN=5.02TeV. A comparison is made with corresponding cross sections obtained with pp data measured at the same collision energy and scaled by the Pb nucleus mass number. The nuclear modification factor for [Formula presented] is found to be [Formula presented]. Similar results for the excited states indicate a sequential suppression pattern, such that [Formula presented]. The suppression of all states is much less pronounced in pPb than in PbPb collisions, and independent of transverse momentum [Formula presented] and center-of-mass rapidity [Formula presented] of the individual [Formula presented] state in the studied range [Formula presented] and [Formula presented]. Models that incorporate final-state effects of bottomonia in pPb collisions are in better agreement with the data than those which only assume initial-state modifications., 0, CMS Collaboration, info:eu-repo/semantics/published

In this article the author name Luigi Calligaris was incorrectly written as A. Calligaris. The original article has been corrected., 0, info:eu-repo/semantics/published

A search is reported for high-mass hadronic resonances that decay to a parton and a Lorentz-boosted resonance, which in turn decays into a pair of partons. The search is based on data collected with the CMS detector at the LHC in proton-proton collisions at s=13TeV, corresponding to an integrated luminosity of 138fb−1. The boosted resonance is reconstructed as a single wide jet with substructure consistent with a two-body decay. The high-mass resonance is thus considered as a dijet system. The jet substructure information and the kinematic properties of cascade resonance decays are exploited to disentangle the signal from the large quantum chromodynamics multijet background. The dijet mass spectrum is analyzed for the presence of new high-mass resonances, and is found to be consistent with the standard model background predictions. Results are interpreted in a warped extra dimension model where the high-mass resonance is a Kaluza–Klein gluon, the boosted resonance is a radion, and the final state partons are all gluons. Limits on the production cross section are set as a function of the Kaluza–Klein gluon and radion masses. These limits exclude at 95% confidence level models with Kaluza–Klein gluon masses in the range 2.0 to 4.3 TeV and radion masses in the range 0.20 to 0.74 TeV. By exploring a novel experimental signature, the observed limits on the Kaluza–Klein gluon mass are extended by up to about 1 TeV compared to previous searches., 0, CMS Collaboration, info:eu-repo/semantics/published

The region of the toe in the cosmic-ray spectrum, located at about 45 EeV by the Pierre Auger Collaboration, is of primary interest in the search for the origin of ultra-high energy cosmic rays (UHECRs). The suppression of the flux with increasing energy can be explained by the interaction of UHECRs with intergalactic photons, resulting in a shrinking of the observable universe, and/or by cut-offs in acceleration potential at the astrophysical sources, yielding a high-rigidity sample of single (or few) UHECR species around the toe. The predominance of foreground sources combined with reduced deflections could thus offer a path towards localizing ultra-high energy accelerators, through the study of UHECR arrival directions. In this contribution, we present the results of blind and astrophysically-motivated searches for anisotropies with data collected above 32 EeV during the first phase of the Pierre Auger Observatory, i.e. prior to the AugerPrime upgrade, for an exposure of over 120,000 km2 yr sr. We have conducted model-independent searches for overdensities at small and intermediate angular scales, correlation studies with several astrophysical structures, and cross-correlation analyses with catalogs of candidate extragalactic sources. These analyses provide the most important evidence to date for anisotropy in UHECR arrival directions around the toe as measured from a single observatory., 0, Proceedings of Science :37th International Cosmic Ray Conference, ICRC 2021Virtual, Berlin, 12 July - 23 July 2021, Code 177942, info:eu-repo/semantics/published

The reconstruction of event-level information, such as the direction or energy of a neutrino interacting in IceCube DeepCore, is a crucial ingredient to many physics analyses. Algorithms to extract this high level information from the detector’s raw data have been successfully developed and used for high energy events. In this work, we address unique challenges associated with the reconstruction of lower energy events in the range of a few to hundreds of GeV and present two separate, state-of-the-art algorithms. One algorithm focuses on the fast directional reconstruction of events based on unscattered light. The second algorithm is a likelihood-based multipurpose reconstruction offering superior resolutions, at the expense of larger computational cost., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

A search is presented for a heavy W′ boson resonance decaying to a B or T vector-like quark and a t or a b quark, respectively. The analysis is performed using proton-proton collisions collected with the CMS detector at the LHC. The data correspond to an integrated luminosity of 138 fb−1 at a center-of-mass energy of 13 TeV. Both decay channels result in a signature with a t quark, a Higgs or Z boson, and a b quark, each produced with a significant Lorentz boost. The all-hadronic decays of the Higgs or Z boson and of the t quark are selected using jet substructure techniques to reduce standard model backgrounds, resulting in a distinct three-jet W′ boson decay signature. No significant deviation in data with respect to the standard model background prediction is observed. Upper limits are set at 95% confidence level on the product of the W′ boson cross section and the final state branching fraction. A W′ boson with a mass below 3.1 TeV is excluded, given the benchmark model assumption of democratic branching fractions. In addition, limits are set based on generalizations of these assumptions. These are the most sensitive limits to date for this final state. [Figure not available: see fulltext.], 0, info:eu-repo/semantics/published

Proton-proton interactions resulting in final states with two photons are studied in a search for the signature of flavor-changing neutral current interactions of top quarks (t) and Higgs bosons (H). The analysis is based on data collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, corresponding to an integrated luminosity of 137 fb-1. No significant excess above the background prediction is observed. Upper limits on the branching fractions (B) of the top quark decaying to a Higgs boson and an up (u) or charm (c) quark are derived through a binned fit to the diphoton invariant mass spectrum. The observed (expected) 95% confidence level upper limits are found to be 0.019% (0.031%) for B(t→Hu) and 0.073% (0.051%) for B(t→Hc). These are the strictest upper limits yet determined., 0, CMS Collaboration, info:eu-repo/semantics/published

Multiparticle azimuthal correlations of prompt D0 mesons are measured in Pb-Pb collisions at a nucleon-nucleon center-of-mass energy of sNN=5.02 TeV. For the first time, a four-particle cumulant method is used to extract the second Fourier coefficient of the azimuthal distribution (v2) of D0 mesons as a function of event centrality and the D0 transverse momentum. The ratios of the four-particle v2 values to previously measured two-particle cumulant results provide direct experimental access to event-by-event fluctuations of charm quark azimuthal anisotropies. These ratios are also found to be comparable to those of inclusive charged particles in the event. However, hints of deviations are seen in the most central and peripheral collisions. To investigate the origin of flow fluctuations in the charm sector, these measurements are compared to a model implementing fluctuations of charm quark energy loss via collisional or radiative processes in the quark-gluon plasma. These models cannot quantitatively describe the data over the full transverse momentum and centrality ranges, although the calculations with collisional energy loss provide a better description of the data., 0, CMS Collaboration, info:eu-repo/semantics/published

A measurement of the forward-backward asymmetry of pairs of oppositely charged leptons (dimuons and dielectrons) produced by the Drell-Yan process in proton-proton collisions is presented. The data sample corresponds to an integrated luminosity of 138 fb−1 collected with the CMS detector at the LHC at a center-of-mass energy of 13 TeV. The asymmetry is measured as a function of lepton pair mass for masses larger than 170 GeV and compared with standard model predictions. An inclusive measurement across both channels and the full mass range yields an asymmetry of 0.612 ± 0.005 (stat) ± 0.007 (syst). As a test of lepton flavor universality, the difference between the dimuon and dielectron asymmetries is measured as well. No statistically significant deviations from standard model predictions are observed. The measurements are used to set limits on the presence of additional gauge bosons. For a Z′ boson in the sequential standard model the observed (expected) 95% confidence level lower limit on the Z′ mass is 4.4 TeV (3.7 TeV). [Figure not available: see fulltext.], 0, CMS Collaboration, info:eu-repo/semantics/published

We summarize initial results for high-energy neutrino counterpart searches coinciding with gravitational-wave events in LIGO/Virgo's GWTC-2 catalog using IceCube's neutrino triggers. We did not find any statistically significant high-energy neutrino counterpart and derived upper limits on the time-integrated neutrino emission on Earth as well as the isotropic equivalent energy emitted in high-energy neutrinos for each event. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, 0, Proceedings of Science :37th International Cosmic Ray Conference, ICRC 2021Virtual, Berlin, 12 July to 23 July 2021 Code 177942, info:eu-repo/semantics/published

The Telescope Array (TA) cosmic rays detector located in the State of Utah in the United States is the largest ultra high energy cosmic rays detector in the northern hemisphere. The Telescope Array Low Energy Extension (TALE) fluorescence detector (FD) was added to TA in order to lower the detector’s energy threshold, and has succeeded in measuring the cosmic rays energy spectrum down to PeV energies, by making use of the direct Cherenkov light produced by air showers. In this contribution we present the results of a measurement of the cosmic-ray energy spectrum using TALE FD data collected over a period of ∼7 years. The data set used for this measurement is the same one used for the mass composition measurement that is presented, as a separate contribution, at this conference. The energy spectrum shows features consistent with the "knee" and the "second knee"; a similar result to our previous energy spectrum publication. This time using a different hadronic model, and different event selection criteria as explained in the text of this proceeding, 0, Proceedings of Science :37th International Cosmic Ray Conference, ICRC 2021Virtual, Berlin, 12 July to 23 July 2021 Code 177942, info:eu-repo/semantics/published

Since the discovery of a flux of high-energy astrophysical neutrinos, searches for their origins have focused primarily at TeV-PeV energies. Compared to sub-TeV searches, high-energy searches benefit from an increase in the neutrino cross section, improved angular resolution on the neutrino direction, and a reduced background from atmospheric neutrinos and muons. However, the focus on high energy does not preclude the existence of sub-TeV neutrino emission where IceCube retains sensitivity. Here we present the first all-flavor search from IceCube for transient emission of low-energy neutrinos, focusing on the energy region of 5.6-100 GeV using three years of data obtained with the IceCube-DeepCore detector. We find no evidence of transient neutrino emission in the data, thus leading to a constraint on the volumetric rate of astrophysical transient sources in the range of ∼ 705-2301 Gpc-3 yr-1 for sources following a subphotospheric energy spectrum with a mean energy of 100 GeV and a bolometric energy of 1052 erg., SCOPUS: ar.j, SCOPUS: ar.j, info:eu-repo/semantics/published

This study explores how researchers’ analytical choices affect the reliability of scientific findings. Most discussions of reliability problems in science focus on systematic biases. We broaden the lens to emphasize the idiosyncrasy of conscious and unconscious decisions that researchers make during data analysis. We coordinated 161 researchers in 73 research teams and observed their research decisions as they used the same data to independently test the same prominent social science hypothesis: that greater immigration reduces support for social policies among the public. In this typical case of social science research, research teams reported both widely diverging numerical findings and substantive conclusions despite identical start conditions. Researchers’ expertise, prior beliefs, and expectations barely predict the wide variation in research outcomes. More than 95% of the total variance in numerical results remains unexplained even after qualitative coding of all identifiable decisions in each team’s workflow. This reveals a universe of uncertainty that remains hidden when considering a single study in isolation. The idiosyncratic nature of how researchers’ results and conclusions varied is a previously underappreciated explanation for why many scientific hypotheses remain contested. These results call for greater epistemic humility and clarity in reporting scientific findings., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

We report a study on the conversion of a giant cosmic ray observatory for air shower observation to observe cosmic ray intensity variations caused by solar activity, anisotropy associated with interplanetary disturbances, and detection of sudden cosmic ray events on the earth’s surface. In this report, we use data from the surface detectors operated by the Telescope Array experiment located at 39°N, 112°W (total detector area: 2250 m2). In order to evaluate the cosmic ray intensity variations, we will compare the data with some of the corrections considered and with available world wide database such as Nagoya Muon detector and other observatories that have been in stable operation at different geographic longitudes. Finally, we will report on the intensity variations due to weather and solar activity recorded during the observation period., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

Since its full commissioning in 2008, the Pierre Auger Observatory has consistently demonstrated its scientific productivity. A major upgrade of the Surface Detector array (SD) improves the capabilities of measuring the different components of extensive air showers. One of the elements of the upgrade consists of new Scintillator Surface Detectors (SSD) placed on top of the Water-Cherenkov stations of the SD. At the Observatory, the integration of the SSD components and their deployment in the array is well advanced. In this paper, the main challenges and characteristics of the construction and installation will be reviewed. Started in 2016, an Engineering Array of twelve upgraded stations has been taking data in the field. In March 2019, a preproduction array of 77 SSDs started data acquisition with an adapted version of non-upgraded electronics. It is collecting events and proving the goodness of SSD design. Since December 2020, the upgraded electronics boards are being deployed in the field together with the photomultiplier tubes, increasing the number of SSD detectors, which are taking data continuosly with good stability. In this paper, the-long term performance of a subset of stations acquiring data for more than two years will be discussed. The data collected so far demonstrate the quality of the new detectors and the physics potential of the upgrade project., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The AugerPrime Radio Detector will significantly increase the sky coverage of mass-sensitive measurements of ultra-high energy cosmic rays with the Pierre Auger Observatory. The detection of highly inclined air showers with the world’s largest 3000 km2 radio-antenna array in coincidence with the Auger water-Cherenkov detector provides a clean separation of the electromagnetic and muonic shower components. The combination of these highly complementary measurements yields a strong sensitivity to the mass composition of cosmic rays. We will present the first results of an end-to-end simulation study of the performance of the AugerPrime Radio Detector. The study features a complete description of the AugerPrime radio antennas and reconstruction of the properties of inclined air showers, in particular the electromagnetic energy. The performance is evaluated utilizing a comprehensive set of simulated air showers together with recorded background. The estimation of an energy- and direction-dependent aperture yields an estimation of the expected 10-year event statistics. The potential to measure the number of muons in air showers with the achieved statistics is outlined. Based on the achieved energy resolution, the potential to discriminate between different cosmic-ray primaries is presented., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

Work on the Offline Framework for the Pierre Auger Observatory was started in 2003 to create a universal framework for event reconstruction and simulation. The development and installation of the AugerPrime upgrade of the Pierre Auger Observatory require an update of the Offline Framework to handle the additional detector components and the upgraded Surface Detector Electronics. The design of the Offline Framework proved to be sufficiently flexible to accommodate the changes needed to be able to handle the AugerPrime detector. This flexibility has been a goal since the development of the code started. The framework separates data structures from processing modules. The detector components map directly onto data structures. It was straightforward to update or add processing modules to handle the additional information from the new detectors. We will discuss the general structure of the Offline Framework, explaining the design decisions that provided its flexibility and point out the few of the features of the original design that required deeper changes, which could have been avoided in hindsight. Given the disruptive nature of the AugerPrime upgrade, the developers decided that the update for AugerPrime was the moment to change also the language standard for the implementation and move to the latest version of C++, to break strict backward compatibility eliminating deprecated interfaces, and to modernize the development infrastructure. We will discuss the changes that were made to the structure in general and the modules that were added to the framework to handle the new detector components., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The IceCube Observatory has collected over 577 billion cosmic-ray induced muon events in its final configuration from May 2011 to May 2020. We used this data set to provide an unprecedented statistically accurate map of the cosmic ray arrival direction distribution in the TeV-PeV energy range scale in the Southern Hemisphere. Such an increase in event statistics makes it possible to extend the sensitivity to anisotropies at higher cosmic ray energies and smaller angular scales. It will also facilitate a more detailed assessment of the observatory stability over both short- and long-time scales. This will enable us to study the time variability of the cosmic ray anisotropy on a yearly-base and over the entire data sample period covering most of the solar cycle 24. We present the preliminary results from the study with the extended event sample., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The study of large-scale anisotropy at the highest energies is essential for understanding the transition from cosmic rays of galactic origin to those of extra-galactic origin, along with the magnetic fields in the galaxy and those beyond. Motivated by a significant detection of the large-scale anisotropy above 8 EeV by the Pierre Auger Observatory (Auger), we had previously reported, using 11 years of Telescope Array (TA) surface array data, a result compatible both with that of Auger, and with an isotropic source distribution [1]. In this contribution, we will show the preliminary updated results using 12 years TA SD data to search for the large-scale anisotropy at the highest energies., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

Telescope Array (TA) is the largest ultra-high-energy cosmic-ray (UHECR) observatory in the Northern Hemisphere. It is dedicated to detect extensive air showers (EAS) in hybrid mode, both by measuring the shower’s longitudinal profile with fluorescence telescopes and their particle footprint on the ground from the surface detector (SD) array. While fluorescence telescopes can measure the most composition-sensitive characteristic of EAS, the depth of the shower maximum (Xmax), they also have the drawback of small duty cycle. This work aims to study the UHECR composition based solely on the surface detector data. For this task, a set of composition-sensitive observables obtained from the SD data is used in a machine-learning method – the Boosted Decision Trees. We will present the results of the UHECR mass composition based on the 12-year data from the TA SD using this technique, and we will discuss of the possible systematics imposed by the hadronic interaction models., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The combined fit of the energy spectrum and mass composition data above 5 · 1018 eV suggested the presence of extragalactic sources ejecting ultra-high-energy cosmic rays with relatively low maximum energies, hard spectral indices and mixed chemical compositions, dominated by the contribution of intermediate mass groups. Here we present an extension of the fit to lower energies, to include the feature observed near 5 · 1018 eV in the all-particle energy spectrum, the so-called ankle. We show that it is possible to generate such a change of slope assuming that the flux below the ankle is provided by the superposition of different contributions. The simplest extension of this sort consists of introducing a supplemental extragalactic component at low energy, characterised by different physical parameters with respect to the one being dominant above the ankle: such a component may originate from a different population of sources or be provided by interactions occurring in the acceleration sites. In this framework we also explore the possibility of including the end of a Galactic contribution at low energies. The fit suggests that these scenarios provide a reasonable description of the measurements across the ankle, without significantly affecting the interpretation obtained for the above-ankle region. In order to evaluate our capability to constrain the source models, we finally discuss the impact of the main experimental systematic uncertainties and of the theoretical models choice on the fit results., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

We test the hypothesis of an anisotropy laying along the galactic plane which depends on the mass of primary cosmic-rays. The sensitivity to primary mass is provided by the depth of shower maximum, Xmax, from hybrid events measured at the Pierre Auger Observatory. The 14 years of available data are split into on- and off-plane regions using the galactic latitude of each event to form two distributions in Xmax, which are compared using the Anderson-Darling 2-samples test. A scan over a subset of the data is used to select an optimal threshold energy of 1018.7 eV and a galactic latitude splitting at, 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

IceTop, the surface array of the IceCube Neutrino Observatory, consists of 162 ice-Cherenkov tanks distributed over an area of 1km2. Besides being used as a veto for the in-ice neutrino detector, IceTop is a powerful cosmic-ray detector. In the upcoming years, the capabilities of the IceTop array will be enhanced by augmenting the existing ice-Cherenkov tanks with an array of elevated scintillator panels and radio antennas. Combining the data obtained from the different detectors will improve the reconstruction of cosmic-ray energy and primary mass while reducing the energy threshold and increasing the aperture of the array. In January 2020, a prototype station consisting of 8 scintillation detectors and 3 antennas was deployed at the IceTop site. The prototype detectors are connected to one data-acquisition system and the readout of the radio antennas is triggered using the signals from the scintillators. This allows us to regularly observe secondary air shower particles hitting the scintillators, as well as the radio emission of high-energy air showers. In this contribution, we will discuss the results obtained from the prototype station in the past year, present the first cosmic-ray air showers measured with this prototype station, and show how the observations with the different detector types complement each other., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

In this talk, we summarise the results of recent anisotropy studies conducted by the Telescope Array (TA) collaboration. At largest scales we test the TA data for the presence of a dipole. On smaller scales, an update on the excess of events in the direction of Ursa Major previously found in the TA data will be presented. These flux variations may trace the distribution of UHECR sources. We will examine the data for correlations with large-scale structures in the nearby Universe, and as a result, hints for the chemical composition of primaries will be provided. We also discuss a related anisotropy of the UHECR spectrum., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

Even though there are strong astrophysical and cosmological indications to support the existence of dark matter, its exact nature remains unknown. We expect dark matter to produce standard model particles when annihilating or decaying, assuming that it is composed of Weakly Interacting Massive Particles (WIMPs). These standard model particles could in turn yield neutrinos that can be detected by the IceCube neutrino telescope. The Milky Way is expected to be permeated by a dark matter halo with an increased density towards its centre. This halo is expected to yield the strongest dark matter annihilation signal at Earth coming from any celestial object, making it an ideal target for indirect searches. In this contribution, we present the sensitivities of an indirect search for dark matter in the Galactic Centre using IceCube data. This low energy dark matter search allows us to cover dark matter masses ranging from 5 GeV to 1 TeV. The sensitivities obtained for this analysis show considerable improvements over previous IceCube results in the considered energy range., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The Pierre Auger Observatory investigates the properties of the highest-energy cosmic rays with unprecedented precision. The aim of the AugerPrime upgrade is to improve the sensitivity to the primary particle type. The improved mass sensitivity is the key to exploring the origin of the highest-energy particles in the Universe. The purpose of the Radio Detector (as part of AugerPrime) is to extend the sensitivity of the mass measurements to zenith angles in the range from 65° to 85°. A radio antenna, sensitive in two polarization directions and covering a bandwidth from 30 to 80 MHz, will be added to each of the 1661 surface detector stations over the full 3000 km2 area, forming the world’s largest radio array for the detection of cosmic particles. Since November 2019, an engineering array comprised of ten stations has been installed in the field. The radio antennas are calibrated using the Galactic (diffuse) emission. The sidereal modulation of this signal is monitored continuously and is used to obtain an end-to-end calibration from the receiving antenna to the ADC in the read-out electronics. The calibration method and first results will be presented. The engineering array is also fully integrated in the data acquisition of the Observatory and records air showers regularly. The first air showers detected simultaneously with the water-Cherenkov detectors and the Radio Detectors will be presented. Simulations of the detected showers, based on the reconstructed quantities, have been conducted with CORSIKA/CoREAS. A comparison of the measured radio signals with those predicted by simulations exhibits satisfying agreement., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

The Pierre Auger Observatory is used to study the extensive air-showers produced by cosmic rays above 1017 eV. The Observatory is operated by a Collaboration of about 400 scientists, engineers, technicians and students from more than 90 institutions in 18 countries. The Collaboration is committed to the public release of their data for the purpose of re-use by a wide community including professional scientists, in educational and outreach initiatives, and by citizen scientists. The Open Access Data for 2021 comprises 10% of the samples used for results reported at the Madison ICRC 2019, amounting to over 20000 showers measured with the surface-detector array and over 3000 showers recorded simultaneously by the surface and fluorescence detectors. Data are available in pseudo-raw (JSON) format with summary CSV file containing the reconstructed parameters. A dedicated website is used to host the datasets that are available for download. Their detailed description, along with auxiliary information needed for data analysis, is given. An online event display is also available. Simplified codes derived from those used for published analyses are provided by means of Python notebooks prepared to guide the reader to an understanding of the physics results. Here we describe the Open Access data, discuss the notebooks available and show material accessible to the user at https://opendata.auger.org, 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

We present a method based on the use of Recurrent Neural Networks to extract the muon component from the time traces registered with water-Cherenkov detector (WCD) stations of the Surface Detector of the Pierre Auger Observatory. The design of the WCDs does not allow to separate the contribution of muons to the time traces obtained from the WCDs from those of photons, electrons and positrons for all events. Separating the muon and electromagnetic components is crucial for the determination of the nature of the primary cosmic rays and properties of the hadronic interactions at ultra-high energies. We trained a neural network to extract the muon and the electromagnetic components from the WCD traces using a large set of simulated air showers, with around 450 000 simulated events. For training and evaluating the performance of the neural network, simulated events with energies between 1018.5 eV and 1020 eV and zenith angles below 60 degrees were used. We also study the performance of this method on experimental data of the Pierre Auger Observatory and show that our predicted muon lateral distributions agree with the parameterizations obtained by the AGASA collaboration., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12 - 23 July 2021 Code 177942, info:eu-repo/semantics/published

With the knowledge and statistical power of over a decade and a half of measurements, the Auger Collaboration has developed, assessed, and refined robust methods for reconstructing the energies and arrival directions of the highest-energy cosmic rays from the signal and timing measurements of its surface detector array. Concurrently, the unearthing of an increasingly complex astrophysical scenario and tensions with hadronic interaction models have demanded the addition of primary mass as an observable measurable using the surface detector. Access to information on the mass hinges on the disentanglement of the electromagnetic and muonic components of extensive air showers. Consequently, an upgrade to the Observatory, AugerPrime, is being carried out by equipping existing water-Cherenkov stations with a 3.8 m2 Scintillator Surface Detector (SSD). The SSDs, with their high sensitivity to electrons and positrons, will provide samples of the lateral distribution of particles at the ground that complement those of the water-Cherenkov detectors, which are significantly more sensitive to muons. When used together, the two measurements enable extraction of the number of incident muons, which is a quantity that strongly correlates with primary mass. We describe the reconstruction methods being developed for application to measurements of the surface detector of the Observatory with a particular focus on the enhancement of these methods with data of the SSDs of AugerPrime. Results from the reconstruction of thousands of high-energy events already measured with deployed SSDs are also shown., 0, info:eu-repo/semantics/published

A search for dark matter in the form of strongly interacting massive particles (SIMPs) using the CMS detector at the LHC is presented. The SIMPs would be produced in pairs that manifest themselves as pairs of jets without tracks. The energy fraction of jets carried by charged particles is used as a key discriminator to suppress efficiently the large multijet background, and the remaining background is estimated directly from data. The search is performed using proton–proton collision data corresponding to an integrated luminosity of 16.1fb-1, collected with the CMS detector in 2016. No significant excess of events is observed above the expected background. For the simplified dark matter model under consideration, SIMPs with masses up to 100GeV are excluded and further sensitivity is explored towards higher masses., 0, CMS Collaboratio, info:eu-repo/semantics/published

IceCube is a cubic-kilometer Cherenkov detector installed in deep ice at the geographic South Pole. IceCube’s surface array, IceTop, measures the electromagnetic signal and mainly low-energy muons from extensive air showers above several 100 TeV primary energy, with shower bundles and high-energy muons detected by the in-ice detector IceCube. In combination, the in-ice detector and IceTop provide unique opportunities to study cosmic rays in detail with large statistics. This contribution summarizes recent results from these studies. In addition, the IceCube-Upgrade will include a considerable enhancement of the surface detector through the installation of scintillation detectors and radio antennas and possibly small air-Cherenkov telescopes. We will discuss the results of the prototype detectors installed at the South Pole and the prospects of this enhancement as well as the surface array planned for IceCube-Gen2., 0, 37th International Cosmic Ray Conference, ICRC 2021 Virtual, Berlin12-23 July 2021 Code 177942, info:eu-repo/semantics/published

The measurement of the cross section for the production of a Z boson, decaying to dielectrons or dimuons, in association with at least one bottom quark jet is performed with proton-proton collision data at s=13 TeV. The data sample corresponds to an integrated luminosity of 137 fb-1, collected by the CMS experiment at the LHC during 2016-2018. The integrated cross sections for Z+≥1 b jet and Z+≥2 b jets are reported for the electron, muon, and combined channels. The fiducial cross sections in the combined channel are 6.52±0.04(stat)±0.40(syst)±0.14(theo) pb for Z+≥1 b jet and 0.65±0.03(stat)±0.07(syst)±0.02(theo) pb for Z+≥2 b jets. The differential cross section distributions are measured as functions of various kinematic observables that are useful for precision tests of perturbative quantum chromodynamics predictions. The ratios of integrated and differential cross sections for Z+≥2b jets and Z+≥1 b jet processes are also determined. The value of the integrated cross section ratio measured in the combined channel is 0.100±0.005(stat)±0.007(syst)±0.003(theo). All measurements are compared with predictions from various event generators., 0, CMS Collaboration, info:eu-repo/semantics/published

The first collider search for dark matter arising from a strongly coupled hidden sector is presented and uses a data sample corresponding to 138 fb−1, collected with the CMS detector at the CERN LHC, at s = 13 TeV. The hidden sector is hypothesized to couple to the standard model (SM) via a heavy leptophobic Z′ mediator produced as a resonance in proton-proton collisions. The mediator decay results in two “semivisible” jets, containing both visible matter and invisible dark matter. The final state therefore includes moderate missing energy aligned with one of the jets, a signature ignored by most dark matter searches. No structure in the dijet transverse mass spectra compatible with the signal is observed. Assuming the Z′ boson has a universal coupling of 0.25 to the SM quarks, an inclusive search, relevant to any model that exhibits this kinematic behavior, excludes mediator masses of 1.5–4.0 TeV at 95% confidence level, depending on the other signal model parameters. To enhance the sensitivity of the search for this particular class of hidden sector models, a boosted decision tree (BDT) is trained using jet substructure variables to distinguish between semivisible jets and SM jets from background processes. When the BDT is employed to identify each jet in the dijet system as semivisible, the mediator mass exclusion increases to 5.1 TeV, for wider ranges of the other signal model parameters. These limits exclude a wide range of strongly coupled hidden sector models for the first time. [Figure not available: see fulltext.], 0, CMS Collaboration, info:eu-repo/semantics/published

A search for resonances decaying into a W boson and a radion, where the radion decays into two W bosons, is presented. The data analyzed correspond to an integrated luminosity of 138 fb-1 recorded in proton-proton collisions with the CMS detector at s=13 TeV. One isolated charged lepton is required, together with missing transverse momentum and one or two massive large-radius jets, containing the decay products of either two or one W bosons, respectively. No excess over the background estimation is observed. The results are combined with those from a complementary channel with an all-hadronic final state, described in an accompanying paper. Limits are set on parameters of an extended warped extra-dimensional model. These searches are the first of their kind at the LHC., 0, CMS Collaboration, info:eu-repo/semantics/published

In this article the author name Luigi Calligaris was incorrectly written as A. Calligaris. The original article has been corrected., 0, info:eu-repo/semantics/published

The Laser Interferometer Space Antenna (LISA) has the potential to reveal wonders about the fundamental theory of nature at play in the extreme gravity regime, where the gravitational interaction is both strong and dynamical. In this white paper, the Fundamental Physics Working Group of the LISA Consortium summarizes the current topics in fundamental physics where LISA observations of gravitational waves can be expected to provide key input. We provide the briefest of reviews to then delineate avenues for future research directions and to discuss connections between this working group, other working groups and the consortium work package teams. These connections must be developed for LISA to live up to its science potential in these areas., 0, SCOPUS: ar.j, info:eu-repo/semantics/published

The Short Strip ASIC (SSA) is one of the four front-end chips designed for the upgrade of the CMS Outer Tracker for the High Luminosity LHC. Together with the Macro-Pixel ASIC (MPA) it will instrument modules containing a strip and a macro-pixel sensor stacked on top of each other. The SSA provides both full readout of the strip hit information when triggered, and, together with the MPA, correlated clusters called stubs from the two sensors for use by the CMS Level-1 (L1) trigger system. Results from the first prototype module consisting of a sensor and two SSA chips are presented. The prototype module has been characterized at the Fermilab Test Beam Facility using a 120 GeV proton beam., 0, info:eu-repo/semantics/published

Isolated neutron stars that are asymmetric with respect to their spin axis are possible sources of detectable continuous gravitational waves. This paper presents a fully coherent search for such signals from eighteen pulsars in data from LIGO and Virgo's third observing run (O3). For known pulsars, efficient and sensitive matched-filter searches can be carried out if one assumes the gravitational radiation is phase-locked to the electromagnetic emission. In the search presented here, we relax this assumption and allow both the frequency and the time derivative of the frequency of the gravitational waves to vary in a small range around those inferred from electromagnetic observations. We find no evidence for continuous gravitational waves, and set upper limits on the strain amplitude for each target. These limits are more constraining for seven of the targets than the spin-down limit defined by ascribing all rotational energy loss to gravitational radiation. In an additional search, we look in O3 data for long-duration (hours-months) transient gravitational waves in the aftermath of pulsar glitches for six targets with a total of nine glitches. We report two marginal outliers from this search, but find no clear evidence for such emission either. The resulting duration-dependent strain upper limits do not surpass indirect energy constraints for any of these targets., 0, info:eu-repo/semantics/published

A search is presented for single production of a vector-like T quark with charge 2/3 e, in the decay channel featuring a top quark and a Z boson, with the top quark decaying hadronically and the Z boson decaying to neutrinos. The search uses data collected by the CMS experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1 recorded at the CERN LHC in 2016–2018. The search is sensitive to a T quark mass between 0.6 and 1.8 TeV with decay widths ranging from negligibly small up to 30% of the T quark mass. Reconstruction strategies for the top quark are based on the degree of Lorentz boosting of its final state. At 95% confidence level, the upper limit on the product of the cross section and branching fraction for a T quark of small decay width varies between 15 and 602 fb, depending on its mass. For a T quark with decay widths between 10 and 30% of its mass, this upper limit ranges between 16 and 836 fb. For most of the studied range, the results provide the best limits to date. This is the first search for single T quark production based on the full Run 2 data set of the LHC. [Figure not available: see fulltext.], 0, CMS Collaboration, info:eu-repo/semantics/published

A search for invisible decays of the Higgs boson produced via vector boson fusion (VBF) has been performed with 101 fb-1 of proton-proton collisions delivered by the LHC at s=13 TeV and collected by the CMS detector in 2017 and 2018. The sensitivity to the VBF production mechanism is enhanced by constructing two analysis categories, one based on missing transverse momentum and a second based on the properties of jets. In addition to control regions with Z and W boson candidate events, a highly populated control region, based on the production of a photon in association with jets, is used to constrain the dominant irreducible background from the invisible decay of a Z boson produced in association with jets. The results of this search are combined with all previous measurements in the VBF topology, based on data collected in 2012 (at s=8 TeV), 2015, and 2016, corresponding to integrated luminosities of 19.7, 2.3, and 36.3 fb-1, respectively. The observed (expected) upper limit on the invisible branching fraction of the Higgs boson is found to be 0.18 (0.10) at the 95% confidence level, assuming the standard model production cross section. The results are also interpreted in the context of Higgs-portal models., 0, CMS Collaboration, info:eu-repo/semantics/published

We report the results of the first joint observation of the KAGRA detector with GEO 600. KAGRA is a cryogenic and underground gravitational-wave detector consisting of a laser interferometer with 3 km arms, located in Kamioka, Gifu, Japan. GEO 600 is a British-German laser interferometer with 600 m arms, located near Hannover, Germany. GEO 600 and KAGRA performed a joint observing run from April 7 to 20, 2020. We present the results of the joint analysis of the GEO-KAGRA data for transient gravitational-wave signals, including the coalescence of neutron-star binaries and generic unmodeled transients. We also perform dedicated searches for binary coalescence signals and generic transients associated with gamma-ray burst events observed during the joint run. No gravitational-wave events were identified. We evaluate the minimum detectable amplitude for various types of transient signals and the spacetime volume for which the network is sensitive to binary neutron-star coalescences. We also place lower limits on the distances to the gamma-ray bursts analyzed based on the non-detection of an associated gravitational-wave signal for several signal models, including binary coalescences. These analyses demonstrate the feasibility and utility of KAGRA as a member of the global gravitational-wave detector network, 0, info:eu-repo/semantics/published