1,201 research outputs found
Robust Limits from Upcoming Neutrino Telescopes and Implications on Minimal Dark Matter Models
Experimental developments in neutrino telescopes are drastically improving
their ability to constrain the annihilation cross-section of dark matter. In
this paper, we employ an angular power spectrum analysis method to probe the
galactic and extra-galactic dark matter signals with neutrino telescopes. We
first derive projections for a next generation of neutrino telescope that is
inspired by KM3NeT. We emphasise that such analysis is much less sensitive to
the choice of dark matter density profile. Remarkably, the projected
sensitivity is improved by more than an order of magnitude with respect to the
existing limits obtained by assuming the Burkert dark matter density profile
describing the galactic halo. Second, we analyse minimal extensions to the
Standard Model that will be maximally probed by the next generation of neutrino
telescopes. As benchmark scenarios, we consider Dirac dark matter in - and
-channel models with vector and scalar mediators. We follow a global
approach by examining all relevant complementary experimental constraints. We
find that neutrino telescopes will be able to competitively probe significant
portions of parameter space. Interestingly, the anomaly-free
model can potentially be explored in regions where the relic abundance is
achieved through freeze-out mechanism
Towards detecting super-GeV dark matter via annihilation to neutrinos
The next generation of neutrino telescopes will feature unprecedented
sensitivities in the detection of neutrinos. Here we study the capabilities of
a large-scale neutrino telescope, like the fully-operating KM3NeT experiment in
the near future, for detecting dark matter annihilation signals from the
Galactic Centre. We consider both ORCA and ARCA detectors, covering dark matter
masses from a few GeV to 100 TeV. We obtain the sensitivities with a
maximum-likelihood analysis method and present them as upper limits in the
thermally averaged annihilation cross-section into Standard Model fermions. Our
projections show that the sensitivity of such a neutrino telescope can reach
the thermal relic line for and for few GeV, for the NFW dark matter density profile. This demonstrates
that ORCA- and ARCA-like detectors will be able to perform competitive dark
matter searches in a wide range of masses. The implications of these striking
projections are investigated in a few selected dark matter particle models,
where we show that neutrino telescopes are able to probe new parameter space
KM3NeT front-end and readout electronics system: hardware, firmware, and software
[EN] The KM3NeT research infrastructure being built at the bottom of the Mediterranean Sea will host
water-Cherenkov telescopes for the detection of cosmic neutrinos. The neutrino telescopes will consist of large
volume three-dimensional grids of optical modules to detect the Cherenkov light from charged particles produced
by neutrino-induced interactions. Each optical module houses 31 3-in. photomultiplier tubes, instrumentation for
calibration of the photomultiplier signal and positioning of the optical module, and all associated electronics
boards. By design, the total electrical power consumption of an optical module has been capped at seven
Watts. We present an overview of the front-end and readout electronics system inside the optical module, which
has been designed for a 1-ns synchronization between the clocks of all optical modules in the grid during a life
time of at least 20 years.The authors acknowledge financial support from the funding agencies: Agence Nationale de la Recherche (Grant No. ANR-15-CE31-0020), Centre National de la Recherche Scientifique (CNRS), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (Grant Nos. ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Paris Ile-de-France Region, France; Shota Rustaveli National Science Foundation of Georgia (SRNSFG, Grant No. FR-18-1268), Georgia; Deutsche Forschungsgemeinschaft (DFG), Germany; The General Secretariat of Research and Technology (GSRT), Greece; Istituto Nazionale di Fisica Nucleare (INFN), Ministero dell'Istruzione, dell'Universita e della Ricerca (MIUR), PRIN 2017 program (Grant NAT-NET 2017W4HA7S) Italy; Ministry of Higher Education, Scientific Research and Professional Training, Morocco; Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; The National Science Centre, Poland (2015/18/E/ST2/00758); National Authority for Scientific Research (ANCS), Romania; Plan Estatal de Investigacion [refs. FPA2015-65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)], Severo Ochoa Centre of Excellence program (MINECO), Red Consolider MultiDark (ref. FPA2017-90566-REDC, MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), "la Caixa" Foundation (ID 100010434) through the fellowship LCF/BQ/IN17/11620019, and the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie Grant Agreement No. 713673, Spain.Aiello, S.; Ameli, F.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid RamĂrez, M.... (2019). KM3NeT front-end and readout electronics system: hardware, firmware, and software. Journal of Astronomical Telescopes, Instruments, and Systems. 5(4):1-15. https://doi.org/10.1117/1.JATIS.5.4.046001S1155
First observation of the cosmic ray shadow of the Moon and the Sun with KM3NeT/ORCA
This article reports the first observation of the Moon and the Sun shadows in the sky distribution of cosmic-ray induced muons measured by the KM3NeT/ORCA detector. The analysed data-taking period spans from February 2020 to November 2021, when the detector had 6 Detection Units deployed at the bottom of the Mediterranean Sea, each composed of 18 Digital Optical Modules. The shadows induced by the Moon and the Sun were detected at their nominal position with a statistical significance of 4.2 Ď and 6.2 Ď , and an angular resolution of Ďres= 0. 49 â and Ďres= 0. 66 â , respectively, consistent with the prediction of 0. 53 â from simulations. This early result confirms the effectiveness of the detector calibration, in time, position and orientation and the accuracy of the event direction reconstruction. This also demonstrates the performance and the competitiveness of the detector in terms of pointing accuracy and angular resolution
Sensitivity to light sterile neutrino mixing parameters with KM3NeT/ORCA
KM3NeT/ORCA is a next-generation neutrino telescope optimised for atmospheric neutrino oscillations studies. In this paper, the sensitivity of ORCA to the presence of a light sterile neutrino in a 3+1 model is presented. After three years of data taking, ORCA will be able to probe the active-sterile mixing angles θ14, θ24, θ34 and the effective angle θΟe, over a broad range of mass squared difference âm412 âź [10â5, 10] eV2, allowing to test the eV-mass sterile neutrino hypothesis as the origin of short baseline anomalies, as well as probing the hypothesis of a very light sterile neutrino, not yet constrained by cosmology. ORCA will be able to explore a relevant fraction of the parameter space not yet reached by present measurements. [Figure not available: see fulltext.
Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at âs = 8 TeV
A search for new physics is performed in multijet events with large missing transverse momentum produced in proton-proton collisions at TeX = 8 TeV using a data sample corresponding to an integrated luminosity of 19.5 fbâ1 collected with the CMS detector at the LHC. The data sample is divided into three jet multiplicity categories (3-5, 6-7, and âĽ8 jets), and studied further in bins of two variables: the scalar sum of jet transverse momenta and the missing transverse momentum. The observed numbers of events in various categories are consistent with backgrounds expected from standard model processes. Exclusion limits are presented for several simplified supersymmetric models of squark or gluino pair production
Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at âs=8 TeV
The top-antitop quark (t (t) over bar) production cross section is measured in proton-proton collisions at root s = 8 TeV with the CMS experiment at the LHC, using a data sample corresponding to an integrated luminosity of 5.3 fb(-1). The measurement is performed by analysing events with a pair of electrons or muons, or one electron and one muon, and at least two jets, one of which is identified as originating from hadronisation of a bottom quark. The measured cross section is 239 +/- 2 (stat.) +/- 11 (syst.) +/- 6 (lum.) pb, for an assumed top-quark mass of 172.5 GeV, in agreement with the prediction of the standard model
Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV
We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5 Ă109 protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to âź10 GV and âź20 GV , respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
Implementation and first results of the KM3NeT real-time core-collapse supernova neutrino search
The KM3NeT research infrastructure is unconstruction in the Mediterranean Sea. KM3NeT will study atmospheric and astrophysical neutrinos with two multi-purpose neutrino detectors, ARCA and ORCA, primarily aimed at GeVâPeV neutrinos. Thanks to the multi-photomultiplier tube design of the digital optical modules, KM3NeT is capable of detecting the neutrino burst from a Galactic or near-Galactic core-collapse supernova. This potential is already exploitable with the first detection units deployed in the sea. This paper describes the real-time implementation of the supernova neutrino search, operating on the two KM3NeT detectors since the first months of 2019. A quasi-online astronomy analysis is introduced to study the time profile of the detected neutrinos for especially significant events. The mechanism of generation and distribution of alerts, as well as the integration into the SNEWS and SNEWS 2.0 global alert systems, are described. The approach for the follow-up of external alerts with a search for a neutrino excess in the archival data is defined. Finally, an overview of the current detector capabilities and a report after the first two years of operation are given
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