The search for high-energy neutrinos coincident with fast radio bursts with the ANTARES neutrino telescope

[EN] In the past decade, a new class of bright transient radio sources with millisecond duration has been discovered. The origin of these so-called fast radio bursts (FRBs) is still a mystery, despite the growing observational efforts made by various multiwavelength and multimessenger facilities. To date, many models have been proposed to explain FRBs, but neither the progenitors nor the radiative and the particle acceleration processes at work have been clearly identified. In this paper, we assess whether hadronic processes may occur in the vicinity of the FRB source. If they do, FRBs may contribute to the high-energy cosmic-ray and neutrino fluxes. A search for these hadronic signatures was carried out using the ANTARES neutrino telescope. The analysis consists in looking for high-energy neutrinos, in the TeV-PeV regime, that are spatially and temporally coincident with the detected FRBs. Most of the FRBs discovered in the period 2013-2017 were in the field of view of the ANTARES detector, which is sensitive mostly to events originating from the Southern hemisphere. From this period, 12 FRBs were selected and no coincident neutrino candidate was observed. Upper limits on the per-burst neutrino fluence were derived using a power-law spectrum, dN/DE nu proportional to E-nu(-gamma), for the incoming neutrino flux, assuming spectral indexes gamma = 1.0, 2.0, 2.5. Finally, the neutrino energy was constrained by computing the total energy radiated in neutrinos, assuming different distances for the FRBs. Constraints on the neutrino fluence and on the energy released were derived from the associated null results.The authors acknowledge financial support from the following funding agencies: Centre National de la Recherche Scientifique (CNRS), Commissariat a l'energie atomique et aux energies alternatives (CEA), Commission Europeenne (FEDER fund and Marie Curie Program), Institut Universitaire de France (IUF), IdEx program and UnivEarthS Labex program at Sorbonne Paris Cite (ANR-10-LABX-0023 and ANR-11-IDEX-0005-02), Labex OCEVU (ANR-11-LABX-0060) and the A*MIDEX project (ANR-11-IDEX-0001-02), Region Ile-de-France (DIM-ACAV), Region Alsace (contrat CPER), Region Provence-Alpes-Cote d'Azur, Departement du Var and Ville de La Seyne-sur-Mer, France; Bundesministerium fur Bildung und Forschung (BMBF), Germany; Istituto Nazionale di Fisica Nucleare (INFN), Italy; Stichting voor Fundamenteel Onderzoek der Materie (FOM), Nederlandse organisatie voor Wetenschappelijk Onderzoek (NWO), the Netherlands; Council of the President of the Russian Federation for young scientists and leading scientific schools supporting grants, Russia; National Authority for Scientific Research (ANCS), Romania; Ministerio de Economia y Competitividad (MINECO): Plan Estatal de Investigacion (refs. FPA2015-65150-C3-1-P, -2-P and -3-P, (MINECO/FEDER)), Severo Ochoa Centre of Excellence and MultiDark Consolider (MINECO), and Prometeo and Grisolia programs (Generalitat Valenciana), Spain; Ministry of Higher Education, Scientific Research and Professional Training, Morocco. We also acknowledge technical support from Ifremer, AIM and Foselev Marine for the sea operation and CC-IN2P3 for the computing facilities.Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Ardid Ramírez, M.; Aubert, J.; Aublin, J.... (2019). The search for high-energy neutrinos coincident with fast radio bursts with the ANTARES neutrino telescope. Monthly Notices of the Royal Astronomical Society. 482(1):184-193. https://doi.org/10.1093/mnras/sty2621S1841934821Aartsen, M. G., Abbasi, R., Abdou, Y., Ackermann, M., Adams, J., Aguilar, J. A., … Bai, X. (2013). First Observation of PeV-Energy Neutrinos with IceCube. Physical Review Letters, 111(2). doi:10.1103/physrevlett.111.021103Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Arlen, T. C. (2015). Atmospheric and astrophysical neutrinos above 1 TeV interacting in IceCube. Physical Review D, 91(2). doi:10.1103/physrevd.91.022001Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Archinger, M. (2015). A COMBINED MAXIMUM-LIKELIHOOD ANALYSIS OF THE HIGH-ENERGY ASTROPHYSICAL NEUTRINO FLUX MEASURED WITH ICECUBE. The Astrophysical Journal, 809(1), 98. doi:10.1088/0004-637x/809/1/98Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Arlen, T. C. (2015). SEARCH FOR PROMPT NEUTRINO EMISSION FROM GAMMA-RAY BURSTS WITH ICECUBE. The Astrophysical Journal, 805(1), L5. doi:10.1088/2041-8205/805/1/l5Aartsen, M. G., Abraham, K., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., … Anderson, T. (2016). OBSERVATION AND CHARACTERIZATION OF A COSMIC MUON NEUTRINO FLUX FROM THE NORTHERN HEMISPHERE USING SIX YEARS OF ICECUBE DATA. The Astrophysical Journal, 833(1), 3. doi:10.3847/0004-637x/833/1/3Aartsen, M. G., Ackermann, M., Adams, J., Aguilar, J. A., Ahlers, M., Ahrens, M., … Anderson, T. (2018). A Search for Neutrino Emission from Fast Radio Bursts with Six Years of IceCube Data. The Astrophysical Journal, 857(2), 117. doi:10.3847/1538-4357/aab4f8Abbott, B. P., Abbott, R., Abbott, T. D., Acernese, F., Ackley, K., Adams, C., … Adya, V. B. (2017). GW170817: Observation of Gravitational Waves from a Binary Neutron Star Inspiral. Physical Review Letters, 119(16). doi:10.1103/physrevlett.119.161101Abbott, B. P., Abbott, R., Abbott, T. D., Acernese, F., Ackley, K., Adams, C., … Adya, V. B. (2017). Gravitational Waves and Gamma-Rays from a Binary Neutron Star Merger: GW170817 and GRB 170817A. The Astrophysical Journal, 848(2), L13. doi:10.3847/2041-8213/aa920cAdrián-Martínez, S., Al Samarai, I., Albert, A., André, M., Anghinolfi, M., Anton, G., … Aubert, J.-J. (2012). SEARCH FOR COSMIC NEUTRINO POINT SOURCES WITH FOUR YEARS OF DATA FROM THE ANTARES TELESCOPE. The Astrophysical Journal, 760(1), 53. doi:10.1088/0004-637x/760/1/53Adrián-Martínez, S., Ageron, M., Aharonian, F., Aiello, S., Albert, A., Ameli, F., … Anghinolfi, M. (2016). Letter of intent for KM3NeT 2.0. Journal of Physics G: Nuclear and Particle Physics, 43(8), 084001. doi:10.1088/0954-3899/43/8/084001Ageron, M., Aguilar, J. A., Al Samarai, I., Albert, A., Ameli, F., André, M., … Ardid, M. (2011). ANTARES: The first undersea neutrino telescope. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 656(1), 11-38. doi:10.1016/j.nima.2011.06.103Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). All-sky search for high-energy neutrinos from gravitational wave event GW170104 with the Antares neutrino telescope. The European Physical Journal C, 77(12). doi:10.1140/epjc/s10052-017-5451-zAlbert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). First all-flavor neutrino pointlike source search with the ANTARES neutrino telescope. Physical Review D, 96(8). doi:10.1103/physrevd.96.082001Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Basa, S. (2017). Search for high-energy neutrinos from bright GRBs with ANTARES. Monthly Notices of the Royal Astronomical Society, 469(1), 906-915. doi:10.1093/mnras/stx902Albert, A., André, M., Anghinolfi, M., Anton, G., Ardid, M., Aubert, J.-J., … Barrios-Martí, J. (2018). All-flavor Search for a Diffuse Flux of Cosmic Neutrinos with Nine Years of ANTARES Data. The Astrophysical Journal, 853(1), L7. doi:10.3847/2041-8213/aaa4f6Bailes, M., Jameson, A., Flynn, C., Bateman, T., Barr, E. D., Bhandari, S., … Temby, D. (2017). The UTMOST: A Hybrid Digital Signal Processor Transforms the Molonglo Observatory Synthesis Telescope. Publications of the Astronomical Society of Australia, 34. doi:10.1017/pasa.2017.39Bannister, K. W., Shannon, R. M., Macquart, J.-P., Flynn, C., Edwards, P. G., O’Neill, M., … Clarke, N. (2017). The Detection of an Extremely Bright Fast Radio Burst in a Phased Array Feed Survey. The Astrophysical Journal, 841(1), L12. doi:10.3847/2041-8213/aa71ffBhandari, S., Keane, E. F., Barr, E. D., Jameson, A., Petroff, E., Johnston, S., … Burke-Spolaor, S. (2017). The SUrvey for Pulsars and Extragalactic Radio Bursts – II. New FRB discoveries and their follow-up. Monthly Notices of the Royal Astronomical Society, 475(2), 1427-1446. doi:10.1093/mnras/stx3074Biehl, D., Heinze, J., & Winter, W. (2018). Expected neutrino fluence from short Gamma-Ray Burst 170817A and off-axis angle constraints. Monthly Notices of the Royal Astronomical Society, 476(1), 1191-1197. doi:10.1093/mnras/sty285Caleb, M., Flynn, C., Bailes, M., Barr, E. D., Bateman, T., Bhandari, S., … Krishnan, V. V. (2016). Fast Radio Transient searches with UTMOST at 843 MHz. Monthly Notices of the Royal Astronomical Society, 458(1), 718-725. doi:10.1093/mnras/stw109Caleb, M., Flynn, C., Bailes, M., Barr, E. D., Bateman, T., Bhandari, S., … Venkatraman Krishnan, V. (2017). The first interferometric detections of fast radio bursts. Monthly Notices of the Royal Astronomical Society, 468(3), 3746-3756. doi:10.1093/mnras/stx638Cao, X.-F., & Yu, Y.-W. (2018). Superconducting cosmic string loops as sources for fast radio bursts. Physical Review D, 97(2). doi:10.1103/physrevd.97.023022Champion, D. J., Petroff, E., Kramer, M., Keith, M. J., Bailes, M., Barr, E. D., … Lyne, A. G. (2016). Five new fast radio bursts from the HTRU high-latitude survey at Parkes: first evidence for two-component bursts. Monthly Notices of the Royal Astronomical Society: Letters, 460(1), L30-L34. doi:10.1093/mnrasl/slw069Chatterjee, S., Law, C. J., Wharton, R. S., Burke-Spolaor, S., Hessels, J. W. T., Bower, G. C., … van Langevelde, H. J. (2017). A direct localization of a fast radio burst and its host. Nature, 541(7635), 58-61. doi:10.1038/nature20797Cordes, J. M., & Wasserman, I. (2016). Supergiant pulses from extragalactic neutron stars. Monthly Notices of the Royal Astronomical Society, 457(1), 232-257. doi:10.1093/mnras/stv2948DeLaunay, J. J., Fox, D. B., Murase, K., Mészáros, P., Keivani, A., Messick, C., … Turley, C. F. (2016). DISCOVERY OF A TRANSIENT GAMMA-RAY COUNTERPART TO FRB 131104. The Astrophysical Journal, 832(1), L1. doi:10.3847/2041-8205/832/1/l1Dey, R. K., Ray, S., & Dam, S. (2016). Searching for PeV neutrinos from photomeson interactions in magnetars. EPL (Europhysics Letters), 115(6), 69002. doi:10.1209/0295-5075/115/69002Fahey, S., Kheirandish, A., Vandenbroucke, J., & Xu, D. (2017). A Search for Neutrinos from Fast Radio Bursts with IceCube. The Astrophysical Journal, 845(1), 14. doi:10.3847/1538-4357/aa7e28Falcke, H., & Rezzolla, L. (2014). Fast radio bursts: the last sign of supramassive neutron stars. Astronomy & Astrophysics, 562, A137. doi:10.1051/0004-6361/201321996Goldstein, A., Preece, R. D., Mallozzi, R. S., Briggs, M. S., Fishman, G. J., Kouveliotou, C., … Burgess, J. M. (2013). THE BATSE 5B GAMMA-RAY BURST SPECTRAL CATALOG. The Astrophysical Journal Supplement Series, 208(2), 21. doi:10.1088/0067-0049/208/2/21Guetta, D., Hooper, D., Alvarez-Muñiz, J., Halzen, F., & Reuveni, E. (2004). Neutrinos from individual gamma-ray bursts in the BATSE catalog. Astroparticle Physics, 20(4), 429-455. doi:10.1016/s0927-6505(03)00211-1Hümmer, S., Rüger, M., Spanier, F., & Winter, W. (2010). SIMPLIFIED MODELS FOR PHOTOHADRONIC INTERACTIONS IN COSMIC ACCELERATORS. The Astrophysical Journal, 721(1), 630-652. doi:10.1088/0004-637x/721/1/630Hümmer, S., Baerwald, P., & Winter, W. (2012). Neutrino Emission from Gamma-Ray Burst Fireballs, Revised. Physical Review Letters, 108(23). doi:10.1103/physrevlett.108.231101Johnston, S., Taylor, R., Bailes, M., Bartel, N., Baugh, C., Bietenholz, M., … Wolleben, M. (2008). Science with ASKAP. Experimental Astronomy, 22(3), 151-273. doi:10.1007/s10686-008-9124-7Katz, J. I. (2014). Coherent emission in fast radio bursts. Physical Review D, 89(10). doi:10.1103/physrevd.89.103009Keane, E. F., Johnston, S., Bhandari, S., Barr, E., Bhat, N. D. R., Burgay, M., … Bassa, C. (2016). The host galaxy of a fast radio burst. Nature, 530(7591), 453-456. doi:10.1038/nature17140Li, X., Zhou, B., He, H.-N., Fan, Y.-Z., & Wei, D.-M. (2014). MODEL-DEPENDENT ESTIMATE ON THE CONNECTION BETWEEN FAST RADIO BURSTS AND ULTRA HIGH ENERGY COSMIC RAYS. The Astrophysical Journal, 797(1), 33. doi:10.1088/0004-637x/797/1/33Lorimer, D. R., Bailes, M., McLaughlin, M. A., Narkevic, D. J., & Crawford, F. (2007). A Bright Millisecond Radio Burst of Extragalactic Origin. Science, 318(5851), 777-780. doi:10.1126/science.1147532Lyubarsky, Y. (2014). A model for fast extragalactic radio bursts. Monthly Notices of the Royal Astronomical Society: Letters, 442(1), L9-L13. doi:10.1093/mnrasl/slu046Marcote, B., Paragi, Z., Hessels, J. W. T., Keimpema, A., Langevelde, H. J. van, Huang, Y., … Wharton, R. S. (2017). The Repeating Fast Radio Burst FRB 121102 as Seen on Milliarcsecond Angular Scales. The Astrophysical Journal, 834(2), L8. doi:10.3847/2041-8213/834/2/l8Murase, K., & Nagataki, S. (2006). High energy neutrino emission and neutrino background from gamma-ray bursts in the internal shock model. Physical Review D, 73(6). doi:10.1103/physrevd.73.063002Murase, K., Kashiyama, K., & Mészáros, P. (2016). A burst in a wind bubble and the impact on baryonic ejecta: high-energy gamma-ray flashes and afterglows from fast radio bursts and pulsar-driven supernova remnants. Monthly Notices of the Royal Astronomical Society, 461(2), 1498-1511. doi:10.1093/mnras/stw1328Murase, K., Mészáros, P., & Fox, D. B. (2017). Fast Radio Bursts with Extended Gamma-Ray Emission? The Astrophysical Journal, 836(1), L6. doi:10.3847/2041-8213/836/1/l6Palaniswamy, D., Wayth, R. B., Trott, C. M., McCallum, J. N., Tingay, S. J., & Reynolds, C. (2014). A SEARCH FOR FAST RADIO BURSTS ASSOCIATED WITH GAMMA-RAY BURSTS. The Astrophysical Journal, 790(1), 63. doi:10.1088/0004-637x/790/1/63Palmer, D. M., Barthelmy, S., Gehrels, N., Kippen, R. M., Cayton, T., Kouveliotou, C., … Tueller, J. (2005). A giant γ-ray flare from the magnetar SGR 1806–20. Nature, 434(7037), 1107-1109. doi:10.1038/nature03525Pen, U.-L., & Connor, L. (2015). LOCAL CIRCUMNUCLEAR MAGNETAR SOLUTION TO EXTRAGALACTIC FAST RADIO BURSTS. The Astrophysical Journal, 807(2), 179. doi:10.1088/0004-637x/807/2/179Petroff, E., Johnston, S., Keane, E. F., van Straten, W., Bailes, M., Barr, E. D., … Stappers, B. W. (2015). A survey of FRB fields: limits on repeatability. Monthly Notices of the Royal Astronomical Society, 454(1), 457-462. doi:10.1093/mnras/stv1953Petroff, E., Bailes, M., Barr, E. D., Barsdell, B. R., Bhat, N. D. R., Bian, F., … Wolf, C. (2014). A real-time fast radio burst: polarization detection and multiwavelength follow-up. Monthly Notices of the Royal Astronomical Society, 447(1), 246-255. doi:10.1093/mnras/stu2419Petroff, E., Barr, E. D., Jameson, A., Keane, E. F., Bailes, M., Kramer, M., … van Straten, W. (2016). FRBCAT: The Fast Radio Burst Catalogue. Publications of the Astronomical Society of Australia, 33. doi:10.1017/pasa.2016.35Ravi, V., & Lasky, P. D. (2014). The birth of black holes: neutron star collapse times, gamma-ray bursts and fast radio bursts. Monthly Notices of the Royal Astronomical Society, 441(3), 2433-2439. doi:10.1093/mnras/stu720Ravi, V., Shannon, R. M., & Jameson, A. (2015). A FAST RADIO BURST IN THE DIRECTION OF THE CARINA DWARF SPHEROIDAL GALAXY. The Astrophysical Journal, 799(1), L5. doi:10.1088/2041-8205/799/1/l5Scholz, P., Spitler, L. G., Hessels, J. W. T., Chatterjee, S., Cordes, J. M., Kaspi, V. M., … Tendulkar, S. P. (2016). THE REPEATING FAST RADIO BURST FRB 121102: MULTI-WAVELENGTH OBSERVATIONS AND ADDITIONAL BURSTS. The Astrophysical Journal, 833(2), 177. doi:10.3847/1538-4357/833/2/177Scholz, P., Bogdanov, S., Hessels, J. W. T., Lynch, R. S., Spitler, L. G., Bassa, C. G., … Wharton, R. S. (2017). Simultaneous X-Ray, Gamma-Ray, and Radio Observations of the Repeating Fast Radio Burst FRB 121102. The Astrophysical Journal, 846(1), 80. doi:10.3847/1538-4357/aa8456Spitler, L. G., Scholz, P., Hessels, J. W. T., Bogdanov, S., Brazier, A., Camilo, F., … Zhu, W. W. (2016). A repeating fast radio burst. Nature, 531(7593), 202-205. doi:10.1038/nature17168Tendulkar, S. P., Bassa, C. G., Cordes, J. M., Bower, G. C., Law, C. J., Chatterjee, S., … Wharton, R. S. (2017). The Host Galaxy and Redshift of the Repeating Fast Radio Burst FRB 121102. The Astrophysical Journal, 834(2), L7. doi:10.3847/2041-8213/834/2/l7Thornton, D., Stappers, B., Bailes, M., Barsdell, B., Bates, S., Bhat, N. D. R., … van Straten, W. (2013). A Population of Fast Radio Bursts at Cosmological Distances. Science, 341(6141), 53-56. doi:10.1126/science.1236789Totani, T. (2013). Cosmological Fast Radio Bursts from Binary Neutron Star Mergers. Publications of the Astronomical Society of Japan, 65(5), L12. doi:10.1093/pasj/65.5.l12Wang, J.-S., Yang, Y.-P., Wu, X.-F., Dai, Z.-G., & Wang, F.-Y. (2016). FAST RADIO BURSTS FROM THE INSPIRAL OF DOUBLE NEUTRON STARS. The Astrophysical Journal, 822(1), L7. doi:10.3847/2041-8205/822/1/l7Waxman, E., & Bahcall, J. (1997). High Energy Neutrinos from Cosmological Gamma-Ray Burst Fireballs. Physical Review Letters, 78(12), 2292-2295. doi:10.1103/physrevlett.78.2292Ye, J., Wang, K., & Cai, Y.-F. (2017). Superconducting cosmic strings as sources of cosmological fast radio bursts. The European Physical Journal C, 77(11). doi:10.1140/epjc/s10052-017-5319-2Zhang, B. (2013). A POSSIBLE CONNECTION BETWEEN FAST RADIO BURSTS AND GAMMA-RAY BURSTS. The Astrophysical Journal, 780(2), L21. doi:10.1088/2041-8205/780/2/l21Zhang, B., & Kumar, P. (2013). Model-Dependent High-Energy Neutrino Flux from Gamma-Ray Bursts. Physical Review Letters, 110(12). doi:10.1103/physrevlett.110.121101Zhang, B., Xu, R. X., & Qiao, G. J. (2000). Nature and Nurture: a Model for Soft Gamma-Ray Repeaters. The Astrophysical Journal, 545(2), L127-L130. doi:10.1086/317889Zhang, B., Dai, Z. G., Meszaros, P., Waxman, E., & Harding, A. K. (2003). High‐Energy Neutrinos from Magnetars. The Astrophysical Journal, 595(1), 346-351. doi:10.1086/37719

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The identification of helium nuclei at LHCb is achieved using a method based on measurements of ionisation losses in the silicon sensors and timing measurements in the Outer Tracker drift tubes. The background from photon conversions is reduced using the RICH detectors and an isolation requirement. The method is developed using pp collision data at √(s) = 13 TeV recorded by the LHCb experiment in the years 2016 to 2018, corresponding to an integrated luminosity of 5.5 fb-1. A total of around 105 helium and antihelium candidates are identified with negligible background contamination. The helium identification efficiency is estimated to be approximately 50% with a corresponding background rejection rate of up to O(10^12). These results demonstrate the feasibility of a rich programme of measurements of QCD and astrophysics interest involving light nuclei

Curvature-bias corrections using a pseudomass method

Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √(s)=13 TeV during 2016, 2017 and 2018. The biases are determined using Z→μ + μ - decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z→μ + μ - mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass