Real-Time Online Monitoring of the Ion Range by Means of Prompt Secondary Radiations

International audiencePrompt secondary radiations such as gamma rays and protons can be used for ion-range monitoring during ion therapy either on an energy-slice basis or on a pencil-beam basis. We present a review of the ongoing activities in terms of detector developments, imaging, experimental and theoretical physics issues concerning the correlation between the physical dose and hadronic processe

2012 Activity Report of the Regional Research Programme on Hadrontherapy for the ETOILE Center

2012 is the penultimate year of financial support by the CPER 2007-2013 for ETOILE's research program, sustained by the PRRH at the University Claude Bernard. As with each edition we make the annual review of the research in this group, so active for over 12 years now. Over the difficulties in the decision-making process for the implementation of the ETOILE Center, towards which all our efforts are focussed, some "themes" (work packages) were strengthened, others have progressed, or have been dropped. This is the case of the eighth theme (technological developments), centered around the technology for rotative beam distribution heads (gantries) and, after being synchronized with the developments of ULICE's WP6, remained so by ceasing its activities, coinciding also with the retirement of its historic leader at IPNL, Marcel Bajard. Topic number 5 ("In silico simulations") has suffered the departure of its leader, Benjamin Ribba, although the work has still been provided by Branka Bernard, a former postdoctoral fellow in Lyon Sud, and now back home in Croatia, still in contract with UCBL for the ULICE project. Aside from these two issues (and the fact that the theme "Medico-economical simulations" is now directly linked to the first one ("Medical Project"), the rest of the teams are growing, as evidenced by the publication statistics at the beginning of this report. This is obviously due to the financial support of our always faithful regional institutions, but also to the synergy that the previous years, the European projects, the arrival of the PRIMES LabEx, and the national France Hadron infrastructure have managed to impulse. The Rhone-Alpes hadron team, which naturally includes the researchers of LPC at Clermont, should also see its influence result in a strong presence in France Hadron's regional node, which is being organized. The future of this regional research is not yet fully guaranteed, especially in the still uncertain context of ETOILE, but the tracks are beginning to emerge to allow past and present efforts translate into a long future that we all want to see established. Each of the researchers in PRRH is aware that 2013 will be (and already is) the year of great challenge : for ETOILE, for the PRRH, for hadron therapy in France, for French hadrontherapy in Europe (after the opening and beginning of treatments in the German [HIT Heidelberg, Marburg], Italian [CNAO, Pavia] and Austrian [MedAustron, Wien Neuerstadt]) centers. Let us meet again in early 2014 for a comprehensive review of the past and a perspective for the future ..

Measurement of Astrophysical Tau Neutrinos in IceCube's High-Energy Starting Events

We present the results of a search for astrophysical tau neutrinos in 7.5 years of IceCube's high-energy starting event data. At high energies, two energy depositions stemming from the tau neutrino charged-current interaction and subsequent tau lepton decay may be resolved. We report the first detection of two such events, with probabilities of $\sim 76\%$ and $\sim 98\%$ of being produced by astrophysical tau neutrinos. The resultant astrophysical neutrino flavor measurement is consistent with expectations, disfavoring a no-astrophysical tau neutrino flux scenario with 2.8$\sigma$ significance.Comment: This article is supported by a long-form paper that discusses the high-energy starting event selection titled: "The IceCube high-energy starting event sample: Description and flux characterization with 7.5 years of data.

Detection of astrophysical tau neutrino candidates in IceCube

High-energy tau neutrinos are rarely produced in atmospheric cosmic-ray showers or at cosmic particle accelerators, but are expected to emerge during neutrino propagation over cosmic distances due to flavor mixing. When high energy tau neutrinos interact inside the IceCube detector, two spatially separated energy depositions may be resolved, the first from the charged current interaction and the second from the tau lepton decay. We report a novel analysis of 7.5 years of IceCube data that identifies two candidate tau neutrinos among the 60 “High-Energy Starting Events” (HESE) collected during that period. The HESE sample offers high purity, all-sky sensitivity, and distinct observational signatures for each neutrino flavor, enabling a new measurement of the flavor composition. The measured astrophysical neutrino flavor composition is consistent with expectations, and an astrophysical tau neutrino flux is indicated at 2.8$\sigma$ significance

Measurement of the high-energy all-flavor neutrino-nucleon cross section with IceCube

The flux of high-energy neutrinos passing through the Earth is attenuated due to their interactions with matter. The interaction rate is determined by the neutrino interaction cross section and affects the flux arriving at the IceCube Neutrino Observatory, a cubic-kilometer neutrino detector embedded in the Antarctic ice sheet. We present a measurement of the neutrino cross section between 60 TeV and 10 PeV using the high-energy starting event (HESE) sample from IceCube with 7.5 years of data. The result is binned in neutrino energy and obtained using both Bayesian and frequentist statistics. We find it compatible with predictions from the Standard Model. While the cross section is expected to be flavor independent above 1 TeV, additional constraints on the measurement are included through updated experimental particle identification (PID) classifiers, proxies for the three neutrino flavors. This is the first such measurement to use a ternary PID observable and the first to account for neutrinos from tau decay

A search for time-dependent astrophysical neutrino emission with IceCube data from 2012 to 2017

High-energy neutrinos are unique messengers of the high-energy universe, tracing the processes of cosmic-ray acceleration. This paper presents analyses focusing on time-dependent neutrino point-source searches. A scan of the whole sky, making no prior assumption about source candidates, is performed, looking for a space and time clustering of high-energy neutrinos in data collected by the IceCube Neutrino Observatory between 2012 and 2017. No statistically significant evidence for a time-dependent neutrino signal is found with this search during this period since all results are consistent with the background expectation. Within this study period, the blazar 3C 279, showed strong variability, inducing a very prominent gamma-ray flare observed in 2015 June. This event motivated a dedicated study of the blazar, which consists of searching for a time-dependent neutrino signal correlated with the gamma-ray emission. No evidence for a time-dependent signal is found. Hence, an upper limit on the neutrino fluence is derived, allowing us to constrain a hadronic emission model

LeptonInjector and LeptonWeighter: A neutrino event generator and weighter for neutrino observatories

We present a high-energy neutrino event generator, called LeptonInjector, alongside an event weighter, called LeptonWeighter. Both are designed for large-volume Cherenkov neutrino telescopes such as IceCube. The neutrino event generator allows for quick and flexible simulation of neutrino events within and around the detector volume, and implements the leading Standard Model neutrino interaction processes relevant for neutrino observatories: neutrino-nucleon deep-inelastic scattering and neutrino-electron annihilation. In this paper, we discuss the event generation algorithm, the weighting algorithm, and the main functions of the publicly available code, with examples.Comment: 28 pages, 10 figures, 3 table

Multimessenger Gamma-Ray and Neutrino Coincidence Alerts using HAWC and IceCube sub-threshold Data

The High Altitude Water Cherenkov (HAWC) and IceCube observatories, through the Astrophysical Multimessenger Observatory Network (AMON) framework, have developed a multimessenger joint search for extragalactic astrophysical sources. This analysis looks for sources that emit both cosmic neutrinos and gamma rays that are produced in photo-hadronic or hadronic interactions. The AMON system is running continuously, receiving sub-threshold data (i.e. data that is not suited on its own to do astrophysical searches) from HAWC and IceCube, and combining them in real-time. We present here the analysis algorithm, as well as results from archival data collected between June 2015 and August 2018, with a total live-time of 3.0 years. During this period we found two coincident events that have a false alarm rate (FAR) of $<1$ coincidence per year, consistent with the background expectations. The real-time implementation of the analysis in the AMON system began on November 20th, 2019, and issues alerts to the community through the Gamma-ray Coordinates Network with a FAR threshold of $<4$ coincidences per year.Comment: 14 pages, 5 figures, 3 table

Limits on Neutrino Emission from GRB 221009A from MeV to PeV using the IceCube Neutrino Observatory

Gamma-ray bursts (GRBs) have long been considered a possible source of high-energy neutrinos. While no correlations have yet been detected between high-energy neutrinos and GRBs, the recent observation of GRB 221009A - the brightest GRB observed by Fermi-GBM to date and the first one to be observed above an energy of 10 TeV - provides a unique opportunity to test for hadronic emission. In this paper, we leverage the wide energy range of the IceCube Neutrino Observatory to search for neutrinos from GRB 221009A. We find no significant deviation from background expectation across event samples ranging from MeV to PeV energies, placing stringent upper limits on the neutrino emission from this source.Comment: Version in ApJ Letters Focus on the Ultra-luminous Gamma-Ray Burst GRB 221009

Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing

We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011–2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be sin2θ23=0.51±0.05 and Δm232=2.41±0.07×10−3  eV2, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties