The APPEC General Assembly (GA) came together in Lisbon at the Laboratory of Instrumentation and Experimental Particle Physics (LIP). The meeting started on the evening of 2 December with an excellent dinner, which was already used for first informal discussions. On the next day the APPEC Chair Teresa Montaruli and the local organizer and representative of Portugal, Mario Pimenta welcomed the GA and Pimenta opened the session with an overview on Astroparticle Physics in Portugal. Subsequently, the resumption of Poland participation to APPEC with CAMK representing it was approved by the General Assembly. Prof. Leszek Roszkowski will be the selected representative of Poland in the GA. He informed the Assembly of the excellent European Community financed AstroCENT (https://astrocent.camk.edu.pl), which has the scope of developing dedicated projects in astroparticle physics with the scope to develop innovation at the border between this field, computing, sensor and electronic development and medical applications.
Then the list of discussion points was worked through. It covered
an status report on the European Particle Physics Strategy Update and proposed recommendations,
the proposal towards a more sustainable APPEC,
the organisation of the next Town Meeting,
the proposal of a technology forum of APPEC open to ECFA and NuPECC,
and the progress of the Scientific Advisory Committee.
Regarding the last point we would like to highlight the final report of the Neutrinoless Double Beta Decay sub-committee, see also here.
The time for the meeting was by then almost over and the remaining was used for a report from the Joint Secretary (JS). Unfortunately we had to let one of our JS colleagues go and we would like to take this opportunity to thank Francesca Moglia for her time at APPEC and wish her all the best for her future.
A new instrument mounted atop a telescope in Arizona has aimed its robotic array of 5,000 fiber-optic “eyes” at the night sky to capture the first images showing its unique view of galaxy light.
DESI’s 5000 spectroscopic “eyes” can cover an area of sky about 38 times larger than that of the full moon, as seen in this overlay of DESI’s focal plane on the night sky (top). Each one of these robotically controlled eyes can fix a fiber-optic cable on a single object to gather its light. The gathered light collected from a small region in the Triangulum galaxy (bottom) by a single fiber-optic cable (red dot) is split into a spectrum (bottom) that reveals the fingerprints of the elements present in the galaxy and aid in gauging the distance to the galaxy. The test spectrum shown here was collected by DESI on Oct. 22. (Credit: DESI Collaboration; Legacy Surveys; NASA/JPL-Caltech/UCLA)
It was the first test of the Dark Energy Spectroscopic Instrument, known as DESI, with its nearly complete complement of components. The long-awaited instrument is designed to explore the mystery of dark energy, which makes up about 68 percent of the universe and is speeding up its expansion.
DESI’s components are designed to automatically point at preselected sets of galaxies, gather their light, and then split that light into narrow bands of color to precisely map their distance from Earth and gauge how much the universe expanded as this light traveled to Earth. In ideal conditions DESI can cycle through a new set of 5,000 galaxies every 20 minutes.
The latest milestone, achieved Oct. 22, marks the opening of DESI’s final testing toward the formal start of observations in early 2020. Installation of DESI began in February 2018 at the Nicholas U. Mayall Telescope at Kitt Peak National Observatory near Tucson, Arizona. Over the past 18 months, a bevy of DESI components were shipped to the site from institutions around the globe and installed on the telescope.
A view of DESI’s fully installed focal plane, which features 5,000 automated robotic positioners, each carrying a fiber-optic cable to gather galaxies’ light. (Credit: DESI Collaboration)
DESI’s focal plane, which carries 5,000 robotic positioners that swivel in a choreographed “dance” to individually focus on galaxies, is at the top of the telescope. These little robots – which each hold a light-gathering fiber-optic cable that is about the average width of a human hair – serve as DESI’s eyes. It takes about 10 seconds for the positioners to swivel to a new sequence of targeted galaxies. With its unprecedented surveying speed, DESI will map over 20 times more objects than any predecessor experiment. The focal plane is fed by corrector optics which provide a 3-degree-diameter field of view. The optical fibers mounted to the positioners extend 50 meters down the telescope to feed 10 broad-band spectrographs, each containing three detectors. The spectrographs cover a spectral range of 360 nanometers (nm) to 980 nm with a resolution of 2,000 to 5,000, enabling DESI to probe redshifts up to 1.7 for emission line galaxies and 3.5 for the lyman-α spectra from quasars.
“This is a very exciting moment,” said Nathalie Palanque-Delabrouille, a DESI spokesperson and an astrophysics researcher at France’s Atomic Energy Commission (CEA) who has participated in the selection process to determine which galaxies and other objects DESI will observe. “The instrument is all there. It has been very exciting to be a part of this from the start,” she said. “This is a very significant advance compared to previous experiments. By looking at objects very far away from us, we can actually map the history of the universe and see what the universe is composed of by looking at very different objects from different eras.”
All this was only possible with substantial contributions to DESI from European partners: The University College London oversaw the optical system of large lenses in the corrector, Durham University the fiber optic system that brings light from the focal plane to the spectrographs. The Aix-Marseille University worked closely with the spectrograph vendor Winlight (in Pertuis, France) to assemble and test the spectrographs, CEA/Saclay provided the system of 30 cryostats for the ultra low-noise sensors inside each spectrograph, the Laboratoire de Physique Nucléaire et de Hautes Énergies in Paris developed and installed the calibration system for the spectrographs. A Barcelona-Madrid consortium including IFAE (Institut de Fisica d’Altes Energies), ICE (Institut de Ciències de l’Espai), CIEMAT (Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas) and IFT (Instituto de Física Teórica) developed the ten high-sensitivity guiders that reside on the focal plane – these guide the Mayall telescope on our targets. The École Polytechnique Fédérale de Lausanne worked with US partners and the Swiss vendor Maxon (in Sachsein, Switzerland) to develop the robotic system in DESI.
Interview with Anatael Cabrera on the development of an opaque scintillator.
In this issue we would like to give Anatael Cabrera the opportunity to present his new development of a liquid scintillation detector — “LiquidO”. In contrast to established scintillators, which are transparent, LiquidO consists of an opaque scintillator and a dense array of fibres. Anatael Cabrera will tell us more about it:
Can you briefly explain the idea behind LiquidO? What is the difference between this detector and the established scintillators?
LiquidO is essentially an evolution of the popular scintillator detectors pioneered by the Reines (et al.) in the 50’s for the neutrino discovery. Their approach used transparency so that the light emitted upon
neutrino interactions is detected by photo-sensors located up to some meters apart. Their detection principle shaped much of the neutrino detection technology since. Instead, LiquidO breaks with the need for transparency to, ironically maybe, allow for unprecedented sub-atomic particle imaging based on scintillation light for the first time. Counter-intuitively, light diffusion is used to sharpen otherwise blurred patterns, as optical photons are stochastically confined locally to each particle energy deposition. The level of detail is at first glance spectacular. For example, one could recognise the annihilation of anti-matter, such as a positron (e+), even with negligible kinetic energy as illustrated in figure 1.
Figure 1: The back-to-back pattern is due to the two γ-rays (511keV) obtained upon the annihilation of a positron (e+), whose imaging could be exploited to tag low energy anti-neutrino CC interactions and medical practical applications in the PET scanner instrumentation. Each point represents a fibre, pitched 1cm apart. The colour code is proportional to the number of photons hit per fibre, while in today’s technology, the photon detection efficiency is ≤5.0% (~1/20x less). All other event-displays are done using detected photons. However, today, the light level is subjected to possible optimisations, particularly envisaged for energy deposition <1MeV.
This imaging allows, in turn, event-wise particle identification for the first time in liquid scintillator medium up to the MeV in energy. This game-changing capability may help us impact much of today’s neutrino detection paradigm. For example, we might reduce our dependence on passive shielding, including deep overburden in underground laboratories to yield major background rejection. Besides, the light opaque medium offers a relaxed optical scenario enabling us to consider both new scintillation technology — first explorations are ongoing — and the ability to accommodate large doping levels, boosted by up to one order of magnitude relative to today’s state of the art. Altogether, LiquidO seems to offer a novel detection framework inheriting many feature from the well known scintillation detection legacy while capable, should performance allows, to seed some degree of revolution in some physics channels.
You also illustrated your idea in a poster at the JENAS 2019, the Joint ECFA-NuPECC-APPEC Seminar. Could all the three disciplines benefit from the new technology?
I think so. Let me suggest two examples below.
First, LiquidO was born in neutrino physics; a subject historically bridging across particle, nuclear and astro-particle physics domains like very few. A concrete example is laid by our most recent studies, where the potential of LiquidO for GeV neutrino physics have been explored. This was first presented in November 2019 in the context of the DUNE experiment. A LiquidO detector there could play a competitive role in particle physics via the first explorations of leptonic CP-violation. Neutrinos, in turn, are unique probes to challenging nuclear physics where LiquidO may offer new handles — under active study — aimed for the better control of systematics and background recognition. Our preliminary studies suggest that LiquidO may yield comparable topology to the exquisite liquid-argon TPC detectors. We have identified even some unique additional but complementary features, as illustrated in FIG II. In such a large detector located far from reactors, even the first explorations on 40K geo-neutrinos may be considered for the first time, see here, thus providing unique insight to our understanding of our planet, that might draw other general lessons in the context of astro-physical planet formation and dynamics.
Second, there appears an increasing number of cases where LiquidO might offer a rich detection framework beyond neutrino and rare decay. Since, I am far less of an expert, I’d just quote a few examples. Some colleagues are interested in calorimetry and search for rare particles in HEP colliders, thus exploiting LiquidO’s calorimetric-tracking ability and its high duty-cycle. This might benefit LHC or future FCC/ILC programmes. Even, possible societal/industrial applications, such as medical and reactor nuclear industry, are under active consideration. Our teams are exploring LiquidO as possible technology for a full-body PET scanners and remote reactor monitoring — a topic of high interest to the IAEA in the context of non-proliferation.
Which experiments may benefit from the LiquidO technology?
Figure 2: An electron neutrino CC interaction is illustrated, where the detected light is coloured coded. The leading lepton (e±) undergoes an electromagnetic shower. A halo of low energy depositions, including e+ annihilation, surround the shower. An outgoing track (π±) decays into a μ± when stopped. An energetic neutron (n) is also ejected from the interaction point. The n is recognised from the proton-recoil ionisation and its energy can be measured via time-of-flight.
Well, the more we study LiquidO, the more it appears this question may have more answers than we originally suspected. Although LiquidO was forged in reactor neutrino brainstorming, it appears surprisingly versatile beyond. Personally, I think that its ability to handle low MeV is most precious, even boosting its ability to handle higher energies with rich details, as shown in figure 2. Besides, the neutrino MeV range is rich in challenges, including many neutrino sources, such as the sun, the Earth, supernovae, reactors and decay at rest beam neutrinos. Today, much of our effort is devoted to address your question, where several publications are envisaged or even under preparation. We keep careful track of the physics to design and target the critical ongoing detector R&D — always limited by our very humble resources, specially manpower.
Figure 3: The most explored p→π0 + e+ proton decay channel is illustrated. The decay kinematical back-to-back pattern is expected, where the π0 decay into two γ’s is particularly clear thanks to the low density and long radiation length of LiquidO. The e+ electromagnetic shower can also be observed. The full pattern provides a strong event-wise rejection to possible background cases with high efficienc
As of today, our main studies, so far, had brought us to consider two main potential experimental topics — leptonic unitarity and high mass ββ decay searches. These subjects are renown for their possible discovery potential beyond our successful Standard Model of Particle Physics. While still early, the first feasibility publications are materialising shortly with very promising results. A remarkable research potential beyond today’s reach seems attainable. The observation of leptonic unitarity violation would imply the direct manifestation of new physics via the existence of non-standard neutrino states and/or non-standard interactions — either way, a breakthrough. Likewise, the positive observation of the neutrinoless double beta decay might reveal the deepest nature of the neutrino itself for the first time, including direct and unique sensitivity to its absolute mass scale. The first project was first presented in the EPS-HEP conference (July 2019), where we highlighted the potential to improve the precision on θ13 by almost one order of magnitude. We have developed a full strategy employing reactor neutrinos with a 10 kton LiquidO detector located at Chooz (France), thus the historical Chooz remains one of the best reactor sites in Europe. This hypothetical project, called for now “Super Chooz”, offers an additional uniquely “open sky” research programme, including proton decay as well as supernovae and solar neutrinos detection. LiquidO may excel in the proton decay discovery potential, as illustrated in figure 3. Whereas unprecedented explorations of the sun, and even supernovae, neutrinos may be possible via interactions on doped indium (Raghavan 1976), leading to a robust coincide signature for detection. Although indium based detection has never seen light in an experiment, much of the past groundbreaking R&D demonstrated that large doping levels (order 10%) are feasible. The second project was however first hinted in the NOW-2018 conference (September 2018) and a publication is in preparation. These ambitious experimental goals have so far encounter no evident scientific showstopper. However, we are looking forward to further pushing our detector performance quantification for consolidation in feasibility. While more challenges will surely be ahead, today I can tell that the background control for the ββ programme is one of the most extreme requirements so far.
Have you already gained some experience with the new detector or is it all based on simulations?
First prototype of the LiquidO detector.
Indeed, the experimental validation was, for me, a critical necessary condition to disclose LiquidO, conceived around 2013 but otherwise kept secret till the materialisation of its robust proof-of-principle. Until then, “it looked too good to be true”. Ironically, since LiquidO inherits from the well known scintillation detection, the addition of light scattering may have appeared as a trivial extrapolation. And while it may well be true, the new powerful imaging goes so far beyond today’s performance — and intuition — that dedicated experimental demonstration was highly desirable to ensure performance beyond surprises. This was achieved between mid-2018 and early-2019 using a “tiny” 0.25 litre prototype. The data was easily obtained with our new opaque scintillator (see Novel Opaque Scintillator for Neutrino Detection), but much thinking, extra support laboratory measurements and simulations aided the final corroboration, thus succeeding our first unambiguous experimental proof-of-principle. Since then, we have found no evidence whatsoever of any inconsistency to our scattering dominated model. Hence, LiquidO was decided to be officially released in June 2019 along with our first publication (see LiquidO: Novel Opaque Neutrino Detection Technology and Neutrino Physics with an Opaque Detector).
What are the next steps you have planned?
In 2020, we expect the culmination of our small prototype based R&D and much of the ongoing physics prospect explorations. This should lead to several beautiful publications. Beyond that, we believe neutrino based data is needed to sizeably proceed and yield final consolidating demonstration. Hence, we aim for a few tons full scale demonstrator LiquidO detector to yield accurate performance quantification for physics feasibility. While scaling always entails somewhat a step into the unknown, the experimental programme proposed enables demonstration via leading measurements in the context of neutrino detection and ββ-decay background sensitivity hosted in two European underground laboratories. This programme, proposed in Europe, is led by four principal investigators, including spokespersons from 3 experiments and the extra support by the recently formed LiquidO proto-collaboration and cooperators. We are ready to proceed, as soon as the funding comes along.
Anatael Cabrera is a neutrino physicist since 2001 when he started his DPhil degree at the University of Oxford (UK) within the MINOS experiment. He is currently CNRS/IN2P3 scientific staff at the Linear Accelerator Laboratory (Orsay, France). Since 2014, he is director of the underground LNCA laboratory (Chooz, France). He is currently spokesperson in the Double Chooz and also supports the JUNO experiment, where he led the co-coordination of the JUNO electronics/trigger system. In 2015, he conceived, proposed and co-coordinates since the Dual Calorimetry system aimed for extra high precision calorimetry control and its dedicated physics programme. Around 2013, he conceived the LiquidO detection technique. Today, LiquidO stands as an international scientific project supported by a proto-collaboration. He is co-spokesperson of LiquidO along with Prof. F. Suekane (RCNS/Tohoku University, Japan).
The APPEC General Assembly and the Scientific Advisory Committee (SAC) appointed a sub-committee to discuss the searches for the neutrinoless double beta decay and the future of the European programme. This sub-committee should advise APPEC on the European (and international) programme in double beta decay physics. It should report to the APPEC SAC, providing an assessment of the current and future scientific opportunities in double beta decay over the next 10 year period. In October this year, the sub-committee published their report on arXiv: https://arxiv.org/abs/1910.04688. This document, which was approved by the APPEC SAC was then discussed during the APPEC Community Meeting on Neutrinoless Double Beta Decay held in London on Oct. 31, 2019. About 50 people attended it and discussed the contents of the document and the necessary future steps for neutrinoless double beta (0nubb) decay especially in Europe. All presentations are collected in https://indico.cern.ch/event/832454/timetable/#20191031.
The meeting was opened by the APPEC Chair, Teresa Montaruli, who highlighted the importance to receive comments from the APPEC Community on the document and endorse it and the recommendations contained in it. The Chair of the SAC, Laura Baudis, remembered the APPEC Roadmap recommendation on neutrinoless double beta decay: APPEC strongly supports the present range of direct-neutrino mass measurements and searches for neutrinoless double-beta decay. Guided by the results of experiments currently in operation and in consultation of its global partners, APPEC intends to converge on a roadmap for the next generation of experiments into neutrino mass and nature by 2020. Laura Baudis explained the full process of forming the panel who edited the document and the mandate of the panel defined by the SAC to execute APPEC recommendation of the panel.
“Given the importance of neutrinoless double beta decay searches, the leading role Europe is playing and the prospects for the future, we provide below the key recommendations in order of relevance.
Recommendation 1. The search for neutrinoless double beta decay searches is a top priority in particle and astroparticle physics.
Recommendation 2. A sustained and enhanced support of the European experimental programme is required to maintain the leadership in the field and exploit the broad range of expertise and infrastructure,and fostering existing and future international collaborations.
Recommendation 3. A multi-isotope program at the highest level of sensitivity should supported in Europe in order to mitigate the risks and to extend the physics reach of a possible discovery.
Recommendation 4. A programme of R&D should be devised on the path towards the meV scale for the effective Majorana mass parameter.
Recommendation 5. The European underground laboratories should provide the required space and infrastructures for next generation double beta decay experiments and coordinate efforts in screening and prototyping.
Recommendation 6. The theoretical assessment of the particle physics implications of a positive observation and of the broader physics reach of these experiments should be continued. A dedicated theoretical and experimental effort, in collaboration with the nuclear physics community, is needed to achieve a more accurate determination of the NMEs.“
The KM3NeT Collaboration launches the drawing contest “Draw me a neutrino”:
Participants from France, Georgia, Greece, Italy, Morocco, South Africa, and Spain are invited to submit, before March 15h 2020, their best interpretation of a neutrino. The drawings can be realised using any technique or support (digital drawings are welcome) and will be judged based on their originality, the creativity demonstrated by the author and the harmony with the properties and origin of the neutrinos.
Three different groups will enter the competition:
The budding scientists will imagine how is an electron neutrino like;
Teenagers that have already been in contact with physics are in charge of drawing a muon neutrino;
Adults are invited to tackle the tau neutrino.
In addition to the national contests organised in the countries previously mentioned, an international competition will be organised. Selected drawings will be part of the Art & Science across Italy exhibition at the National Archeological Museum in Napoli, Italy in May 2020. Besides receiving a selection of KM3NeT goodies, the winners will also have the opportunity to give their names to one of the sensors deployed in the Mediterranean Sea that will participate to the next discoveries made with KM3NeT.
Through this contest, the KM3NeT Collaboration is seeking to familiarize the broad public to the science carried out with this new European facility that is currently under construction more than 2000 metres deep in the Mediterranean Sea. While the completion of the detector, whose sites will be located off-shore Toulon in France and Capo Passero in Italy, is expected for 2025, the Collaboration is already searching for the best illustration of the neutrinos it will detect!
More information about the contest, the rules, and the neutrino itself can be found on: http://wos.ba.infn.it
The 4th Workshop of Big Data Science in Astroparticle Physics – Deep Learning & Open Data – will take place from 17 -19 February 2020 in Aachen, Germany. The workshop covers the following topics:
Hands-on tutorials
Deep Learning
Open Data-Software-Analysis
Actual developments
For those who never worked with deep network there is the possibility to participate in a beginners tutorial on Deep Learning.
This workshop is supported by Helmholtz Alliance for Astroparticle Physics HAP and Arbeitskreis Physik, moderne Informationstechnologie und Künstliche Intelligenz der Deutschen Physikalischen Gesellschaft e. V. AKPIK.
In November 2019 about 300 scientists and guests from all over the world celebrated the 20th anniversary of the Pierre Auger Observatory with a ceremony and a scientific symposium at the site of the Observatory in Argentina. The Pierre Auger Observatory has been built to study ultra-high energy cosmic rays, particles of the highest energies ever observed.
The participants of the celebration lined up in front of the main building of the observatory for a group picture (photo: Miguel Martin).
Ultra-High Energy Cosmic-Rays
Cosmic-rays are charged particles constantly bombarding the Earth and are one of the cosmic messengers that help us understand our Universe. At the highest energies, they are not much deflected by the Galactic and extragalactic magnetic fields, opening up the possibility of a new window in astronomy, the observation of the near-by Universe with charged-particles. The goal of the Pierre Auger Observatory is to study the nature and origin of those ultra-high energy cosmic rays, whose energy exceeds more than 100,000 times the energy that can be achieved in man-made accelerators.
The Pierre Auger Observatory
The Pierre Auger Observatory was conceived by Jim Cronin, Alan Watson and other scientists in 1991 to address the mysteries of the origin and nature of the highest-energy cosmic rays. It was clear to them that only a very large detector would reach the exposure to collect enough events to answer the questions raised by a century of earlier experiments. The Observatory design employs a „hybrid“ detector system consisting of a 3000 km2 array of 1660 particle detectors overlooked by 27 optical telescopes. These complementary detector techniques record both the particles and the faint fluorescence light resulting from the gigantic particle cascade initiated in the atmosphere by these mysterious cosmic rays. Soon after the foundation in 1999, construction of the Observatory started and was completed in 2008.
20th Anniversary
f.l.t.r.: Roberto Rivarola (Member of Board of Directors of CONICET), Fernando Ferroni (Chair of Finance Board), Ingo Allekotte (Bariloche, Project Manager Pierre Auger Observatory), Jorge Vergara Martínez (Mayor of Malargüe), Paula Nahirñak (Sub-secretary of State in Secretariat for Science and Technology), Osvaldo Calzetta (President CNEA), Ralph Engel (KIT, Spokesperson Pierre Auger Observatory), Alberto Etchegoyen (CNEA, Site Spokesperson), Julio Cobos (National Senator for the Province of Mendoza), Laura Montero (Vice-governor of the Province of Mendoza), Ernesto Maqueda (CNEA), Alan Watson (former Spokesperson Pierre Auger Observatory) (photo: Miguel Martin)
Scientists of the 90 participating institutes and groups, as well as representatives of all 17 member states of the international collaboration met in Malargüe, Argentina in mid-November to celebrate the 20th anniversary of the experiment as well as the scientific results achieved so far. A scientific symposium opened the festivities and highlighted the state of research. On the second day, the participants visited the detectors of the Observatory in the Argentine Pampa. Many of the scientists and guests participated also in the parade for the anniversary of the city of Malargüe. The meeting continued with a ceremonial act at the campus of the Observatory. Venerable members of the collaboration as well as representatives of funding agencies and local politicians addressed the audience and congratulated the collaboration not only on the scientific successes, but also on the social relevance and impact of the project in the province of Mendoza. One highlight of the ceremony was the conferral of the status “Honorable Senator” to the Pierre Auger Observatory by the Senate of Argentina. After unveiling a sculpture by Juan Pezzani symbolizing the role of the Pierre Auger Observatory in Argentina, the meeting concluded with a dinner banquet with typical Argentine barbecue and wine.
A Bright Future
Spurred by the science results obtained so far, the Observatory is currently undergoing an upgrade („AugerPrime“), mostly aimed at improving the sensitivity of the observatory to the particle type and mass of ultra-high energy cosmic rays. This is done by installing new electronics, and additional and complementary detectors, allowing for a better separation of the type of the incoming particle on an event-by-event basis. The added observables are critical to select the subset of particle cascades that were produced most likely by lighter primary cosmic rays, which in turn may hold the key to identifying and studying the cosmic accelerators outside our own galaxy. More generally, the data collected with AugerPrime will also be used to explore fundamental particle physics at energies beyond those accessible at terrestrial accelerators, and perhaps yield the observation of new physics phenomena.
— CANCELLED/POSTPONED, please check the website of the event for further information —
The second EPS (European Physical Society) Conference on Gravitation is held at King’s College (London, UK) from April 7th to April 9th, 2020. The aim of the conference is to discuss experimental aspects of Gravity, including General Relativity tests, measurements of the G constant, Geodesy, and Gravitational Waves.
The conference is organized in days focused around key topics introduced by invited speakers and followed by contributed talks. There will also be a poster session, together with four Young Scientist Awards to the best poster contributions by skilled young researchers .
Early registration ends 1st March, 2020 and abstract submission ends 2nd February, 2020.
— CANCELLED/POSTPONED, please check the website of the event for further information —
The first Pollica Summer Workshop on Dark Matter aims to bring together the world’s leading experts, both from theory and experiment, working on a broad range of ideas, existing and proposed experiments. This workshop, which will take place in the beautiful setting of the medieval town of Pollica in the Cilento region in Italy is an opportunity to galvanize theoretical efforts in a period where new experiments come online and the particle physics community must think broadly about new frontiers ahead. This is an exciting time to connect fundamental physics to the upcoming experimental landscape. The workshop is scheduled for the dates of 15-26 June 2020 and will be hosted in the 14th century Castello Dei Principi Capano.
The deadline for applications is January 31st 2020.
Gamma-ray bursts can be triggered by the explosion of a dying, super massive star, collapsing into a black hole. From the vicinity of the black hole, powerful jets shoot in opposite directions into space, accelerating electrically charged particles, which in turn interact with magnetic fields and radiation to produce gamma rays. Credit: DESY, Science Communication Lab
Gamma-ray bursts (GRBs) are sudden, short bursts of gamma radiation happening about once a day somewhere in the visible universe. According to current knowledge, they originate from colliding neutron stars or from supernova explosions of giant suns collapsing into a black hole. Since their discovery in the 1960s astronomers have been studying GRBs with satellites, as Earth’s atmosphere very effectively absorbs gamma rays. Astronomers have developed specialised telescopes that can observe a faint blue glow called Cherenkov light that cosmic gamma rays induce in the atmosphere, but these instruments are only sensitive to gamma rays with very high energies. Unfortunately, the brightness of GRBs falls steeply with increasing energy. Cherenkov telescopes have identified many sources of cosmic gamma rays at very high energies, but no GRBs to date. Satellites, on the other hand, have much too small detectors to be sensitive to the low brightness of gamma-ray bursts at very high-energies. So, it was effectively unknown, if these explosions emit gamma rays also in the very high-energy regime.
Cherenkov telescopes detect the bluish Cherenkov light generated by faster-than-light particles in Earth’s atmosphere, produced by cosmic gamma rays. Credit: DESY, Science Communication Lab
Between summer 2018 and January 2019, two international teams of astronomers, detected gamma rays from two GRB events for the first time from the ground. On 20 July 2018, faint afterglow emission of GRB 180720B in the gamma-ray regime was observed with the High-Energy Stereoscopic System (H.E.S.S.) in Namibia. On 14 January 2019, bright early emission from GRB 190114C was detected by the Major Atmospheric Gamma Imaging Cherenkov (MAGIC) telescopes on La Palma, and immediately announced to the astronomical community.
MAGIC registered gamma-rays with energies between 200 and 1000 giga-electron volts (GeV). The rapid discovery, only 60 seconds after the alarm was received, allowed to quickly alert the entire observational astronomy community. As a result, more than twenty different telescopes had a deeper look at the target. This allowed to pinpoint the details of the physical mechanism responsible for the highest energy emission, as described in a paper led by the MAGIC collaboration. Follow-up observations placed GRB 190114C at a distance of more than four billion light years.
GRB 180720B, at a distance of six billion light years even further away, could still be detected in gamma rays at energies between 100 and 440 GeV after the initial blast. The H.E.S.S. detection came quite unexpected, as gamma-ray bursts are fading fast, leaving behind an afterglow which can be seen for hours to days across many wavelengths from radio to X-rays, but had never been detected in very high-energy gamma rays before. This success is also due to an improved follow-up strategy in which observations at later times after the actual star collapse are conducted.
The detection of gamma-ray bursts at very high energies provides important new insights into the gigantic explosions. To explain how the observed very high-energy gamma rays are generated is challenging and will require more detailed theoretical modelling and measurements of more GRBs in very-high-energy gamma rays. These two groundbreaking observations have established GRBs as sources for terrestrial gamma-ray telescopes and has the potential to significantly advance our understanding of these violent phenomena. The scientists estimate that up to ten such events per year can be observed with the planned Cherenkov Telescope Array (CTA), the next generation gamma-ray observatory. The CTA will consist of more than 100 individual telescopes of three types that will be built at two locations in the northern and southern hemispheres. CTA observations are expected to start in 2023.
The full press release from DESY is available here.
Subsequently, the resumption of Poland participation to APPEC with CAMK representing it was approved by the General Assembly. Prof. Leszek Roszkowski will be the selected representative of Poland in the GA. He informed the Assembly of the excellent European Community financed AstroCENT (https://astrocent.camk.edu.pl), which has the scope of developing dedicated projects in astroparticle physics with the scope to develop innovation at the border between this field, computing, sensor and electronic development and medical applications. 
Regarding the last point we would like to highlight the final report of the Neutrinoless Double Beta Decay sub-committee, see also here.
The APPEC General Assembly and the Scientific Advisory Committee (SAC) appointed a sub-committee to discuss the searches for the neutrinoless double beta decay and the future of the European programme. This sub-committee should advise APPEC on the European (and international) programme in double beta decay physics. It should report to the APPEC SAC, providing an assessment of the current and future scientific opportunities in double beta decay over the next 10 year period. In October this year, the sub-committee published their report on arXiv: 
Participants from France, Georgia, Greece, Italy, Morocco, South Africa, and Spain are invited to submit, before March 15h 2020, their best interpretation of a neutrino. The drawings can be realised using any technique or support (digital drawings are welcome) and will be judged based on their originality, the creativity demonstrated by the author and the harmony with the properties and origin of the neutrinos.
The 4th Workshop of Big Data Science in Astroparticle Physics – Deep Learning & Open Data – will take place from 17 -19 February 2020 in Aachen, Germany. The workshop covers the following topics:
