June 2020 – Particle detector for SKA-Low calibrated at IKP
The recent tests were performed at KCETA Institute IKP, which has the facilities and expertise to more precisely measure the performance of the final design. KIT also provided the scintillator material, used in an earlier cosmic-ray experiment called KASCADE.
June 19, 2020 – CMS collaboration submits thousandth publication
On June 19, 2020, the CMS Collaboration reached a historic milestone: the thousandth scientific publication was submitted to a journal. Never before in the history of particle physics has an experiment achieved so many publications. KIT physicists were significantly involved in about 80 of these publications.
Only publications of the entire CMS collaboration in peer-reviewed journals are counted; in addition, there are special technical publications, some of which are published only by the group that built and operates the CMS track detector, and conference proceedings.
The first publication of the CMS Collaboration in 2008 was titled "The CMS experiment at the CERN LHC" and describes the construction of the detector. Since then, about 100 publications have been published every year. The most famous CMS publication deals with the discovery of the Higgs boson. It was published in 2012 and has been cited more than 10000 times in other publications. For almost 25 years, KIT, formerly the Universität Karlsruhe (TH), under the direction of Prof. Müller (Institute for Experimental Particle Physics) together with colleagues Husemann, Quast, and Weber and their working groups have been involved in the construction, operation, and analysis of the CMS experiment. "We expect to double the number of publications in the next ten years and gain deep insights into the nature of the smallest particles," the researchers promise.
A chronological list of all publications of the CMS collaboration can be found here.
All publications with collision data are graphically listed here sorted by topic as a function of the time of submission.
June 17, 2020 – Surprising Signal in the XENON1T Dark Matter Experiment
Scientists from the international XENON collaboration announced today that data from their XENON1T, the world's most sensitive dark matter experiment, show a surprising excess of events. The scientists do not claim to have found dark matter. Instead, they say to have observed an unexpected rate of events, the source of which is not yet fully understood. The signature of the excess is similar to what might result from a tiny residual amount of tritium (super heavy hydrogen), but could also be a sign of something more exciting: the existence of a new particle known as the solar axion or the indication of previously unknown properties of neutrinos... read more in the press release
The KIT team has recently joined the XENON collaboration and participates in the work on XENONnT, as well as in the preparation of the future planned DARWIN observatory.
Prof. Kathrin Valerius, KCETA scientist at the Institute of Nuclear Physics confirms: "The XENON group of the KIT is also very pleased about the impressive sensitivity achieved with XENON1T. It lays the foundation for the even more sensitive XENONnT detector which is currently under construction"
Observation of Excess Electronic Recoil Events in XENON1T, XENON Collaboration
June 14, 2020 – Belle II: World record in the accelerator ring
Tailwind for the search for rare particle decays and exotic phenomena at the Belle II experiment in the KEK laboratory in Tsukuba, Japan: The "SuperKEKB" accelerator ring has achieved the highest luminosity ever measured. The electron-positron accelerator thus beats not only its predecessor KEKB, but also the Large Hadron Collider (LHC) at CERN. This has now been announced by the Japanese research centre KEK, the operator of the accelerator.
Read all details here (German only)
June 2020 – CMS Detector Award for Dr. Stefan Maier
Dr. Stefan Maier, research associate at ETP, has been one of two scientists to receive the "Detector Award" of the CMS Tracker for the year 2019, for his "[...] outstanding contributions to the upgrade of the Outer Tracker, including development of procedures and systems in 2S module assembly and qualification and the development of a high-rate test stand for the module readout chain." Dr. Maier has built several prototypes of the newly developed dual-layer silicon strip detectors for the CMS Tracker renewal program and has optimized the procedures and tools for this. He has also developed a setup in which LEDs are used to feed electrical pulses at highest rates into the readout electronics. This allows high track densities to be simulated and the modules to be tested under realistic trigger rates. Dr. Maier carried out the work, which was so excellent, as part of his doctorate, which was funded by the KSETA graduate school. "We are very happy with Stefan about this award for his outstanding work at ETP", says project leader and PhD supervisor Prof. Ulrich Husemann.
While the award had already been announced in February, the festive presentation of the award plaque was to take place during the CMS week in April. However, due to the protection rules in connection with the COVID 19 pandemic, the CMS week had to take place online, so that the plaque is now waiting for Dr. Maier at CERN.
June 5, 2020 – CERN Courier: Funky physics at KIT
A new experiment at Karlsruhe Institute of Technology (KIT) called FUNK – Finding U(1)s of a Novel Kind – has reported its first results in the search for ultralight dark matter. Using a large spherical mirror as an electromagnetic dark-matter antenna, the FUNK team has set an improved limit on the existence of hidden photons as candidates for dark matter with masses in the eV range.
It is the doctoral thesis of KSETA member Arnaud Andrianavalomahefa and partly also the work of Christoph Schäfer. KCETA scientist Dr. Darko Veberic provided strong support and supervision... Read more in the CERN Courier
May 4, 2020 – "Physik in unserer Zeit" writes about KATRIN
After more than 60 years of research on neutrinos, their masses are still unknown. The Karlsruhe tritium neutrino experiment KATRIN is expected to improve the current measurement accuracy by a factor of ten. Last autumn, the facility delivered its first preliminary results and thus already narrowed down the neutrino mass by a factor of two more than before.
The German language physics magazine "Physik in unserer Zeit" in its current issue (Vol. 51/No. 3) dedicated its Cover story to KATRIN, written by Prof. Guido Drexlin (KIT/KCETA), Prof. Christian Weinheimer (University of Münster) and Prof. Kathrin Valerius (KIT/KCETA).
April 14, 2020 – Searching for the Z‘-Boson
The Belle II experiment has been in operation for about a year at the Japanese Research Centre for Particle Physics KEK in Tsukuba, about 50 kilometres north of Tokyo. Here, an international team of researchers with the participation of the Karlsruhe Institute of Technology (KIT) is searching for exotic particles that will advance our understanding of dark matter in the universe. For one of these particles, the so-called Z' boson, the mass and strength of its interaction have now been narrowed down with previously unattainable precision. The results have just been published in the renowned scientific journal Physical Review Letters.
Research Fellowship for Go Mishima
Dr. Go Mishima, postdoc at IKP, has won a "Research Fellowship for Young Scientists"
of the Japanese science foundation JSPS. It permits him to do three years of research at a university of his choice. He will stay for half a year at KIT and will then move to Tohoku University in Sendai, Japan.
November 29, 2019 – KATRIN on the Cover of the Physical Review Letters
On November 25, 2006, the main spectrometer of the KATRIN experiment was transported in a spectacular action through Eggenstein-Leopoldshafen to Campus North of KIT.
Exactly thirteen years later, the collaboration published its first results of the neutrinomass measurements. That's worth a place on the cover of the Physics Review Letters!
November 2019 – Kathrin Valerius among the "Young Elite – top 40 under 40"
KCETA scientist Dr. Kathrin Valerius was chosen by the business journal CAPITAL as one of Germany’s “Young Elite - top 40 under 40” in the category science and society. Each year the honors go to the top 40 under 40 from economy, politics, science, and society, who have the potential to influence and shape the future of Germany.
On November 21st, they came together at the “Young Elite Summit” in Berlin to exchange ideas beyond their usual sphere of action and set new impulses for society.
Juli 5, 2019 – Nobel Laureate Shipping 2019
A total of 18 Nobel Prize winners and around 600 young international scientists from 80 countries took part in the trip to the island of Mainau under the motto "Your first step to Stockholm: Baden-Württemberg". On board the "MS Sonnenkönigin", Baden-Württemberg universities and research centres presented current work and results on this year's main topic of physics with a special focus on cosmology, laser physics and gravitational waves.
Dr. Magnus Schlösser presented the KATRIN experiment at KIT. His stand was also visited by Ulrich Steinbach, Ministerial Director and Head of Office in the Ministry of Science, Research and the Arts of Baden-Württemberg.
July 16, 2019 – IceCube becomes Antarctic Neutrino Laboratory
With the IceCube Neutrino Observatory, which is part of the American Amundsen-Scott South Pole Station, convincing evidence of a first source of high-energy cosmic neutrinos was found in 2017. Now the observatory is being upgraded into an international neutrino laboratory with German participation. The IceCube detector will be extended to lower energies in order to measure the properties of neutrinos with unprecedented accuracy. A working group of KCETA is also involved in the upgrade of IceCube.
July 2019 – The two most massive quarks put the spotlight on the Higgs boson
The two heaviest known elementary particles, the top (t) quark and the Higgs (H) boson, are deeply connected. They provide an essential probe of the Standard Model (SM) of particle physics, our best attempt so far at describing the fundamental particles and their interaction, and of hypothetical new physics beyond the SM. In the SM, the strength of the interaction between the Higgs boson and matter particles (quarks and leptons) is proportional to their mass. Since the top quark is the heaviest of all particles, the interaction between the Higgs boson and top quarks is also the strongest. As a result of that top-Higgs interaction, Higgs bosons can be produced in association with top quark pairs (this is called the ttH process and was first confirmed in 2018). Measuring the rate at which this rare process happens in the collisions between protons at the LHC, i.e. the probability that a given collision results in the simultaneous production of a top quark pair and a Higgs boson, is the most direct way to study the top-Higgs interaction. In turn, this tells us a lot about the nature of the Higgs boson and helps us answer questions such as: is the Higgs boson actually elementary? Are there other kinds of Higgs bosons out there? Is the universe stable?
April 18, 2019 – nature: Radio telescope LOFAR looks deep into lightning
What exactly happens when lightning strikes occur is still unclear. Using high-resolution data from the LOFAR radio telescope, an international team of researchers has now discovered needle-shaped structures that could bring light into the discharge processes. Important foundations for the measurement of flashes with the world's largest antenna array were laid at the KIT. What lies behind the previously unknown needles has now been published in the journal "nature".
When ice crystals collide in a thunderstorm cloud, they charge electrically. Winds can separate the crystals, so that one part of the cloud is positively charged, the other negatively. If the resulting electric field becomes too large, a violent discharge occurs, which we perceive as lightning and thunder. The discharge begins with a small volume of air in which electrons separate from the air molecules. This ionized air, also called plasma, is electrically conductive. The plasma spreads out as branched channels until it hits the earth and the electrical voltage of the clouds discharges as lightning. The exact processes in these channels up to the recent discovery of the "lightning needles" are revealed by high-resolution data derived from radio signals of lightning, measured with the Dutch radio telescope LOFAR (Low Frequency Array), in which the KIT participates.
"Thanks to the high spatial and temporal resolution of LOFAR, we can investigate the formation of flashes in a completely new order of magnitude, right down to the primary processes," explains Dr. Brian Hare from the University of Groningen and first author of the publication in the journal "Nature". LOFAR consists of thousands of antennas spread across Europe - an array primarily developed for astronomical observations, but now also used to measure cosmic rays. The signals triggered by the cosmic particles in the atmosphere are buffered at the individual antennas and then read out for various analyses. "This technology, which is being advanced at KIT, is now also being used to measure and store radio signals emitted by lightning," explains KCETA-scientist Dr. Tim Huege from the Institute of Nuclear Physics at KIT and a member of the "LOFAR Cosmic Ray Key Science Project".
3-D animations of lightning development in radio light
Credits: Stijn Buitink (Vrije Universiteit Brussel) and Brian Hare (University of Groningen)
Slow motion of a developing lightning, which in reality lasts 0.2 seconds and spans about 5 kilometres in all directions. The yellow dots show current radio signals, the white dots the past ones for illustration.
Close-up of a plasma channel that in reality lasts 0.1 seconds and spans 400 meters. One of the newly discovered needle-shaped structures is marked in red.
Brian Hare, Olaf Scholten et al. Needle-like structures discovered on positively charged lightning branches. Nature, 18 April 2019, https://www.nature.com, DOI: 10.1038/s41586-019-1086-6.
March 2019 – Installation of the first antenna for the AugerPrime Radio Upgrade
Young scientists cheer after installing the first antenna for the AugerPrime radio upgrade!
Also on site: KSETA PhD student and member of the Helmholtz International Research School (HIRSAP) Felix Schlüter (second from left).
The radio upgrade, which is part of the AugerPrime upgrade, is a very important part of the future research of the Pierre Auger Observatory by adding array-based composition sensitivity for large zenith angles, for which the scintillator upgrade is not effective. Having good composition-sensitive information up to very large zenith angles is crucial for composition-improved anisotropy studies and adds to the overall aperture of the observatory.
January 2019 – KASCADE goes Outback
A trial detector for studying cosmic rays has been set up alongside the Murchison Widefield Array (MWA) at the Murchison Radio-astronomy Observatory (MRO) in Western Australia. This 'proof of concept' detector is the first step in developing a set of detectors for the low-frequency Square Kilometre Array (SKA1-low) telescope, which is to be built at the MRO. In the longer term, these kinds of detectors will be used to trigger the MWA to capture the radio pulse associated with an incoming cosmic ray, a synergy of radio astronomy with astroparticle physics. The used particle detector is based on a donation from the dismantled cosmic ray experiment KASCADE at KIT.