PENTAQUARKS OBSERVED

(News version only available in english) LHCb, one of the four major experiments at the LHC Large Hadron Collider, CERN’s supercollider in Geneva, reported the discovery of a class of exotic particles composed of five quarks, known as pentaquarks. The pentaquark that was observed is not simply a new particle but a new way in which quarks, which are the fundamental constituents of protons and neutrons, can combine with each other, and follows a pattern never observed before in over fifty years of experimental research. The result of the LHCb experiment is founded on extremely accurate and rigorous data analysis, based on very high-level statistics never achieved before, as well as on the extremely high accuracy of the detector. This result is not conclusive, as pentaquarks are a class of particles that can open the door to a much deeper understanding of matter. The next step will be to study how quarks are bounded within the pentaquarks. Further studies will therefore be needed, and the new data that LHCb will collect during LHC RUN2 will allow progress to be made in this field.

INFN AT THE CHINA SCIENCE FESTIVAL IN BEIJING

Only news version - Light and colours. For the International Year of Light, IYL2015. This is the theme of the second China Science Festival and Youth Science Education Expo 2015, Beijing’s science festival. This year Italy is the guest of honour, and the Istituto Nazionale di Fisica Nucleare (National Institute of Nuclear Physics) – INFN – is also taking part. For the event, held at the Beijing Exhibition Center from July 17 to August 2, INFN has set up two interactive installations in its exhibition space. One of the installations is dedicated to particle accelerators and the other to the Higgs boson. Here, the young Chinese audience, on whom the festival is focused, can have fun while becoming acquainted with some fundamental concepts of physics. Besides the installations, posters and videos tell young people about the world of elementary particles and their interactions, as well as the work of physics researchers.

ULTRA FAST DETECTORS FOR PHOTOGRAPHING PARTICLES IN 4D

Develop a new ultra fast detector based on silicon and capable of providing a four-dimensional image of the particles that pass through it, simultaneously "photographing" both the position and time of transit of the particles: this is the core of the Ultra-Fast Silicon Detector (UFSD) project proposed by Nicolo Cartiglia of the INFN Turin section and winner of an ERC Advanced Grant of 1.8 million euros lasting five years. The project is based on the development of a new type of silicon detector, similar to those used in many particle physics experiments, but which is characterised by the ability to determine the time of transit of a particle in an extremely precise manner, with a resolution of approximately 10 picoseconds. That is: a detector capable of an accuracy of 10 thousandths of a billionth of a second and equal, in the spatial dimensions, to that of a very thin hair. The possibility of adding the time dimension to the tracking process is critical to properly associate the particles that belong to the same event, discarding instead those that transited in the detector at subsequent times. This new type of technology can be applied in contexts in which the detector must be very thin or very resistant to radiation, such as for example in oncological hadrontherapy in which very high precision technologies are developed to be used in dosimetry. The activity that led to proposing the Ultra-Fast Silicon Detector project began in 2013 as part of the research of the Fifth National Commission INFN, which deals with technological and interdisciplinary research, and thanks to the collaboration between the Turin INFN division, Trento and Florence INFN groups and the Bruno Kessler Foundation (FBK). The Turin INFN division, which coordinate the project, will take care of the design, drawing and testing of the sensors, and will be also involved in the development of a simulator of silicon detectors (Weightfield2 project). In 2014, UFSD was recognised as an "Italy-USA project of great scientific importance" and received a grant for a period of two years from the Ministry of Foreign Affairs. In 2015, it has been included in the European project AIDA2 (Advanced European Infrastructures for Detector Accelerators).