TWIST will build detector modules for PET scanners that offer high sensitivity together with precise position and time resolution. TWIST will deliver high-resolution PET images with low background using a lower dosage of radio-tracer. The breakthrough is obtained due to the successful development of the new Strip Silicon PhotoMultiplier (SSiPM) within the ERC TICAL project. PET (Positron Emission Tomography) scanners create images of the distribution of positron emitters in the body of subjects under investigation. PET scans have a fundamental advantage over other forms of medical imaging, such as CT scans; since they are sensitive to the functioning of biological processes. Biomarkers are involved in chemical reactions active in molecular pathways of interest for diagnosing diseases; the image will alter according to molecular changes occurring within the area of interest. Since the imaging technique operates at the sub-cellular and molecular level of the body, it is known as molecular imaging. Although PET imaging is a very powerful diagnostic tool, an injection of a radiotracer is required. The precise time resolution of the TWIST modules with substantially reduce the background generating clearer images. The image resolution will be further enhanced due to the determination of the 511 keV gamma interaction point (including the depth of interaction). Since the depth of interaction is well determined, longer crystals can be used and the detection modules can be mounted close to the subject being scanned. This results in higher resolution images with a significant reduction (at least x5) use of radio tracer. For all developments, it is important to move from tests in the laboratory to building a system of multiple units, because this is the stage that these new developments become useful and open up commercial possibilities. The creation of a business plan to manufacture modules on a commercial basis is integrated within this proposal.
Almost all we know about particle physics and the Standard Model comes from scattering experiments and our ability to predict them via scattering amplitudes (these measure probabilities of scattering processes). To meet the impressive technological advances of particle colliders like the Large Hadron Collider at CERN, new tools and concepts have emerged over the last 25 years. More than giving methods, they have triggered a revolution in our understanding of the formal microscopic structure of particle physics, a subject people thought they knew everything about. My program is based on a set of formulæ due to Cachazo, He & Yuan (CHY), that challenge the way we think about scattering amplitudes. They relate to 'twistor' ideas and string theory. The former aims at manifesting the geometry of field theories, but failed so far to grasp their quantum-ness. The latter, in spite of its mathematical beauty, has the drawback of having additional contributions that are hard to decouple from the field theory ones. The CHY formulæ retain the advantages of both methods, and lead to a variety of remarkable expressions for scattering amplitudes in a increasing number of theories, including gauge, gravity and scalar theories. In a crucial work, I showed that these methods actually carry over to the first quantum correction: this was the first time ever that twistor methods were shown to work at the quantum level. My project aims to extend this and reformulate the full pertubative quantum expansion of field theories in the CHY language. This would be a major conceptual advance. I explain that to do so will require to understand a more fundamental object called Null String, whose quantization will shed light on my 'quantum CHY formalism'. I also propose applications of the formalism of interest for LHC physic, like a third order calculation for the 2 to 3 gluon scattering in gauge theory, that all other existing methods have failed to determine so far.