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Gas detectors: general principles

Gas-based detectors measure the trajectories of charged particles through the ionisation electrons that are deposited in the gas. An electric field, and sometimes a magnetic field, guide(s) these electrons to amplification structures where an avalanche occurs. Avalanches produce electrons and ions and it is their motion that generates electric signals on the read-out electrodes. In this presentation we review these mechanisms.

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A Grand-Unified Nelson-Barr Model

I will discuss the structure of the Nelson-Barr approach to the strong CP Problem, and argue that these solutions can be naturally embedded into E6 Grand-Unified Theories, since the E6 fundamental contains all necessary fermions.The main benefit of the unified structure is the predictivity in the SM fermion sector, and a perfect fit to all SM observables can be obtained despite being over-constrained. Definite predictions are made for the neutrino sector, with a Dirac CP phase that is correlated to the CKM phase, allowing to test this model in the near future.

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High resolution TPC based on optically readout GEM

Large granularity and hight sensitivity commercial CMOS readout systems, open the possibility of developing particle detectors with very interesting performance for different applications, from the search of rare and exotics events, such as dark matter directional candidates, to high quality neutron/ion/hadron beam monitor, mainly for medical applications. This idea driven the CYGNUS group to exploit the gas scintillation mechanisms for starting an R&D on large TPC-based detector, equipped with a Triple GEM amplification stage optically readout. This approach, not only provides tracking capability with space resolutions of the order of tens of microns and energy measurements with a precision of about 25%, but also gives precious information allowing very good particle discrimination. Spectacular examples of captured images due to X-rays and high energy photons, cosmic muons, electrons from beam and neutrons interactions will be shown in this seminar together with quantitative analysis about the system performance.

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JUNO-Italia Meeting

Aim of the workshop: The JUNO-Italia Meeting will take place at the INFN Frascati Laboratories from March 14th to 15th, in the Salvini room (located in the ground floor of the High Energy building). The meeting will start in the morning of March 14th and will end in the early afternoon of March 15th.  

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Self focusing trailing bunch for high quality PWFA experiment at SPARC_LAB

In this work we propose a scheme for high quality beam driven plasma wakefield acceleration that exploits a combination of the wakefield generated by a low density driving bunch and an high beam loading effect of the trailing bunch. The trailing bunch is injected in a region where the focusing field generated by the driving bunch is negligible and the focusing effect derives mostly from the transverse self generated wake. The linear cold plasma fluid equations are used to derive the transverse matching conditions for the driving bunch. We develop the trailing bunch transverse matching conditions using a variant of the ion column model. The energy spread growth is derived and minimized analytically. A realistic working point to be exploited at SPARC_LAB is designed and numerically tested using simulation codes.

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Towards the EDM Polarimetry – Tests of LYSO Modules

Various symmetries are one of the most basic concepts in modern physics. Every conservation law is related to some symmetry. However, it is known that some of the symmetries are violated in weak interactions. One of the most important nature symmetries are parity (P), time reversal (T) and charge-conjugation (C). Confirmation of breaking one of those symmetries in strong interactions would have significant impact on strong interactions theory and on our understanding of the Universe. Also, particle-antiparticle asymmetry in nature is strictly connected with T symmetry breaking which should occurred in an early time of the Universe. Up to now systematic searches of T violation have been done with use of neutral particles. For charged particles, due to special difficulties of applying electric fields on charged particles, only indirect experiments, with limited precision, have been performed. Just recently, an alternative approach has been proposed. Using storage rings to accumulate polarized particles it is possible to measure electric dipole moment (EDM) – a quantity which is strictly related to T and P symmetry. To undertake measurement of EDM of charged particles, new international collaboration JEDI has been established in 2011. JEDI (Jülich Electric Dipole moment Investigations) links together researchers from all over the world. The most important institutions involved are: Forschungszentrum Julich, RWTH Aachen, Tbilisi State University, SPSC Grenoble, University of Ferrara, Jagiellonian University, Joint Institute for Nuclear Research in Dubna, Institute for Basic Science in Daejeon. The main objective of JEDI is to build a dedicated storage ring for a ...

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Winter Institute 2018 – Hunting for Physics Beyond the Standard Model: current status and prospects at future colliders

Despite the great achievement of the discovery of the Higgs boson, the Large Hadron Collider has found no evidence of physics Beyond the Standard Model and the exclusion limits on new physics have now become pretty strong. The LNF Winter Institute 2018 will discuss the prospects to discover new physics at the present LHC run, in its high-luminosity and high-energy phases, as well as at other future colliders. In particular, we shall debate the searches for Z’ bosons, predicted by U(1) gauge groups inspired by Grand Unification Theories, taking particular care about supersymmetric and leptophobic scenarios and Dark Matter signature in models based on extended Higgs sectors, possibly CP-violating. We will also investigate the perpectives at future circular colliders from the viewpoint of Higgs and top-quark phenomenology.

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Studying the properties of domain wall network as QCD vacuum

The general underlying purpose of this study is a renement of understanding the mechanism of connement in quantum chromodynamics (QCD) within the approach based on the specic background vacuum gluon congurations { almost everywhere homogeneous Abelian gluon elds represented by the statistical ensemble of domain wall networks. In particular, the aim of the present study is to investigate the role of quark low-lying modes in the presence of these background elds for stabilization of a nite size of a space-time regions (domains) where the background (anti-)self-dual Abelian eld can be seen as homogeneous. This task is of principal importance for justication of the domain model of connement, chiral symmetry realization and colorless hadron formation in QCD. This estimation indicates that, based solely on the requirement of minimal energy, the quark zero modes may provide for a self- consistent mechanism of formation of the domain structured vacuum gluon congurations.The regular solution of the problem related to explicit evaluation of the energy of the Abelian (anti-self-)dual domain with nite size, that is also formulated in this work but not yet solved, can lead to the very interesting mechanism of the domain size stabilization due to the quasi-zero modes of the quark elds in the (anti-) self-dual background.

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Resummation of transverse observables at LHC

Transverse observables in colour-singlet hadro-production, like the Higgs transverse momentum in gluon fusion or the $phi*$ angle in Drell-Yan processes, provide a clean experimental and theoretical environment for precision physics at colliders. I will discuss a new method for performing the resummation of transverse observables in momentum space up to N3LL accuracy.

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