Editoria - gennaio 2019
Giornale di Fisica Vol. 59 N. 4 (2018)
È online FREE TO READ fino al termine di gennaio 2019 e in stampa il quarto numero del Vol. 59 del 2018.
Accanto ai lavori "Nel laboratorio di fisica con Arduino" (Giuseppe Fera, Bruno Loregian, David Merlin), "Conoscenze di fisica di base degli studenti al termine della scuola secondaria" (Giuliana Capasso, Arturo Colantonio, Jole Coppeta, Silvia Galano, Umberto Scotti di Uccio, Gaspare Serroni, Italo Testa), "Evoluzione dell'idea di molecola" (Antonio Di Meo, Clara Frontali), "Il Premio Nobel per la Fisica 2018" (Sandro De Silvestri), "50 anni di EPS" (Rüdiger Voss), da segnalare l'articolo di Francesco Guerra e Nadia Robotti "Il Premio Nobel a Enrico Fermi" in cui si evidenzia come il Premio Nobel per la Fisica 1938 attribuito a Enrico Fermi sia stato un vero trionfo della sua intuizione fisica, del suo coraggio e della sua determinazione. Usando al meglio i pochi mezzi disponibili in via Panisperna, Fermi aveva ottenuto il pieno successo in una impresa mai tentata prima, e da molti considerata impossibile: la creazione di nuovi elementi radioattivi mediante il bombardamento con neutroni. Con la successiva scoperta del potere selettivo dei neutroni lenti, Roma diventa il centro di ricerca più importante sulla fisica del neutrone a livello internazionale, con conseguenze che diventeranno di grande valore strategico nel corso della seconda guerra mondiale, dopo l'espatrio di Fermi negli Stati Uniti.
NOVITÀ: dal 2019 i soci in regola della Società Italiana di Fisica avranno accesso gratuitamente alla versione online del Giornale di Fisica
La Rivista del Nuovo Cimento Vol. 42 N. 1 (2019)
Spin orbit correlations and the structure of the nucleon
H. Avakian, B. Parsamyan, A. Prokudin
Parton distribution and fragmentation functions, generalized to describe the transverse motion of partons, are often referred to as three-dimensional partonic distributions. They have stimulated in recent years a major theoretical interest, and triggered extensive experimental measurements of spin and azimuthal asymmetries in various hard scattering processes. Ongoing and planned measurements worldwide, providing remarkably higher precision of Semi-Inclusive Deep Inelastic Scattering (SIDIS) data, require development of a comprehensive extraction framework to facilitate extraction of three-dimensional nucleon structure. In this review, the latest developments in the field of the spin asymmetries are presented with emphasis on observables beyond the leading terms in SIDIS, which are indispensable for studies of the complex 3D nucleon structure. Different components involved in precision extraction of 3D partonic distribution and fragmentation functions are discussed.
EPJ A – Highlights
Lattice improvement in lattice effective field theory
N. Klein, D. Lee, U.-G. Meißner
Lattice calculations using the framework of effective field theory have been applied to a wide range of few-body and many-body systems. One of the challenges of these calculations is to remove systematic errors arising from the nonzero lattice spacing. While the lattice improvement program pioneered by Symanzik provides a formalism for doing this and has already been utilized in lattice effective field theory calculations, the effectiveness of the improvement program has not been systematically benchmarked. In this work lattice improvement is used to remove lattice errors for a one-dimensional system of bosons with zero-range interactions. To this aim the improved lattice action up to next-to-next-to-leading order is constructed and it is verified that the remaining errors scale as the fourth power of the lattice spacing for observables involving as many as five particles.
EPJ – Call for papers
EPJ B: Topical Issue on Recent Advances in the Theory of Disordered Systems
Editors: F. Iglói, H. Rieger
Disordered systems in condensed matter theory and in statistical physics occur in various contexts: electrons or phonons in solids with many impurities, spins on aperiodic or random lattices, molecules in structural glasses, and many more. In recent years much progress has been made in understanding collective phenomena emerging from the interplay of the interaction between many fast degrees of freedom and the disordered environment: many body localization and quantum phase transitions in disordered quantum many body systems, dynamical heterogeneities in spin glasses and glassy materials, phase transitions in random ferromagnets and random field systems and much more. This Topical Issue intends to collect original research articles, mini-reviews and pedagogical introductions that report recent advances in these areas of active research: the theory of disordered systems.
Contributions should be submitted to the Editorial Office of EPJ B.
EPJ E – Highlights
Topology and ground state degeneracy of tetrahedral smectic vesicles
F. Serafin, M. J. Bowick, S. R. Nagel
Imagine a micron-sized ball of fluid enclosed in a thin film, similar to the film in soap bubbles, but made up of molecules resembling liquid crystal. These molecules can lower their overall energy by aligning their directions with their ever-changing neighbours—a state referred to as smectic phase. This means stacks of parallel stripe-like liquid-crystal layers form in the film. In a new study published in EPJ E, Francesco Serafin, affiliated with both Syracuse University, New York, and the Kavli Institute for Theoretical Physics (KITP) at UCSB, USA, together with his advisor Mark Bowick, also at the KITP, and Sid Nagel, from the University of Chicago, IL,USA, map out all the possible smectic patterns of such spherical films, or sac, at zero temperature. They determine the conditions under which it becomes easier for such sacs to pass through biological membranes and, potentially, deliver molecules attached to them at specific locations.
EPJ Plus – Highlights
Synchrotron radiation micro-computed tomography for the investigation of finishing
G. Fiocco et al.
Italian violin-making masters of the distant past developed varnishing techniques that lent their instruments both an excellent musical tone and impressive appearance. Few records from this era have survived, as techniques were most often passed down orally to apprentices; only scarce information is available on the original methods used for finishing the instruments. In a new study published in EPJ Plus, Giacomo Fiocco, affiliated with both Pavia and Torino Universities in Italy, and his colleagues use the synchrotron facility in Trieste to develop a non-invasive 3D-scanning approach that yields insights into the main morphological features of the overlapping finishing layers used on violins. In turn, the morphological images can be used to determine the chemical nature of the coating. This newly developed method could help scientists rediscover the procedures and materials used, and reproduce the multi-layered coating methods of the ancient masters.