Standard Model physics at the LHC

In this contribution to the volume "From My Vast Repertoire -- The Legacy of Guido Altarelli" I discuss selected topics of Standard Model (SM) physics at the LHC and their connection to the work of Guido Altarelli. An overarching connection is given by Guido's fundamental contributions to our understanding of the strong force, parton distribution functions and their evolution, and techniques to calculate theoretical predictions through perturbative Quantum Chromodynamics. The increasingly precise LHC measurements of diverse processes can be confronted with SM predictions relying on these foundations to test the SM and contribute to the knowledge of the proton structure. The LHC experiments have also started to perform precise measurements of SM parameters, such as the mass of the W boson, and have measured a variety of processes sensitive to interactions of multiple electroweak bosons. The discovery of the Higgs boson in 2012 and the measurements of its properties are crucial to establish the nature of the mechanism of electroweak symmetry breaking and the status of these studies is summarised.Comment: Contribution to the volume "From my Vast Repertoire - the Legacy of Guido Altarelli" : 24 pages, 13 figure

A Converse Hawking-Unruh Effect and dS^2/CFT Correspondance

Given a local quantum field theory net A on the de Sitter spacetime dS^d, where geodesic observers are thermalized at Gibbons-Hawking temperature, we look for observers that feel to be in a ground state, i.e. particle evolutions with positive generator, providing a sort of converse to the Hawking-Unruh effect. Such positive energy evolutions always exist as noncommutative flows, but have only a partial geometric meaning, yet they map localized observables into localized observables. We characterize the local conformal nets on dS^d. Only in this case our positive energy evolutions have a complete geometrical meaning. We show that each net has a unique maximal expected conformal subnet, where our evolutions are thus geometrical. In the two-dimensional case, we construct a holographic one-to-one correspondence between local nets A on dS^2 and local conformal non-isotonic families (pseudonets) B on S^1. The pseudonet B gives rise to two local conformal nets B(+/-) on S^1, that correspond to the H(+/-)-horizon components of A, and to the chiral components of the maximal conformal subnet of A. In particular, A is holographically reconstructed by a single horizon component, namely the pseudonet is a net, iff the translations on H(+/-) have positive energy and the translations on H(-/+) are trivial. This is the case iff the one-parameter unitary group implementing rotations on dS^2 has positive/negative generator.Comment: The title has changed. 38 pages, figures. To appear on Annales H. Poincare

The non-Gaussian tail of cosmic-shear statistics

Due to gravitational instability, an initially Gaussian density field develops non-Gaussian features as the Universe evolves. The most prominent non-Gaussian features are massive haloes, visible as clusters of galaxies. The distortion of high-redshift galaxy images due to the tidal gravitational field of the large-scale matter distribution, called cosmic shear, can be used to investigate the statistical properties of the LSS. In particular, non-Gaussian properties of the LSS will lead to a non-Gaussian distribution of cosmic-shear statistics. The aperture mass ($M_{\rm ap}$) statistics, recently introduced as a measure for cosmic shear, is particularly well suited for measuring these non-Gaussian properties. In this paper we calculate the highly non-Gaussian tail of the aperture mass probability distribution, assuming Press-Schechter theory for the halo abundance and the `universal' density profile of haloes as obtained from numerical simulations. We find that for values of $M_{\rm ap}$ much larger than its dispersion, this probability distribution is closely approximated by an exponential, rather than a Gaussian. We determine the amplitude and shape of this exponential for various cosmological models and aperture sizes, and show that wide-field imaging surveys can be used to distinguish between some of the currently most popular cosmogonies. Our study here is complementary to earlier cosmic-shear investigations which focussed more on two-point statistical properties.Comment: 9 pages, 5 figures, submitted to MNRA

Guido Altarelli and the evolution of QCD

I describe the contributions of Guido Altarelli to the development of Quantum Chromodynamics from the discovery of asymptotic freedom until the end of the Sp¯ pS collider era, 1973–1985

Guido Altarelli and the evolution of QCD

I describe the contributions of Guido Altarelli to the development of Quantum Chromodynamics from the discovery of asymptotic freedom until the end of the Sp¯ pS collider era, 1973–1985

Microconfined flow behavior of red blood cells by image analysis techniques

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Red blood cells (RBCs) perform essential functions in human body, such as gas exchange between blood and tissues, thanks to their ability to deform and flow in the microvascular network. The high RBC deformability is mainly due to the viscoelastic properties of the cell membrane. Since an impaired RBC deformability could be found in some diseases, such as malaria, sickle cell anemia, diabetes and hereditary disorders, there is the need to provide further insight into measurement of RBC deformability in a physiologically-relevant flow field. Here, we report on an imaging-based in vitro systematic microfluidic investigation of RBCs flowing either in microcapillaries or in a microcirculation-mimicking device containing a network of microchannels of diameter comparable to cell size. RBC membrane shear elastic modulus and surface viscosity have been investigated by using diverging channels, while RBC time recovery constant have been measured in start-up experiments. Moreover, RBC volume and surface area have been measured in microcapillary flow. The comprehension of the single cell behavior led to the analysis of the RBC flow-induced clustering. Overall, our results provide a novel technique to estimate RBC deformability, that can be used for the analysis of pathological RBCs, for which reliable quantitative methods are still lacking

Evolution of multiple organizational identities after an M&A: appropriateness of managerial responses and social construction of identities

1Dottorato di Ricerca in Management (XXIII ciclo), LUISS Guido Carli, Roma, 2011. Relatore: Prof. Luca Giustiniano.openTheoretical background. Research questions. Appropriateness of an "aggregation" managerial response to multiple Organizational Identities after Merger & Acquisition in pharmaceutical industry. Organizational identities evolution: sensemaking and causal maps. A case study of M&A in banking industry. Effects of Information Systems adoption, implementation and assimilation on Organizational Identity during the integration process after a M&A.openDottorato di Ricerca in ManagementDe Bernardis, LuigiDe Bernardis, Luig