Seminari 2016

1 Jan 2016, 08:00 → 30 Dec 2016, 18:00 Europe/Rome

stanza 412, blocco C (Dipartimento di Fisica e Scienze della terra)

Stefania Vecchi (FE)

Lista dei seminari di Fisica del Dipartimento di Fisica e Scienze della Terra e della sezione INFN di Ferrara

Tuesday, 2 February

15:00 → 16:00 The simulation of intrinsic energy resolution for liquid-scintillator experiments

An energy resolution of JUNO experiment is a key question in neutrino mass hierarchy determination. For that reason, an accurate investigation of energy resolution is needed. In the first part of the report an actual physical meaning of terms a, b, c in a formula for the energy resolution was discussed. A correspondence between energy scale and PMT's-collected-charge scale was shown. A new term, called intrinsic energy resolution (IER), gives specific contribution to the energy resolution. The hypothesis of IER are based on Birks phenomenological model for light-yield quenching and fluctuations in delta-rays production. GEANT4 simulations of electron and gamma-ray interactions in liquid scintillator were performed and IER with respect to particle energy was estimated. Moreover, as it was shown, Cherenkov radiation also contributes to intrinsic resolution for energy for 1 MeV and higher. IER phenomenon are not included in current Monte Carlo simulations of Borexino experime! nt. Compared to radioactive source calibration data, energy resolution of simulated detector to monoenergetic particles is slightly better. It was demonstrated that IER could totally or partially explain this minor divergence.

Speaker: Andrey Formozov

Thursday, 11 February

15:00 → 16:00 Constraining gravity theories on cosmological scales

Understanding how gravity works on scales larger than the Solar system is one of the biggest challenge of modern cosmology. Some interesting results have been found in recent experiments, like Planck, and more precise tests will be enabled by ongoing and future large-scale surveys. In this context the search for efficient ways to test systematically a broad class of gravity theories is crucial to succeed in probing gravity with cosmological data. In this talk I will summarize the state-of-the-art of the cosmological gravity constraints, I will present the Effective Field Theory of Dark Energy (EFT) as promising framework to explore gravity theories and I will show some of the results we can obtain by applying this formalism.

Speaker: Valentina Salvatelli (Centre de Physique Théorique, Aix-Marseille Université)

16:30 → 17:30 Collegamento con la conferenza stampa sui risultati dell'esperimento LIGO

Thursday, 17 March

15:00 → 16:00 Estimating the continental geoneutrino signal

Measuring the geoneutrino flux from the decay of radioactive elements in the Earth (U, Th, K) constrains compositional models of the silicate Earth (Crust + Mantle) and defines the radiogenic power of the planet. The luminous geoneutrino signal from the crust overpowers that from the mantle, necessitating high-resolution studies to more accurately define the crustal contribution in order to decipher the weak mantle signal. Low-resolution global models of the crust are paired with high-resolution local models around detectors such as Borexino and KamLAND. All models take advantage of available data to assign abundances of radiogenic elements to different crustal layers and therefore better define the sources of the geoneutrino signal. Novel and creative ways to improve upon model estimates of the crustal signal will be discussed.

Speaker: Scott Alan Wipperfurth

Tuesday, 5 April

10:00 → 11:00 Creation of Environmentally and Energetically High Effective Arc Plasma Reactor for Recycling of Freons

Speaker: Paata Kervalishvili (GTU (Politecnico di Tbilisi))

11:00 → 12:00 Development of new semiconductor systems for high effective energy converters.

Speaker: Tamara Berberashvili (GTU (Politecnico di Tbilisi))

12:00 → 13:00 Development of sensory networks for landslide monitoring

Speaker: Panos Yannakopoulos (Piraeus University of Applied Sciences (Technological Education Institute of Piraeus))

Tuesday, 19 April

15:00 → 16:00 The Cosmic landscape: what a physicist should know about Cosmology

In this talk, I will briefly review the cosmic evolution of our visible Universe. The starting point of cosmic evolution is about 14 billion years ago, everything began with an explosion that we call Big Bang. At this early time, the universe was hot and dense, and the interactions between particles were frequent and energetic. This primordial plasma comes in the form of free electrons and atomic nuclei with light bouncing between them. As the temperature of the Universe goes down due to the cosmic expansion, the light elements—hydrogen, helium and lithium—started to form. At some point, the energy had dropped enough for the first stable atoms to exist. At that moment, photons decoupled from matter and they started to travel reaching the observers today. We observe this afterglow of the Big Bang as microwave radiation. This radiation is well described by a Black Body spectrum at the same temperature (about 2.7 K) in all directions. Although this high uniformity, the cosmic microwave background contains small variations in temperature at a level of 10^{-5}. Parts of the sky are slightly hotter, parts slightly colder. These fluctuations reflect tiny variations in the primordial density of matter. Over time, and under the influence of gravity, these matter fluctuations grew. Dense regions were getting denser. Eventually, galaxies, stars and planets formed. From Cosmic Microwave Background experiments (like COBE, WMAP, Planck) we know that the highest quantity of Universe is unknown, in fact, we know that the Universe is made up of: dark matter (27%), dark energy (68%), baryons (5%). Dark matter is required to explain the stability of galaxies and the rate of formation of large-scale structures. Dark energy is required to explain the striking fact that the expansion of the universe started to accelerate recently (meaning a few billion years ago). What dark matter and dark energy are is still a mystery. Finally, there is growing evidence that the primordial density perturbations originated from microscopic quantum fluctuations, stretched to cosmic sizes during a period of inflationary expansion. One of the predictions of the inflationary theory is a background of primordial gravitational waves: one of the next challenge in Cosmology is seeking to this signal, and several experiments are dedicated to pursue this aim (Planck, BICEP-2, PolarBear...). It is worthwhile to study and looking in this direction also because recently the LIGO Collaboration delivered the analysis of the first direct observations of gravitational waves confirming once again the General Relativity theory.

Speaker: Eloisa Menegoni (LUTh (Laboratoire Univers et Theories, Observatoire de Paris))

Tuesday, 26 April

10:30 → 11:30 From seismic noise to signal: A novel way to study the Earth interior

Seismology went throughout a revolution with the advent of digital and continuous recording system. Seismic stations all around the world record gigabytes of data every day, with the main target of monitoring the earthquake activity. Earthquakes are transient signals with duration from few seconds to few minutes, and represent the ~1% of the data recorded by the seismic stations. The remnant 99% is the so-called seismic noise, considered a nuisance so far. Following the well known correlation property of the diffuse wavefield, seismologists started to see the seismic noise as a quasi-diffuse field, from which the impulse response of the Earth interior can be extracted from correlation of noise between a couple of recording stations. In my talk I will present the main results of the ambient seismic noise correlation method, focusing on the most recent advancements, which permit to study in great detail the structure of the Earth from the crust up to the core. The latter results are obtained after intensive study aimed to derive bulk waves from ambient noise correlation, and represent a major advancement in the seismological community.

Speaker: Pietro Poli (MIT - Massachusetts Institute of Technology, Cambridge, MA, United States)

Wednesday, 27 April

15:00 → 16:00 Options for the Understanding of the LIGO gravitational event GW150914.

Speaker: Remo Ruffini (ICRANet)

Wednesday, 11 May

11:00 → 12:00 Solving the lithium problem with sterile neutrinos

The so-called “cosmological lithium problem” appears to be the only missing piece of the, otherwise mostly coherent, Big Bang Nucleosynthesis (BBN) scenario. In fact, there is still a discrepancy between predicted and observed values of primordial lithium, the latter being ~3 times smaller than the former. In this talk I will briefly revise the Standard BBN model focusing on the formation of mass-7 nuclei (i.e. lithium and beryllium). I will propose a purely electromagnetic solution of the lithium problem. In this scenario a heavy (MeV) sterile neutrino decay will produce a photon energy injection able to destroy beryllium, preventing its conversion into lithium through electron capture. I will constrain the properties of this particle taking into account also the other decay channels and their effects of other cosmological observables, such as CMB anisotropies and spectral distortions.

Speaker: Laura Salvati (Universita di Roma "La Sapienza")

14:00 → 15:00 Jordan and Freudenthal meet Bekenstein and Hawking: non-linear symmetries of black hole entropy

Freudenthal duality can be defined as an anti-involutive, non-linear map acting on symplectic spaces. After a general introduction on some aspects of extended (super)gravity theories in four dimensions and the structure of their U-orbits, I will consider their U-duality Lie groups "of type E7", and the corresponding notion of Freudenthal duality. I will elucidate and comment on the relation between the Hessian of the black hole entropy and the pseudo-Riemannian, rigid, para-special Kaehler metric of the pre-homogeneous vector spaces associated to the U-orbits. I will conclude with some hints for further future developments, including the extension to Abelian gaugings of supergravity, exploiting the theory of (Jordan) C*-algebras.

Speaker: Alessio Marrani (Centro "Enrico Fermi", Roma, & Physics Dept of Univ. of Padova, & INFN Padova.)

15:30 → 16:30 Rosetta & Dawn missions: study of small bodies, big questions

Comets and Asteroids represent a small portion of the overall mass of the Solar System and for many years have been considered a target of interest only for the dynamical studies. With the evidence of the crucial role of impacts in the formation of the planets and the evolution of the cosmological theories, starting from the ’70s the importance of the study of the so called small bodies became more and more a key aspect for the understanding the formation basic mechanisms as well as for the calibration of the theories. Asteroids dimensions and orbits show a large variability going from small pebbles to very large objects, some of them coming from the extreme borders of the Solar System, some others with orbits crossing the Earth orbit and therefore having an intrinsic risk potential. Comets may have played an essential role also in the presence of water on Earth and as carrier of the elemental bricks of life. The Rosetta and the Dawn missions are the two most recent and successful missions devoted to the study of these bodies and both of them have on board an essential contribution of Italian science.

Speaker: Enrico Flamini (Direttore Scientifico dell'Agenzia Spaziale Italiana (ASI) e Vice-Presidente dello Science Programme Committee (SPC) di ESA)

Thursday, 12 May

15:00 → 16:00 Distributed Storage for the LHC Experiments

Questo seminario introdurra' i concetti e le tecnologie di base utilizzati al CERN per gestire il volume crescente di dati degli esperimenti di LHC. Dopo una breve introduzione sul CERN e in particolare sull'andamento del Run 2 appena ripartito, verranno illustrate le tecnologie di storage oggi in esercizio per gli esperimenti. Particolare attenzione verra' dedicata agli Object Store distribuiti (Hadoop, Ceph) ed al loro ruolo nell'evoluzione di sistemi basati su file system tradizionali. Infine, verra' accennato un esempio di corruzione dati verificatosi al Data Center del CERN e le misure adottate per rilevare e correggere i dati corrotti.

Speaker: Giuseppe Lo Presti (CERN)

Thursday, 26 May

11:00 → 12:00 An overview of biomedical imaging using Cerenkov radiation: from mouse to man

Cerenkov luminescence imaging (CLI) is a novel method for preclinical research based on optical imaging approaches. CLI has been developed using small animal and allows to image the bio-distribution of radiopharmaceutical labeled with beta emitters. Recently applications of CLI to humans for both in vivo and ex vivo (tissue) imaging were published by our group and others. There has been also a considerable interest in the possible uses of CLI to monitor external-beam radiation therapy. In the seminar we will provide an overview of the most recent results and applications of CLI to biomedical imaging.

Speaker: Antonello Spinelli (Ospedale San Raffaele IRCCS, Milano)

Thursday, 14 July

14:00 → 15:00 An unconventional charmonium model to explain: Imaginary Charmonium Strong Decay Amplitudes

An unexpected feature of the J/psi has been recently pointed out mostly by BESIII, namely that there is a phase between strong and e.m. decay amplitudes, close to 90 deg. In other words, assuming the e.m. one is real, the strong one is purely imaginary, in contrast with a Breit Wigner description of the J/psi. A model is reported to explain such a behavior, that might be checked by PANDA. The psi(2S), psi(3770) and, for the first time, the Y(1S) present data are also examined in this context.

Speaker: Rinaldo Baldini Ferroli (LNF)

Monday, 18 July

15:00 → 16:00 Real-time precision searches for New Physics at LHCb

In 2015 LHCb became the first HEP experiment to be fully aligned, calibrated, and have its data reconstructed and analyzed in real-time. I will discuss the physics motivation for this development, in particular how it will expand LHCb’s ability to search for physics beyond the Standard Model. I will also cover its importance to the upgrade of both LHCb and other LHC experiments, and the technical challenges which were overcome in the implementation.

Speaker: Vladimir Gligorov (LPNHE, Université Pierre et Marie Curie, Université Paris Diderot, CNRS/IN2P3 Paris)

Tuesday, 19 July

15:00 → 16:00 On the Possibility of Quark Matter inside Compact Stars

Compact stars, generally known as ordinary neutron stars, are a unique laboratory for exploring matter under extreme densities. The aim is to understand their interior through global observables, such as mass and radii. In this talk I will review different scenarios for the composition of compact stars, focussing in particular on the possibility of absolutely stable strange quark matter. The observations of massive pulsars with about two solar masses imply strong constraints on the properties of matter at densities as in the core of compact stars. Effective models aiming to describe strongly-interacting matter can thereby be considerably constrained. In this context, a chiral quark-meson model based on a SU(3) linear sigma-model with a vacuum pressure and vector meson exchange is discussed in this presentation. The impact of its various terms and parameters on the equation of state and resulting maximum mass of compact stars are delineated to check whether pure quark stars with two solar masses are feasible within this approach. Large vector meson coupling constant and a small vacuum pressure allow indeed for maximum masses of two or more solar masses. However, pure quark stars made of absolutely stable strange quark matter turn out to be restricted to a quite small parameter range.

Speaker: Rainer Stiele (Universite' Claude Bernard Lyon)

Thursday, 8 September

14:30 → 15:30 Overview on the BESIII experiment

Beijing electron position collider (BEPCII) covers the tau-charm energy region from 2 to 4.6 GeV. It's peak luminosity reaches to 1x10^33 cm^-2s^-1 at 3.773GeV. The BESIII detector is a generic spectrometer, which views the e^+e^- annihilations with 93% acceptance of the full solid angle. From 2009 till now, BESIII has accumulated over 15/fb data in the whole energy coverage. Based on these data sets, we have produced many results on R-QCD, light hadron spectroscopy, charmonia, XYZ and charmed hadrons. In my talk, I will firstly briefly introduce the instrumental facility and its performance, and then present the highlights of the physics outputs. Finally, I will give some future prospective about the BEPCII and BESIII.

Speaker: Prof. Lyu Xiao-Rui (BESIII physics coordinator)

Thursday, 13 October

15:00 → 16:00 Developments in airborne gamma-ray spectrometry

This presentation will review recent research at Minty Geophysics in the field of to airborne gamma-ray spectrometry. The talk will focus on 3 areas: The reduction of noise in multichannel airborne gamma-ray spectra using principal component –type analyses; the automatic detection of radioelement anomalies from 3-channel gamma-ray spectrometric data; and the inversion of airborne gamma-ray spectrometric data to elemental concentrations on the ground. Most of the talk will focus on this last topic. A new method will be presented for inverting airborne gamma-ray spectrometric line data to a regular grid of concentrations on the ground that incorporates both the observation height and the 3D terrain within the field of view of the spectrometer. The method uses a model that accommodates both the directional sensitivity of rectangular detectors and a source model comprising vertical rectangular prisms with the same horizontal dimensions as the required grid cell size. The top of each prism is a plane surface derived from a best-fit plane to the digital elevation model of the earth’s surface within each grid cell area. The method is a significant improvement on current methods, and gives superior interpolation between flight lines. It also eliminates terrain effects that would normally remain in the data with the use of conventional gridding methods.

Speaker: Brian Minty (Minty Geophysics - Weston Creek - Australia)

Tuesday, 18 October

15:00 → 16:00 Tidal disruption events from different kinds of astrophysical objects: a preliminary analysis

Tidal disruption events (TDEs) are useful tools to study quiescent black holes (BHs). In the last two decades, the interest for these astrophysical phenomena has grown due to the availability of more data. Furthermore, with the growing power of computers, simulations of TDEs are accessible, allowing for comparing theoretical models with data. The main theory states that about half of the debris released from a disrupted star is bound to the BH, circularizes and eventually accretes, while the other half is unbound. There are important aspects which are yet not fully understood, e.g. on the circularization process, on the energy release and where the radio, optical/UV and X-ray radiation is produced. Massive black holes (MBHs) can be found in the center of galaxies. The nearest MBH is the one residing in the Galactic Center (GC), which, thanks to its proximity, provides us with the possibility to study the MBH environment in detail. Also, the GC environment harbours a variety of astrophysical objects. While the study of the bound debris of a TDE can give us direct information regarding the BH, the unbound debris tells us about the surrounding environment. In this respect, we're investigating the possible outcomes of the tidal disruption of stars, planets and asteroids. The ultimate goal is to constrain the BH and its surroundings through the study of TDEs.

Speaker: Aurora Clerici (University of Nova Gorica, Slovenia)

Wednesday, 23 November

16:00 → 17:00 Global MASTER Robotic Net and Great Physical Experiments

Speaker: Vladimir Lipunov (Moscow University)

Thursday, 24 November

16:00 → 17:00 Astrophysical implications of the Gravitational Wave Discovery

Speaker: Vladimir Lipunov (Moscow University)

Friday, 25 November

15:00 → 17:00 An introduction to physical cosmology for non experts. Lesson 1/5

1. Basic cosmological equation and cosmological parameters.

Speaker: Alexander Dolgov (Novosibirsk State University)

Monday, 28 November

15:30 → 17:30 An introduction to physical cosmology for non experts. Lesson 2/5

2. Cosmic matter budget: Dark Energy, Dark Matter, baryons.

Speaker: Alexander Dolgov (Novosibirsk State University)

Tuesday, 29 November

15:30 → 17:30 An introduction to physical cosmology for non experts. Lesson 3/5

3. Universe history from beginning to the present time.

Speaker: Alexander Dolgov (Novosibirsk State University)

Wednesday, 30 November

15:00 → 17:00 An introduction to physical cosmology for non experts. Lesson 4/5

4. Present day or near-present day universe: new discoveries and new mysteries

Speaker: Alexander Dolgov (Novosibirsk State University)

Thursday, 1 December

14:00 → 15:00 The restless gamma-ray sky and clues on new physics: eight years of discoveries with Fermi Large Area Telescope

After eight years of mission, the Fermi satellite with its principal instrument on board, the Large Area Telescope (LAT), has revealed the high energy cosmos over more than five decades in energy (~30 MeV - 300 GeV). The LAT is a powerful space observatory, to explore the most extreme environments in the Universe, search for signs of new physics and answer the long-lasting questions concerning the acceleration mechanisms and their sites. In this talk we highlight some of the scientific achievements of the last years with Fermi and we look towards what the next years could reveal. In particular, I will focus on multi-wavelegth astrophysics, discussing simultaneous observations from radio to gamma, in order to understand the nature of gamma-ray sources.

Speaker: Sara Cutini (ASI Science Data Center and INFN)

15:00 → 17:00 An introduction to physical cosmology for non experts. Lesson 5/5

5. Gravitational waves form Black Hole coalescence and related problems.

Speaker: Alexander Dolgov (Novosibirsk State University)

Friday, 2 December

11:00 → 12:00 Chiral symmetry restoration in heavy-ion collisions

Heavy-ion collisions (HIC) are the unique experimental way to study matter at high temperature and density and to probe the Quantum Chromo Dynamics (QCD) phase diagram. The challenge is to identify in the final particle distributions those signatures, which allow to shed some light on the dynamics of chiral symmetry restoration and of the phase transition from bound hadrons to interacting quarks and gluons in the Quark-Gluon-Plasma (QGP). We rely on effective theories to describe HIC and the Parton-Hadron-String Dynamics(PHSD) is a powerful transport approach which has been successfully used to study HIC observables in a wide energy range, from SIS to LHC energies. We present an investigation of the effect of chiral symmetry restoration (CSR) on HIC observables within PHSD. Our systematic studies show that CSR plays a crucial role in the description of HIC at $\sqrt{s_{NN}}$=3--20\,GeV, realizing an increase of the hadronic particle production in the strangeness sector with respect to the non-strange one. We identify particle abundances and rapidity spectra to be suitable probes in order to extract information about the CSR mechanism. Our results provide the first microscopic explanation for the "horn" structure in the excitation function of the $K^+/\pi^+$ ratio: the CSR in the hadronic phase produces the steep increase of this particle ratio up to $\sqrt{s_{NN}} \approx$ 7 GeV, while the drop at higher energies is associated to the appearance of a deconfined partonic medium.

Speaker: Alessia Palmese (Giessen University)

Wednesday, 14 December

11:00 → 12:00 An introduction to partial wave analysis

In this talk, I will present the introduction of partial waves, and the general approach to build a model with intermediate resonances and partial waves. I will also introduce hot to fit data and extract informations with the built model. At last, the mass indipendent partial wave analysis technique will be introduced.

Speaker: ZHANG Jingqing (IHEP di Pechino)