January 20^th - Back to top

09:00 - 09:20: Welcome (Prof. Fucito, Prof. Santonico)

• 09:20 - 09:40 Gianluca Inverso - (University of Rome Tor Vergata)
  "Vacua of Maximal Supergravity and the cosmological constant"

  I will discuss recent developments in the construction of supergravity models in four dimensions with gauge interactions and in the identification of their vacua.
  The issue of stability of these solutions will be addressed and a link between gauge interactions and allowed values of the cosmological constant will be discussed.
  I will also outline an interesting structure that arises among the different new theories and vacua that have been found.

• 09:40 - 10:00 Andrea Mammarella (University of Rome Tor Vergata)
  "Extra U(1) and Asymmetry"

  Among the possible beyond the standard model (BSM) physics extra neutral gauge Z's are theoretically one of the well motivated.
  The measurement of the asymmetry at the LHC has been showed to be very important to detect this Z's and to point out some of their properties.
  We have calculated the asymmetry at the LHC for a model in which the MSSM is extended by an extra U(1) gauge symmetry (MiAUMSSM) whose related anomalies are cancelled by the Green-Schwarz (GS) mechanism. We have performed the calculation of the asymmetry related to the process $pp \rightarrow e^+e^-$ for different definitions of the asymmetry at the LHC.
  Then we have studied its dependence on the charges of the model, giving suitable fits after having optimized the results.

• 10:00 - 10:20 Simone Amoroso (University of Freiburg)
  "A Model Independent General Search for New Physics in ATLAS"

  The start of the Large Hadron Collider in 2009 has opened a new window for high energy physics. It is expected to provide answers to some of the long-standing questions in particle physics; namely the details of the electroweak symmetry breaking mechanism in the Standard Model, and the possibility of new and exotic physics at the TeV-scale.
  In this talk preliminary results of a novel model independent general search for new physics with the ATLAS detector are presented.
  In contrast to specific ”model-driven” searches this analysis follows an orthogonal approach. Instead of concentrating on a specific sub-model of new physics, the ATLAS data is systematically searched for deviations from the Standard Model predictions with a model-independent approach; with the only assumption that new physics will appear in high transverse momentum events.
  Events containing leptons ($\mu$, $e$), jets and missing transverse energy, $E_T^{miss}$, are considered and subdivided into exclusive classes according to their final states. At this point a merging algorithm is employed to reduce the potentially infinite number of classes to a finite number without loosing discovery potential.
  As a second step in each class a search algorithm is used to find the region in the $M_{eff}$ distribution showing the largest discrepancy with the MC expectations; taking into account both statistical and systematics uncertainties. The significance for such a deviation to occur is than corrected for the trial factors, both for the individual channel and for all channels combined. Preliminary results over 2.052 fb$^{-1}$ of 2011 data are reported with a good overall agreement is observed in most of the event classes.

• 10:20 - 10:40 Giulio Cornelio Grossi (University of Rome Tor Vergata)
  "Measurement of Z-boson forward-backward asymmetry in the muon channel with the ATLAS experiment at LHC"

  The V-A nature of the electroweak current leads to an asymmetry in the lepton polar angle distribution in the rest frame of Z/γ* : the measurement of such a quantity, around the Z pole, can provide a precise determination of the weak mixing angle of the Standard Model. In this contribution, the asymmetry measurement in the muon channel will be presented with data collected with the ATLAS experiment during 2011.

10:40 - 11:10 Introduction to the poster session

11:10 - 11:40 Coffee Break with posters

• 11:40 - 12:00 Alessandro Rizzo (LNF - INFN and University of Rome Tor Vergata)
  "Kaonic atoms measurements at the DAFNE collider: the SIDDHARTA experiment"

  Kaonic Hydrogen and Helium X-ray measurements play nowadays a fundamental role in testing the reliability of the Chiral Perturbation Theory as a different realisation of Quantum Chromodynamics at low energies. Dictated by both electromagnetic and strong interaction, X-ray transitions at lower energy levels of these complex bound systems offer indeed the unique opportunity to perform a threshold measurements of zero-energy meson-nucleon scattering. Nowadays the SIDDHARTA experiment at DAFNE collider is the only apparatus which can provide such kind of measurements with the high precision needed to disentangle different theoretical calculation scenarios. After a review on the physics of Light Kaonic Atoms with a focus on the so-called internal and external processes to understand measurement difficulties, in this work we present the peculiarity of the SIDDHARTA experiment and its results. A detailed discussion about Silicon Drift Detectors which allow the implementation on of a kaon-trigger mechanism and the use of gaseous target are presented to better understand SIDDHARTA performances and its results, nowadays the best available.

• 12:00 - 12:20 Giovanna Rosa Fois (University of Cagliari)
  "Monte Carlo simulations of microbeam radiation therapy with carbon ions for an interleaved irradiation geometry"

  Microbeam Radiation Therapy (MRT) uses an array of parallel microbeams in order to spare normal tissue and preferentially damage tumors.
  In this study, dose-distribution calculations for interleaved microbeam radiation therapy were performed with carbon ions, using the Monte Carlo code MCNPX.
  The dose was calculated in a rabbit head model to study brain-cancer treatment using ion microbeams.
  Depth-dose profile, beam broadening and peak-to-valley dose ratios were calculated for interleaved carbon microbeams.

• 12:20 - 12:40 Luca Di Fino (University of Rome Tor Vergata)
  "The ALTEA and ALTEA-Shield experiment onboard the International Space Station"

  Anomalous Long Term Effects in Astronaut’s Central Nervous System (ALTEA) is a helmet-shaped device holding six silicon particle detectors that has been used to measure the effect of the exposure of crewmembers to cosmic radiation on brain activity and visual perception, including astronauts’ perceptions of light flashes behind their eyelids as a result of high-energy radiation. Because of its ability to be operated without a crewmember, it is also being used as a dosimeter to provide quantitative data on high-energy radiation particles passing into the ISS. ALTEA capabilities are also used to give additional information on the exposure of crewmembers to radiation during their stays on ISS for use in health monitoring.
  The ALTEA experiment was designed by the Italian Space Agency (ASI) in collaboration with a science team led by Professor L. Narici of Tor Vergata University, Rome. The experiment onboard the International Space Station since July 2006 and it has been used as operative instrument by the Space Radiation Analysis Group (SRAG) of NASA.
  Since September 2010 ALTEA detectors are used on a different support for the ESA experiment ALTEA-Shield, which is designed to assess radiation flux in different positions inside the UsLab module. ALTEA-Shield will also provide data about radiation shielding effects by a variety of special materials.
  A description of the experiment and a summary of the main results obtained by ALTEA and ALTEA-Shield investigation will be presented.

• 12:40 - 13:00 Martina Cardillo (INAF-IASF and University of Rome Tor Vergata)
  "Direct proof of Cosmic Ray acceleration by Supernova Remnants with the AGILE satellite"

  On behalf of AGILE team, I present our work on cosmic-ray acceleration by the some Supernova Remnants, focusing on the SNR W44.
  Recent analyses suggest that several SNR observations can be understood in terms of hadrons accelerated in correspondence of the SNR forward shock.
  Until now, however, the leptonic contribution can not be definitely exclude. In the gamma energy band, Fermi/LAT satellite can give only data at energies > 200 MeV because its sensitivity is no so good at lower energies.
  In the case of W44,AGILE extends the Fermi/LAT spectrum (Abdo et al., 2010) at energies < 200 MeV, showing clearly a low energy decrease.
  This feature allows us, assuming three different particle distributions, to exclude definetely for the first time the leptonic origin of the gamma-ray emission from a SNR and to show that the hadronic scenario is the only one that can model the W44 broad band energy spectrum. We give an unambiguous proof of the cosmic-ray origin from Supernova Remnants.

13:00 - 14:20 Lunch with posters

• 14:20 - 14:40 Laura Inno (University of Rome Tor Vergata)
  "Distance and geometry of the magellanic clouds using the Classical Cepheid Period Wesenheit relations"

  Read pdf

• 14:40 - 15:00 Sara Turriziani (University of Rome Tor Vergata)
  "Optical identifications of celestial high energy sources with the Telescopio Nazionale Galileo"

  To ascertain the nature of celestial high energy sources, it is crucial to identify their optical counterparts.
  However, the currently available astronomical public optical databases do not provide an adequate support for a systematic high energy sources identification work. In particular, the optical limiting magnitude represents a severe limitation since the deepest flux limits reached by X-ray surveys require of course similarly deeper optical catalogs to homogeneously sample the available parameter space.
  Nonetheless, dedicated spectroscopic campaigns are being carried out successfully with the Telescopio Nazionale Galileo (TNG), a 4-m class telescope. To set up a winning observational campaign, the first and most important step is to define a strong science case, as it will allow for selections of good targets for observations: the key is to increase the identification efficiency while keeping down the required telescope time.
  In this context, as the Principal Investigator, I will give an overview of the first spectroscopic campaign carried out at the TNG to identify Swift X-ray serendipitous sources, and I will show the valuable results achieved with only one night of observations.
  As a second example, I will review the strategy for the northern-sky classification of candidate blazars associated to unidentified Fermi gamma-ray sources, and I will show the results coming from the related observational campaigns at TNG I have been involved during the last two years.

• 15:00 - 15:30 Iacopo Bartalucci, Ilaria Formicola, Rossella Martino (University of Rome Tor Vergata)
  "Galaxy clusters mass measurements techniques"

  Galaxy clusters are the largest gravitationally bounded objects in the Universe. They are massive structures (M = 10^13 - 10^15 M_sun) containing tens to hundreds of galaxies interacting in a common potential well. Observations show that 10-20% of the total mass is made by hot (T=10^7-10^8 K) and diffuse ne= 10^(-4) - 10^(-2) cm^(-1) called IntraClusterMedium(ICM), emitting in the X-Ray band by thermal Bremsstrahlung. Stars and galaxies form only 3% of the total mass, so the main contribute to mass (80%) is given by non baryonic matter called dark matter.
  The Cold Dark Mattermodel suggests that galaxy clusters, as observed today, are formed by hierarchical clustering of smaller structures. In this context, studying galaxy cluster mass function is crucial to trace the expansion history of the Universe and the cosmological structure formation, allowing us to constrain cosmological parameters. In order to determine the cluster mass function, galaxy cluster mass measurements on large cluster samples are required. Two widely used approaches to do this are based on the weak gravitational lensing effect and on the X-ray emission for thermal Bremsstrahlung from ICM. Weak gravitational lensing is a unique technique that allows to probe the distribution of dark matter in the Universe. Mass determination uses measurements of small distortions in the shape of background galaxy images, caused by the relativistic curvature of space-time due to foreground mass structures. We present the weak lensing analysis of the cluster Abell 2219, describing the technique used to obtain accurate measurements of the shape as well as the removal of the systematic effects. An accurate mass estimation requires also a careful selection of background galaxies to not include unlensed sources which lead to a dilution, underestimating the signal up to a factor 3 in the inner region. To this aim we select galaxies using the Cosmos photometry and photometric redshifts to identify where low and high redshift galaxies lie in color-color diagrams. The weak lensing technique has the advantage that does not require assumptions on morphology or dynamical state of the cluster, although it gives a measurement of projected mass instead of the three dimensional one and is sensible to projection effects. Complementary, the X-Ray emission measures the 3D mass but strongly depends on assumptions made on the models. In this framework we present a volume limited sample of 51 clusters observed by Chandra and XMM-Newton. The data are used to derive X-ray brightness surface and 2-D temperature proles. These proles are deprojected and used to estimate the hydrostatical total mass and gas mass profiles. The innovation of our analysis technique is the use of a new particle background models for both Chandra and XMM observations. In particular we present the Chandra ACIS-I camera particle background. We  studied particle background behavior for the continuum and lines obtaining an analytical model that predicts the spatial variation of the background to better than 1% on the continuum and 5% on the lines. This accuracy allow us to separate background from signal also up to the outskirts of the cluster where thermal Bremsstrahlung emission is very low.

  We use our data to investigate the effect on the mass measurements due to cross calibration between Chandra and XMM-Newton instruments. Furthermore, X-ray mass profiles are compared with gravitational lensing mass estimates to investigate the bias differences, predicted by numerical N-body simulations, of the two mass measurements techniques.

• 15:30 - 15:50 Larissa Santos (University of Rome Tor Vergata)
  "Fisher constraints on isocurvature models: axion and curvaton scenarios"

  Some inflationary models predict the existence of isocurvature primordial fluctuations, in addition to the well known adiabatic perturbation. Such mixed models are not yet ruled out by available data sets. In this paper we explore the possibility of obtaining better constraints on the isocurvature contribution from future data.
  We consider the axion and curvaton inflationary scenarios, and use Planck satellite experimental specifications together with SDSS galaxy survey to forecast for the best parameter error estimation by means of the Fisher information matrix formalism.
  In addition, we also consider how CMB lensing information can improve this forecast. We found substantial improvements for all the considered cosmological parameters.
  In the case of isocurvature amplitude this improvement is strongly model dependent, varying between 0.17% and 23.33% around its fiducial value.
  Furthermore, CMB lensing enables the degeneracy break between the isocurvature amplitude and correlation phase in one of the models, and between the Hubble parameter an the dark energy equation of state in all chosen models.
  In this sense, CMB lensing information should not be neglected in analyzing the data.

• 15:50 - 16:10 Sergio Fabiani (INAF - IAPS and University of Rome Tor Vergata)
  "Evolving X-ray Polarimetry towards high energy and solar science"

  The Sun is an astrophysical source with a strong emission in the X-ray band.
  The study of solar flares is a key point for understanding the behaviour of the magnetic field of our star.
  In literature there are a lot of theories about polarization predictions, for a wide range of solar flares models but observations in the X-ray band have never been exhaustive.
  I will explore the possibility to employ the photoelectric polarimeter Gas Pixel Detector (GPD) to achieve X-ray polarimetric measurements up to 35 keV.
  This instrument can be coupled with a Compton scattering polarimeter to extend the observable energy band to higher energies and cover a wide portion of the solar flares X-ray spectrum.

16:10 - 16:40 Coffee Break with posters

• 16:40 - 17:00 Luca Giovannelli (University of Rome Tor Vergata)
  "The birth of "Tor Vergata" Fabry-Pérot interferometer"

  Fabry-Pérot tunable filters are of great interest in high spectral resolution imaging for both ground-based and space astronomical observations. The prototype here presented has been developed as part of the study for the narrow band channel of the ADAHELI mission.
  The ADvanced Astronomy for HELIophysics (ADAHELI) is a solar satellite designed to investigate the dynamics of solar atmosphere as part of the Italian Space Agency (ASI) program.
  Fabry-Pérot narrow filters are of great interest for the study of extended astronomical sources, such as the solar photosphere. The high transparency of the instrument allows for the necessary high time-resolution for fast dynamic processes observations.

• 17:00 - 17:20 Claudia Violante (University of Rome Tor Vergata)
  "Structural, electronic and optical properties of the two isomers of Si(111)2x1"

  The Si(111)2x1 surface, which appears on cleaved surfaces at low and room temperature, has been among the most studied semiconductor surfaces ever.
  Although apparently simple, it shows several intriguing and not completely understood features.
  The atomic structure of the Si(111)2x1 surface has been known for decades to consist of Pandey chains [1], that can tilt with two possible directions, generating two almost degenerate structures called isomers: the Si(111)2x1 negative buckling and the Si(111)2x1 positive buckling.
  Although it is currently believed that for a sample of Si(111)2x1 at room temperature the most stable configuration is the positive buckling structure[2], it has been recently shown by STS measurements that for highly n-doped Si(111)2x1, at low temperature, both positive and negative isomers may coexist on the surface [3].
  A confirmation of this experimental observations could come from the study of optical properties of these two isomers.
  In this talk I will show and discuss the results of our theoretical simulations for the calculation of structural, electronic and optical properties (RAS spectra [4]) of the two
  structures, obtained by ab-initio calculations within the most reliable state-of-the-art methods based on density functional theory and many-body perturbative techniques.

• 17:20 - 17:40 Fabio Manca (University of Cagliari)
  "Gibbs and Helmholtz ensembles for flexible and semiflexible polymers with elastic bonds"

  Stretching experiments on arbitrarily long single molecules opened the way for studying the statistical mechanics of small systems.
  In many cases in which the thermodynamic limit is not satisfied, different macroscopic boundary conditions, corresponding to different statistical mechanics ensembles, yield different macroscopic force-displacement curves, or constitutive equations.
  We formulate analytical expressions to quantitatively evaluate the difference between the behaviour of the Helmholtz and the Gibbs ensembles for a wide range of polymer models of biological relevance, including generalization of the freely jointed chain model and of the worm like chain model with extensible bonds.

17:40 Final Remarks 

Social meeting

Poster Session - Back to top

• Andrea Longobardo (IAPS-INAF and La Sapienza University of Rome): "VISTA for DREAMS-ExoMars 2016" & "Venus cloud properties inferred by limb darkening curves"
• Giuseppe Sindoni (IAPS-INAF and La Sapienza University of Rome): "Planetary Waves in the Martian Atmosphere observed with PFS/MEX Data"
• Matteo Serra (University of Cagliari): "Exact solutions of Einstein and Einstein-Maxwell gravity minimally coupled to a scalar field"
• Chiara Trombetta (Tor Vergata University of Rome): "Computer aided measurement laser (CAML): Technique to quantify post-mastectomy lymphoedema" 
• Antonella Felici (Tor Vergata University of Rome): "Oximetry: a new non invasive method to detect metabolic effects induced by a local application of mechanical vibration"
• Michele Fabrizio (Tor Vergata University of Rome): "A spectroscopic view of the Carina dwarf Spheroidal galaxy"