LABORATORI NAZIONALI DI FRASCATI
Home » Evento

# Tag Archives: Evento scientifico

## LNF Mini-Workshop Series: Multi-messenger Astronomy

On August 17th, 2017, a new era in the multi-messenger astronomy has started. The detection of gravitational waves produced by the merging of two neutron stars with three detectors (the two Advanced LIGO and Advanced VIRGO) has allowed the source localization, making possible the observation of the electromagnetic follow-up by many telescopes around the world. This mini-workshop will deal with the detection of the event as well as with its scientific impact on different fields, ranging from gravitational waves to astrophysics.

Scopri di più »

## Dark Matter, Double Supernova Neutrino Explosion, Degenerate Vacua, Pre-determination ? Why Standard Model Group ?

We propose a model for dark matter, which in principle ONLY use the Standard Model, although it only works under use of speculated NONPERURBATIVE effects. In this model the dark matter consists of insect sized pearls or better bubbles made from a different phase of vacuum (“condensate vacuum”) consisting of a fluid of top and anti top quarks – likely in the form of bound states of 6 top + 6 anti top quarks – pumped up by usual atoms under very high pressure to compensate the very strong surface tension of the bubbles. We take as fitted values of the size of the bubbles a diameter of 1 cm and a mass of $10^8$ kg, and correspondingly the distance between the individual bubbles is between our distance to the moon and to the sun. Impacts – one about every century – would fit with causing the special type of volcanoes called kimberlite pipes, of which there are about 6500 known on the earth. In the supernova SN1987A in the Large Margellanic Cloud there were observed a controversial neutrino signal in Mont Blanc by LSD about 5 hours before the main neutrino burst observed later; this is speculated to be due to our pearls.

Scopri di più »

## Quantum Field Theory for Gravity

Much of the community has been exploring exotic solutions for the UV completion of gravity. I am interested in exploring a different possibility, that of an asymptotically free quantum field theory. There are obstacles of course, and the talk will be a discussion of the problems and a possible pathway through them.

Scopri di più »

## 6th Rome Joint Workshop: Weird Theoretical Ideas (Thinking outside the box)

Aim of the workshop: In spite of its consolidated experimental success, the Standard Model of particle physics falls short of describing all observed phenomena. Elegant and well motivated theoretical ideas, such as Supersymmetry, Technicolor or Grand Unification, have so far found no support from experimental results. The longed-for discovery of some kind of physics beyond the Standard Model, that could guide us to replace these ideas with new theoretical paradigms, has so far escaped all experimental efforts. Given this situation, any serious attempt to approach the incompleteness of the Standard Model from originally different and unconventional perspectives should receive proper consideration. Fearless exploration outside the box might provide more insights than lengthy struggles through standard thinking. During this 3-day workshop we plan to review some recent attempts to approach fundamental physics issues from non standard perspectives. We plan to have only two or three talks each day and plenty of time to analyze jointly the good and bad of the various proposals, confront ideas and discuss. Scientific Program and Speakers: John Donoghue (Massachusetts U., Amherst) "Quantum Field Theory for Gravity" Gia Dvali  (LMU, ASC & MPI, Munich & NYU, CCPP, New York)  "Classicalization" Renate Loll (Radboud U., NL) "Quantum Gravity, or: Give me (more) observables!"  Matthew McCullough  (CERN) "Hyperbolic Higgs, Clockwork and Relaxion" Holger F.B. Nielsen (Bohr Inst.) "Dark Matter, Double Supernova Neutrino Explosion, Degenerate Vacua, Predetermination? Why the SM Group?" Roberto Percacci  (SISSA)    "Asymptotic Safety" Eugenio Bianchi  (Penn State) "Entanglement in Loop Quantum Gravity"  Michael Spannowsky  (Durham U. & Durham U., IPPP) "Higgsplosion, Higgspersion ...

Scopri di più »

## TRANSVERSITY 2017

Modern developments in hadron physics emphasize the role of parton intrinsic motion and spin, and their correlations, which are crucial to our full understanding of the nucleon structure in terms of the quark and gluon degrees of freedom in QCD. The main aim of the workshop is to provide an environment in which present theoretical and experimental knowledge in the field of transversity, transverse-momentum dependent distribution and fragmentation functions as well as generalized parton distribution functions will be presented and discussed in depth, together with new theoretical ideas and experimental perspectives. The scientific program will consist of presentations (by invitation only), featuring review talks (30 minutes + 10 minutes for discussion) and research talks (20 minutes + 5 minutes or 15 minutes + 5 minutes for discussion). In addition a round-table will be devoted to the perspectives of the field. The Workshop follows the successful editions held in : 2005 on Lake Como (Italy), 2008 Ferrara (Italy), 2011 in Losinj (Croatia), 2014 Cagliari (Italy).

Scopri di più »

## FAMU Muonic Hydrogen Spectroscopic Transitions Measurements

FAMU will realize the first measurement of the hyperfine splitting (hfs) in the 1S state of muonic hydrogen ΔEhfs(μ-p)1S – providing crucial information on proton structure and muon-nucleon interaction – by using an intense pulsed muon beam, and an on-purpose developed high-energy mid infrared tunable laser. FAMU initiates a new class of experiments representing a significant leap forward in the quality of spectroscopic measurements in muonic atoms; specifically, it will provide the proton Zemach radius rZ with higher precision than previously possible, disentangling discordant theoretical values and will quantify any level of discrepancy that may exist between values of rZ as extracted from normal and muonic hydrogen atoms. It will set a needed cornerstone result about not yet explained anomalies within the proton charge rch radius. The Zemach radius rZ and the r.m.s charge radius rch are the only proton shape-related values that can be directly extracted from experimental data, and rZ is the only one that carries information about the proton’s magnetic dipole moment distribution. A pulsed intense muon beam entering the MUST hydrogen gas target will form muonic hydrogen atoms. FAMU’s theoretical and experimental effort will establish new limits on the proton structure parameters measuring the muonic hydrogen transition ΔEhfs(μ-p)1S with unprecedented precision – δλ/λ < 10-5 – and will shed light on the low momentum limit of the magnetic-to-charge form factor ratio.

Scopri di più »

## Photon-Stimulated Desorption from Cold Molecular Films with Synchrotron Radiation

In cold regions of the Interstellar Medium (ISM), like star-forming regions or protoplanetary disks, molecules form or accrete on the surface of micron-sized dust particles. The resulting icy mantles represent the main reservoir of molecular material (beside H2). In these regions, thermal desorption can be neglected, but energetic processes, for instance induced by cosmic rays or photon impact on the ices, can promote their desorption into gas phase. Providing experimental constraints on these processes is important for astrophysical modelling and for explaining the presence of organic compounds in UV-X irradiated regions. Desorption of neutral particles and ions is also crucial for the vacuum performance of cryogenic parts present in accelerators, such as the superconducting magnets of the Large Hadron Collider (LHC) at CERN or in use at synchrotron radiation facilities, which depends critically on the photodesorption of molecular gases by synchrotron emission originating from the relativistic particles. We have developed an experimental approach for the study of the photodesorption from thin molecular films at low temperatures (10-15 K), using the brilliance and the tunability of synchrotron radiation at the SOLEIL facility in order to get absolute desorption yields in the UV energy range (DESIRS beamline) and more recently in the soft X-ray energy range (SEXTANTS beamline). The main results obtained from the irradiation of pure and mixed-ices of weakly bound species will be reviewed. Emphasis will be put an efficient desorption induced by the electronic relaxation of the first electronic excited state of CO in the 8-10 eV range and ...

Scopri di più »

## The FOOT pixel tracker: a CMOS pixel sensors application example

A better knowledge of the nuclear cross sections is becoming essential for the Hadrontherapy improvement and for the astronauts radio-protection. For this purpose the experiment FOOT ( FragmentatiOn Of Target ) has been envisaged. The direct and inverse kinematic approach will be used to measure the cross sections respectively after the Bragg peak and in the proton entrance channel. For this purpose a key element in FOOT is the magnetic spectrometer based on the monolithic active pixel sensor. The pixel tracker is composed by three main elements: the Vertex detector, the bending permanent magnet and a larger acceptance two layer inner tracker. Both the four layer Vertex and the downstream tracker will use the MIMOSA28 pixel sensors developed by the Strasbourg PICSEL group. An overview of the detector with its main simulated characteristics will be described and some details on main implementation problems will also be underlined.

Scopri di più »

## Recent advances in CMOS pixel sensors, towards more applications

Pixel sensors built directly from the CMOS integrated circuit technology, as known as CPS or MAPS, are gaining more and more enthusiasts for vertexing and tracking in subatomic physics. Indeed CMOS pixel sensors feature genuinely spatial resolution in the micrometers range and material budget well below 1% of radiation length, which are key assets for these applications. It was less straightforward, and took some developments, to bring MAPS in the realm of nanosecond range time resolution or microsecond integration time, and radiation tolerance matching 10^15 neutron (1 Mev equivalent) per cm2. These last achievements required the depletion of the sensitive volume, which in turn yield an interesting byproduct in term of energy resolution. For instance, 6 keV X-rays can be reconstructed with about 300 eV resolution, roughly just a factor 3 from the absolute Fano limit. Such a performance opens up perspectives for spectroscopy in a broad range of applications, well beyond high energy physics. A less well recognised but nonetheless very strong point of MAPS is their ability to be easily integrated in a system. This stems from two main reasons: these sensors rely on an industrial technology widely used on the consumer market and they can reach extremely low power dissipation, since there is not much amplification required. This seminar intends to introduce briefly the basic operational concept of CMOS pixel sensors and then to cover the latest developments pushing performances (energy, timing, smartness) to their current limits. These discussions will embark us on a journey through the ...

Scopri di più »

## Proposal for using DAFNE as pulse stretcher for the Linac positron beam

A possible application of DAFNE after the end of the Siddharta RUN is using the positron ring as Linac pulse stretcher to produce a high duty=factor beam. The PADME experiment, dedicated to the search for the dark photon (A’), is going to use the BTF beam with 200 ns pulse length and 49 Hz repetition rate, corresponding to a duty-factor of 10e-5. The low duty-factor is the major limitation for the PADME experiment at BTF. By injecting the beam in the DAFNE positron ring and by extracting it with a slow resonant extraction on the m/3 resonance, a duty factor (10e-2 = 0.2/20 ms) nearly a factor 1000 larger can be achieved. This extracted beam would be extremely interesting for PADME. In this talk the modifications required for the ring and the transfer line and a lattice satisfying the conditions for the resonant extraction will be presented. A preliminary estimate of the characteristics of the extracted beam extraction and a description of the work still needed to optimize the parameters will be given.

Scopri di più »