YOUNG RESEARCHERS WORKSHOP
 
 MONDAY  12th
   
 16:30-16:45 Sofiane Boucenna   (IFIC - CSIC, U. Valencia, Spain):  
Calculable neutrino masses from gauge lepton number violation

I will present a new mechanism for generating exactly calculable small neutrino masses in a 3-3-1 theory. In this extended gauge sector framework, Lepton number is broken by the gauge interactions alone which then lead to neutrinos masses at 1-loop order. The neutrino masses depend essentially only on the gauge couplings and the scale of SU(3)_L x U(1)_X breaking that can be low. Some phenomenological consequences are also discussed.
 16:45- 17:00 Cesar Bonilla   (IFIC - CSIC, U. Valencia, Spain):  
Dirac neutrinos from flavor symmetry

In this talk I will present a model where Majorana neutrino mass terms are forbidden by the flavor symmetry group Delta(27). Neutrinos are Dirac fermions and their masses arise in the same way as that of the charged fermions, due to very small Yukawa couplings. The model fits current neutrino oscillation data and correlates the atmospheric angle with the magnitude of the lightest neutrino mass.
 17:00-17:15 Carolina Arbelaez   (IFIC - CSIC, U. Valencia, Spain):  
LHC-scale left-right symmetry, unification and DM

We construct a comprehensive list of non-supersymmetric standard model extensions with a low-scale LR-symmetric intermediate stage that may be obtained as simple low-energy effective theories within a class of SO(10) GUTs. Many of our examples support gauge coupling unification even if the LR scale is in the LHC domain, at a price of (a few copies of) one or two types of extra fields pulled down to the TeV-scale. We discuss the main aspects of realistic model building conforming the basic constraints from the quark and lepton sector flavour structure, proton decay, etc. We observe a general tendency for the models without new coloured states in the TeV domain to be on the verge of incompatibility with the proton stability constraints. In this kind of scenarios, where SO(10) is broken to the SM like via SU(3)_c x SU(2)_L x SU(2)_R x U(1)_{B-L} --> SM, a Z_2 might survive as a remnant symmetry and therefore some realistic DM candidates could emerge.
 17:15-17:30 Martin Krauss   (INFN-LNF, Frascati, Italy):  
Testing Models with Higher Dimensional Effective Interactions at the LHC and Dark Matter Experiments

New physics can be described by effective field theories in a model independent way. It is possible that the dominant contribution to low-energy effects of new physics is generated by higher-dimensional operators, which are more suppressed than the usually discussed ones. Thus neutrino mass models can be connected to TeV scale physics, for instance. The possible existence of TeV scale particles is interesting, since they can be potentially observed at collider experiments, such as the Large Hadron Collider. Higher dimensional effective operators can also be used to study the interactions relevant for dark matter detection experiments, which we will also discuss.


 17:30-17:45 Riccardo Manzoni   (INFN and U. Milano Bicocca, Milan, Italy) : 
Evidence of the SM Higgs Boson in the Decay Channel into Tau Lepton

A search for the standard model Higgs boson decaying into a pair of tau leptons is performed using events recorded by the CMS experiment at the LHC in 2011 and 2012. The dataset corresponds to an integrated luminosity of 4.9 fb$^{-1}$ at a centre-of-mass energy of 7 TeV and 19.7 fb$^{-1}$ at 8 TeV. An excess of events is observed over the expected background contributions, with a local significance larger than 3 standard deviations for $m_H$ values between 110 and 130 GeV.
 17:45-18:00 Nestor Quintero   (CINVESTAV-IPN, Mexico City, Mexico) : 
Di-leptons production in the top quark decay and New Physic

The heaviness of the top quark makes its 2-body decay mode $t \to b W^+$ to be dominant, at such level that hardly any other decay mode reaches a detectable branching ratio (BR) within the SM. Here we study the decay $t \to b W^+\ell^-\ell^+$ ($\ell=e, \mu, \tau$), which diverges for massless leptons, and it can reach a BR $\sim O(10^{-5} - 10^{-6})$ for reasonable values of the low energy cut in the lepton-pair invariant mass. This rate surpasses almost any other rare decays such as $t \to c X$ ($X=\gamma,Z,g,H, W^+W^-$), and thus offers the possibility of being detectable. Furthermore, the estimate of this channel is relevant because it can mimic the signal arising from the lepton number violating decay $t\to b W^- \ell^+ \ell^+$, when the $W$ boson decays into lepton channels.
 
  THURSDAY 15th
 
 16:30-16:45 Gaetana Anamiati   (INFN and U. Calabria, Cosenza, Italy) : 
Z0 inclusion at leading order in DISENT Monte Carlo

Even after the final shutdown of the HERA experiment, the precision in the determination of the strong coupling constant and of the parton distribution functions can be improved by re-analysing data through Monte Carlo's which include subleading effects. In this thesis we considered the Monte Carlo program DISENT for the inclusive jet production at HERA, that in the original version contained only the exchange of the photon, and we modified it to include the exchange of the Z0 boson at the lowest order. The numerical results obtained confirmed that the Z0 contribution is particularly relevant in the region of high $Q^2$.
 16:45-17:00 Simone Biondini :  (Technische Universitat Munchen, Germany) : 
Effective field theory: from Cosmology to Quark Gluon Plasma

The dark matter abundance and the baryon asymmetry of the Universe are accurately determined from CMB data. The Standard Model can not account for these evidences. In leptogenesis Majorana neutrinos are at the origin of the baryon asymmetry. The non-relativistic regime comes up to be relevant during the lepton asymmetry generation. Moreover, all the interactions occur in a thermal medium. We discuss an effective field theory for non-relativistic Majorana particles to simplify calculations in a thermal medium, and we apply it to the case of a heavy Majorana neutrino decaying in the early Universe. Thermal corrections to the neutrino width are addressed. These techniques are analogous to those used for studying heavy-ions collisions at LHC. For instance, heavy quarkonia suppression and jet quenching are effects induced by a hot QCD medium. We show the similarities with the former case of Majorana neutrinos. The development of resummation techniques in hot QCD and in cosmology can benefit both fields.
 17:00-17:15 Aleksander Gajos   (Krakow U., Poland) : 
A direct test of T symmetry in the neutral K meson system with $K_S K_L -> \pi \ell \nu$ and $K_L -> 3 \pi^0$ at the KLOE-2 experiment

Quantum entanglement of K and B mesons allows for a direct experimental test of time-reversal symmetry independent of CP violation. The T symmetry can be probed by exchange of initial and final states in the reversible transitions between flavor and CP-definite states of the mesons which are only connected by the T conjugation. While such a test was successfully performed by the BaBar experiment with neutral B mesons, the KLOE-2 detector can probe T-violation in the neutral kaons system by investigating the process with $K_S\to \pi^{\pm} l^{\mp} \nu_{l}$ and $K_L\to3\pi^0$ decays. Analysis of the latter is facilitated by a novel reconstruction method for the vertex of $K_L\to3\pi^0$ decay which only involves neutral particles. Details of this new vertex reconstruction technique will be presented as well as prospects for conducting the direct T symmetry test at the KLOE-2 experiment.
 17:15-17:30 Daria Kaminska   (Krakow U., Poland) : 
Status of measurement of $K_S -> \pi e \nu$ branching ratio and lepton charge asymmetry with the KLOE detector

We present the current status of the analysis of about 1.7 billion K_S K_L pair events collected at DAFNE with the KLOE detector to determine the branching ratio of $K_S -> \pi e \nu $ decay and the lepton charge asymmetry. This sample is approx. 4 times larger in statistics than the one used in a previous KLOE analysis, allowing us to improve the accuracy of the measurement and of the related tests of CPT symmetry and $\Delta S = \Delta Q$ rule.
 17:30-17:45 Ciro Riccio   (U. Federico II, Naples, Italy) : 
T2K neutrino oscillation results

The Tokai to Kamioka (T2K) experiment is a long baseline neutrino oscillation experiment situated in Japan. A high intensity neutrino beam is produced at the Japan Proton Accelerator Research Complex (JPARC). A near detector complex, situated 280 m from the neutrino production target, and the far detector (the 50kt SuperKamiokande water-Cerenkov detector) at 295 km, are used to detect the neutrinos from this beam. T2K has delivered the first evidence for a non-zero mixing angle $\Theta_{13}$ in an appearance experiment and improved our knowledge of the oscillation parameters $\Theta{23}$ and $\Delta m^2_{23}$. In this talk, results from T2K are presented and the prospect of future results is discussed.
 17:45-18:00 Carmelo Pellegrino   (U. Bologna, Italy): 
Data acquisition system for the KM3NeT neutrino telescope

KM3NeT is the next generation underwater Cherenkov neutrino telescope. The main technological innovation is represented by the optical module that will host 31 3" photomultipliers, allowing a better optical background rejection. The "all data to shore" approach will be adopted. A software trigger will be performed only on-shore with a dedicated computing infrastructure, aiming to reduce the large detector throughput (up to 500 Gbps) by almost 4 orders of magnitude. The challenging trigger and data acquisition system (TriDAS) requires special fast data filtering algorithms, and efficient computing infrastructure. The technological solutions for KM3NeT and the expected performance of the detector are presented and discussed.
 18:00-18:15 Marco Sessa   (U. Roma III, Rome, Italy) : 
Construction and performance study of Micromegas muon chambers for ATLAS upgrade.

One of the most important ATLAS Phase-1 upgrades concerns the replacement of the the first muon station in the forward region of the Muon Spectrometer with the New Small Wheel (NSW), that will be installed during the next Long Shutdown in 2018. The NWS will employ micromegas (MM) and small-strip Thing Gap Chambers (sTGC) detectors. The MM chambers will be the primary detector for precision tracking also providing online segments for trigger. The status and plans of the MM project will be presented, with emphasis on recent analysis of MM performance in magnetic field from test-beam data. The status of the MM detectors construction phase and the mechanical tests on MM carried out by Roma Tre INFN group will also be presented.