IFAE 2012

Ricerca di "Dark Forces" a KLOE

12 Apr 2012, 11:55

10m

Aula Magna (Ferrara)

Presentazione 12 minuti Fisica Astroparticellare Astroparticelle

Speaker

Dr Ivano Sarra (LNF)

Description

Recenti osservazioni in ambito astrofisico non mostrano una chiara interpretazione in termini del modello standard (MS). Tra queste evidenze sperimentali ci sono, ad esempio, l'eccesso di positroni nei CR riportato da PAMELA e il flusso totale di elettroni e positroni misurato da ATIC, FERMI e HESS. \\ Benchè esistano differenti teorie in grado di spiegare questi fenomeni, una estensione dello MS dà una possibile interpretazione unica tramite processi di produzione e annichilazione di materia oscura (DM); in tal contesto, è introdotta una nuova simmetria di gauge, debolmente accoppiata con Modello Standard tramite un meccanismo di mixing tra il fotone e il nuovo mediatore di forza, il bosone vettore U. Le caratteristiche aspettate per questo bosone vettore, cioe' massa dell'ordine del GeV e costante di accoppiamento della carica elettrica $\epsilon \sim 10^{-3}$, fanno si' che possa essere prodotto ad esperimenti di basse energie. \noindent L'esperimento KLOE, che ha raccolto una statistica di circa 2.5 fb$^{-1}$ alla massa del mesone $\phi$ puo' contribuire alla ricerca del bosone U tramite 3 diversi canali di produzione: \begin{itemize} \item Decadimenti dei mesoni leggeri, come ad esempio $\phi\to\eta U$, $\eta/\pi^0\to U\gamma$; \item produzione diretta del bosone U tramite $e^+e^-\rightarrow U\gamma$; \item h$'$ strahlung: $e^+e^-\rightarrow U^* \rightarrow Uh'$, nell'ipotesi in cui la nuova simmetria sia spontaneamente rotta tramite un meccanismo alla Higgs. \end{itemize} \noindent Con un campione di 1.5 fb-1, e' stato studiato il decadimento $\phi\to\eta U$, utilizzando lo stato finale $\eta\to\pi^+\pi^-\pi^0$, $U\to e^+ e^-$. Semplici tagli di analisi forniscono circa 14,000 eventi di fondo irriducibile dovuto al decadimento radiativo $\phi\to\eta e^+ e^-$, mentre il contributo di altri canali di decadimento e' trascurabile. La massa invariante della coppia $e^+ e^-$ e' stata utilizzata per ottenere un limite superiore per il processo $\phi\to\eta U$. Il plot di esclusione risultante copre l'intervallo di massa $5

Inserire un breve CV (solo per dottorandi che richiedono un contributo spese)

SARRA IVANO
Address: Via Pietrabbondante n.11 00132, Roma
Phone number.: 06/94038204 (cell.: 328/3584459)
Email: ivano.sarra@lnf.infn.it

Personal information
• Date and place of birth: February 12, 1982 - Rome
• Marital status: single
• Citizenzship: Italian

Education
• PhD student from November 2009 at “Tor Vergata” Rome University.
• “Tor Vergata” Rome University, Laurea in Physics. Final mark: 110/110 with distinction.
The argument of the thesis is: “Characterization of silicon photomultipliers connected to optical fibers and scintillators for electromagnetic calorimetry” - May 2009.
• Rome University “Tor Vergata”, Bachelor in Physics. The thesis argument is: “Development
and programming of a VME programmable logic interface (FPGA)” - 2005.
• Liceo Edoardo Amaldi, Rome, Diploma di Maturita’ scientifica – 2001.

Professional Experience
• FNAL (Fermi National Accelerator Laboratory of Chicago, USA): collaboration at the research program of the Dott. Robert Bernestein for Mu2e experiment. 15 of June – 10 of September 2011.
• FNAL (Fermi National Accelerator Laboratory of Chicago, USA): collaboration at the research program of the Dott. Robert Bernestein for Mu2e experiment. 8 of July – 11 of September 2010.
• FNAL (Fermi National Accelerator Laboratory of Chicago, USA): collaboration at the research program of the Dott. Robert Bernestein for Mu2e experiment. 16 of June – 10 of September 2009.
• Rome University “Tor Vergata” – INFN, Fellowship for young scientists; development and testing of electronics for nuclear physics. March 2006 – March 2008.
• Rome University “Tor Vergata”, Teaching assistant at the electronic degree course of Physics. 2005 – 2007.

Research Activity
Since 2008:
Participation to the R&D program for the electromagnetic calorimeter at low angle for the KLOE-2 experiment as starting job for his laurea thesis. In particular, he designs and develops new preamplifiers for the readout of Hamamatsu Silicon Photomultiplier (SIPM) and realizes a test-setup for the measurement of the SIPM characteristics (Gain, Dark Noise, dependences on Vbias, Temperature and so on.). Moreover, he participated to two different test beams:

1) In may 2008 and feb 2009 at the Beam test facility of LNF, where a beam of single electron of energies ranging from 100 to 500 MeV was used to characterize different prototypes of crystal calorimeters (PBWO+SIPM, LSO+APD).
2) In October 2008, at the blue hall neutron beam of the TSL laboratory of Uppsala, Sweden, where a prototype of the KLOE calorimeter has been exposed to neutron beams of 174 MeV energy.
Completed the design and the realization of a new amplification board for the readout of APD on crystal calorimeters.

From 16 of June to 10 of September 2009:
Participation at the research program for the Mu2e experiment @ FNAL. Simulation, in GEANT4, of the background brought from the radiative absorption of the negative pions for the violation of the lepton number with conversion on Al nucleus mu+N->e+N.
Simulation of the Radiative Pi Capture, internal note Mu2e-doc-665-v2.

From 8 of July to 11 of September 2010:
Participation at the research program for the Mu2e experiment @ FNAL.
Simulation in GEANT4:
Multiple Coulomb Scattering of a 105 MeV electron on Kapton, internal note Mu2e-doc-1080.
LSO crystal e.m. calorimeter response to a 105 MeV/c electron, internal note Mu2e-doc-1025.

2010-2011:
Completed the design and the realization of a new HV board for the APD.
Completed Proto LYSO Crystal Calorimeter for Mu2e experiment. The calorimeter is tested at the MAMI beam facility, Mainz-Germany, with a photons’ beam with energy between 30 and 300 MeV, March 2011.

From 15 of June to 10 of September 2011:
Participation at the research program for the mu2e experiment @ FNAL.
Simulation in GEANT4:
Clustering algorithms for the Mu2e calorimeter, internal note Mu2e-doc-1741;
Position reconstruction algorithm for Mu2e calorimeter, internal note Mu2e-doc-1807;
Calorimeter Trigger Study, internal note Mu2e-doc-1974.

Presentation materials

Slides

sarra-IFAE.pdf