Salta ai contenuti. | Salta alla navigazione

Strumenti personali

sito non più aggiornato
 

Sezioni

Tu sei qui: Home / Ricerca / 2012

Responsabile Michele Arneodo
Settore di ricerca Fisica Applicata
Personale docente Marta Ruspa   
Personale non-docente Roberta Arcidiacono  Maria Margherita Obertino                  
Obiettivi della ricerca 1) Studio di collisioni protone-protone al collisore LHC presso il laboratorio CERN di Ginevra.
Risultati ottenuti 1) Al CERN, l`organizzazione europea per la ricerca nucleare (http://www.cern.ch), è in funzione il Large Hadron Collider (LHC), un anello di collisioni in grado di accelerare due fasci di protoni (p) fino a un`energia di 7000 GeV e poi farli scontrare. R. Arcidiacono, M. Arneodo, M.M. Obertino e M. Ruspa sono membri della collaborazione internazionale CMS (http://cmsdoc.cern.ch) che ha allestito un sistema di rivelatori che misurano i prodotti delle collisioni. Lo scopo principale del LHC è l`indagine della struttura della materia e delle interazioni tra i suoi costituenti, con risoluzione spaziale e a una scala di energia mai raggiunte finora. Sono stati raccolti dati da febbraio a dicembre.

L`attività del gruppo di Novara, nell`anno 2012, si è concentrata sugli aspetti seguenti:

o) Coordinamento della calibrazione del calorimetro elettromagnetico.
o) Coordinamento delle attivita` di selezione online degli eventi (trigger).
o) Coordinamento delle analisi di eventi diffrattivi.
o) Studio della fattibilità di rivelare eventi con protoni diffusi a basso angolo con energia pari almeno all`80% di quella dei protoni incidenti utilizzando l`apparato CMS e quello della Collaborazione TOTEM (http://totem.web.cern.ch), che ha realizzato un sistema di sensori di particelle cariche adiacenti ai tubi a vuoto dei fasci uscenti dal punto di collisione.

Il risultato di maggiore interesse nel 2012 e` la scoperta di una nuova particella di massa circa 125 GeV, le cui caratteristiche appaiono finora consistenti con quelle del cosiddetto Bosone di Higgs, pietra angolare del "Modello Standard", la teoria che descrive la fisica sub-nucleare (ref. 67 nell`elenco delle pubblicazioni).

 
Obiettivi della ricerca 2) Studio dell`interazione nucleare forte mediante collisioni positrone-protone al collisore HERA presso il laboratorio DESY di Amburgo.
Risultati ottenuti 2) Si veda la scheda della Dott.ssa Ruspa
 
Obiettivi della ricerca 3) Studio delle prestazioni dei rivelatori al silicio per radiazione ionizzante "pixel 3D edgeless detectors".
Risultati ottenuti 3) Si veda la scheda della Dott.ssa Ruspa
 
Collaborazioni in atto M. Arneodo e M. Ruspa fanno parte della collaborazione ZEUS che consiste di circa 450 fisici appartenenti ai seguenti paesi: Canada, Corea, Germania, Giappone, Gran Bretagna, Israele, Italia (Bologna, Cosenza, Firenze, Padova, Piemonte Orientale, Roma, Torino), Kazakhistan, Olanda, Polonia, Russia, Spagna, USA. Per maggiori dettagli, si veda http://www-zeus.desy.de .

R. Arcidiacono, M. Arneodo, M.M. Obertino e M. Ruspa fanno inoltre parte della collaborazione CMS, che consiste di circa 3000 fisici appartenenti a 152 Universita` e Laboratori di 36 paesi. Per maggiori dettagli, si veda http://cmsinfo.cern.ch/Welcome.html/ .  
Comunicazioni a congressi M. Arneodo ha fatto parte dell`International Advisory Committee di "DIFFRACTION 2012 International Workshop on Diffraction in High-Energy Physics", Puerto del Carmen, Lanzarote Canary Islands (Spain), 10-15 settembre 2012

R. Arcidiacono, "QCD and Forward Physics Results from CMS", Les Rencontres de Physique de la Vallée d`Aoste , La Thuile (Italy) , febbraio 2012 (relazione su invito)

M.M. Obertino, "Performance of CMS 3D silicon pixel detectors from FBK before and after irradiation", RESMDD12 – 9th International Conference on Radiation Effects on Semiconductor Materials Detector and Devices", Firenze (Italy), 2012 
Pubblicazioni
Combined search for the quarks of a sequential fourth generation
Search for three-jet resonances in pp collisions at root s=7 TeV
Observation of Sequential upsilon Suppression in PbPb Collisions
Measurement of the t(t)over-bar production cross section in the dilepton channel in pp collisions at root s=7 TeV
Search for supersymmetry in events with b-quark jets and missing transverse energy in pp collisions at 7 TeV
Measurement of the top-quark mass in t(t)over-bar events with dilepton final states in pp collisions at root s=7 TeV
Performance of tau-lepton reconstruction and identification in CMS
Measurement of the production cross section for pairs of isolated photons in pp collisions at root s=7 TeV
J/psi and psi(2S) production in pp collisions at root s=7 TeV
Inclusive search for squarks and gluinos in pp collisions at root s=7 TeV
Search for single-top production in ep collisions at HERA
Measurement of the rapidity and transverse momentum distributions of Z bosons in pp collisions at root(s)=7 TeV
Measurement of the t dependence in exclusive photoproduction of gamma(1s) mesons at HERA
Study of high-p(T) charged particle suppression in PbPb compared to pp collisions at root s(NN)=2.76 TeV
Search for the standard model Higgs boson in the H -> ZZ -> l(+)l(-)tau(+)tau(-) decay channel in pp collisions at root s=7 TeV
Search for the standard model Higgs boson in the H -> ZZ -> 2l2v channel in pp collisions at root s=7 TeV
Scaled momentum distributions for K-S(0) and Lambda/(Lambda)over-bar in DIS at HERA
Search for Signatures of Extra Dimensions in the Diphoton Mass Spectrum at the Large Hadron Collider
Search for the Standard Model Higgs Boson in the Decay Channel H -> ZZ -> 4l in pp Collisions at root s=7 TeV
Measurement of the charge asymmetry in top-quark pair production in proton-proton collisions at root s=7 TeV
Angular correlations in three-jet events in ep collisions at HERA
Search for the standard model Higgs boson decaying to W+W- in the fully leptonic final state in pp collisions at root s=7 TeV
Combined results of searches for the standard model Higgs boson in pp collisions at root s=7 TeV
Search for B-S(0) -> mu(+)mu(-) and B-0 -> mu(+)mu(-) decays
Search for microscopic black holes in pp collisions at root s=7 TeV
Inclusive b-jet production in pp collisions at root s=7 TeV
Search for a Higgs boson in the decay channel H -> ZZ((*)) -> q(q)over-barl(-)l(+) in pp collisions at root s=7 TeV
Search for the standard model Higgs boson decaying to bottom quarks in pp collisions at root s=7 TeV
Measurement of isolated photon production in pp and PbPb collisions at root s(NN)=2.76 TeV
Search for the standard model Higgs boson decaying into two photons in pp collisions at root s=7 TeV
Search for large extra dimensions in dimuon and dielectron events in pp collisions at root s=7 TeV
Centrality dependence of dihadron correlations and azimuthal anisotropy harmonics in PbPb collisions at root s(NN)=2.76 TeV
Search for heavy bottom-like quarks in 4.9 fb(-1) of pp collisions at root s=7 TeV
Suppression of non-prompt J/psi, prompt J/psi, and Upsilon(1S) in PbPb collisions at root s(NN)=2.76 TeV
Search for quark compositeness in dijet angular distributions from pp collisions at root s=7 TeV
Measurement of the inclusive production cross sections for forward jets and for dijet events with one forward and one central jet in pp collisions at root s=7 TeV
Measurement of the mass difference between top and antitop quarks
Measurement of the Z/gamma* plus b-jet cross section in pp collisions at root s=7 TeV
Measurement of the cross section for production of b(b)over-barX decaying to muons in pp collisions at root s=7TeV
Search for anomalous production of multilepton events in pp collisions at root s=7 TeV
Shape, transverse size, and charged-hadron multiplicity of jets in pp collisions at root s=7 TeV
Jet momentum dependence of jet quenching in PbPb collisions at root s(NN)=2.76 TeV
Measurement of the t(t)over-bar production cross section in pp collisions at root s=7 TeV in dilepton final states containing a tau
Search for neutral Higgs bosons decaying to tau pairs in pp collisions at root s=7 TeV
Observation of a New Xi(b) Baryon
Search for Dark Matter and Large Extra Dimensions in pp Collisions Yielding a Photon and Missing Transverse Energy
Search for a light charged Higgs boson in top quark decays in pp collisions at root s=7 TeV
Azimuthal Anisotropy of Charged Particles at High Transverse Momenta in Pb-Pb Collisions at root S-NN=2.76 TeV
Search for first-generation leptoquarks at HERA
Search for heavy long-lived charged particles in pp collisions at root s=7 TeV
Search for stopped long-lived particles produced in pp collisions at root s=7 TeV
Search for new physics in events with same-sign dileptons and b-tagged jets in pp collisions at root s=7 TeV
Search for leptonic decays of W ` bosons in pp collisions at root s=7TeV
Measurement of the underlying event activity in pp collisions at root s=0 9 and 7 TeV with the novel jet-area/median approach
Search for narrow resonances in dilepton mass spectra in pp collisions at root s=7 TeV CMS Collaboration
Measurement of the Lambda(b) cross section and the (Lambda)over-bar(b) to Lambda(b) ratio with J/psi Lambda decays in pp collisions at root s=7 TeV CMS Collaboration
Search for New Physics with Same-Sign Isolated Dilepton Events with Jets and Missing Transverse Energy
Measurement of isolated photons accompanied by jets in deep inelastic ep scattering
Study of W boson production in PbPb and pp collisions at root s(NN)=2.76 TeV
Measurement of the underlying event in the Drell-Yan process in proton-proton collisions at root s=7 TeV
Search for a fermiophobic Higgs boson in pp collisions at root s=7 TeV
Search for dark matter and large extra dimensions in monojet events in pp collisions at root s=7 TeV
Search for anomalous t(t)over-bar production in the highly-boosted all-hadronic final state
Measurement of the Electron Charge Asymmetry in Inclusive W Production in pp Collisions at root s=7 TeV
Search for heavy, top-like quark pair production in the dilepton final state in pp collisions at. root s=7 TeV
Search for high-mass resonances decaying into tau-lepton pairs in pp collisions at root s=7 TeV
Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
Search for physics beyond the standard model in events with a Z boson, jets, and missing transverse energy in pp collisions at root s=7 TeV
Search for a Light Pseudoscalar Higgs Boson in the Dimuon Decay Channel in pp Collisions at root s=7 TeV
Search for pair production of first- and second-generation scalar leptoquarks in pp collisions at root s=7 TeV
Study of the inclusive production of charged pions, kaons, and protons in pp collisions at root s=0.9, 2.76, and 7 TeV
Combined inclusive diffractive cross sections measured with forward proton spectrometers in deep inelastic ep scattering at HERA
Measurement of jet fragmentation into charged particles in pp and PbPb collisions at root s(NN)=2.76 TeV
Search for supersymmetry in hadronic final states using M-T2 in pp collisions at root s=7 TeV
Performance of CMS muon reconstruction in pp collision events at root s=7Tev
Measurement of the Pseudorapidity and Centrality Dependence of the Transverse Energy Density in Pb-Pb Collisions at root s(NN)=2.76 TeV
Inclusive and differential measurements of the t(t)over-bar charge asymmetry in proton-proton collisions root s=7 TeV
Search for heavy Majorana neutrinos in mu(+/-)mu(+/-) + jets and e(+/-)e(+/-) + jets events in pp collisions at root s=7 TeV
Search for New Physics in the Multijet and Missing Transverse Momentum Final State in Proton-Proton Collisions at root s=7 TeV
Search for charge-asymmetric production of W ` bosons in t(t)over-bar + jet events from pp collisions at root s=7 TeV
Inclusive-jet photoproduction at HERA and determination of alpha(s)
Search for electroweak production of charginos and neutralinos using leptonic final states in pp collisions at root s=7 TeV
Search for new physics with long-lived particles decaying to photons and missing energy in pp collisions at root s=7 TeV
Search for the standard model Higgs boson produced in association with W and Z bosons in pp collisions at root s=7 TeV
Search for exclusive or semi-exclusive gamma gamma production and observation of exclusive and semi-exclusive e(+)e(-) production in pp collisions at root s=7 TeV
Ratios of dijet production cross sections as a function of the absolute difference in rapidity between jets in proton-proton collisions at root s=7 TeV
A search for a doubly-charged Higgs boson in pp collisions at root s=7 TeV
Search for heavy lepton partners of neutrinos in proton-proton collisions in the context of the type III seesaw mechanism
Search for pair produced fourth-generation up-type quarks in pp collisions at root s=7 TeV with a lepton in the final state
Study of the Dijet Mass Spectrum in pp -> W + jets Events at root s=7 TeV
Search for Heavy Neutrinos and W-R Bosons with Right-Handed Couplings in a Left-Right Symmetric Model in pp Collisions at root s=7 TeV
Exclusive gamma gamma -> mu(+)mu(-) production in proton-proton collisions at root s=7TeV
Jet production rates in association with W and Z bosons in pp collisions at root s=7 TeV
Exclusive electroproduction of two pions at HERA
Forward energy flow, central charged-particle multiplicities, and pseudorapidity gaps in W and Z boson events from pp collisions at root s=7 TeV