14 research outputs found
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Search for Heavy Down-Type Vector-Like Quarks in the Lepton-Plus-Jets Final State in 8 TeV proton-proton Collisions Using the ATLAS Detector at the LHC
No full textThis dissertation presents a search for pair production of heavy down-type vector-like quarks (VLQ B) using the full 2012 data set of proton-proton collisions at the center of mass 8 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider, corresponding to an integrated luminosity of 20.3 1/fb. Events with a single charged lepton, which can be either an electron or muon, missing transverse energy, at least six jets, at least one tagged as a b-jet, and at least one reconstructed hadronically-decaying W/Z boson candidate are analyzed. No significant deviation from the Standard Model background prediction is observed.
Under the assumption that only the B->Wt/Zb/Hb decay modes are allowed, 95% CL upper limits are derived in the two dimensional plane of the B->Wt branching ratio versus B->Hb branching ratio. In the specific case where the branching ratios are consistent with a SU(2) singlet scenario, the observed (expected) 95% CL lower limit on the VLQ B mass is 640 GeV (505 GeV). In the chiral B scenario with a 100% branching ratio of the decay B->Wt, the observed (expected) 95% CL lower limit on the B mass is 814 GeV (756 GeV)
Turin chronicles: Braunschweig e Leonardo Lidi
No full textUna lunga recensione di due spettacoli prodotti nel 2024 dal Teatro Stabile di Torino, La vita che ti diedi di Pirandello, messinscena del regista francese Stéphane Braunschweig, e Medea di Euripide, regia di Leonardo Lidi, giovane regista del Teatro Stabile torinese. Il regista francese è uno dei pochi, se non l’unico, ancora vivente e attivo, della grande tradizione dei metteurs en scène cui si deve la fondazione della regia nell’Europa del secondo Novecento, da Strehler a Ronconi. Autore di spettacoli ibseniani mirabili e anche di alcune felici realizzazioni pirandelliane. Meno riuscito invece quest’ultima prova, in parte per la debolezza del testo del drammaturgo siciliano, molto cerebrale e didascalico, ma un po’ anche per i limiti di un cast che non sempre è riuscito a tradurre le indicazioni di una regia interessata ad accostare il testo al filone pirandelliano del cosiddetto teatro nel teatro. Molto interessante e provocatorio l’impianto scenografico della Medea, ma meno convincente la drastica riscrittura del testo, soprattutto nella parte finale, e lo spostamento di asse interpretativo, un po’ gratuito, a mera tragedia d’amore, affidata peraltro a due attori caratteristi di notevole valore, ma impiegati in ruoli primari che non ne esaltano le qualità professionali.A long review of two shows produced in 2024 by the Teatro Stabile of Turin, La vita che ti diedi by Pirandello, staged by the French director Stéphane Braunschweig, and Medea by Euripide, directed by Leonardo Lidi, young director of the Teatro Stabile of Turin. The French director is one of the few, if not the only one, still alive and active, of the great tradition of metteurs en scène who was responsible for the foundation of direction in late twentieth century Europe, from Strehler to Ronconi. Author of wonderful Ibsenian shows and also of some successful Pirandellian creations. This last attempt, however, was less successful, partly due to the weakness of the text by the Sicilian playwright, very cerebral and didactic, but also partly due to the limitations of a cast that was not always able to translate the indications of a director interested in combining the text in the Pirandellian vein of the so-called theatre within the theatre. The scenographic structure of Medea is very interesting and provocative, but less convincing is the drastic rewriting of the text, especially in the final part, and the somewhat gratuitous shift of the interpretative axis to a mere love tragedy, also entrusted to two character actors of considerable value, but employed in primary roles that do not enhance their professional qualities
Le Muse dei Bonarelli. Il teatro di Prospero e l'eredità di Guidubaldo
No full textIl contributo prende in esame le modalità con le quali Prospero Bonarelli (1588-1659) diedi inizio alla sua carriera letteraria e teatrale mettendo a frutto il prestigio derivante dalla fama di suo fratello Guidubaldo (1563-1608), autore della celebre favola pastorale Filli di Sciro. Come attraversamento tematico di carattere preliminare, l’articolo si apre prendendo in esame le modalità con le quali Prospero tematizza la continuità tra la sua produzione letteraria e quella del fratello nel suo epistolario e in due testi in particolare: l’Introduzione Alle Opere di Guidubaldo da lui stesso curate e nella supplica a Ferdinando II, il cui testo è pubblicato in appendice. Nelle restanti pagine il saggio si articola in tre parti. Nella prima parte l’autore ricostruisce le vicende della famiglia Bonarelli tra il 1575 e il 1655; nella seconda parte analizza come Prospero amministrò l’eredità letteraria del fratello, tra le scene e la tipografia, in un periodo compreso tra il 1608, data di morte di Guidubaldo, e il 1612; nella parte conclusiva si sofferma sulle modalità con le quali Prospero mise a frutto la rete di contatti ereditata dal fratello in occasione del suo esordio in veste di autore teatrale con il Solimano.The essay provides an analysis of how Prospero Bonarelli (1588-1659) started his literary and theatrical career taking advantage of the fame of his brother Guidubaldo (1563-1608), author of the famous pastoral play Filli di Sciro. As an introduction to such an argument the essay studies how Prospero represented his relationship with the “heritage” of his brother in his letters and in two different texts: the Introduction to the edition of Guidubaldo’s Works he edited and a petition to the Duke of Tuscany Ferdinando II, a document which is here published as an appendix. The rest of the essay is divided into three parts. In the first part the author provides a reconstruction of the history of Bonarelli’s family in the years from 1575 to 1655; in the second part he studies how Prospero managed, both metaphorically and practically, the heritage of manuscripts and fame his brother provided him from 1608 (the year of Guidubaldo’s death) to 1612; in the third and last part he shows how Prospero used the network of friends and patrons “inherited” by his brother in order to promote his first theatrical work, the tragedy Solimano
Measurement of differential production cross-sections and forward-backward ratio in p+Pb collisions with the ATLAS detector
No full textSee paper for full list of authors - 13 pages plus author list + cover pages (26 pages total), 8 figures, 8 tables, submitted to Phys. Rev. C. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2013-07/International audienceMeasurements of differential cross-sections for production in p+Pb collisions at = 5.02 TeV at the LHC with the ATLAS detector are presented. The data set used corresponds to an integrated luminosity of 28.1 nb. The mesons are reconstructed in the dimuon decay channel over the transverse momentum range GeV and over the center-of-mass rapidity range . Prompt are separated from resulting from -hadron decays through an analysis of the distance between the decay vertex and the event primary vertex. The differential cross-section for production of nonprompt is compared to a FONLL calculation that does not include nuclear effects. Forward-backward production ratios are presented and compared to theoretical predictions. These results constrain the kinematic dependence of nuclear modifications of charmonium and -quark production in p+Pb collisions
Search for Scalar Charm Quark Pair Production in pp Collisions at s√=8 TeV with the ATLAS Detector
No full textSee paper for full list of authors – Comments: 5 pages plus author list + cover page (19 pages total), 2 figures, 1 table, submitted to Phys. Rev. Lett., All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2014-03International audienceThe results of a dedicated search for pair production of scalar partners of charm quarks are reported. The search is based on an integrated luminosity of 20.3 fb of pp collisions at TeV recorded with the ATLAS detector at the LHC. The search is performed using events with large missing transverse momentum and at least two jets, where the two leading jets are each tagged as originating from c-quarks. Events containing isolated electrons or muons are vetoed. In an R-parity-conserving minimal supersymmetric scenario in which a single scalar-charm state is kinematically accessible, and where it decays exclusively into a charm quark and a neutralino, 95% confidence-level upper limits are obtained in the scalar-charm-neutralino mass plane such that, for neutralino masses below 200 GeV, scalar-charm masses up to 490 GeV are excluded
Measurements of the Total and Differential Higgs Boson Production Cross Sections Combining the H→γγ and H→ZZ∗→4ℓ Decay Channels at s√=8 TeV with the ATLAS Detector
No full text6 pages plus author list + cover page + supplemental material (26 pages total), 7 figures, 23 tables, submitted to Physical Review Letters. All figures including auxiliary figures are available at this http URL - See paper for full list of authorsInternational audienceMeasurements of the total and differential cross sections of Higgs boson production are performed using 20.3 fb−1 of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of s√=8 TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H→γγ and H→ZZ∗→4ℓ event yields, which are combined accounting for detector efficiencies, fiducial acceptances and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be σpp→H=33.0±5.3(stat)±1.6(sys)pb. The measurements are compared to state-of-the-art predictions
Study of the B+c → J/ψD+s and B+c → J/ψD*s+ decays with the ATLAS detector
No full textThe decays B-c(+) -> J/psi D-s(+) and B-c(+) -> J/psi D-s*(+) are studied with the ATLAS detector at the LHC using a dataset corresponding to integrated luminosities of 4.9 and 20.6 fb(-1) of pp collisions collected at centre-of-mass energies root s = 7 TeV and 8 TeV, respectively. Signal candidates are identified through J/psi -> mu(+)mu(-) and D-s(()*()+) -> phi pi(+)(gamma/pi(0)) decays. With a two-dimensional likelihood fit involving the B-c(+) reconstructed invariant mass and an angle between the mu(+) and D-s(+) candidate momenta in the muon pair rest frame, the yields of B-c(+) -> J/psi D-s(+) and B-c(+) -> J/psi D-s*(+), and the transverse polarisation fraction in B-c(+) -> J/psi D-s*(+) decay are measured. The transverse polarisation fraction is determined to be Gamma +/-+/-(B-c(+) -> J/psi D-s*(+))/Gamma(B-c(+) -> J/psi D-s*(+)) = 0.38 +/- 0.23 +/- 0.07, and the derived ratio of the branching fractions of the two modes is B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi D-s(+) = 2.8(-0.8)(+1.2) +/- 0.3, where the first error is statistical and the second is systematic. Finally, a sample of B-c(+) -> J/psi pi(+) decays is used to derive the ratios of branching fractions B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi pi(+) = 3.8 +/- 1.1 +/- 0.4 +/- 0.2 and B-Bc+ -> J/psi D-s*+/B-Bc+ -> J/psi pi(+) = 10.4 +/- 3.1 +/- 1.5 +/- 0.6, where the third error corresponds to the uncertainty of the branching fraction of D-s(+) -> phi(K+ K-)pi(+) decay. The available theoretical predictions are generally consistent with the measurement.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-015-3743-8</p
Measurement of the boson pair-production cross section in collisions at TeV with the ATLAS Detector
No full textThe production of events in proton--proton collisions at a centre-of-mass energy of 13 TeV is measured with the ATLAS detector at the LHC. The collected data correspond to an integrated luminosity of 3.2 fb. The candidates are reconstructed using leptonic decays of the gauge bosons into electrons or muons. The measured inclusive cross section in the detector fiducial region for leptonic decay modes is (stat.) (sys.) (lumi.) fb. In comparison, the next-to-leading-order Standard Model prediction is fb. The extrapolation of the measurement from the fiducial to the total phase space yields (stat.) (sys.) (th.) (lumi.) pb, in agreement with a recent next-to-next-to-leading-order calculation of pb. The cross section as a function of jet multiplicity is also measured, together with the charge-dependent and cross sections and their ratio
Observation and measurements of the production of prompt and non-prompt J/psi mesons in association with a Z boson in pp collisions at root s=8 TeV with the ATLAS detector
No full textThe production of a Z boson in association with a J/psi meson in proton-proton collisions probes the production mechanisms of quarkonium and heavy flavour in association with vector bosons, and allows studies of multiple parton scattering. Using 20.3 fb(-1) of data collected with theATLAS experiment at the LHC in pp collisions at root s = 8 TeV, the first measurement of associated Z + J/psi production is presented for both prompt and non-prompt J/psi production, with both signatures having a significance in excess of 5 sigma. The inclusive production cross-sections for Z boson production (analysed in mu(+) mu(-) or e(+) e(-) decay modes) in association with prompt and non-prompt J/psi (-> mu(+) mu(-)) are measured relative to the inclusive production rate of Z bosons in the same fiducial volume to be (36.8 +/- 6.7 +/- 2.5) x 10(-7) and (65.8 +/- 9.2 +/- 4.2) x 10(-7) respectively. Normalised differential production cross-section ratios are also determined as a function of the J/psi transverse momentum. The fraction of signal events arising from single and double parton scattering is estimated, and a lower limit of 5.3 (3.7) mb at 68 (95)% confidence level is placed on the effective cross-section regulating double parton interactions.ATLAS Collaboration, for complete list of authors see http://dx.doi.org/10.1140/epjc/s10052-015-3406-9</p
