University of Perugia

About: University of Perugia is a education organization based out in Perugia, Umbria, Italy. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 13365 authors who have published 39516 publications receiving 1265601 citations. The organization is also known as: Universitá degli Studi di Perugia & Universita degli Studi di Perugia.

Measurement of the inclusive W and Z production cross sections in pp collisions at √s = 7 TeV with the CMS experiment

Abstract: A measurement of inclusive W and Z production cross sections in pp collisions at sqrt(s)=7 TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 inverse picobarns. The measured inclusive cross sections are sigma(pp-> WX) B(W-> l nu) = 10.30 +/- 0.02 (stat.) +/- 0.10 (syst.) +/- 0.10 (th.) +/- 0.41 (lumi.) nb and sigma(pp -> ZX) B(Z-> l^+l^-) = 0.974 +/- 0.007 (stat.) +/- 0.007 (syst.) +/- 0.018 (th.) +/- 0.039 (lumi.) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are [sigma(pp->WX) B(W-> l nu)]/[sigma(pp-> ZX) B(Z->l^+l^-)] = 10.54 +/- 0.07 (stat.) +/- 0.08 (syst.) +/- 0.16 (th.) and [sigma(pp->W^+X) B(W^+ -> l^+nu)] / [sigma(pp->W^- X) B(W^- -> l^- nu)] = 1.421 +/- 0.006 (stat.) +/- 0.014 (syst.) +/- 0.029 (th.). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions.

Search for the standard model Higgs boson decaying into two photons in pp collisions at s=7TeV

Abstract: A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.

Optical and radio behaviour of the BL Lacertae object 0716+714 ⋆

Abstract: Eight optical and four radio observatories have been intensively monitoring the BL Lac object 0716+714 in the last years: 4854 data points have been collected in the UBVRI bands since 1994, while radio light curves extendback to 1978. Many of these data, which all together constitute the widest optical and radio database available on this object, are presented here for the first time. Four major optical outbursts were observed at the beginning of 1995, in late 1997, at the end of 2000, and in fall 2001. In particular, an exceptional brightening of 2.3 mag in 9 days was detected in the R band just before the BeppoSAX pointing of October 30, 2000. A big radio outburst lasted from early 1998 to the end of 1999. The long-term trend shown by the optical light curves seems to vary with a characteristic time scale of about 3.3 years, while a longer period of 5.5-6 years seems to characterize the radio long-term variations. In general, optical colour indices are only weakly correlated with brightness; a clear spectral steepening trend was observed during at least one long-lasting dimming phase. Moreover, the optical spectrum became steeper after JD ∼ 2451 000, the change occurring in the decaying phase of the late-1997 outburst. The radio flux behaviour at different frequencies is similar, but the flux variation amplitude decreases with increasing wavelength. The radio spectral index varies with brightness (harder when brighter), but the radio fluxes seem to be the sum of two different-spectrum contributions: a steady base level and a harder-spectrum variable component. Once the base level is removed, the radio variations appear as essentially achromatic, similarly to the optical behaviour. Flux variations at the higher radio frequencies lead the lower-frequency ones with week-month time scales. The behaviour of the optical and radio light curves is quite different, the broad radio outbursts not corresponding in time to the faster optical ones and the cross-correlation analysis indicating only weak correlation with long time lags. However, minor radio flux enhancements simultaneous with the major optical flares can be recognized, which may imply that the mechanism producing the strong flux increases in the optical band also marginally affects the radio one. On the contrary, the process responsible for the big radio outbursts does not seem to affect the optical emission.

Impact of immune-related adverse events on survival in patients with advanced non-small cell lung cancer treated with nivolumab: long-term outcomes from a multi-institutional analysis

Abstract: Immune-checkpoint inhibitors (ICIs) represent the standard of care for platinum-pretreated advanced non-small cell lung cancer patients. Patients treated with ICIs may experience immune-related adverse events (irAEs), that might reflect antitumor responses. Here we evaluated nivolumab efficacy according to the development of irAEs. We conducted a multicenter retrospective study of patients with advanced NSCLC treated with nivolumab between October 2013 and September 2017. IrAEs were defined as AEs having immunological basis that required intensive monitoring and interventions. Among 195 patients [median (range) age, 63 (30–84) years; 128 men (65.6%), 67 women (34.4%)], irAEs were observed in 85 patients (43.6%), including 15 patients (7.6%) with grade 3 or 4 events. Median PFS was 5.7 months in irAEs group compared to 2.0 months of no-irAEs group [HR: 0.41 (95% CI 0.3–0.57), P < 0.0001]. Median OS was 17.8 months compared to 4.0 months of no-irAEs group [HR: 0.33 (95% CI 0.23–0.47), P < 0.0001]. IrAEs were significantly associated with improved clinical outcome in 12- and 6-week landmark analysis. Patients who developed ≥ 2 irAEs during treatment (n: 37) had a significantly longer median PFS and OS compared to those with one (n: 48) or none AEs (n: 110) (PFS: 8.5 months vs. 4.6 vs. 2.0, P < 0.0001; OS: 26.8 months vs. 11.9 vs. 4.0, P < 0.0001). Multivariable analysis revealed that irAEs were positively associated with PFS [HR: 0.48 (95% CI 0.34–0.67), P < 0.0001] and OS [HR: 0.38 (95% CI 0.26–0.56), P < 0.0001]. In this study we confirmed that the development of irAEs was a strong predictor of survival outcomes in NSCLC patients treated with nivolumab monotherapy in landmark and multivariable models. Patients who experienced ≥ 2 irAEs had a more pronounced survival benefit compared to those with 1 irAE further suggesting a mechanistic association between irAEs and immunotherapy efficacy.