Asimmetria di CP nei decadimenti charmless di mesoni B a CDF

Riassunto: La non-conservazione della simmetria CP (composizione degli operatori di Coniugazione di carica (C) e Parità (P)) è spiegata nel Modello Standard delle interazioni fondamentali (MS) attraverso l'introduzione di una singola fase complessa nella matrice di mescolamento tra i quark. L’attuale quadro sperimentale e’ sostanzialmente in accordo con il modello entro le incertezze, tuttavia la possibilità che le asimmetrie osservate risentano degli effetti di particelle non previste dal MS non e' esclusa sperimentalmente, anche perche’ interi settori, come quello dei decadimenti del mesone B0s , rimangono ancora relativamente inesplorati. Inoltre recentemente si vanno consolidando un certo numero di discrepanze tra predizioni teoriche e risultati sperimentali. L’osservazione di una significativa e inaspettata discrepanza tra l’asimmetria di CP "diretta" nel decadimento B0->K+pi- e quella nel decadimento B+ ->K+pi0 ha generato un’ampia discussione. Da una parte si sostiene che le cause siano effetti non completamente compresi di fisica MS (interazioni adroniche a bassa energia); altri invece interpretano la discrepanza come indicazione della presenza di un qualche genere di nuova fisica dotata di asimmetria CP. Un esempio tra gli altri e’ la possibile presenza di una 4a generazione di quark molto pesanti, che spiegherebbe anche il modesto disaccordo con il MS osservato nelle recenti misure della fase di oscillazione in decadimenti B0s ->J/psi phi. E’ chiaro quindi che aumentare e raffinare l’informazione sperimentale sui decadimenti di mesoni B, e in particolare riguardo al poco conosciuto B0s, diventa cruciale per discriminare tra le varie possibilita’ in gioco. Una notevole opportunita’ in questo senso e’ offerta dall'esperimento CDF al Tevatron di Fermilab. Il Tevatron produce collisioni protone-antiprotone ad un'energia nel centro di massa di \sqrt{s} =1.96 TeV, ed e' l'unica macchina oggi disponibile in cui si possono studiare decadimenti sia del mesoni B0 che del Bs . L'accesso simultaneo ai decadimenti di mesoni B neutri di entrambi i "sapori", offre l'opportunità di una parziale cancellazione delle incertezze sulle previsioni teoriche, oltre che delle incertezze sistematiche. Utilizzando un campione corrispondente a 1 fb-1, CDF ha gia’ prodotto una misura preliminare di ACP(B0->K+pi-) al 2% di precisione e la prima osservazione del decadimento Bs ->K-pi+. La disponibilita’ attuale di un campione quasi tre volte piu’ grande offre una buona opportunita’ per migliorare la nostra comprensione delle interazioni adroniche a bassa energia. In particolare, la asimmetria di CP di Bs ->K-pi+, attualmente accessibile esclusivamente a CDF, e’ prevista essere inusualmente grande e quindi ben misurabile. Per di piu’, alcuni autori ritengono che nel MS ci sia una solida relazione tra questa asimmetria e quella del modo B0->K+pi-, largamente indipendente da specifici modelli o assunzioni sui contributi adronici. Tale relazione sarebbe invece del tutto accidentale in presenza di un qualunque possibile nuovo meccanismo di violazione di CP; la sua verifica sperimentale costituisce percio' un test di rara utilità per mettere in evidenza l’eventuale presenza di nuova fisica. Questo lavoro di tesi e' finalizzato alla misura della asimmetria di CP nel decadimento del B0s->K-pi+ utilizzando un campione di circa 3 fb-1 raccolto dall’esperimento CDF tra febbraio 2002 e aprile 2008; questa misura richiede tuttavia una analisi complessiva di tutti decadimenti adronici di mesoni B0 e B0s in coppie di K e \pi carichi ( B -> h+h'- ), e quindi costituisce la base per diverse altre misure di alto profilo. La misura si articola in tre passi principali: l'estrazione del segnale del B-> h+h- dal fondo, la separazione dei diversi canali (che appaiono sovrapposti in un unico picco di massa), mediante un fit che combina la cinematica con le informazioni sull'identità delle particelle nello stato finale, e le correzioni di efficienza per l'estrazione delle misure di asimmetria CP. Il punto centrale di questa nuova analisi, che ha costituito la parte maggiore del lavoro di tesi, e’ il miglioramento della risoluzione statistica rispetto alla misura precedente, al di la’ del semplice incremento del campione. Il fit di Likelihood sviluppato nella precedente analisi e’ stato esteso con l’aggiunta una nuova variabile discriminante, l’isolamento, al fine di migliorare la separazione segnale-fondo, passando da un fit 5-dimensionale ad uno 6-dimensionale. A questo fine e' stata svolta un’accurata analisi della fenomenologia dell’isolamento, per studiarne la distribuzione e le correlazioni con le altre variabili usate nella funzione di Likelihood e parametrizzarne la distribuzione. Una volta introdotto l’isolamento nella struttura di fit si e’ passati alla determinazione, nella nuova configurazione, della selezione ottimale del campione ai fini di ottenere la migliore possibile risoluzione statistica sulla misura di ACP(B0s->K-pi+). Il risultato e' stato un significativo miglioramento della risoluzione rispetto alla precedente versione di questa analisi. A parita’ di statistica, il miglioramento ottenuto e’ di circa il 15%, che corrisponde a una incertezza statistica su ACP(B0s->K-pi+) di circa il 9%, da confrontare con un valore centrale di 30%-50% predetto dalla teoria. Questo risultato rende quindi molto realistica la possibilita’ di osservare per la prima volta l’asimmetria CP diretta nel B0s in questo campione. In aggiunta, i miglioramenti ottenuti porteranno un beneficio sostanziale anche a tutte le altre misure accessibili con questa analisi: ACP(B0->Kpi) e i tassi di decadimento di B0s->Kpi, B0s->KK, e B0s->pipi , che forniranno ulteriori nuovi importanti dati sulla dinamica delle interazioni adroniche a bassa energia

Pathological and clinical features of multiple cancers and lung adenocarcinoma: a multicentre study

OBJECTIVES: Lung cancer is increasingly diagnosed as a second cancer. Our goal was to analyse the characteristics and outcomes of early-stage resected lung adenocarcinomas in patients with previous cancers (PC) and correlations with adenocarcinoma subtypes.METHODS: We retrospectively reviewed data of patients radically operated on for stage I-II lung adenocarcinoma in 9 thoracic surgery departments between 2014 and 2017. Overall survival (OS) and time to disease relapse were evaluated between subgroups.RESULTS: We included 700 consecutive patients. PC were present in 260 (37.1%). Breast adenocarcinoma, lung cancer and prostate cancer were the most frequent (21.5%, 11.5% and 11.2%, respectively). No significant differences in OS were observed between the PC and non-PC groups (P = 0.378), with 31 and 75 deaths, respectively. Patients with PC had smaller tumours and were more likely to receive sublobar resection and to be operated on with a minimally invasive approach. Previous gastric cancer (P = 0.042) and synchronous PC (when diagnosed up to 6 months before lung adenocarcinoma; P = 0.044) were related, with a worse OS. Colon and breast adenocarcinomas and melanomas were significantly related to a lower incidence of high grade (solid or micropapillary, P = 0.0039, P = 0.005 and P = 0.028 respectively), whereas patients affected by a previous lymphoma had a higher incidence of a micropapillary pattern (P = 0.008).CONCLUSIONS: In patients with PC, we found smaller tumours more frequently treated with minimally invasive techniques and sublobar resection, probably due to a more careful follow-up. The impact on survival is not uniform and predictable; however, breast and colon cancers and melanoma showed a lower incidence of solid or micropapillary patterns whereas patients with lymphomas had a higher incidence of a micropapillary pattern

Impact of High‑Grade Patterns in Early‑Stage Lung Adenocarcinoma: A Multicentric Analysis

Objective The presence of micropapillary and solid adenocarcinoma patterns leads to a worse survival and a signifcantly higher tendency to recur. This study aims to assess the impact of pT descriptor combined with the presence of high-grade components on long-term outcomes in early-stage lung adenocarcinomas. Methods We retrospectively collected data of consecutive resected pT1-T3N0 lung adenocarcinoma from nine European Thoracic Centers. All patients who underwent a radical resection with lymph-node dissection between 2014 and 2017 were included. Diferences in Overall Survival (OS) and Disease-Free Survival (DFS) and possible prognostic factors associated with outcomes were evaluated also after performing a propensity score matching to compare tumors containing non-highgrade and high-grade patterns. Results Among 607 patients, the majority were male and received a lobectomy. At least one high-grade histological pattern was seen in 230 cases (37.9%), of which 169 solid and 75 micropapillary. T1a-b-c without high-grade pattern had a signifcant better prognosis compared to T1a-b-c with high-grade pattern (p=0.020), but the latter had similar OS compared to T2a (p=0.277). Concurrently, T1a-b-c without micropapillary or solid patterns had a signifcantly better DFS compared to those with high-grade patterns (p=0.034), and it was similar to T2a (p=0.839). Multivariable analysis confrms the role of T descriptor according to high-grade pattern both for OS (p=0.024; HR 1.285 95% CI 1.033–1.599) and DFS (p=0.003; HR 1.196, 95% CI 1.054–1.344, respectively). These results were confrmed after the propensity score matching analysis. Conclusions pT1 lung adenocarcinomas with a high-grade component have similar prognosis of pT2a tumors

Observation of Exclusive Gamma Gamma Production in p pbar Collisions at sqrt{s}=1.96 TeV

We have observed exclusive \gamma\gamma production in proton-antiproton collisions at \sqrt{s}=1.96 TeV, using data from 1.11 \pm 0.07 fb^{-1} integrated luminosity taken by the Run II Collider Detector at Fermilab. We selected events with two electromagnetic showers, each with transverse energy E_T > 2.5 GeV and pseudorapidity |\eta| < 1.0, with no other particles detected in -7.4 < \eta < +7.4. The two showers have similar E_T and azimuthal angle separation \Delta\phi \sim \pi; 34 events have two charged particle tracks, consistent with the QED process p \bar{p} to p + e^+e^- + \bar{p} by two-photon exchange, while 43 events have no charged tracks. The number of these events that are exclusive \pi^0\pi^0 is consistent with zero and is < 15 at 95% C.L. The cross section for p\bar{p} to p+\gamma\gamma+\bar{p} with |\eta(\gamma)| < 1.0 and E_T(\gamma) > 2.5$ GeV is 2.48^{+0.40}_{-0.35}(stat)^{+0.40}_{-0.51}(syst) pb.Comment: 7 pages, 4 figure

Estimated GFR reporting is not sufficient to allow detection of chronic kidney disease in an Italian regional hospital

<p>Abstract</p> <p>Background</p> <p>Chronic kidney disease (CKD) is an emerging worldwide problem. The lack of attention paid to kidney disease is well known and has been described in previous publications. However, little is known about the magnitude of the problem in highly specialized hospitals where serum creatinine values are used to estimate GFR values.</p> <p>Methods</p> <p>We performed a cross-sectional evaluation of hospitalized adult patients who were admitted to the medical or surgical department of Santa Maria della Misericordia Hospital in 2007. Information regarding admissions was derived from a database. Our goal was to assess the prevalence of CKD (defined as an estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m²) and detection of CKD using diagnostic codes (Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM]). To reduce the impact of acute renal failure on the study, the last eGFR obtained during hospitalization was the value used for analysis, and intensive care and nephrology unit admissions were excluded. We also excluded patients who had ICD-9-CM codes for renal replacement therapy, acute renal failure, and contrast administration listed as discharge diagnoses.</p> <p>Results</p> <p>Of the 18,412 patients included in the study, 4,748 (25.8%) had reduced eGFRs, falling into the category of Kidney Disease Outcomes Quality Initiative (KDOQI) stage 3 (or higher) CKD. However, the diagnosis of CKD was only reported in 19% of these patients (904/4,748). It is therefore evident that there was a "gray area" corresponding to stage 3 CKD (eGFR 30-59 ml/min), in which most CKD diagnoses are missed. The ICD-9 code sensitivity for detecting CKD was significantly higher in patients with diabetes, hypertension, and cardiovascular disease (26.8%, 22.2%, and 23.7%, respectively) than in subjects without diabetes, hypertension, or cardiovascular disease (p < 0.001), but these values are low when the widely described relationship between such comorbidities and CKD is considered.</p> <p>Conclusion</p> <p>Although CKD was common in this patient population at a large inpatient regional hospital, the low rates of CKD detection emphasize the primary role nephrologists must play in continued medical education, and the need for ongoing efforts to train physicians (particularly primary care providers) regarding eGFR interpretation and systematic screening for CKD in high-risk patients (i.e., the elderly, diabetics, hypertensives, and patients with CV disease).</p

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p &lt; .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p &lt; .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

A study of CP violation in B-+/- -&gt; DK +/- and B-+/- -&gt; D pi(+/-) decays with D -&gt; (KSK +/-)-K-0 pi(-/+) final states

A first study of CP violation in the decay modes $B^\pm\to [K^0_{\rm S} K^\pm \pi^\mp]_D h^\pm$ and $B^\pm\to [K^0_{\rm S} K^\mp \pi^\pm]_D h^\pm$, where $h$ labels a $K$ or $\pi$ meson and $D$ labels a $D^0$ or $\overline{D}^0$ meson, is performed. The analysis uses the LHCb data set collected in $pp$ collisions, corresponding to an integrated luminosity of 3 fb$^{-1}$. The analysis is sensitive to the CP-violating CKM phase $\gamma$ through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of $\gamma$ using other decay modes