121 research outputs found
The Mu2e experiment at Fermilab
The Mu2e experiment searches for the neutrino-less muon to electron
conversion in the field of a nucleus, which is a charged lepton flavor
violating process. The goal of the experiment is to reach a single event
sensitivity of 2.8 x 10^{-17}, setting an upper limit on the muon conversion
rate at 6.7 x 10^{-17}. This corresponds to a four order of magnitude
improvement with respect to the existing limits.Comment: Submitted to Nuovo Ciment
The Mu2e experiment at Fermilab
The Mu2e experiment searches for the neutrinoless muon to electron conversion in the field of a nucleus, which is a charged lepton flavor violating process. The goal of the experiment is to reach a single event sensitivity of 2.8×10−17, setting an upper limit on the muon conversion rate of 6.7×10−17. This corresponds to a four order of magnitude improvement with respect to the existing limits
The Mu2e experiment at Fermilab: Design and status
The Mu2e experiment at Fermilab will search for coherent, neutrinoless conversion of negative muons into electrons in the field of an aluminum nucleus. The dynamics of such charged lepton flavour violating (CLFV) process is a twobody decay, resulting in a mono-energetic electron with an energy slightly below the muon rest mass. If no events are observed in three years of running, Mu2e will set an upper limit on the ratio between the conversion and the capture rates Rμe of ≤ 6 × 10−17 (@90% C.L.). This will improve the current limit of four order of magnitudes with respect to the previous best experiment. Mu2e complements
and extends the current search for μ → eγ decay at MEG as well as the direct searches for new physics at the LHC. Indeed, such a CLFV process probes new physics at a scale inaccessible to direct searches at either present or planned high energy colliders. Observation of a signal will be a clear evidence for new physics beyond the Standard Model. To search for the muon conversion process, a very intense pulsed beam of negative muons (∼ 1010 μ/s) is stopped on an aluminum target inside a very long solenoid where the detector is also located. The Mu2e
detector is composed of a straw tube tracker and an electromagnetic calorimeter consisting of arrays of CsI crystals. An external veto for cosmic rays is surrounding
the detector solenoid. In 2016, Mu2e has passed the final approval stage from DOE and has started its construction phase. Data collection is planned for the end of 2021. An overview of the physics motivations for Mu2e, the current status of the experiment and design of the muon beam-line and the detector is presented
Pre-Production and Quality Assurance of the Mu2e Calorimeter Silicon Photomultipliers
The Mu2e electromagnetic calorimeter has to provide precise information on
energy, time and position for 100 MeV electrons. It is composed of 1348
un-doped CsI crystals, each coupled to two large area Silicon Photomultipliers
(SiPMs). A modular and custom SiPM layout consisting of a 32 array of
66 mm UV-extended monolithic SiPMs has been developed to fulfill
the Mu2e calorimeter requirements and a pre-production of 150 prototypes has
been procured by three international firms (Hamamatsu, SensL and Advansid). A
detailed quality assurance process has been carried out on this first batch of
photosensors: the breakdown voltage, the gain, the quenching time, the dark
current and the Photon Detection Efficiency (PDE) have been determined for each
monolithic cell of each SiPMs array. One sample for each vendor has been
exposed to a neutron fluency up to 8.5~~10 1 MeV (Si) eq.
n/cm and a linear increase of the dark current up to tens of mA has been
observed. Others 5 samples for each vendor have undergone an accelerated aging
in order to verify a Mean Time To Failure (MTTF) higher than 10
hours.Comment: NDIP 2017 - New Developments In Photodetection, 3-7 July 2017, Tours
(France
Cross-sectional relationship among different anthropometric parameters and cardiometabolic risk factors in a cohort of patients with overweight or obesity
Background Body fat distribution influences the risk of cardio-metabolic disease in people with overweight. This study was aimed at identifying the anthropometric parameters more strongly associated with the majority of cardio-metabolic risk factors. Methods This study included 1214 subjects (840 women), with a body-mass-index (BMI) = 25 Kg/ m2, aged 39.2 ± 13 years. Fasting blood glucose (FBG), triglycerides (TG), total, HDL- and LDL-cholesterol, uric acid, vitamin D, high-sensitive C-reactive protein (hs-CRP), white blood cells (WBC), platelets, insulin and insulin resistance (HOMA-IR), systolic (SBP) and diastolic blood pressure (DBP), smoking habit and snoring were evaluated as cardio-metabolic risk factors.We also included the Systematic COronary Risk Evaluation (SCORE) to estimate cardiovascular risk in our study population. BMI, waist circumference (WC), waistto- height-ratio (WHtR) and neck circumference (NC) were evaluated as anthropometric parameters. Results All four anthropometric parameters were positively associated to SBP, DBP, TG, FBG, insulin, HOMA-IR, WBC, and snoring (p<0.001), and negatively associated with HDL-cholesterol (p<0.001). NC showed a positive association with LDL-cholesterol (ß = 0.76; p = 0.01; 95% C.I. 0.19 to 1.32), while vitamin D was negatively associated to WC (ß = -0.16; p<0.001; 95% C.I. -0.24 to -0.09), BMI (ß = 0.42); p<0.001; 95% C.I. -0.56 to -0.28) and WHtR (ß = -24.46; p<0.001; 95% C.I. -37 to -11.9). Hs-CRP was positively correlated with WC (ß = 0.003; p = 0.003; 95% C.I. 0.001 to 0.006), BMI (ß = 0.01; p = 0.02; 95% C.I. 0.001 to 0.012) and WHtR (ß = 0.55; p = 0.01; 95% C.I. 0.14 to 0.96). SCORE was associated to NC (ß = 0.15; 95% CI 0.12 to 0.18; p<0.001), BMI (ß = -0.18; 95% CI -0.22 to 0.14; p<0.001) and WHtR (ß = 7.56; 95% CI 5.30 to 9.82; p<0.001). Conclusions NC, combined with BMI and WC or WHtR could represent an essential tool for use in clinical practice to define the cardio-metabolic risk in individuals with excess body weight
Traditional old dietary pattern of castellana grotte (Apulia) is associated with healthy outcomes
Background: There is still room for further studies aimed at investigating the most widespread diets in the Mediterranean area. The objective of the study is to analyze the relation of food group intake to clinical chemical indicators of health, and also to compare the food group intake with healthy well-known diet indices. Methods: Lifestyle, dietary, and clinical data collected in 2005/2006 and 2012/2018 from Castellana Grotte, located in the rural area of Apulia, were analyzed. The study populations included newly recruited subjects at each time period (n = 1870) as well as subjects examined twice and compared over time regarding health indicators (n = 734). Diet was assessed through a validated food frequency questionnaire. Three healthy diet indices were calculated and related to 29 food groups. We also performed prospective regression of food group consumption with health indicators. Results: The diet over the time period of observation was very stable and consisted of a high proportion of vegetables, fruit and grains. No major changes in body mass index (BMI) and blood pressure were observed. Consumption of low-fat dairy, juices, olive oil, and water were related to reductions in weight gain, systolic blood pressure, high-density lipoprotein (HDL)-cholesterol and cholesterol (total and HDL) levels, in that order. Over the time periods we observed only a slight decrease of adherence to the Meddietscore. The correlations of the healthy diet indices with food groups revealed some differences among the indices, mostly regarding the intake of fruit and vegetables. Conclusions: The dietary pattern of Apulia is in line with many principles of a healthy diet and the cohort population seems to be less liable to undergo a transition to a westernized diet
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