This paper describes the performance of a prototype timing detector, based on 50 micrometer thick Ultra Fast Silicon Detector, as measured in a beam test using a 180 GeV/c momentum pion beam. The ...dependence of the time precision on the pixel capacitance and the bias voltage is investigated here. A timing precision from 30 ps to 100 ps, depending on the pixel capacitance, has been measured at a bias voltage of 180 V. Timing precision has also been measured as a function of the bias voltage.
The TOTEM experiment at the LHC has performed the first measurement at
$\sqrt{s} = 13$ TeV of the $\rho$ parameter, the real to imaginary ratio of the
nuclear elastic scattering amplitude at $t=0$, ...obtaining the following results:
$\rho = 0.09 \pm 0.01$ and $\rho = 0.10 \pm 0.01$, depending on different
physics assumptions and mathematical modelling. The unprecedented precision of
the $\rho$ measurement, combined with the TOTEM total cross-section
measurements in an energy range larger than 10 TeV (from 2.76 to 13 TeV), has
implied the exclusion of all the models classified and published by COMPETE.
The $\rho$ results obtained by TOTEM are compatible with the predictions, from
alternative theoretical models both in the Regge-like framework and in the QCD
framework, of a colourless 3-gluon bound state exchange in the $t$-channel of
the proton-proton elastic scattering. On the contrary, if shown that the
3-gluon bound state $t$-channel exchange is not of importance for the
description of elastic scattering, the $\rho$ value determined by TOTEM would
represent a first evidence of a slowing down of the total cross-section growth
at higher energies. The very low-$|t|$ reach allowed also to determine the
absolute normalisation using the Coulomb amplitude for the first time at the
LHC and obtain a new total proton-proton cross-section measurement
$\sigma_{tot} = 110.3 \pm 3.5$ mb, completely independent from the previous
TOTEM determination. Combining the two TOTEM results yields $\sigma_{tot} =
110.5 \pm 2.4$ mb.
The TOTEM collaboration has measured the proton-proton total cross section at
$\sqrt{s}=13$ TeV with a luminosity-independent method. Using dedicated
$\beta^{*}=90$ m beam optics, the Roman Pots were ...inserted very close to the
beam. The inelastic scattering rate has been measured by the T1 and T2
telescopes during the same LHC fill. After applying the optical theorem the
total proton-proton cross section is $\sigma_{\rm tot}=(110.6 \pm 3.4$) mb,
well in agreement with the extrapolation from lower energies. This method also
allows one to derive the luminosity-independent elastic and inelastic cross
sections: $\sigma_{\rm el} = (31.0 \pm 1.7)$ mb and $\sigma_{\rm inel} = (79.5
\pm 1.8)$ mb.
The TOTEM collaboration at the CERN LHC has measured the differential cross-section of elastic proton-proton scattering at \(\sqrt{s} = 8\ {\rm TeV}\) in the squared four-momentum transfer range ...\(0.2\ {\rm GeV^{2}} < |t| < 1.9\ {\rm GeV^{2}}\). This interval includes the structure with a diffractive minimum ("dip") and a secondary maximum ("bump") that has also been observed at all other LHC energies, where measurements were made. A detailed characterisation of this structure for \(\sqrt{s} = 8\ {\rm TeV}\) yields the positions, \(|t|_{\rm dip} = (0.521 \pm 0.007)\ {\rm GeV^2}\) and \(|t|_{\rm bump} = (0.695 \pm 0.026)\ {\rm GeV^2}\), as well as the cross-section values, \({{\rm d}\sigma/{\rm d} t}_{\rm dip} = (15.1 \pm 2.5)\ {\rm{\mu b/GeV^2}}\) and \({{\rm d}\sigma/{\rm d} t}_{\rm bump} = (29.7 \pm 1.8)\ {\rm{\mu b/GeV^2}}\), for the dip and the bump, respectively.
We describe an analysis comparing the \(p\bar{p}\) elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in \(pp\) collisions as measured by the ...TOTEM Collaboration at 2.76, 7, 8, and 13 TeV using a model-independent approach. The TOTEM cross sections extrapolated to a center-of-mass energy of \(\sqrt{s} =\) 1.96 TeV are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the \(pp\) cross section. The two data sets disagree at the 3.4\(\sigma\) level and thus provide evidence for the \(t\)-channel exchange of a colorless, \(C\)-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same \(C\)-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic scattering amplitude in \(pp\) scattering. The combined significance of these results is larger than 5\(\sigma\) and is interpreted as the first observation of the exchange of a colorless, \(C\)-odd gluonic compound.
The TOTEM experiment at the LHC has performed the first measurement at \(\sqrt{s} = 13\) TeV of the \(\rho\) parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at ...\(t=0\), obtaining the following results: \(\rho = 0.09 \pm 0.01\) and \(\rho = 0.10 \pm 0.01\), depending on different physics assumptions and mathematical modelling. The unprecedented precision of the \(\rho\) measurement, combined with the TOTEM total cross-section measurements in an energy range larger than 10 TeV (from 2.76 to 13 TeV), has implied the exclusion of all the models classified and published by COMPETE. The \(\rho\) results obtained by TOTEM are compatible with the predictions, from alternative theoretical models both in the Regge-like framework and in the QCD framework, of a colourless 3-gluon bound state exchange in the \(t\)-channel of the proton-proton elastic scattering. On the contrary, if shown that the 3-gluon bound state \(t\)-channel exchange is not of importance for the description of elastic scattering, the \(\rho\) value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-\(|t|\) reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton-proton cross-section measurement \(\sigma_{tot} = 110.3 \pm 3.5\) mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields \(\sigma_{tot} = 110.5 \pm 2.4\) mb.
The TOTEM collaboration has measured the proton-proton total cross section at \(\sqrt{s}=13\) TeV with a luminosity-independent method. Using dedicated \(\beta^{*}=90\) m beam optics, the Roman Pots ...were inserted very close to the beam. The inelastic scattering rate has been measured by the T1 and T2 telescopes during the same LHC fill. After applying the optical theorem the total proton-proton cross section is \(\sigma_{\rm tot}=(110.6 \pm 3.4\)) mb, well in agreement with the extrapolation from lower energies. This method also allows one to derive the luminosity-independent elastic and inelastic cross sections: \(\sigma_{\rm el} = (31.0 \pm 1.7)\) mb and \(\sigma_{\rm inel} = (79.5 \pm 1.8)\) mb.
Summary
Objectives The role of androgen decline in the sexual activity of adult males is controversial. To clarify whether sexual function would benefit from testosterone (T) treatment in men with ...partially or severely reduced serum T levels, we conducted a systematic review and meta‐analysis of placebo‐controlled studies published in the past 30 years. The aim of this study was to assess and compare the effects of T on the different domains of sexual life.
Data source A comprehensive search of all published randomized clinical trials was performed in MEDLINE, the Cochrane Library, EMBASE and Current Contents databases.
Review methods Guided by prespecified criteria, software‐assisted data ion and quality assessed by two independent reviewers, a total of 17 randomized placebo‐controlled trials were found to be eligible. For each domain of sexual function we calculated the standardized mean difference relative to T and reported the results of pooled estimates of T treatment using the random effect model of meta‐analysis. Heterogeneity, reproducibility and consistency of the findings across studies were explored using sensitivity and meta‐regression analysis.
Results Overall, 656 subjects were evaluated: 284 were randomized to T, 284 to placebo (P) and 88 treated in cross‐over. The median study length was 3 months (range 1–36 months). Our meta‐analysis showed that in men with an average T level at baseline below 12 nmol/l, T treatment moderately improved the number of nocturnal erections, sexual thoughts and motivation, number of successful intercourses, scores of erectile function and overall sexual satisfaction, whereas T had no effect on erectile function in eugonadal men compared to placebo. Heterogeneity was explored by grouping studies according to the characteristics of the study population. A cut‐off value of 10 nmol/l for the mean T of the study population failed to predict the effect of treatment, whereas the presence of risk factors for vasculogenic erectile dysfunction (ED), comorbidities and shorter evaluation periods were associated with greater treatment effects in the studies performed in hypogonadal, but not in eugonadal, men. Meta‐regression analysis showed that the effects of T on erectile function, but not libido, were inversely related to the mean baseline T concentration. The meta‐analysis of available studies indicates that T treatment might be useful for improving vasculogenic ED in selected subjects with low or low‐normal T levels. The evidence for a beneficial effect of T treatment on erectile function should be tempered with the caveats that the effect tends to decline over time, is progressively smaller with increasing baseline T levels, and long‐term safety data are not available. The present meta‐analysis highlights the need, and pitfalls, for large‐scale, long‐term, randomized controlled trials to formally investigate the efficacy of T replacement in symptomatic middle‐aged and elderly men with reduced T levels and ED.
Summary
Objectives Ageing in men is associated with a gradual decline in serum testosterone levels and a concomitant loss of muscle mass, accumulation of central adiposity, impaired mobility and ...increased risk of bone fractures. Whether androgen treatment might be beneficial in these subjects is still under debate. We have carried out a systematic review of randomized controlled trials (RCTs) evaluating the effects of testosterone (T) administration to middle‐aged and ageing men on body composition, muscle strength, bone density, markers of bone metabolism and serum lipid profile.
Data source A comprehensive search of all published randomized clinical trials was performed using the MEDLINE, Cochrane Library, EMBASE and Current Contents databases.
Review methods Guided by prespecified criteria, software‐assisted data ion and quality assessed by two independent reviewers, 29 RCTs were found to be eligible. For each investigated variable, we reported the results of pooled estimates of testosterone treatment using the random effect model of meta‐analysis. Heterogeneity, reproducibility and consistency of the findings across studies were explored using sensitivity and meta‐regression analysis.
Results Overall, 1083 subjects were evaluated, 625 randomized to T, 427 to placebo and 31 to observation (control group). Weighted mean age was 64·5 years (range 49·9–77·6) and mean serum testosterone was 10·9 nmol/l (range 7·8–19). Testosterone treatment produced: (i) a reduction of 1·6 kg (CI: 2·5–0·6) of total body fat, corresponding to −6·2% (CI: 9·2–3·3) variation of initial body fat, (ii) an increase in fat free mass of 1·6 kg (CI: 0·6–2·6), corresponding to +2·7% (CI: 1·1–4·4) increase over baseline and (iii) no change in body weight. The effects of T on muscle strength were heterogeneous, showing a tendency towards improvement only at the leg/knee extension and handgrip of the dominant arm (pooled effect size = 0·3 standard mean difference (SMD), CI: −0·0 to 0·6). Testosterone improved bone mineral density (BMD) at the lumbar spine by +3·7% (CI: 1·0–6·4%) compared to placebo, but not at the femoral neck, and produced a consistent reduction in bone resorption markers (pooled effect size = −0·6 SMD, CI: −1·0 to −0·2). Testosterone also reduced total cholesterol by 0·23 mmol/l (CI: −0·37 to −0·10), especially in men with lower baseline T concentrations, with no change in low density lipoprotein (LDL)‐cholesterol. A significant reduction of high density lipoprotein (HDL)‐cholesterol was found only in studies with higher mean T‐values at baseline (−0·085 mmol/l, CI: −0·017 to −0·003). Sensitivity and meta‐regression analysis revealed that the dose/type of T used, in particular the possibility of aromatization, explained the heterogeneity in findings observed on bone density and HDL‐cholesterol among studies.
Conclusion The present analysis provides an estimate of the average treatment effects of testosterone therapy in middle‐aged men. Our findings are sufficiently strong to justify further interventional studies focused on alternative targets of androgenic treatment carrying more stringent clinical implications, in particular the cardiovascular, metabolic and neurological systems.
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