NA60 results on thermal dimuons Arnaldi, R.; Banicz, K.; Borer, K. ...
European physical journal. C, Particles and fields,
06/2009, Letnik:
61, Številka:
4
Journal Article, Conference Proceeding
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The NA60 experiment at the CERN SPS has measured muon pairs with unprecedented precision in 158
A
GeV In–In collisions. A strong excess of pairs above the known sources is observed in the whole ...mass region 0.2<
M
<2.6 GeV. The mass spectrum for
M
<1 GeV is consistent with a dominant contribution from
π
+
π
−
→
ρ
→
μ
+
μ
−
annihilation. The associated
ρ
spectral function shows a strong broadening, but essentially no shift in mass. For
M
>1 GeV, the excess is found to be prompt, not due to enhanced charm production, with pronounced differences to Drell–Yan pairs. The slope parameter
T
eff
associated with the transverse momentum spectra rises with mass up to the
ρ
, followed by a sudden decline above. The rise for
M
<1 GeV is consistent with radial flow of a hadronic emission source. The seeming absence of significant flow for
M
>1 GeV and its relation to parton–hadron duality is discussed in detail, suggesting a dominantly partonic emission source in this region. A comparison of the data to the present status of theoretical modeling is also contained. The accumulated empirical evidence, including also a Planck-like shape of the mass spectra at low
p
T
and the lack of polarization, is consistent with a global interpretation of the excess dimuons as thermal radiation. We conclude with first results on
ω
in-medium effects.
The aim of this study is to evaluate the performances in the early stages of biogas production of various unconventional and low inputs crops, such as: kenaf (Hibiscus cannabinus L.), amaranthus ...(Amarathus cruentus L.), sorghum (Sorghum bicolor L.), and sunflower (Helianthus annuus L.). Moreover, according to a circular economy approach, that foreseen the re-use of all the materials, a wide range of agro-industrial residues were tested such as: pomace, olive oil cake, cow milk whey, ewe milk whey, beer residues, jatropha (Jatropha curcas L.) oil cake and pelargonium (Pelargonium graveolens L.) residues after essential oil extraction. The biogas production was estimated starting from the chemical composition of the substrates as well as through tests in bench’s static reactors. The results showed that the use of silage from crops with reduced agronomic requests (kenaf and amaranthus) versus a conventional crop (corn) led to comparable, or even better, biogas production performances during the initial stages. Moreover, the performance of some residues from the milk industry allowed to conclude that the ewe milk whey can be considered a booster feedstock for the first phase of digestion. All the tested substrates produced a digestate suitable, according to the Italian rules, for soil fertilization or amendment.
We present a new measurement of $J/\psi$ production in Pb-Pb collisions at 158 GeV/nucleon, from the data sample collected in year 2000 by the NA50 Collaboration, under improved experimental ...conditions with respect to previous years. With the target system placed in vacuum, the setup was better adapted to study, in particular, the most peripheral nuclear collisions with unprecedented accuracy. The analysis of this data sample shows that the ($J/\psi$)/Drell-Yan cross-sections ratio measured in the most peripheral Pb-Pb interactions is in good agreement with the nuclear absorption pattern extrapolated from the studies of proton-nucleus collisions. Furthermore, this new measurement confirms our previous observation that the ($J/\psi$)/Drell-Yan cross-sections ratio departs from the normal nuclear absorption pattern for semi-central Pb-Pb collisions and that this ratio persistently decreases up to the most central collisions.
Intercropping (IC) cereals and legumes could be an option for obtaining forage suitable for ensiling and enabling reduced N fertilization. Two experiments were performed in central Italy with durum ...wheat (Triticum durum Desf.) and field bean (Vicia faba L. var. minor) grown for forage production in IC and as sole crops (SC) with different N rates (20 and 50 kg ha−1) and row ratios (1:1 and 2:1 cereal/legume). The aims were to assess (i) whether IC is a feasible option to reduce N fertilization; (ii) the best combination of practices to obtain forage suitable for ensiling; and (iii) competition/facilitation effects exerted by field bean on durum wheat. Results showed IC allowed fertilizer‐N reduction and led to improved forage yield with better quality, compared with SC. Land equivalent ratio indicated a high efficiency of the IC, by up to 26% with respect to SC. Field bean was the dominant species of IC, but N fertilization reduced its competitive ability and enhanced that of wheat. In the intercrop fertilized with 50 kg N ha−1, the proportion of the wheat in the herbage (0·34–0·41 of the total dry matter) was sufficient for ensiling of the forage mass. Field bean exerted both competition and facilitation effects on the cereal. N uptake of durum wheat was greater under IC with beans than as wheat SC.
To determine the risk of climate change for agriculture it is necessary to define a set of agrometeorological parameters, derived from the classic climate parameters, that are capable of indicating ...the consequences of climate change for crop production. In this study high-quality daily rainfall, evaporation and mean, minimum and maximum temperature data collected since 1878 at the meteorological station of the Department of Agronomy and Agroecosystem Management of the University of Pisa, Italy (
H=6
m a.s.l.; latitude=43°41′N; longitude=10°23′E) were used to calculate extreme temperature and rainfall events, frost risk, flooding risk and drought risk. Time trends for all variables were analysed using linear regression techniques.
Results indicate that the changes in extreme events in Pisa have not changed in a way that is likely to negatively affect crop production. The risk of crop damage due to frost has decreased and sowing time in spring can safely be anticipated. The soil moisture surplus (SMS) and theoretical irrigation requirement (TIR) have not changed despite a decreasing rainfall trend. The number of soil moisture surplus days in autumn has decreased indicating a decrease in flooding risk, which can have a positive effect on soil workability.
Plants of miscanthus were grown in nutrient solution supplied with 0, 0.25, 0.50, and 0.75
mg
l
−1 cadmium and were harvested after 1 and 3 months of treatment. With cadmium up to 0.50
mg
l
−1 ...biomass of secondary culms and roots was increased at both harvests, whereas biomass of the main culm and the rhizome was slightly increased at the first harvest and decreased at the second. With 0.75
mg
l
−1 Cd biomass of all plant parts except roots was decreased at both harvests. The biomass of the entire plant was always higher than in controls with 0.25 and 0.50
mg
l
−1 Cd and lower with 0.75
mg
l
−1 Cd. Relative growth rates (RGRs) showed that the two lower Cd levels stimulated growth only during the first growth period, whereas during the second they reduced growth of the main culm and the rhizome and did not affect that of secondary culms and roots. Root morphology changed with 0.75
mg
l
−1 Cd: length, surface, and volume drastically decreased, whereas dry weight was not affected and root average diameter increased. All Cd levels decreased specific dry weight increment (SDWI) but did not affect the (net uptake rates) NUR of nitrogen and the N-concentration of different plant parts. Roots showed the highest Cd-concentrations at both harvests and with all Cd levels, and leaves the lowest. The Cd-concentration of aerial plant parts was highest with 0.50
mg
l
−1 Cd and lowest with 0.75
mg
l
−1, whereas that of roots increased with Cd supply. Between the first and the second harvest the Cd-concentration of roots, rhizome, and main culm increased only with the highest Cd-level, whereas that of leaves and secondary culms with all levels. The Cd-NUR was linearly related to the concentration of the metal in the nutrient solution during the first month of application and was very low during the following two. Above summarized patterns suggest that cadmium flows passively into roots but the saturation of binding sites limits its uptake. The metal is slowly translocated to the shoot due to mechanisms that restrict internal Cd-transport. This regulation is partially disrupted with 0.75
mg
l
−1 Cd but translocation to aerial organs is still restricted probably due to reduced transpiration. In this research, the maximum Cd-content achieved by miscanthus was 3.8
mg per plant after a 3-month treatment with 0.75
mg
l
−1 Cd, but the maximum content of the shoot was 1
mg per plant and was obtained with 0.50
mg
l
−1 Cd.
The NA60 experiment has studied low-mass muon pair production in proton–nucleus collisions with a system of Be, Cu, In, W, Pb and U targets, using a 400 GeV proton beam at the CERN SPS. The ...transverse momentum spectra of the
ρ
/
ω
and
ϕ
mesons are measured in the full
p
T
range accessible, from
p
T
=
0
up to
2
GeV/c
. The nuclear dependence of the production cross sections of the
η
,
ω
and
ϕ
mesons has been found to be consistent with the power law
σ
pA
∝
A
α
, with the
α
parameter increasing as a function of
p
T
for all the particles, and an approximate hierarchy
α
η
≈
α
ϕ
>
α
ω
. The cross section ratios
σ
η
/
σ
ω
,
σ
ρ
/
σ
ω
and
σ
ϕ
/
σ
ω
have been studied as a function of the size A of the production target, and an increase of the
η
and
ϕ
yields relative to the
ω
is observed from p–Be to p–U collisions.
The NA60 experiment has studied J/ψ production in p–A collisions at 158 and 400 GeV, at the CERN SPS. Nuclear effects on the J/ψ yield have been estimated from the A-dependence of the production ...cross section ratios σJ/ψA/σJ/ψBe (A=Al, Cu, In, W, Pb, U). We observe a significant nuclear suppression of the J/ψ yield per nucleon–nucleon collision, with a larger effect at lower incident energy, and we compare this result with previous observations by other fixed-target experiments. An attempt to disentangle the different contributions to the observed suppression has been carried out by studying the dependence of nuclear effects on x2, the fraction of the nucleon momentum carried by the interacting parton in the target nucleus.
The aim of this study was to analyze the association between the presence of actinic lesions (solar keratosis and non-melanoma skin cancer) and osteoporotic hip fractures in older patients. Both ...pathologies are common conditions in this age group. Since cumulative sun exposure is difficult to quantify, the presence of actinic lesions can be used to indirectly analyze the association between ultraviolet radiation and osteoporotic hip fractures. This was an observational case–control study. We reviewed the centralized medical records of patients with hip fracture (cases,
n
= 51) and patients with other diseases hospitalized in the same institution and period (controls,
n
= 59). The mean age of the patients was 80 ± 8.3 years (range 50–103 years). Differences in maternal hip fracture history were found between cases and controls (14.8 and 8 %, respectively;
p
= 0.047). Falls history in the past year was higher in cases than in controls (
p
< 0.0001). Actinic lesions were observed in 32.7 % of patients (prevalence rate 23.5 % in cases, 40.7 % in controls;
p
= 0.04). When considering patients with actinic lesions, controls have a higher FRAX score compared with cases. Although sun exposure is recommended for bone health, it represents a risk factor for actinic lesions. The presence of actinic lesions may indicate a lower osteoporotic hip fracture risk. A balance between adequate lifetime sun exposure and protection against its adverse effects is required for each patient, in the context of geographic location.
Objectives: The purpose of this research was to explore the performance of anthropometric tools in the assessment of low muscle mass in a group of postmenopausal women.
Method: Fifty consecutive ...ambulatory postmenopausal women were studied. A complete clinical examination and an anthropometric evaluation following a standardized procedure were performed. Three indicators were devised: upper limb adjusted perimeter (ULAP), lower limb adjusted perimeter (LLAP), and appendicular adjusted perimeter (AAP).
Results: Sixteen sarcopenic patients (32%) were identified using the DXA appendicular lean mass/h
2
threshold. ULAP and AAP correctly classified 82% of the patients, while LLAP showed a lower performance (72%). The sensitivity and specificity values of ULAP and AAP were higher than those obtained using LLAP; their positive and negative predictive values were 65.2%, 96.3% and 68.4%, 90.3%, respectively. A highly significant concordance was observed for the three anthropometric indicators.
Conclusion: The availability of reliable and simple clinical instruments to identify low muscle mass is of great relevance. Anthropometric methods reported in this paper could represent an innovative resource for muscle mass assessment in daily practice. The contribution of these approaches in the detection and management of sarcopenia should allow the physician to make early interventions and thus prevent or modify its relevant health consequences.
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