The NA60 experiment at the CERN SPS has studied low-mass dimuon production in 158A GeV In-In collisions. An excess of pairs above the known meson decays has been reported before. We now present ...precision results on the associated transverse momentum spectra. The slope parameter Teff extracted from the spectra rises with dimuon mass up to the rho, followed by a sudden decline above. While the initial rise is consistent with the expectations for radial flow of a hadronic decay source, the decline signals a transition to an emission source with much smaller flow. This may well represent the first direct evidence for thermal radiation of partonic origin in nuclear collisions.
Plants of miscanthus were grown in a Cd-free solution up to 1 month before heading and then were exposed to 0, 0.75, 1.5, 2.25 and 3
mg
l
−1 cadmium for 36 days. All cadmium levels were toxic to ...miscanthus. Growth response was not dose-dependent and two toxicity thresholds were identified: one between 0 and 0.75
mg
l
−1 Cd, the other between 2.25 and 3
mg
l
−1 Cd. The former caused a biomass decrease by about 50%, whereas the latter completely inhibited growth and disrupted the mechanisms that restricted Cd translocation to the shoot. Growth of the aerial part was affected by cadmium more than that of the hypogeal one. Cadmium did not change the N concentration of different plant parts, but markedly reduced the N uptake of the plant, the N net uptake rate (NUR) and the N net translocation rate (NTR) from the rhizome to the aerial part. These two indexes equalled zero when plants ceased to grow. Otherwise, the Cd-NUR increased with Cd supply and the Cd-NTR from rhizome to aerial part showed the highest increment when plants did not grow at all. This suggests different uptake pathways for the two elements, active for nitrogen and passive for cadmium. The Cd concentration and the Cd content markedly increased with all Cd levels, following the order roots
≫
rhizome
>
culms
>
leaves. The Cd concentration and the Cd content of aerial organs increased with Cd supply, but increments were highest between 2.25 and 3
mg
l
−1 Cd. The highest Cd concentrations were recorded in plants grown with 3
mg
l
−1 Cd and were 41 and 122
mg
kg
−1, respectively, for the aerial and the hypogeal plant parts. The hypogeal plant part retained most of the cadmium taken up from solution, accounting for approximately 87% of total plant cadmium with the three lower Cd levels, and for 73% with the highest one. The maximum Cd content of the entire plant was achieved with the two higher Cd levels and was approximately 4.7
mg, while the Cd content of the aerial part was highest with 3
mg
l
−1 Cd (1.2
mg Cd per plant) and that of the hypogeal one with 2.25
mg
l
−1 Cd (4
mg Cd per plant). The highest aerial content achieved in this experiment was 10-fold that obtained in a previous research when small-sized plants were exposed to the same Cd level.
The NA60 experiment studies muon pair production at the CERN Super Proton Synchrotron. In this Letter we report on a precision measurement of J/psi in In-In collisions. We have studied the J/psi ...centrality distribution, and we have compared it with the one expected if absorption in cold nuclear matter were the only active suppression mechanism. For collisions involving more than approximately 80 participant nucleons, we find that an extra suppression is present. This result is in qualitative agreement with previous Pb-Pb measurements by the NA50 experiment, but no theoretical explanation is presently able to coherently describe both results.
The perennial C
4 grass
Miscanthus has been proposed as a biomass energy crop in Europe. Effects of crop age, irrigation and nitrogen fertilization on biomass and energy yields and N content of
...Miscanthus were investigated and the energy costs of production determined. After an establishment period of 1 year, cultivation of
Miscanthus resulted in a dry matter production of over 37
t
ha
−1
year
−1 over a period of 4 years. Irrigation and nitrogen level greatly affected
Miscanthus biomass yield. In absence of N fertilization, irrigation did not modify biomass yield and the effect of irrigation increased with the increase in N level. The average N response ranged from 37 to 50
kg biomass kg
−1 N applied. Because the calorific value of
Miscanthus biomass (16.5
MJ
kg
−1) was not affected by irrigation and N fertilization, energy production depended exclusively on biomass yield. Maximum energy yield was 564
GJ
ha
−1
year
−1. Without N supply and irrigation, energy yield was 291
GJ
h
−1. Net energy yield, calculated as the difference between energy output and input, but without inclusion of drying costs, was 543
GJ
ha
−1 with N fertilization and irrigation and 284
GJ
ha
−1 without; the ratios of energy output to input in crop production were 22 and 47, respectively.
We report a new measurement of J/ψ, ψ′ and Drell–Yan cross-sections, in the kinematical domain -0.425<ycm<0.575 and -0.5<cosθCS<0.5, performed at the CERN-SPS using 400 GeV/c incident protons on Be, ...Al, Cu, Ag, W and Pb targets. The dependence of the charmonia production cross-sections on the size of the target nucleus allows to quantify the so-called normal nuclear absorption. In the framework of the Glauber model, this new measurement is combined with results previously obtained with the same apparatus, under different experimental conditions, and leads to a precise determination of the J/ψ and ψ′ absorption cross-sections in the surrounding nuclear matter.
The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 AGeV In-In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. After ...subtraction of the decay sources, the shape of the resulting mass spectrum is largely consistent with a dominant contribution from
π
+
π
−
→
ρ
→
μ
+
μ
−
annihilation. The associated
ρ spectral function exhibits considerable broadening, but essentially no shift in mass. The acceptance-corrected
p
T
spectra have a shape atypical for radial flow. They also significantly depend on mass, pointing to different sources in different mass regions. Both mass and
p
T
spectra are compared to recent theoretical predictions.
ψ′ production is studied in Pb–Pb collisions at 158 GeV/c per nucleon incident momentum. Absolute cross-sections are measured and production rates are investigated as a function of the centrality of ...the collision. The results are compared with those obtained for lighter colliding systems and also for the J/ψ meson produced under identical conditions.
Durum wheat (Triticum turgidum L. var. durum Desf.) is commonly grown in Mediterranean conditions, where temperature stress during grain filling can limit productivity. This research was performed to ...evaluate the effect of temperature during grain filling on dry matter and nitrogen dynamics in two Italian durum wheat varieties, Appio and Creso, grown with different nitrogen availabilities. The experiment compared two different temperature regimens, one within the normal range occurring during grain filling in Central Italy, the other within the normal range occurring in the southern regions of Italy (20/15 °C and 28/23 °C day/night, respectively). Plants were grown in pots outdoor until anthesis and afterward were placed in growth chambers. Results showed that nitrogen fertilization and post-anthesis temperature affected growth, accumulation and partitioning of dry matter and N in durum wheat which, in turn, modified grain yield and N content. Grain yield was better expressed at 20/15 °C, while grain protein concentration was favoured under the 28/23 °C temperature regime. Higher temperature promoted remobilization of dry matter and restrained current photosynthesis, but reduced grain yield, indicating that the loss of photosynthesis could not compensate for the gain from increased remobilization. Grain N content, on the contrary, was promoted under the higher temperature regime, as high temperature reduced N remobilization but did not inhibit root water and nitrogen uptake, given that no water shortage occur.
Review of Particle Physics Tanabashi, M.; Nakamura, K.; Tanaka, J. ...
Physical review. D,
08/2018, Volume:
98, Issue:
3
Journal Article
Peer reviewed
Open access
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 2,873 new measurements from 758 papers, we list, evaluate, and average measured properties of ...gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. Particle properties and search limits are listed in Summary Tables. We give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders, Probability and Statistics. Among the 118 reviews are many that are new or heavily revised, including a new review on Neutrinos in Cosmology.
Shifts in sowing date change the combination of temperature and photoperiod to which durum wheat is exposed, affecting crop phenology and grain yield. Three durum wheat (Triticum turgidum L. var. ...durum) varieties were field sown at month intervals over a whole year. The number of spikelets on the main culm and the duration of the period of spikelet initiation were recorded. Grain yield, spike number, and mean kernel weight were determined, too. With all sowing dates, plants formed a spike within the main culm and reached the stage of first node detectable. Physiological maturity was achieved only for sowings performed between October and May. Grain yield was highest in November and both yield and yield components were strongly affected by sowing date. The number of spikelets ranged from 11 to 24, according to sowing date and variety. It decreased from November to May in consequence of the shorter initiation period, and we hypothesize that a 12-h-daylength or longer interrupts spikelet initiation. The decrease of spikelet number was the main determinant of yield reduction with the delay of sowing from November to March.
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