QCD challenges from pp to A–A collisions Adolfsson, J.; Andronic, A.; Bierlich, C. ...
The European physical journal. A, Hadrons and nuclei,
2020, Letnik:
56, Številka:
11
Journal Article
Recenzirano
Odprti dostop
This paper is a write-up of the ideas that were presented, developed and discussed at the third International Workshop on QCD Challenges from pp to A–A, which took place in August 2019 in Lund, ...Sweden (Workshop link:
https://indico.lucas.lu.se/event/1214/
). The goal of the workshop was to focus on some of the open questions in the field and try to come up with concrete suggestions for how to make progress on both the experimental and theoretical sides. The paper gives a brief introduction to each topic and then summarizes the primary results.
Aims To examine incidence and trends of Type 1 diabetes worldwide for the period 1990–1999.
Methods The incidence of Type 1 diabetes (per 100 000/year) was analysed in children aged ≤ 14 years from ...114 populations in 112 centres in 57 countries. Trends in the incidence of Type 1 diabetes were analysed by fitting Poisson regression models to the dataset.
Results A total of 43 013 cases were diagnosed in the study populations of 84 million children. The age‐adjusted incidence of Type 1 diabetes among 112 centres (114 populations) varied from 0.1 per 100 000/year in China and Venezuela to 40.9 per 100 000/year in Finland. The average annual increase in incidence calculated from 103 centres was 2.8% (95% CI 2.4–3.2%). During the years 1990–1994, this increase was 2.4% (95% CI 1.3–3.4%) and during the second study period of 1995–1999 it was slightly higher at 3.4% (95% CI 2.7–4.3%). The trends estimated for continents showed statistically significant increases all over the world (4.0% in Asia, 3.2% in Europe and 5.3% in North America), except in Central America and the West Indies where the trend was a decrease of 3.6%. Only among the European populations did the trend in incidence diminish with age.
Conclusions The rising incidence of Type 1 diabetes globally suggests the need for continuous monitoring of incidence by using standardized methods in order to plan or assess prevention strategies.
The present work is motivated by recent experiments aimed to measure the propagation velocity of bound electromagnetic (EM) field (Missevitch, et al. in EPL 93:64004, 2011; de Sangro et al. in Eur ...Phys J C 75:137, 2015) that reveal no retardation in the absence of EM radiation. We show how these findings can be incorporated into the mathematical structure of special relativity theory that allows us to reconsider some selected problems of classical and quantum electrodynamics. In particular, we come to the conclusion that the total four-momentum for a classical system “particles plus fields” ought to be a present state function of moving charges if EM radiation is negligible. In quantum domain, we analyze novel definition of the momentum operator recently suggested in the study of quantum phase effects (Kholmetskii et al. in Sci. Rep. 8:11937, 2018). It implies that bound EM field energy and momentum are to be present state functions, too. Being in agreement with reported experiments, these conclusions suggest the necessity to carry out more precise experimental verifications for additional and independent determination of propagation properties of bound EM fields. A scheme of a possible experiment on this subject is also proposed.
Relatively few studies have been performed about the onset, duration, and intensity of the canícula (midsummer drought) within central México in response to El Niño/Southern Oscillation (ENSO) ...events. The objective of our research is to assess the impact of the El Niño (EN) phase of ENSO upon air temperature (T), precipitation (PP), and drought index (DI = PP/T) during the canícula period. Daily air temperature and precipitation data from weather stations throughout central México are averaged for eight consecutive 10 (or 11)-day periods during the summers of 1960 through 1998. The data are grouped into seven climate regions according to specific precipitation criteria. Statistical comparisons between EN and neutral (N) years for the seven regions are made with pooled average T, PP and DI values from the summer. Results indicate that the EN phase significantly increases air temperatures within the wetter climate regions. The El Niño phase also increases summer precipitation within five of the regions, though not significantly. The added summer rainfall during El Niño phase does not reduce drought intensity with the exception of brief intervals within the wetter regions. Roughly, during EN and N years the canicula begins on July 11 and ends on August 31.
Acute diarrhoea diseases (ADDs) are one of the major health problems in Aguascalientes, Mexico. Due to the risk of significant increases of ADDs in the hot season, it has been necessary to determine ...the weather conditions that might lead to escalating ADD events. The effects of El Niño and La Niña phenomena on the morbidity rate of ADD (MRADD) in the State of Aguascalientes were determined during the period of 2000–2010. The MRADD was calculated from cases reported by the State Health Department. The Oceanic Niño Index (ONI) was obtained from the US National Oceanic and Atmospheric Administration. The impact of El Niño and La Niña on the MRADD was determined using the Pearson correlation coefficient and analysis of variance (ANOVA). The results gave a significant inverse correlation between El Niño phenomenon and MRADD (r = −0.55, P = 0.001), but a correlation was not observed on the La Niña phenomenon (r = −0.022, P = 0.888). Field data showed significant inverse influence of El Niño on MRADD for the years 2000–2010.
This paper is a write-up of the ideas that were presented, developed and discussed at the third International Workshop on QCD Challenges from pp to A-A, which took place in August 2019 in Lund, ...Sweden. The goal of the workshop was to focus on some of the open questions in the field and try to come up with concrete suggestions for how to make progress on both the experimental and theoretical sides. The paper gives a brief introduction to each topic and then summarizes the primary results.
In view of numerous experimental results reported in the past decades on the observation of faster-than-light electromagnetic signals, we analyze the structure of relativistic kinematics, where such ...superluminal signals are allowed. As the first step, we suggest replacing the Einstein postulates with the general relativity principle (the possibility of describing any phenomenon in any frame of reference achievable in nature) applied to an inertial motion in an empty space. Then, as in common relativistic kinematics, we also arrive at the Lorentz transformations between inertial reference frames, where a superluminal motion of massless entities is not prohibited (in particular, for perturbations of bound electromagnetic field). However, for any objects with a finite rest mass, the limited velocity remains always less than the light velocity c, and in such a way we avoid the tachyonic-type theories in their common meaning. We show that the application of superluminal electromagnetic signals to synchronization of distant clocks yields the common expressions for the relativity of the simultaneity of events for different inertial observers. This result confirms the validity of the Lorentz transformations in generalized relativistic kinematics, though along with superluminal signals. Hence we arrive at the invariance of the space-time interval, as in common relativistic kinematics, where, however, the superluminal motion of massless entities is allowed. Even so, no further changes emerge in relativistic dynamics and other common relativistic implications. Finally, we consider causal paradoxes related to the propagation and exchange of superluminal signals between inertial observers and provide their resolution. c 2012 Physics Essays Publication. DOI: 10.4006/0836-1398-25.4.621
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The present work is motivated by our recent experimental results 2-4 that indicate on anomalously small retardation of bound (or velocity-dependent) electromagnetic (EM) fields in the near zone of an ...emitter, whereas in the far zone the retardation tends to the standard value determined by the velocity of light c. Such anomaly is specific only for bound field component, while EM radiation has the constant propagation velocity c in the entire space. One possible explanation of these experimental results can be linked to our earlier finding 6, 8 that conventional EM energy-momentum (EMEM) tensor describes bound and radiative EM fields only in spatial regions free of charges and currents. In this work we show that an additional term has to be included into the standard EMEM tensor in order to make viable the description of the whole system of "charges plus fields". Such approach to the EMEM tensor actually admits anomalously small retardation of bound EM fields in regions very close to a field source, providing the standard propagation in the far zone. Some special implications are also discussed.
During the second semester of 1997 the project "Utilización de pronósticos climáticos para actividades agrícolas en Tlaxcala" was instrumented with the purpose of aiding decision making in ...agricultural activities in the estate of Tlaxcala, México. The main objective of the project was to characterize extreme values of precipitation associated with El Niño/ La Niña events, to produce useful forecasts for decision-making. This was achieved through close contacts with the farmers whose specific needs were taken into account to the extent possible. In a sense such forecasts became "forecasts watched over by producers". The method of ensemble of analogs was applied to historical data. The evaluation of annual and monthly forecasts is presented here. The results show that knowledge about the regional climate has been gained as it is reflected by the skill of the method to forecast. The forecast for the region, for the year 2003 is analyzed in terms of the precipitation anomalies.