Saturation effects in forward-forward dijet production in p+Pb collisions

We study saturation effects in the production of forward dijets in proton-lead collisions at the Large Hadron Collider, using the framework of High Energy Factorization. Such configurations, with both jets produced in the forward direction, probe the gluon density of the lead nucleus at small longitudinal momentum fraction, and also limit the phase space for emissions of additional jets. We find significant suppression of the forward dijet azimuthal correlations in proton-lead versus proton-proton collisions, which we attribute to stronger saturation of the gluon density in the nucleus than in the proton. In order to minimize model dependence of our predictions, we use two different extensions of the Balitsky-Kovchegov equation for evolution of the gluon density with sub-leading corrections.Comment: 13 pages, 4 figures; v2: added figure 4, several clarifying sentences and a reference; version accepted by PR

Forward di-jet production in p+Pb collisions in the small-x improved TMD factorization framework

We study the production of forward di-jets in proton-lead and proton-proton collisions at the Large Hadron Collider. Such configurations, with both jets produced in the forward direction, impose a dilute-dense asymmetry which allows to probe the gluon density of the lead or proton target at small longitudinal momentum fractions. Even though the jet momenta are always much bigger than the saturation scale of the target, $Q_s$, the transverse momentum imbalance of the di-jet system may be either also much larger than $Q_s$, or of the order $Q_s$, implying that the small-$x$ QCD dynamics involved is either linear or non-linear, respectively. The small-$x$ improved TMD factorization framework deals with both situation in the same formalism. In the latter case, which corresponds to nearly back-to-back jets, we find that saturation effects induce a significant suppression of the forward di-jet azimuthal correlations in proton-lead versus proton-proton collisions.Comment: 6 figure

Improved TMD factorization for forward dijet production in dilute-dense hadronic collisions

We study forward dijet production in dilute-dense hadronic collisions. By considering the appropriate limits, we show that both the transverse-momentum-dependent (TMD) and the high-energy factorization formulas can be derived from the Color Glass Condensate framework. Respectively, this happens when the transverse momentum imbalance of the dijet system, $k_t$, is of the order of either the saturation scale, or the hard jet momenta, the former being always much smaller than the latter. We propose a new formula for forward dijets that encompasses both situations and is therefore applicable regardless of the magnitude of $k_t$. That involves generalizing the TMD factorization formula for dijet production to the case where the incoming small-$x$ gluon is off-shell. The derivation is performed in two independent ways, using either Feynman diagram techniques, or color-ordered amplitudes.Comment: The improved version of the manuscript. 37 pages, 8 figures, several table

Consequences of strong fluctuations on high-energy QCD evolution

We investigate the behaviour of the QCD evolution towards high-energy, in the diffusive approximation, in the limit where the fluctuation contribution is large. Our solution for the equivalent stochastic Fisher equation predicts the amplitude as well as the whole set of correlators in the strong noise limit. The speed of the front and the diffusion coefficient are obtained. We analyse the consequences on high-energy evolution in QCD.Comment: 5 pages, 1 figure, more detailed discussions added, version to appear in Phys. Rev.

Azimuthal decorrelation of Mueller-Navelet jets at the Tevatron and the LHC

We study the production of Mueller-Navelet jets at hadron colliders in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) framework. We show that a measurement of the relative azimuthal angle \Delta\Phi between the jets can provide a good testing ground for corrections due to next-leading logarithms (NLL). Besides the well-known azimuthal decorrelation with increasing rapidity interval \Delta\eta between the jets, we propose to also measure this effect as a function of R=k_2/k_1, the ratio between the jets transverse momenta. Using renormalisation-group improved NLL kernel, we obtain predictions for d\sigma/d\Delta\eta dR d\Delta\Phi. We analyse NLL-scheme and renormalisation-scale uncertainties, and energy-momentum conservation effects, in order to motivate a measurement at the Tevatron and the LHC.Comment: 11 pages, 7 figures, energy conservation effects adde

Two Weeks of High-Intensity Interval Training in Combination With a Non-thermal Diffuse Ultrasound Device Improves Lipid Profile and Reduces Body Fat Percentage in Overweight Women

This study evaluated the effectiveness of an innovative strategy which combined low-frequency ultra sound (LOFU) with high-intensity interval training (HIIT) to improve physical fitness and promote body fat loss in overweight sedentary women. A placebo controlled, parallel group randomized experimental design was used to investigate the efficacy of a 2-week combined LOFU and HIIT program (3 sessions per week). Participants were allocated into either the Experimental HIIT group (HIITEXP, n = 10) or Placebo HIIT group (HIITPLA, n = 10). Baseline exercise testing (maximal oxygen uptake, lower limb strength and substrate oxidation test), dietary assessment, anthropometric measures and blood sampling were completed in week 1 and repeated in week 4 to determine changes following the program (Post-HIIT). During each training session, the HIITEXP and HIITPLA groups wore a non-thermal diffuse ultrasound belt. However, the belt was only switched on for the HIITEXP group. Delta change scores were calculated for body weight, body fat percentage (Fat%), muscle mass, V.O2max, hip and waist circumferences, and all lipid variables from Baseline to Post-HIIT. Statistical analysis was completed using a repeated-measures factorial analysis of variance by group (HIITPLA and HIITEXP) and time (Baseline and Post-HIIT). Results showed significant improvements in maximal oxygen uptake (HIITEXP; Baseline 24.7 ± 5.4 mL kg–1 min–1, Post-HIIT 28.1 ± 5.5 mL kg–1 min–1 and HIITPLA; Baseline 28.4 ± 5.9 mL kg–1 min–1, Post-HIIT 31.4 ± 5.5 mL kg–1 min–1) for both groups. Significant decreases in Fat% (HIITEXP; Baseline 32.7 ± 3.2%, Post-HIIT 28.9 ± 3.5% and HIITPLA; Baseline 28.9 ± 3.5%, Post-HIIT 28.9 ± 3.4% kg), waist circumference (HIITEXP; Baseline 95.8 ± 9.6 cm, Post-HIIT 89.3 ± 8.9 cm and HIITPLA; Baseline 104.3 ± 3.5 cm, Post-HIIT 103.6 ± 3.4 cm) and triglycerides (HIITEXP; −29.2%, HIITPLA; −6.7%) were observed in the HIITEXP group only. These results show that HIIT combined with LOFU was an effective intervention to improve body composition, lipid profile, and fitness. This combined strategy allowed overweight, sedentary women to achieve positive health outcomes in as little as 2 weeks

Extra-metabolic energy use and the rise in human hyper-density

Humans, like all organisms, are subject to fundamental biophysical laws. Van Valen predicted that, because of zero-sum dynamics, all populations of all species in a given environment flux the same amount of energy on average. Damuth’s ’energetic equivalence rule’ supported Van Valen´s conjecture by showing a tradeoff between few big animals per area with high individual metabolic rates compared to abundant small species with low energy requirements. We use metabolic scaling theory to compare variation in densities and individual energy use in human societies to other land mammals. We show that hunter-gatherers occurred at densities lower than the average for a mammal of our size. Most modern humans, in contrast, concentrate in large cities at densities up to four orders of magnitude greater than hunter-gatherers, yet consume up to two orders of magnitude more energy per capita. Today, cities across the globe flux greater energy than net primary productivity on a per area basis. This is possible by importing enormous amounts of energy and materials required to sustain hyper-dense, modern humans. The metabolic rift with nature created by modern cities fueled largely by fossil energy poses formidable challenges for establishing a sustainable relationship on a rapidly urbanizing, yet finite planet

Next-to-leading BFKL phenomenology of forward-jet cross sections at HERA

We show that the forward-jet measurements performed at HERA allow for a detailed study of corrections due to next-to-leading logarithms (NLL) in the Balitsky-Fadin-Kuraev-Lipatov (BFKL) approach. While the description of the d\sigma/dx data shows small sensitivity to NLL-BFKL corrections, these can be tested by the triple differential cross section d\sigma/dxdk_T^2dQ^2 recently measured. These data can be successfully described using a renormalization-group improved NLL kernel while the standard next-to-leading-order QCD or leading-logarithm BFKL approaches fail to describe the same data in the whole kinematic range. We present a detailed analysis of the NLL scheme and renormalization-scale dependences and also discuss the photon impact factors.Comment: 15 pages, 9 figures, new title, NLL-BFKL saddle-point approximation replaced by exact integratio

Nonequilibrium evolution of volatility in origination and extinction explains fat-tailed fluctuations in Phanerozoic biodiversity

Fluctuations in biodiversity, large and small, pervade the fossil record, yet we do not understand the processes generating them. Here, we extend theory from nonequilibrium statistical physics to describe the fat-tailed form of fluctuations in Phanerozoic marine invertebrate richness. Using this theory, known as superstatistics, we show that heterogeneous rates of origination and extinction between clades and conserved rates within clades account for this fat-tailed form. We identify orders and families as the taxonomic levels at which clades experience interclade heterogeneity and within-clade homogeneity of rates, indicating that families are subsystems in local statistical equilibrium, while the entire system is not. The separation of timescales between within-clade background rates and the origin of major innovations producing new orders and families allows within-clade dynamics to reach equilibrium, while between-clade dynamics do not. The distribution of different dynamics across clades is consistent with niche conservatism and pulsed exploration of adaptive landscapes.Fil: Rominger, Andrew J.. No especifíca;Fil: Fuentes, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Filosóficas. - Sociedad Argentina de Análisis Filosófico. Instituto de Investigaciones Filosóficas; Argentina. Universidad San Sebastián; ChileFil: Marquet, Pablo A.. Pontificia Universidad Católica de Chile; Chile. Instituto de Ecología y Biodiversidad; Chile. Universidad Nacional Autónoma de México; Méxic