The dipole picture and the non-relativistic expansion

We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small x, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium light-cone wave function in light-cone gauge. Using these corrections we recover results for the NLO decay width of quarkonium to e+e− and we check that the non-relativistic expansion is consistent with ERBL evolution and with B-JIMWLK evolution of the target. The results presented here will allow computing the exclusive quarkonium production rate at NLO once the one loop photon wave function with massive quarks, currently under investigation, is known. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND 4.0).Peer reviewe

Readout circuit with improved sensitivity for contactless LC sensing tags

In this work we present a novel technique to estimate the resonance frequency of LC chipless tags (inductor-capacitor parallel circuit) with improved sensitivity and linearity. The developed reader measures the power consumption of a Colpitts oscillator during a frequency sweep. The readout circuit consists of a Colpitts oscillator with a coil antenna, varactor diodes to change the oscillator frequency, analog circuitry to measure the power consumption and a microcontroller to control the whole system and send the data to a PC via USB. When an LC tag is inductively coupled to the oscillator, without contact, a maximum power peak is found. As shown by an experimental calibration using an LC tag made on FR4 substrate, the frequency of this maximum is related to the resonance frequency. Both parameters, power consumption and resonance frequency, present an excellent linear dependence with a high correlation factor (R 2 = 0.995). Finally, a screen-printed LC tag has been fabricated and used as relative humidity sensor achieving a sensitivity of (−2.41 ± 0.21) kHz/% with an R 2 of 0.946

Influence of serological factors and BMI on the blood pressure/hematocrit association in healthy young men and women.

The association between mean arterial blood pressure (MAP) and hematocrit (Hct) as a surrogate for blood viscosity was investigated in a young (average 20.0±2.3 years), healthy population of 174 men and 442 women. Health status was assessed by clinical examination and serological evaluation. Individuals with severe anemia or hemoconcentration, prior traumas or major surgical intervention, smokers, and pregnant or lactating women were excluded from the study. The MAP/Hct association was positive and significant (P=0.04) for women and negative, albeit not significantly so, for men. The MAP/Hct association was also evaluated in subgroups of the same population with a progressive step-by-step exclusion of: individuals with cholesterol >200 mg/dL; triglycerides >200 mg/dL; body mass index >25 kg/m(2); and glucose >100 mg/dL. This consecutively reduced the strength of the positive MAP/Hct association in women, which became negative - although not significantly so - when all anomalously high factors were excluded. The same trend was found in men. Our study indicates that previously reported positive trends in the relationship between the MAP and Hct in the population are not present in a young, healthy population of men or women that excludes individuals with the confounding factors of above normal serological values and BMI

Homogeneous Boltzmann equation in quantum relativistic kinetic theory.

Abstract Some mathematical questions about Boltzmann equations for quantum particles, relativistic or not, are considered. Relevant particular cases as Bose, Bose-Fermi, photon-electron gases are studied as well as some simplifications (such as the isotropy of the distribution functions) and asymptotic limits (systems where one of the species is at equilibrium) of special interest from a physical point of view and which give rise to interesting mathematical questions. New results about the existence and long time behaviour of the solutions to some of these problems are exposed

Effective field theory and dispersion law of the phonons of a non-relativistic superfluid

We study the recently proposed effective field theory for the phonon of an arbitrary non-relativistic superfluid. After computing the one-loop phonon self-energy, we obtain the low temperature T contributions to the phonon dispersion law at low momentum, and see that the real part of those can be parametrized as a thermal correction to the phonon velocity. Because the phonons are the quanta of the sound waves, at low momentum their velocity should agree with the speed of sound. We find that our results match at order T^4ln(T) with those predicted by Andreev and Khalatnikov for the speed of sound, derived from the superfluid hydrodynamical equations and the phonon kinetic theory. We get also higher order corrections of order T^4, which are not reproduced pushing naively the kinetic theory computation. Finally, as an application, we consider the cold Fermi gas in the unitarity limit, and find a universal expression for the low T relative correction to the speed of sound for these systems.Comment: 14 pages, 2 figures. References adde

General-purpose passive wireless point–of–care platform based on smartphone

A versatile, compact and low-cost analytical platform has been designed, tested and validated to be used in the point-of-care settings. This passive measurement system is powered and complemented by a standard smartphone including a programmed application for measurement configuration and data processing as well as wireless results sharing. Electrochemical and electrochemiluminescence analytical techniques can be configured and realized by this platform that employs standard screen-printed electrodes for the sample managing and off-the-shelf electronic components. The power, electrical and optical signal processing have been studied in depth. The system can harvest energy up to 22.5 mW, set up a voltage in the range of ±1.15 V, and measure potentials in a range of 600 mV with an uncertainty of 1 mV, and current from 2 μA to 0.75 mA with a resolution of 1.1 μA. Moreover, standard tests have been performed to the platform consisting of amperometric, potentiometric, cyclic voltammetry and electrochemiluminescent analytical techniques, showing excellent agreement with a reference instrument. Finally, our design has also been applied to glucose, pH and H2O2 determinations, providing the full analytical parameters which are in very good agreement with the reference instrument results. Ranges (0.065–0.75 M, 0.62–100 mM and 3–9 pH units for glucose, H2O2 and pH, respectively) and limits of detection (0.024 M and 0.03 mM for glucose and H2O2, respectively) make this low-cost platform (<US$8) suitable for analytical applications.This study was supported by projects from the Spanish MINECO (CTQ2016-78754-C2-1- R), European Regional Development Funds (ERDF). and Spanish Ministry of Education, Culture and Sport for a R&D predoctoral grant (FPU13/05032

The effect of bending on laser-cut electro-textile inductors and capacitors attached on denim as wearable structures

In this paper we present the design, fabrication and characterization of electro-textile inductor and capacitor patterns on denim fabric as a basis for the development of wearable e-textiles. Planar coil inductors have been harnessed as antenna structures for the development of Near Field Communication (NFC) tags with temperature sensing capability, while interdigitated electrode (IDE) capacitors have been used as humidity sensors for wearable applications. The effect of bending in the electrical performance of such structures was evaluated, showing variations below 5% in both inductance and capacitance values for bending angles in the range of interest, i.e. those fitting to human limbs. In the case of the fabricated NFC tags, a shift in the resonance frequency below 1.7% was found, meaning that the e-textile tag would still be readable by an NFC- enabled smartphone. In respect of the capacitive humidity sensor, we obtained a minimum capacitance variation of 40% for a relative humidity range from 10% to 90%. Measured thermal shift was below 5% in the range from 10 to 40oC. When compared to the 4% variation due to bending, it can be concluded that this capacitive structure can be harnessed as humidity sensor even under bending strain conditions and moderate temperature variations. The development and characterization of such structures on denim fabrics, which is one of the most popular fabrics for everyday clothing, combined with the additional advantage of affordable and easy fabrication methodologies, means a further step towards the next generation of smart e-textile products