There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

http://repositorium.sdum.uminho.pt/bitstream/1822/48763/1/1-s2.0-S037026931200857X-main.pdf

Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC

https://digital.csic.es/bitstream/10261/108964/1/experiment%20at%20the%20LHC.pdf

Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC

We discuss the theoretical bases that underpin the automation of the computations of tree-level and next-to-leading order cross sections, of their matching to parton shower simulations, and of the merging of matched samples that differ by light-parton multiplicities. We present a computer program, MadGraph5 aMC@NLO, capable of handling all these computations — parton-level fixed order, shower-matched, merged — in a unified framework whose defining features are flexibility, high level of parallelisation, and human intervention limited to input physics quantities. We demonstrate the potential of the program by presenting selected phenomenological applications relevant to the LHC and to a 1-TeV e + e − collider. While next-to-leading order results are restricted to QCD corrections to SM processes in the first public version, we show that from the user viewpoint no changes have to be expected in the case of corrections due to any given renormalisable Lagrangian, and that the implementation of these are well under way.

/pdf/the-automated-computation-of-tree-level-and-next-to-leading-4etm0g6w46.pdf

The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations

Materials like CdTe, CdZnTe, Cd0.8Zn0.2Te and ZnTe are suitable photoconductors for direct conversion digital flat panel x-ray image detectors. The x-ray induced primary electrons inside photoconductor's bulk comprise the initial signal that propagates and forms the final signal (image) on detector's electrodes. An already developed Monte Carlo model that simulates the primary electron generation in photoconducting materials, such as those mentioned above, has been used to study the arithmetics of fluorescent photons, escaping photons and primary electrons in these materials in the mammographic energy range. In this way insights are gained concerning the primitive stage of signal formation that lead to the investigation of the factors that affect the primary electron generation. It was found that for the typical photoconductor thicknesses (300-1000 μm): (i) in all materials and incident energies the escaping of primary photons is negligible and does not influence the number of primary electrons, (ii) the overwhelming majority of escaping photons is backwards escaping fluorescent photons, (iii) the number of primary electrons increases at energies higher than Cd and Te K-edges where the fluorescent photon escaping decreases and their absorption is followed by long atomic deexcitation cascades and (iv) ZnTe has the maximum number of primary electrons produced for energies between 16 and 26 keV while CdTe for higher energies.

https://iopscience.iop.org/article/10.1088/1748-0221/4/06/P06019/pdf

Photon and primary electron arithmetics in photoconductors for digital mammography: Monte Carlo simulation studies

The authors use a recently developed PET scanner model to simulate certain characteristics of the TTV03 CEA-LETL time-of-flight (TOF) PET scanner. It is found that the TOF resolution for a pair of detectors is 400 ps (FWHM), as compared to 750 ps measured with the TTV03 LETI scanner. The authors calculate the true, random, and noise effective count rates as functions of the lower energy threshold and find good agreement with experimental measurements. >

A simulation study of the LETI TTV03 TOF PET scanner

The authors have used simulated images to study 3-D image registration with external markers. They have examined the precision of registration as measured with residual distances in the image after registration. The average residuals as well as their standard deviations depend on the position in the image and on the spatial resolution of the imaging modalities. >

Study of the precision of registration in 3-D multimodality imaging with external markers using simulated images

The ν τ was postulated to exist after the discovery of the tau-lepton in 1975. First ν τ CC interactions was observed in 2000 by the DONuT experiment at Fermilab, which also set a limit on the magnetic moment. Electron positron collider experiments have studied the tau-lepton decays and measured the Michel parameters, the tau lifetime, and the number of the light neutrino species. In addition a direct upper limit of the tau-neutrino mass was measured. This paper gives a short review of the known properties of the tau-neutrino, along with preliminary results from DONuT on the measurement of the ν τ CC DIS cross section.

Properties of the Tau-Neutrino

The available TOFPET (time-of-flight positron-emission tomography) scanners with BaF/sub 2/ have a TOF resolution of about 500 ps. The possible reasons for this can be several, including spread in the time of arrival of photons to the photocathode, transit time spread in the photomultiplier, jitter in the timing from the discriminator and the time-to-digital converters, and systematic channel-to-channel shifts. The authors have developed a Monte Carlo program to study the contribution of each of these effects to the TOF results. They simulate the interactions of 511 KeV gammas with the detector (Compton and photoelectric absorption), the emission and propagation of UV light in the crystal, and the pulse formation in the photomultiplier. The time spread due to each effect is calculated, as well as the time spread due to all these effects combined. Experimental evidence indicates that the length of the crystal has a strong effect on the light collection time spread, both due to reflections and to the exponential distribution of interaction points inside the crystal. To quantify the length effect, the authors calculated the FWHM (full-width half maximum) of the time of production of the first photoelectron on the photocathode. >

G. Tzanakos

Papers

Photon and primary electron arithmetics in photoconductors for digital mammography: Monte Carlo simulation studies

A simulation study of the LETI TTV03 TOF PET scanner

Study of the precision of registration in 3-D multimodality imaging with external markers using simulated images

Properties of the Tau-Neutrino

Time-of-flight PET with BaF/sub 2/