Search results for "Proton"
showing 10 items of 5886 documents
"Table 18" of "Search for heavy charged long-lived particles in the ATLAS detector in 31.6 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 1…
2019
Flavor composition of 800 GeV stop R-hadrons simulated using the generic model as a function of radial distance from the interaction point.
First measurement of the charge asymmetry in beauty-quark pair production.
2014
The difference in the angular distributions between beauty quarks and antiquarks, referred to as the charge asymmetry, is measured for the first time in b[bar over b] pair production at a hadron collider. The data used correspond to an integrated luminosity of 1.0 fb[superscript −1] collected at 7 TeV center-of-mass energy in proton-proton collisions with the LHCb detector. The measurement is performed in three regions of the invariant mass of the b[bar over b] system. The results obtained are A[b[bar over b] over C](40 105 GeV/c[superscript 2]) = 1.6 ± 1.7 ± 0.6%, where A[b[bar over b] over C] is defined as the asymmetry in the difference in rapidity between jets formed from the beauty q…
Twin GEM-TPC prototype (HGB4) beam test at GSI and Jyväskylä : a development for the Super-FRS at FAIR
2017
The FAIR[1] facility is an international accelerator centre for research with ion and antiproton beams. It is being built at Darmstadt, Germany as an extension to the current GSI research institute. One major part of the facility will be the Super-FRS[2] separator, which will be include in phase one of the project construction. The NUSTAR experiments will benefit from the Super-FRS, which will deliver an unprecedented range of radioactive ion beams (RIB). These experiments will use beams of different energies and characteristics in three different branches; the high-energy which utilizes the RIB at relativistic energies 300-1500 MeV/u as created in the production process, the low-energy bra…
End-to-end tests using alanine dosimetry in scanned proton beams
2018
This paper describes end-to-end test procedures as the last fundamental step of medical commissioning before starting clinical operation of the MedAustron synchrotron-based pencil beam scanning (PBS) therapy facility with protons. One in-house homogeneous phantom and two anthropomorphic heterogeneous (head and pelvis) phantoms were used for end-to-end tests at MedAustron. The phantoms were equipped with alanine detectors, radiochromic films and ionization chambers. The correction for the 'quenching' effect of alanine pellets was implemented in the Monte Carlo platform of the evaluation version of RayStation TPS. During the end-to-end tests, the phantoms were transferred through the workflow…
Spectral characterization of laser-accelerated protons with CR-39 nuclear track detector
2018
CR-39 nuclear track material is frequently used for the detection of protons accelerated in laser-plasma interactions. The measurement of track densities allows for determination of particle angular distributions, and information on the kinetic energy can be obtained by the use of passive absorbers. We present a precise method of measuring spectral distributions of laser-accelerated protons in a single etching and analysis process. We make use of a one-to-one relation between proton energy and track size and present a precise calibration based on monoenergetic particle beams. While this relation is limited to proton energies below 1 MeV, we show that the range of spectral measurements can b…
Compact Method for Proton Range Verification Based on Coaxial Prompt Gamma-Ray Monitoring: a Theoretical Study
2020
Range uncertainties in proton therapy hamper treatment precision. Prompt gamma-rays were suggested 16 years ago for real-time range verification, and have already shown promising results in clinical studies with collimated cameras. Simultaneously, alternative imaging concepts without collimation are investigated to reduce the footprint and price of current prototypes. In this manuscript, a compact range verification method is presented. It monitors prompt gamma-rays with a single scintillation detector positioned coaxially to the beam and behind the patient. Thanks to the solid angle effect, proton range deviations can be derived from changes in the number of gamma-rays detected per proton,…
"Table 5" of "Beauty production in pp collisions at $\sqrt{s}$ = 2.76 TeV measured via semi-electronic decays"
2015
The pT-differential inclusive cross section of electrons from beauty hadron decays using the electron-hadron azimuthal correlation method.
"Table 7" of "Beauty production in pp collisions at $\sqrt{s}$ = 2.76 TeV measured via semi-electronic decays"
2015
Inclusive bbbar production cross section per rapidity unit measured.
Synthesis of Macropolycyclic Ligands Based on Tetraazacycloalkanes
1998
A versatile synthesis of spherical macrobicyclic and cylindrical macrotricyclic ligands is described using 1,4,8,11-tetraazacyclotetradecane (cyclam), 1,4,7,10-tetraazacyclododecane (cyclen), or dioxo macrocycles as precursors. Macrobicycles have been obtained by allowing cyclam, cyclen, or 5,12-dioxocyclam (1,4,8,11-tetraazacyclotetradecane-5,12-dione) to react with a bis-electrophilic spacer under high dilution conditions. A surprising selectivity has been observed for 2,6-dioxocyclen (1,4,7,10-tetraazacyclododecane-2,6-dione), which yields only macrotricycles under the same reaction conditions. Molecular modelling studies have been carried out to investigate the selectivity of the reacti…
Toward an Automatic Determination of Enzymatic Reaction Mechanisms and Their Activation Free Energies.
2013
We present a combination of the string method and a path collective variable for the exploration of the free energy surface associated to a chemical reaction in condensed environments. The on-the-fly string method is employed to find the minimum free energy paths on a multidimensional free energy surface defined in terms of interatomic distances, which is a convenient selection to study bond forming/breaking processes. Once the paths have been determined, a reaction coordinate is defined as a measure of the advance of the system along these paths. This reaction coordinate can be then used to trace the reaction Potential of Mean Force from which the activation free energy can be obtained. Th…