Hadron-Hadron Interactions from Nf=2+1+1N_f=2+1+1 Lattice QCD: isospin-1 KKKK scattering length

We present results for the interaction of two kaons at maximal isospin. The calculation is based on $N_f=2+1+1$ flavour gauge configurations generated by the European Twisted Mass Collaboration with pion masses ranging from about $230$ to $450\,\textrm{MeV}$ at three values of the lattice spacing. The elastic scattering length $a_0^{I=1}$ is calculated at several values of the bare strange and light quark masses. We find $M_K a_0 = -0.385(16)_{\textrm{stat}} (^{+0}_{-12})_{m_s}(^{+0}_{-5})_{Z_P}(4)_{r_f}$ as the result of a combined extrapolation to the continuum and to the physical point, where the first error is statistical, and the three following are systematical. This translates to $a_0 = -0.154(6)_{\textrm{stat}}(^{+0}_{-5})_{m_s} (^{+0}_{-2})_{Z_P}(2)_{r_f}\,\textrm{fm}$.Comment: 28 pages, 18 tables, 14 figure

Meson-meson scattering lengths at maximum isospin from lattice QCD

We summarize our lattice QCD determinations of the pion-pion, pion-kaon and kaon-kaon s-wave scattering lengths at maximal isospin with a particular focus on the extrapolation to the physical point and the usage of next-to-leading order chiral perturbation theory to do so. We employ data at three values of the lattice spacing and pion masses ranging from around 230 MeV to around 450 MeV, applying Luescher's finite volume method to compute the scattering lengths. We find that leading order chiral perturbation theory is surprisingly close to our data even in the kaon-kaon case for our entire range of pion masses.Comment: 10 pages, 8 figures, Presented at the 9th International Workshop on Chiral Dynamics, Sept. 17-21, 2018, Duke University, Durham, NC, USA , submitted to PoS, (C18-09-17.6). Funding acknowledgements added in v2 replacement, comma added in abstract. In v3 replacement, corrected typo in equation 6.2 which was referring to the pion-kaon reduced mass instead of the pion mas

Hadron-Hadron Interactions from Nf=2+1+1N_f=2+1+1 Lattice QCD: I=3/2I=3/2 πK\pi K Scattering Length

In this paper we report on results for the s-wave scattering length of the $\pi$-$K$ system in the $I=3/2$ channel from $N_f=2+1+1$ Lattice QCD. The calculation is based on gauge configurations generated by the European Twisted Mass Collaboration with pion masses ranging from about $230$ to $450\,\text{MeV}$ at three values of the lattice spacing. Our main result reads $M_{\pi}\,a_0^{3/2,\text{phys}} = -0.059(2)$. Using chiral perturbation theory we are also able to estimate $M_{\pi}\,a_0^{1/2,\text{phys}} = 0.163(3)$. The error includes statistical and systematic uncertainties, and for the latter in particular errors from the chiral and continuum extrapolations.Comment: 30 pages, 6 figures, 15 table

The η′\eta^\prime meson at the physical point with Nf=2N_f=2 Wilson twisted mass fermions

We present results for the eta prime meson and the topological susceptibility in two flavour lattice QCD. The results are obtained using Wilson twisted mass fermions at maximal twist with pion masses ranging from 340 MeV down to the physical point. A comparison to literature values is performed giving a handle on discretisation effects.Comment: Lattice 2017 proceeding contributio

Non-destructive verification of materials in waste packages using QUANTOM®

The nuclear and non-nuclear industry has produced a considerable amount of low and intermediate-level radioactive wastes during the last decades. The material characterization of waste packages recently became more and more important in order to dispose of these waste packages in a final underground repository. Material characterization remains an indispensable criterion to prevent pollution of the groundwater with toxic materials and is usually required by the national licensing and supervisory authorities. Information on the nature of waste materials can be obtained based on existing documentation or, if the documentation is insufficient, on further destructive or non-destructive analysis. Non-destructive methods are to be preferred to minimize radiation exposures of operating personnel as well as costs. Existing non-destructive techniques (Gamma scanning, X-ray, active/passive neutron counting, muon tomography) do not allow the identification of non-radioactive hazardous substances. An innovative non-destructive measurement system called QUANTOM® (QUantitative ANalysis of TOxic and non-toxic Materials) has been developed. It is based on the prompt and delayed gamma neutron activation analysis (P&DGNAA). This technology is able to identify and quantify the elemental composition (Cd, Cu, B, Pb, Hg, Fe, Al, …) in radioactive packages such as 200-l radioactive drums. This information helps waste producers verify the content of their radioactive wastes, especially regarding the presence of hazardous substances. Different reference materials have been analysed by means of the same technology (P&DGNAA) at the research reactor of BUDAPEST. A comparison of those results for five reference materials is presented. The results show a very good agreement between QUANTOM® and standardized reference analyses

<em>K-K</em> and <em>π-K</em> Scattering Lengths at Maximal Isospin from Lattice QCD

The current work presents calculations of the elastic scattering length a0 for systems of two Kaons and one pion and one Kaon, respectively. The values for a0 have been obtained from lattice QCD simulations with Nf = 2+1+1 dynamical flavors in the sea. The gauge configurations used in this work have been generated by the European twisted mass collaboration (ETMC) and comprise pion masses in the range 230 - 450 MeV at 3 distinct lattice spacings. The gauge configurations are realized in a maximally twisted mass setup. For the valence sector we adopt a mixed action approach with one doublet of mass degenerate light quarks and one Osterwalder-Seiler valence strange quark at different values of the strange quark mass. Within the framework of stochastic Laplacian-Heaviside (sLapH) quark field smearing we calculate the two point correlation functions of the K+ and p+, respectively and the four point correlation function of the p+-K+ and the K+-K+ system. Thermal pollution is handled via a ratio of shifted correlation functions (K+-K+) and two variants of weighting-and-shifting the correlation functions. The energies extracted from the four and two point functions are used to calculate the scattering length a0 for each system via Lüscher's method. Because of the unphysical quark masses, necessary for stable simulations, chiral inter- and extrapolations of the data are in order. We employ two procedures to fix the strange quark mass to its physical value, the Kaon mass at leading order chiral perturbation theory and its next to leading order form. For K+-K+ we resort to a combined chiral and continuum extrapolation, linear in the light quark mass, to arrive at the physical light quark mass. Thus we find MKa0 = -0.385(16)stat(+0-12)ms(+0-5)ZP(4)rf, with systematic uncertainties stemming from the quark mass fixing (ms), the renormalization procedure (ZP) and the neglect of higher order terms in the expansion of the energy shift in terms of the a0 and the inverse lattice volume. In the extrapolation the lattice artifact is found to be negligible. In the case of p+-K+ we extrapolate to the physical pion mass following the next to leading order for the scattering length in SU(3) ChPT. Here we find at the physical point µpKa03/2 = -0.0463(17). In this analysis we are not able to resolve possible lattice artifacts. A further result of this study is that Chiral perturbation theory works well for the systems under considerations. For maximal isospin scattering lengths higher order terms of ChPT contribute only mildly to the leading order behavior

The η′ meson at the physical point with Nf = 2 Wilson twisted mass fermions

We present results for the η′ meson and the topological susceptibility in Nf = 2 flavour lattice QCD. The results are obtained using Wilson twisted mass fermions at maximal twist with pion masses ranging from 340 MeV down to the physical point. A comparison to literature values is performed giving a handle on discretisation effects

Non-destructive verification of materials in waste packages using QUANTOM

The nuclear and non-nuclear industry has produced a considerable amount of low and intermediate-level radioactive wastes during the last decades. The material characterization of waste packages recently became more and more important in order to dispose of these waste packages in a final underground repository. Material characterization remains an indispensable criterion to prevent pollution of the groundwater with toxic materials and is usually required by the national licensing and supervisory authorities. Information on the nature of waste materials can be obtained based on existing documentation or, if the documentation is insufficient, on further destructive or non-destructive analysis. Non-destructive methods are to be preferred to minimize radiation exposures of operating personnel as well as costs. Existing non-destructive techniques (Gamma scanning, X-ray, active/passive neutron counting, muon tomography) do not allow the identification of non-radioactive hazardous substances. An innovative non-destructive measurement system called QUANTOM® (QUantitative ANalysis of TOxic and non-toxic Materials) has been developed. It is based on the prompt and delayed gamma neutron activation analysis (P&DGNAA). This technology is able to identify and quantify the elemental composition (Cd, Cu, B, Pb, Hg, Fe, Al, …) in radioactive packages such as 200-l radioactive drums. This information helps waste producers verify the content of their radioactive wastes, especially regarding the presence of hazardous substances. Different reference materials have been analysed by means of the same technology (P&DGNAA) at the research reactor of BUDAPEST. A comparison of those results for five reference materials is presented. The results show a very good agreement between QUANTOM® and standardized reference analyses