Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften

Vienna, Austria

Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften

Vienna, Austria
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Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Bartl A.,University of Vienna | Ginina E.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Hidaka K.,Tokyo Gakugei University | And 2 more authors.
International Workshop on Future Linear Colliders, LCWS 2014 | Year: 2014

We study the decay of the lightest neutral Higgs boson to a charm quark pair at full one-loop level in the MSSM with non-minimal quark avour violation (QFV). In the numerical analysis we consider mixing between the second and the third squark generation and all relevant constraints from B meson data are taken into account. It is shown that the full one-loop corrected decay width can be quite sensitive to the MSSM QFV parameters due to large c-T mixing and large trilinear couplings. After summarising the theoretical and experimental errors, we conclude that an observation of these SUSY QFV effects is possible at the ILC.

Strauss R.,Max Planck Institute for Physics | Rothe J.,Max Planck Institute for Physics | Angloher G.,Max Planck Institute for Physics | Bento A.,University of Coimbra | And 14 more authors.
Physical Review D | Year: 2017

The energy threshold of a cryogenic calorimeter can be lowered by reducing its size. This is of importance since the resulting increase in signal rate enables new approaches in rare-event searches, including the detection of MeV mass dark matter and coherent scattering of reactor or solar neutrinos. A scaling law for energy threshold vs detector size is given. We analyze the possibility of lowering the threshold of a gram-scale cryogenic calorimeter to the few eV regime. A prototype 0.5 g Al2O3 device achieved an energy threshold of Eth=(19.7±0.9) eV, the lowest value reported for a macroscopic calorimeter. © 2017 American Physical Society.

Strauss R.,Max Planck Institute for Physics | Rothe J.,Max Planck Institute for Physics | Angloher G.,Max Planck Institute for Physics | Bento A.,University of Coimbra | And 14 more authors.
European Physical Journal C | Year: 2017

We discuss a small-scale experiment, called ν-cleus, for the first detection of coherent neutrino–nucleus scattering by probing nuclear-recoil energies down to the 10 eV regime. The detector consists of low-threshold CaWO4 and Al2O3 calorimeter arrays with a total mass of about 10 g and several cryogenic veto detectors operated at millikelvin temperatures. Realizing a fiducial volume and a multi-element target, the detector enables active discrimination of γ, neutron and surface backgrounds. A first prototype Al2O3 device, operated above ground in a setup without shielding, has achieved an energy threshold of ∼ 20 eV and further improvements are in reach. A sensitivity study for the detection of coherent neutrino scattering at nuclear power plants shows a unique discovery potential (5σ) within a measuring time of ≲ 2 weeks. Furthermore, a site at a thermal research reactor and the use of a radioactive neutrino source are investigated. With this technology, real-time monitoring of nuclear power plants is feasible. © 2017, The Author(s).

Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Ginina E.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Bartl A.,University of Vienna | Hidaka K.,Tokyo Gakugei University | Majerotto W.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften
Journal of High Energy Physics | Year: 2016

We calculate the decay width of h0→ bb¯ in the Minimal Supersymmetric Standard Model (MSSM) with quark flavour violation (QFV) at full one-loop level. We study the effect of c˜ − t˜ mixing and s˜ − b˜ mixing taking into account the constraints from the B meson data. We discuss and compare in detail the decays h0→ cc¯ and h0→ bb¯ within the framework of the perturbative mass insertion technique using the Flavour Expansion Theorem. The deviation of both decay widths from the Standard Model values can be quite large. Whereas in h0→ cc¯ it is almost entirely due to the flavour violating part of the MSSM, in h0→ bb¯ it is mainly due to the flavour conserving part. Nevertheless, the QFV contribution to Γ(h0→ bb¯)due to c˜ − t˜ mixing and chargino exchange can go up to ∼ 7%. © 2016, The Author(s).

Bartl A.,University of Vienna | Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Ginina E.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Hidaka K.,Tokyo Gakugei University | And 2 more authors.
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2015

We compute the decay width of h0→cc¯ in the minimal supersymmetric Standard Model with quark flavor violation (QFV) at full one-loop level adopting the DR¯ renormalization scheme. We study the effects of c-t mixing, taking into account the constraints from the B meson data. We show that the full one-loop corrected decay width Γ(h0→cc¯) is very sensitive to the minimal supersymmetric Standard Model QFV parameters. In a scenario with large cL,R-tL,R mixing Γ(h0→cc¯) can differ up to ∼±35% from its Standard Model value. After estimating the uncertainties of the width, we conclude that an observation of these supersymmetry QFV effects is possible at an e+e- collider (International Linear Collider). © 2015 American Physical Society.

Bartl A.,University of Vienna | Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Herrmann B.,German Electron Synchrotron | Herrmann B.,University of Würzburg | And 4 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

We study the effect of squark generation mixing on squark production and decays at LHC in the Minimal Supersymmetric Standard Model (MSSM). We show that the effect can be very large despite the very strong constraints on quark-flavour violation (QFV) from experimental data on B mesons. We find that the two lightest up-type squarks u~1,2 can have large branching ratios for the decays into cχ~10 and tχ~10 at the same time due to squark generation mixing, leading to QFV signals '. pp→ct-(tc-)+missing-ET+X' with a significant rate. The observation of this remarkable signature would provide a powerful test of supersymmetric QFV at LHC. This could have a significant impact on the search for squarks and the determination of the underlying MSSM parameters. © 2011 Elsevier B.V.

Bartl A.,University of Vienna | Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Ginina E.,University of Vienna | Herrmann B.,University of Savoy | And 3 more authors.
International Journal of Modern Physics A | Year: 2014

We study quark flavor violation (QFV) in the squark sector of the Minimal Supersymmetric Standard Model (MSSM). We assume mixing between the second and the third squark generations, i.e. $\tilde{c} {R}-\tilde{t} {L, R}$ mixing. We focus on QFV effects in bosonic squark decays, in particular on the decay into the lightest Higgs boson $h0$, $\tilde{u} 2 \to \tilde{u} 1 h0$, where $\tilde{u} {1, 2}$ are the lightest up-type squarks. We show that the branching ratio of this QFV decay can be quite large (up to 50%) due to large QFV trilinear couplings, and large $\tilde{c} {R}-\tilde{t} {L, R}$ and $\tilde{t} {L}-\tilde{t} {R}$ mixing, despite the strong constraints on QFV from B meson data. This can result in characteristic QFV final states with significant rates at LHC (14 TeV), such as $pp \to \tilde{g} \tilde{g} X \to t + h0 + 3∼{\rm jets}+{\sslE} T + X$ and $pp \to \tilde{g} \tilde{g} X \to t t$ $({\rm or}∼\bar{t}\bar{t}) + h0 + 2∼{\rm jets} + {\sslE} T + X$. The QFV bosonic squark decays can have an influence on the squark and gluino searches at LHC. © 2014 World Scientific Publishing Company.

Eberl H.,Institute For Hochenergiephysik Der Osterreichischen Akademie Der Wissenschaften | Spanos V.C.,National and Kapodistrian University of Athens
Computer Physics Communications | Year: 2016

We present the package GravitinoPack that calculates the two- and three-body decays of unstable supersymmetric particles involving the gravitino in the final or initial state. In a previous paper, we already showed results for the gravitino decaying into two and three particles. In this paper, we incorporate the processes where an unstable neutralino, stau or stop decays into a gravitino and Standard Model particles. This is the case in gravitino dark matter supersymmetric models, where the gravitino is the lightest SUSY particle. We give instructions for the installation and the use of the package. In the numerical analysis, we discuss various MSSM scenarios. We show that the calculation of all the decay channels and the three-body decay branching ratios is essential for the accurate application of cosmological bounds on these models. Program summary: Program title: GravitinoPack. Catalogue identifier: AEZL_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEZL_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland. Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 97708. No. of bytes in distributed program, including test data, etc.: 1217167. Distribution format: tar.gz. Programming language: Fortran 77 and C for the MathLink. Computer: Workstation, PC, Mac. Operating system: Linux, Mac OSX. Classification: 11.1. Nature of problem: If Supersymmetry (SUSY) is realized in nature, each Standard Model (SM) particle is accompanied by its superpartner. The gravitino, the spin 3/2 superpartner of the graviton, belongs to the spectrum of the most important supersymmetric models. The gravitino can be the Lightest Supersymmetric Particle (LSP), in the so-called gravitino Dark Matter (DM) models. Thus, the Next to the Lightest Supersymmetric Particle (NLSP) is long-lived, since it decays gravitationally to the LSP (gravitino) and SM particles. Such decays produce electromagnetic energy and hadrons which can affect the primordial Big-Bang Nucleosynthesis (BBN) predictions for the abundance of the light nuclei. Similarly, when the gravitino is not the LSP it decays into the LSP which can be another SUSY particle, like the neutralino, and SM particles. GravitinoPack provides important results on all these decays, making the application of the BBN data more accurate. Solution method: GravitinoPack is a package for the evaluation of processes with gravitino interaction. The version GravitinoPack1.0 includes all two-body decays of the gravitino and all three-body decays of the gravitino to a neutralino and a pair of two particles. In the case that the gravitino is the LSP all two- and three-body decays of the lightest neutralino, the light stop or stau NLSP are included. GravitinoPack works at Fortran77 level and has a Mathematica interface. Unusual features: MathLink works properly only up to version Mathematica 9. There is still a conflict between Mathematica 10 and the used integration routine CUBA. Running time: All two-body decay widths are calculated in a time far below one second. The three-body decay calculations can be fast, especially the stop and stau decays, or slow with times up to a few minutes, especially when the phase space becomes large and no approximation is chosen. © 2016 Elsevier B.V.