Max Planck Institute for Nuclear Physics
Max Planck Institute for Nuclear Physics
The Max-Planck-Institut für Kernphysik is aresearch institute in Heidelberg, Germany. The institute is one of the 80 institutes of the Max-Planck-Gesellschaft , an independent, non-profit research organization. The Max Planck Institute for Nuclear Physics has been founded in 1958 under the leadership of Wolfgang Gentner. Its precursor was the Institute for Physics at the MPI for Medical Research.Today, the institute's research areas are: crossroads of particle physics and astrophysics andmany-body dynamics of atoms and molecules . There are five scientific divisions and several further research groups and junior groups. Scientific and technical departments as well as the administration support the researchers. The institute has about 390 employees, as well as many diploma students and scientific guests. The research field of Astroparticle Physics, represented by the divisions of Werner Hofmann and Manfred Lindner, combines questions related to macrocosm and microcosm. Unconventional methods of observation for gamma rays and neutrinos open new windows to the universe. What lies behind “dark matter” and “dark energy” is theoretically investigated.The research field of Quantum Dynamics is represented by the divisions of Klaus Blaum, Christoph Keitel and Joachim Ullrich. Using reaction microscopes, simple chemical reactions can be “filmed”. Storage rings and traps allow precision experiments almost under space conditions. The interaction of intense laser light with matter is investigated using quantum-theoretical methods.Further research fields are cosmic dust, atmospheric physics as well as fullerenes and other carbon molecules.Scientists at the MPIK collaborate with other research groups in Europe and all over the world and are involved in numerous international collaborations, partly in a leading role. Particularly close connections to some large-scale facilities like GSI , DESY , CERN , INFN-LNGS exist.In the local region, the Institute cooperates closely with the University of Heidelberg, where the directors and further members of the Institute are teaching. Three International Max Planck Research Schools and a graduate school serve to foster young scientists.The institute operates accelerators injecting highly charged atomic ions or molecular ions into a storage ring . The electron-beam ion trap is able to produce and store 78-fold charged mercury ions. Wikipedia.
Di Piazza A.,Max Planck Institute for Nuclear Physics
Physical Review Letters | Year: 2016
The only available analytical framework for investigating QED processes in a strong laser field systematically relies on approximating the latter as a plane wave. However, realistic high-intensity laser beams feature much more complex space-time structures than plane waves. Here, we show the feasibility of an analytical framework for investigating strong-field QED processes in laser beams of arbitrary space-time structure by determining the energy spectrum of positrons produced via nonlinear Breit-Wheeler pair production as a function of the background field in the realistic assumption that the energy of the incoming photon is the largest dynamical energy in the problem. A numerical evaluation of the angular resolved positron spectrum shows significant quantitative differences with respect to the analogous result in a plane wave, such that the present results will be also important for the design of upcoming strong laser facilities aiming at measuring this process. © 2016 American Physical Society.
Di Piazza A.,Max Planck Institute for Nuclear Physics |
Muller C.,Max Planck Institute for Nuclear Physics |
Muller C.,Heinrich Heine University Düsseldorf |
Hatsagortsyan K.Z.,Max Planck Institute for Nuclear Physics |
Keitel C.H.,Max Planck Institute for Nuclear Physics
Reviews of Modern Physics | Year: 2012
The field of laser-matter interaction traditionally deals with the response of atoms, molecules, and plasmas to an external light wave. However, the recent sustained technological progress is opening up the possibility of employing intense laser radiation to trigger or substantially influence physical processes beyond atomic-physics energy scales. Available optical laser intensities exceeding 1022W/cm2 can push the fundamental light-electron interaction to the extreme limit where radiation-reaction effects dominate the electron dynamics, can shed light on the structure of the quantum vacuum, and can trigger the creation of particles such as electrons, muons, and pions and their corresponding antiparticles. Also, novel sources of intense coherent high-energy photons and laser-based particle colliders can pave the way to nuclear quantum optics and may even allow for the potential discovery of new particles beyond the standard model. These are the main topics of this article, which is devoted to a review of recent investigations on high-energy processes within the realm of relativistic quantum dynamics, quantum electrodynamics, and nuclear and particle physics, occurring in extremely intense laser fields. © 2012 American Physical Society.
Kopp J.,Max Planck Institute for Nuclear Physics
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013
We use recently released data on the positron-to-electron ratio in cosmic rays from the AMS-02 experiment to constrain dark matter annihilation in the Milky Way. Due to the yet unexplained positron excess, limits are generally weaker than those obtained using other probes, especially gamma rays. This also means that explaining the positron excess in terms of dark matter annihilation is difficult. Only if very conservative assumptions on the dark matter distribution in the Galactic center region are adopted, it may be possible to accommodate dark matter annihilating to leptons with a cross section above 10-24 cm3/seca. We comment on several theoretical mechanisms to explain such large annihilation cross sections. © 2013 American Physical Society.
Zhang H.,Max Planck Institute for Nuclear Physics
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012
Motivated by the recent observations on sterile neutrinos, we present a minimal extension of the canonical type-I seesaw by adding one extra singlet fermion. After the decoupling of right-handed neutrinos, an eV-scale mass eigenstate is obtained without the need of artificially inserting tiny mass scales or Yukawa couplings for sterile neutrinos. In particular, the active-sterile mixing is predicted to be of the order of 0.1. Moreover, we show a concrete flavor A 4 model, in which the required structures of the minimal extended seesaw are realized. We also comment on the feasibility of accommodating a keV sterile neutrino as an attractive candidate for warm dark matter. © 2012 Elsevier B.V.
Voitkiv A.B.,Max Planck Institute for Nuclear Physics
Physical Review Letters | Year: 2013
Transfer ionization in fast collisions between a bare ion and an atom, in which one of the atomic electrons is captured by the ion whereas another one is emitted, crucially depends on dynamic electron-electron correlations. We show that in collisions with a highly charged ion a strong field of the ion has a very profound effect on the correlated channels of transfer ionization. In particular, this field weakens (strongly suppresses) electron emission into the direction opposite (perpendicular) to the motion of the ion. Instead, electron emission is redirected into those parts of the momentum space which are very weakly populated in fast collisions with low charged ions. © 2013 American Physical Society.
Weidenmuller H.A.,Max Planck Institute for Nuclear Physics
Physical Review Letters | Year: 2011
A zeptosecond multi-MeV laser pulse may either excite a "plasma" of strongly interacting nucleons or a collective mode. We derive the conditions on laser energy and photon number such that either of these scenarios is realized. We use the nuclear giant dipole resonance as a representative example, and a random-matrix description of the fine-structure states and perturbation theory as tools. © 2011 American Physical Society.
Rodejohann W.,Max Planck Institute for Nuclear Physics
Journal of Physics G: Nuclear and Particle Physics | Year: 2012
The connection of neutrino physics with the neutrinoless double-beta decay is reviewed. After presenting the current status of the Pontecorvo-Maki- Nakagawa-Sakata matrix and the theoretical background of neutrino mass and lepton mixing, we will summarize the various implications of neutrino physics for the double-beta decay. The influence of light sterile neutrinos and other exotic modifications of the three neutrino picture is also discussed. © 2012 IOP Publishing Ltd.
Di Piazza A.,Max Planck Institute for Nuclear Physics
Physical Review Letters | Year: 2014
The feasibility of obtaining exact analytical results in the realm of QED in the presence of a background electromagnetic field is almost exclusively limited to a few tractable cases, where the Dirac equation in the corresponding background field can be solved analytically. This circumstance has restricted, in particular, the theoretical analysis of QED processes in intense laser fields to within the plane wave approximation even at those high intensities, achievable experimentally only by tightly focusing the laser energy in space. Here, within the Wentzel-Kramers-Brillouin approximation, we construct analytically single-particle electron states in the presence of a background electromagnetic field of general space-time structure in the realistic assumption that the initial energy of the electron is the largest dynamical energy scale in the problem. The relatively compact expression of these states opens, in particular, the possibility of investigating analytically strong-field QED processes in the presence of spatially focused laser beams, which is of particular relevance in view of the upcoming experimental campaigns in this field. © 2014 American Physical Society.
Gu P.-H.,Max Planck Institute for Nuclear Physics
Physics of the Dark Universe | Year: 2013
We propose a model of multi-component dark matter with magnetic moments to explain the 130 GeV gamma-ray line hinted by the Fermi-LAT data. Specifically, we consider a U (1). X dark sector which contains two vector-like fermions besides the related gauge and Higgs fields. A very heavy messenger scalar is further introduced to construct the Yukawa couplings of the dark fermions to the heavy [SU (2)]-singlet leptons in the SU(3)c × SU(2)L × SU(2)R × U(1)B-L left-right symmetric models for universal seesaw. A heavier dark fermion with a very long lifetime can mostly decay into a lighter dark fermion and a photon at one-loop level. The dark fermions can serve as the dark matter particles benefited from their annihilations into the dark gauge and Higgs fields. In the presence of a U (1) kinetic mixing, the dark matter fermions can be verified by the ongoing and forthcoming dark matter direct detection experiments. © 2013 Pei-Hong Gu.
Fileviez Perez P.,Max Planck Institute for Nuclear Physics
Physics Reports | Year: 2015
The possible discovery of proton decay, neutron-antineutron oscillation, neutrinoless double beta decay in low energy experiments, and exotic signals related to the violation of the baryon and lepton numbers at collider experiments will change our understanding of the conservation of fundamental symmetries in nature. In this review we discuss the rare processes due to the existence of baryon and lepton number violating interactions. The simplest grand unified theories and the neutrino mass generation mechanisms are discussed. The theories where the baryon and lepton numbers are defined as local gauge symmetries spontaneously broken at the low scale are discussed in detail. The simplest supersymmetric gauge theory which predicts the existence of lepton number violating processes at the low scale is investigated. The main goal of this review is to discuss the main implications of baryon and lepton number violation in physics beyond the Standard Model. © 2015 Elsevier B.V.