121526925
EURECA: The European future of dark matter searches with cryogenic detectors
EURECA (European Underground Rare Event Calorimeter Array) is a new project, searching for dark matter, with largely the present groups of the CRESST and EDELWEISS experiments and already a few new groups. The aim is to explore scalar cross sections in the 10 −9 –10 −10 picobarn region with a target mass of up to one tonne. A major advantage of EURECA is our planned use of more that just one target material (multi target experiment for WIMP identification). In preparation for this large-scale experiment, R&D for EURECA is provided through the current phases of CRESST and EDELWEISS.
122869103
Evidence for Solar-Wind Charge-Exchange X-Ray Emission from the Earth’s Magnetosheath
122921889
SIMULATION OF LOW ENERGY NEUTRON RECOILS WITH GEANT4
119176850
The CRESST II Dark Matter Search
Direct Dark Matter detection with cryodetectors is briefly discussed, with particular mention of the possibility of the identification of the recoil nucleus. Preliminary results from the CRESST II Dark Matter search, with 730 kg-days of data, are presented. Major backgrounds and methods of identifying and dealing with them are indicated.
119283621
Results from 730 kg days of the CRESST-II Dark Matter search
The CRESST-II cryogenic Dark Matter search, aiming at detection of WIMPs via elastic scattering off nuclei in CaWO4 crystals, completed 730 kg days of data taking in 2011. We present the data collected with eight detector modules, each with a two-channel readout; one for a phonon signal and the other for coincidently produced scintillation light. The former provides a precise measure of the energy deposited by an interaction, and the ratio of scintillation light to deposited energy can be used to discriminate different types of interacting particles and thus to distinguish possible signal events from the dominant backgrounds.Sixty-seven events are found in the acceptance region where a WIMP signal in the form of low energy nuclear recoils would be expected. We estimate background contributions to this observation from four sources: (1) “leakage” from the e/γ-band (2) “leakage” from the α-particle band (3) neutrons and (4) 206Pb recoils from 210Po decay. Using a maximum likelihood analysis, we find, at a statistical significance of more than 4σ, that these sources alone are not sufficient to explain the data. The addition of a signal due to scattering of relatively light WIMPs could account for this discrepancy, and we determine the associated WIMP parameters.
12512718
High-resolution X-ray spectroscopy and imaging of the nuclear outflow of the starburst galaxy NGC 253
Aims. Using XMM-Newton  data, we have studied the nuclear outflow of the nearby starburst galaxy NGC 253 in X-rays with respect to its morphology and to spectral variations along the outflow. Methods. We analysed XMM-Newton  RGS spectra, RGS brightness profiles in cross-dispersion direction, narrow-band RGS and EPIC images, and EPIC PN brightness profiles of the nuclear region and of the outflow from NGC 253. Results. We detect a diversity of emission lines along the outflow of NGC 253. This includes the He-like ions of Si, Mg, Ne, and O and their corresponding ions in the next higher ionisation state. Additionally transitions from $\ion{Fe}{xvii}$ and $\ion{Fe}{xviii}$ are prominent. The derived temperatures from line ratios along the outflow range from 0.21 ± 0.01 to 0.79 ± 0.06 keV, and the ratio of $\ion{Fe}{xvii}$ lines indicates a predominantly collisionally ionised plasma. Additionally, we see indications of either a recombining or an underionised plasma in the $\ion{Fe}{xvii}$ line ratio. Derived electron densities are 0.106 ± 0.018 cm -3 for the nuclear region and 0.025 ± 0.003 cm -3 for the outflow region closest to the centre. The RGS image in the $\ion{O}{viii}$ line energy clearly shows the morphology of an outflow extending out to ~750 pc along the southeast minor axis, while the northwest part of the outflow is not seen in $\ion{O}{viii}$ due to the heavy absorption by the galactic disc. This is the first time that the hot wind fluid has been detected directly. The limb brightening in Chandra  and XMM-Newton  EPIC observations is only seen in the energy range that contains the $\ion{Fe}{xvii}$ lines (550-750 eV). In all other energy ranges between 400 and 2000 eV, no clear evidence of limb brightening could be detected.
4976848
Exotic leptons: Higgs, flavor and collider phenomenology
A bstractWe study extensions of the standard model by one generation of vector-like leptons with non-standard hypercharges, which allow for a sizable modification of the h → γγ decay rate for new lepton masses in the 300 GeV-1 TeV range. We analyze vacuum stability implications for different hypercharges. Effects in h → Zγ are typically much smaller than in h → γγ, but distinct among the considered hypercharge assignments. Non-standard hypercharges constrain or entirely forbid possible mixing operators with standard model leptons. As a consequence, the leading contributions to the experimentally strongly constrained electric dipole moments of standard model fermions are only generated at the two loop level by the new CP violating sources of the considered setups. We derive the bounds from dipole moments, electro-weak precision observables and lepton flavor violating processes, and discuss their implications. Finally, we examine the production and decay channels of the vector-like leptons at the LHC, and find that signatures with multiple light leptons or taus are already probing interesting regions of parameter space.
119268040
Constraining RS Models by Future Flavor and Collider Measurements: A Snowmass Whitepaper
Randall-Sundrum models are models of quark flavor, because they explain the hierarchies in the quark masses and mixings in terms of order one localization parameters of extra dimensional wavefunctions. The same small numbers which generate the light quark masses suppress contributions to flavor violating tree level amplitudes. In this note we update universal constraints from electroweak precision parameters and demonstrate how future measurements of flavor violation in ultra rare decay channels of Kaons and B mesons will constrain the parameter space of this type of models. We show how collider signatures are correlated with these flavor measurements and compute projected limits for direct searches at the 14 TeV LHC run, a 14 TeV LHC luminosity upgrade, a 33 TeV LHC energy upgrade, and a potential 100 TeV machine. We further discuss the effects of a warped model of leptons in future measurements of lepton flavor violation.
38251987
Solution to the flavor problem of warped extra-dimension models.
A minimal solution to the flavor problem of warped extra-dimension models, i.e., the excessive mixed-chirality contribution to CP violation in K-K ¯ mixing arising from Kaluza-Klein (KK) gluon exchange, is proposed. Extending the strong-interaction gauge group in the bulk by an additional SU(3), and breaking this symmetry to QCD via boundary conditions, the constraints arising from the ε(K) parameter are significantly relaxed. As a result, KK scales M(KK)~2 TeV are consistent with all flavor observables without significant fine-tuning. The model predicts an extended Higgs sector featuring massive color-octet scalars and a tower of KK pseudoaxial gluon resonances, whose existence is not in conflict with recent LHC dijet bounds.
118577113
Real Time Imaging of Quantum and Thermal Fluctuations: The Case of a Two-Level System
A quantum system in contact with a heat bath undergoes quantum transitions between energy levels upon absorption or emission of energy quanta by the bath. These transitions remain virtual unless the energy of the system is measured repeatedly, even continuously in time. Isolating the two indispensable mechanisms in competition, we describe in a synthetic way the main physical features of thermally activated quantum jumps. Using classical tools of stochastic analysis, we compute in the case of a two-level system the complete statistics of jumps and transition times in the limit when the typical measurement time is small compared to the thermal relaxation time. The emerging picture is that quantum trajectories are similar to those of a classical particle in a noisy environment, subject to transitions à la Kramer in a multi-well landscape, but with a large multiplicative noise.
5911478
Phase transition with the Berezinskii-Kosterlitz-Thouless singularity in the Ising model on a growing network.
We consider the ferromagnetic Ising model on a highly inhomogeneous network created by a growth process. We find that the phase transition in this system is characterized by the Berezinskii-Kosterlitz-Thouless singularity, although critical fluctuations are absent and the mean-field description is exact. Below this infinite order transition, the magnetization behaves as exp((-const/square root of(Tc-T)). We show that the critical point separates the phase with the power-law distribution of the linear response to a local field and the phase where this distribution rapidly decreases. We suggest that this phase transition occurs in a wide range of cooperative models with a strong infinite-range inhomogeneity.