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Search for pair production of gluinos decaying via stop and sbottom in events with $b$-jets and large missing transverse momentum in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector
https://cds.cern.ch/record/2156666
A search for Supersymmetry involving the pair production of gluinos decaying via third-generation squarks to the lightest neutralino is reported. It uses an LHC proton--proton dataset at a center-of-mass energy $\sqrt{s} = 13$ TeV with an integrated luminosity of 3.2 fb$^{-1}$ collected with the ATLAS detector in 2015. The signal is searched for in events containing several energetic jets, of which at least three must be identified as $b$-jets, large missing transverse momentum and, potentially, isolated electrons or muons. Large-radius jets with a high mass are also used to identify highly boosted top quarks. No excess is found above the predicted background. For neutralino masses below approximately 700 GeV, gluino masses of less than 1.78 TeV and 1.76 TeV are excluded at the 95% CL in simplified models of the pair production of gluinos decaying via sbottom and stop, respectively. These results significantly extend the exclusion limits obtained with the $\sqrt{s} = 8$ TeV dataset.ATLAS CollaborationMon, 30 May 2016 15:37:33 GMT30 May 2016CERN-EP-2016-061https://cds.cern.ch/record/21566662016061Search for low mass Higgs-boson like resonances at CMS
https://cds.cern.ch/record/2156655
A search is performed on the 8 TeV LHC data for additional scalars and pseudoscalar with masses below the newly discovered higgs boson h(125). These searches are motivated within several BSM theories, most significantly extensions of the non mininal extensions of the MSSM like the NMSSM, where additional scalar and pseudoscalar states are expected. The mass range from 350 MeV to 110 GeV is explored with different final states. The current status of these searches will be reviewed and prospects will be given to extend these searches in the Run2 of the LHC.Courbon, BenoitMon, 30 May 2016 15:15:57 GMT26 May 2016CMS-CR-2016-106https://cds.cern.ch/record/21566552016106The scalar sector of the standard model
https://cds.cern.ch/record/2156654
Main results and references to original work.Flechl, MartinMon, 30 May 2016 15:15:34 GMT23 May 2016CMS-CR-2016-101https://cds.cern.ch/record/21566542016101Searches for supersymmetry in events with one or more leptons using the ATLAS and CMS experiments
https://cds.cern.ch/record/2156652
Recent results from searches for supersymmetry in final states with one or more leptons by the ATLAS and CMS collaborations are reported. The data for these results has been recorded in 2015 at $\sqrt{s}=13$\,TeV and amounts to an integrated luminosity of 2.2 - 2.3 fb$^{-1}$ for the CMS experiment and 3.2 fb$^{-1}$ for the ATLAS experiment. The results are interpreted in simplified models.Kirschenmann, HenningMon, 30 May 2016 15:14:18 GMT21 May 2016CMS-CR-2016-099https://cds.cern.ch/record/21566522016099Dark Matter search at LHC
https://cds.cern.ch/record/2156651
The results of recent searches for dark matter at the Large Hadron Collider at CERN are reported.The searches for dark matter performed with the first data collected during the LHC Run-2 by the CMS and ATLAS collaborations, corresponding to 2.1~\fb and 3.2~\fb of proton-proton collisions at $\sqrt{s}=13~\TeV$ respectively, are presented and categorized according to the event topology characteristics.No excesses are found above the standard model expectations and the results are interpreted in terms of upper limits in the production of dark matter using simplified theory models.The results are also translated into limits on the dark matter-nucleon spin-dependent and spin-independent cross section to compare with the results of direct detection experiments.Pazzini, JacopoMon, 30 May 2016 15:14:00 GMT17 May 2016CMS-CR-2016-098https://cds.cern.ch/record/21566512016098Search for W' production in the lepton+MET final state at 13 TeV in CMS
https://cds.cern.ch/record/2156650
This note presents the search for new physics in events with an electron or muon and missing transverse energy, using 2.2 $\rm{fb^{-1}}$ of pp collision data at a centre-of-mass energy of 13 $\rm{TeV}$, collected with the CMS detector during 2015. The focus is set on the potential production of a W' boson, as described by the Sequential Standard Model. No evidence of an excess relative to the standard model expectation is observed and upper limits at 95$\%$ confidence level are set on the production cross section times branching fractions of the W' boson, which are translated into lower limits for the new boson mass. Masses below 4.4 TeV are excluded when both the electron and muon final decay channels are combined together. These results significantly extend previously published limits.Escalante Del Valle, AlbertoMon, 30 May 2016 15:13:57 GMT13 May 2016CMS-CR-2016-094https://cds.cern.ch/record/21566502016094Search for New Physics in Z+MET channel at CMS
https://cds.cern.ch/record/2156649
Despite the great understanding of particle interactions in terms of the Standard Model and the recent discovery of the Higgs boson at the LHC, the Standard Model of particle physics can not yet explain various phenomena, such as neutrino masses or the Dark Matter halo in the galaxies. This talk presents new LHC Run II results of a search for New Physics in Z+MET channel, discussing the main experimental features along the uncertainties and finally giving an outlook for the future data in Run II.Brodski, MichaelMon, 30 May 2016 15:13:51 GMT03 May 2016CMS-CR-2016-066https://cds.cern.ch/record/21566492016066Generalized linear sampling method for elastic-wave sensing of heterogeneous fractures
https://cds.cern.ch/record/2156539
A theoretical foundation is developed for active seismic reconstruction of fractures endowed with spatially-varying interfacial condition (e.g.~partially-closed fractures, hydraulic fractures). The proposed indicator functional carries a superior localization property with no significant sensitivity to the fracture's contact condition, measurement errors, and illumination frequency. This is accomplished through the paradigm of the $F_\sharp$-factorization technique and the recently developed Generalized Linear Sampling Method (GLSM) applied to elastodynamics. The direct scattering problem is formulated in the frequency domain where the fracture surface is illuminated by a set of incident plane waves, while monitoring the induced scattered field in the form of (elastic) far-field patterns. The analysis of the well-posedness of the forward problem leads to an admissibility condition on the fracture's (linearized) contact parameters. This in turn contributes toward establishing the applicability of the $F_\sharp$-factorization method, and consequently aids the formulation of a convex GLSM cost functional whose minimizer can be computed without iterations. Such minimizer is then used to construct a robust fracture indicator function, whose performance is illustrated through a set of numerical experiments. For completeness, the results of the GLSM reconstruction are compared to those obtained by the classical linear sampling method (LSM).Pourahmadian, FatemehGuzina, Bojan BHaddar, HoussemMon, 30 May 2016 05:28:56 GMT10 May 2016arXiv:1605.08743https://cds.cern.ch/record/2156539['arXiv:1605.08743']arXiv:1605.08743Mind the scales: Harnessing spatial big data for infectious disease surveillance and inferences
https://cds.cern.ch/record/2156538
Spatial big data have the "velocity," "volume," and "variety" of big data sources and additional geographic information about the record. Digital data sources, such as medical claims, mobile phone call data records, and geo-tagged tweets, have entered infectious disease epidemiology as novel sources of data to complement traditional infectious disease surveillance. In this work, we provide examples of how spatial big data have been used thus far in epidemiological analyses and describe opportunities for these sources to improve public health coordination and disease mitigation strategies. In addition, we consider the technical, practical, and ethical challenges with the use of spatial big data in infectious disease surveillance and inference. Finally, we discuss the implications of the rising use of spatial big data in epidemiology to health risk communications, across-scale public health coordination, and public health policy recommendation.Lee, Elizabeth CAsher, Jason MGoldlust, SandraKraemer, John DLawson, Andrew BBansal, ShwetaMon, 30 May 2016 05:28:56 GMT27 May 2016arXiv:1605.08740https://cds.cern.ch/record/2156538['arXiv:1605.08740']arXiv:1605.08740Framing difficulties in quantum mechanics
https://cds.cern.ch/record/2156537
Students' difficulties in quantum mechanics may be the result of unproductive framing and not fundamental inability to solve the problems or misconceptions about physics content. We observed groups of students solving quantum mechanics problems in an upper-division physics course. Using the lens of the epistemological framing, we investigated four frames in our observational data: algorithmic math, conceptual math, algorithmic physics, and conceptual physics. We then used our framework to seek an underlying structure to the long lists of published difficulties that span many topics in quantum mechanics. We mapped descriptions of published difficulties into errors in epistemological framing and resource use. We analyzed descriptions of students' problem solving to find their frames, and compared students' framing to framing (and frame shifting) required by problem statements. We found three categories of error: mismatches between students' framing and problem statement framing; inappropriate or absent transitions between frames; and insufficient resource activation within an appropriate frame. Given this framework, we can predict the kinds of difficulties that will emerge for a given problem in quantum mechanics: a possible deeper structure to student difficulties.Modir, BaharThompson, John DSayre, Eleanor CMon, 30 May 2016 05:28:56 GMT27 May 2016arXiv:1605.08735https://cds.cern.ch/record/2156537['arXiv:1605.08735']arXiv:1605.08735Thermometry of Guided Molecular Beams from a Cryogenic Buffer-Gas Cell
https://cds.cern.ch/record/2156536
We present a comprehensive characterization of cold molecular beams from a cryogenic buffer-gas cell, providing an insight into the physics of buffer-gas cooling. Cold molecular beams are extracted from a cryogenic cell by electrostatic guiding, which is also used to measure their velocity distribution. Molecules' rotational-state distribution is probed via radio-frequency resonant depletion spectroscopy. With the help of complete trajectory simulations, yielding the guiding efficiency for all of the thermally populated states, we are able to determine both the rotational and the translational temperature of the molecules at the output of the buffer-gas cell. This thermometry method is demonstrated for various regimes of buffer-gas cooling and beam formation as well as for molecular species of different sizes, $\rm{CH_3F}$ and $\rm{CF_3CCH}$. Comparison between the rotational and translational temperatures provides evidence of faster rotational thermalization for the $\rm{CH_3F-He}$ system in the limit of low He density. In addition, the relaxation rates for different rotational states appear to be different.Wu, XGantner, TZeppenfeld, MChervenkov, SRempe, GMon, 30 May 2016 05:28:56 GMT27 May 2016arXiv:1605.08723https://cds.cern.ch/record/2156536['arXiv:1605.08723']arXiv:1605.08723Boosting the accuracy and speed of quantum Monte Carlo: size-consistency and time-step
https://cds.cern.ch/record/2156535
Diffusion Monte Carlo (DMC) simulations for fermions are becoming the standard to provide high quality reference data in systems that are too large to be investigated via quantum chemical approaches. DMC with the fixed-node approximation relies on modifications of the Green function to avoid singularities near the nodal surface of the trial wavefunction. We show that these modifications affect the DMC energies in a way that is not size-consistent, resulting in large time-step errors. Building on the modifications of Umrigar {\em et al.} and of DePasquale {\em et al.} we propose a simple Green function modification that restores size-consistency to large values of time-step; substantially reducing the time-step errors. The new algorithm also yields remarkable speedups of up to two orders of magnitude in the calculation of molecule-molecule binding energies and crystal cohesive energies, thus extending the horizons of what is possible with DMC.Zen, AndreaSorella, SandroGillan, Michael JMichaelides, AngelosAlfè, DarioMon, 30 May 2016 05:28:56 GMT27 May 2016arXiv:1605.08706https://cds.cern.ch/record/2156535['arXiv:1605.08706']arXiv:1605.08706Manifold boundaries give "gray-box" approximations of complex models
https://cds.cern.ch/record/2156534
We discuss a method of parameter reduction in complex models known as the Manifold Boundary Approximation Method (MBAM). This approach, based on a geometric interpretation of statistics, maps the model reduction problem to a geometric approximation problem. It operates iteratively, removing one parameter at a time, by approximating a high-dimension, but thin manifold by its boundary. Although the method makes no explicit assumption about the functional form of the model, it does require that the model manifold exhibit a hierarchy of boundaries, i.e., faces, edges, corners, hyper-corners, etc. We empirically show that a variety of model classes have this curious feature, making them amenable to MBAM. These model classes include models composed of elementary functions (e.g., rational functions, exponentials, and partition functions), a variety of dynamical system (e.g., chemical and biochemical kinetics, Linear Time Invariant (LTI) systems, and compartment models), network models (e.g., Bayesian networks, Markov chains, artificial neural networks, and Markov random fields), log-linear probability distributions, and models with symmetries. We discuss how MBAM recovers many common approximation methods for each model class and discuss potential pitfalls and limitations.Transtrum, Mark KMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08705https://cds.cern.ch/record/2156534['arXiv:1605.08705']arXiv:1605.08705Reply to "Comment on "Normalization of quasinormal modes in leaky optical cavities and plasmonic resonators" " by E. A. Muljarov and W. Langbein
https://cds.cern.ch/record/2156533
We refute all claims of the "Comment on "Normalization of quasinormal modes in leaky optical cavities and plasmonic resonators" " by E. A. Muljarov and W. Langbein (arXiv:1602.07278v1). Based entirely on information already contained in our original article (P. T. Kristensen, R.-C. Ge and S. Hughes, Physical Review A 92, 053810 (2015)), we dismiss every point of criticism as being completely unjustified and point out how important parts of our argumentation appear to have been overlooked by the Comment Authors. In addition, we provide additional calculations showing directly the link between the normalizations by Sauvan et al. and Muljarov et al., which were not included in our original article.Kristensen, Philip TrøstGe, Rong-ChunHughes, StephenMon, 30 May 2016 05:28:55 GMT16 May 2016arXiv:1605.08702https://cds.cern.ch/record/2156533['arXiv:1605.08702']arXiv:1605.08702Validity of the linear viscoelastic model for a polymer cylinder with ultrasonic hysteresis-type absorption in a nonviscous fluid
https://cds.cern.ch/record/2156532
A necessary condition for the validity of the linear viscoelastic model for a (passive) polymeric cylinder with an ultrasonic hysteresis-type absorption submerged in a non-viscous fluid requires that the absorption efficiency is positive (Qabs > 0) satisfying the law of the conservation of energy. This condition imposes restrictions on the values attributed to the normalized absorption coefficients for the compressional and shear-wave wavenumbers for each partial-wave mode n. The forbidden values produce negative axial radiation force, absorption and extinction efficiencies, as well as an enhancement of the scattering efficiency, not in agreement with the conservation of energy law. Numerical results for the radiation force, extinction, absorption and scattering efficiencies are performed for three viscoelastic (VE) polymer cylinders immersed in a non-viscous host liquid (i.e. water) with particular emphasis on the shear-wave absorption coefficient of the cylinder, the dimensionless size parameter and the partial-wave mode number n. Mathematical constraints are established for the non-dimensional absorption coefficients of the longitudinal and shear waves for a cylinder (i.e. 2D case) and a sphere (i.e. 3D case) in terms of the sound velocities in the VE material. The analysis suggests that the domain of validity for any viscoelastic model describing acoustic attenuation inside a lossy cylinder (or sphere) in a non-viscous fluid must be verified based upon the optical theorem.Mitri, F GFellah, Z E AMon, 30 May 2016 05:28:55 GMT13 May 2016arXiv:1605.08699https://cds.cern.ch/record/2156532['arXiv:1605.08699']arXiv:1605.08699Reactive strip method for mixing and reaction in two dimensions
https://cds.cern.ch/record/2156531
A numerical method to efficiently solve for mixing and reaction of scalars in a two-dimensional flow field at large P\'eclet numbers but otherwise arbitrary Damk\"ohler numbers is reported. We consider a strip of one reactant in a pool of another reactant, both of which are advected with the known velocity field. We first establish that the system evolution for such a system under certain conditions is described by a locally one-dimensional reaction-diffusion problem. The approximation of a locally one-dimensional dynamics is true for cases where the strip thickness is smaller than the local radius of curvature and also when the strip thickness is smaller than the distance between adjacent strips. We first demonstrate the method for the transport of a conservative scalar under a linear shear flow, point vortex and a chaotic sine flow. We then proceed to consider the situation with a simple bimolecular reaction between two reactants to yield a single product. The methodology presented herewith essentially generalizes nontrivially the Diffusive Strip Method developed by Meunier and Villermaux (J. Fluid Mech. 662, 134-172 (2010)) to address passive scalar transport, to the generalized situation with multiple reacting species. In essence, the reduction of dimensionality of the problem, which renders the 2D problem 1D, allows one to efficiently model reactive transport under high P\'eclet numbers which are otherwise prohibitively difficult to resolve from classical finite difference or finite element based methods.Bandopadhyay, AdityaBorgne, Tanguy LeMéheust, YvesMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08696https://cds.cern.ch/record/2156531['arXiv:1605.08696']arXiv:1605.08696Superconducting nanowire single-photon imager
https://cds.cern.ch/record/2156530
Detecting spatial and temporal information of individual photons is a crucial technology in today's quantum information science. Among the existing single-photon detectors, superconducting nanowire single-photon detectors (SNSPDs) have been demonstrated with a sub-50 ps timing jitter, near unity detection efficiency1, wide response spectrum from visible to infrared and ~10 ns reset time. However, to gain spatial sensitivity, multiple SNSPDs have to be integrated into an array, whose spatial and temporal resolutions are limited by the multiplexing circuit. Here, we add spatial sensitivity to a single nanowire while preserving the temporal resolution from an SNSPD, thereby turning an SNSPD into a superconducting nanowire single-photon imager (SNSPI). To achieve an SNSPI, we modify a nanowire's electrical behavior from a lumped inductor to a transmission line, where the signal velocity is slowed down to 0.02c (where c is the speed of light). Consequently, we are able to simultaneously read out the landing locations and arrival times of the photons from the output electrical pulses using only two connections. We have demonstrated single-photon imaging by using a 19.7 mm long SNSPI, which is meandered into an imaging area of 286 {\mu}m*193 {\mu}m. The nanowire has a temporal resolution of 50 ps for detecting 1.5 {\mu}m photons. The 2D spatial resolution is 13.0 {\mu}m in the vertical direction and 5.6 {\mu}m in the horizontal direction. The maximum number of resolvable locations (i.e., the effective number of pixels) in such a long nanowire is calculated to be 590. Rather than operating an individual detector in a scanning mode or using SPD arrays, this SNSPI gives an alternative approach to taking large-scale single-photon images and measuring temporal and spatial correlation.Zhao, Qing-YuanZhu, DiCalandri, NiccolòDane, Andrew EMcCaughan, Adam NBellei, FrancescoWang, Hao-ZhuSantavicca, Daniel FBerggren, Karl KMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08693https://cds.cern.ch/record/2156530['arXiv:1605.08693']arXiv:1605.08693The Role of Noise in the Spatial Public Goods Game
https://cds.cern.ch/record/2156528
In this work we aim to analyze the role of noise in the spatial Public Goods Game, one of the most famous games in Evolutionary Game Theory. The dynamics of this game is affected by a number of parameters and processes, namely the topology of interactions among the agents, the synergy factor, and the strategy revision phase. The latter is a process that allows agents to change their strategy. Notably, rational agents tend to imitate richer neighbors, in order to increase the probability to maximize their payoff. By implementing a stochastic revision process, it is possible to control the level of noise in the system, so that even irrational updates may occur. In particular, in this work we study the effect of noise on the macroscopic behavior of a finite structured population playing the Public Goods Game. We consider both the case of a homogeneous population, where the noise in the system is controlled by tuning a parameter representing the level of stochasticity in the strategy revision phase, and a heterogeneous population composed of a variable proportion of rational and irrational agents. In both cases numerical investigations show that the Public Goods Game has a very rich behavior which strongly depends on the amount of noise in the system and on the value of the synergy factor. To conclude, our study sheds a new light on the relations between the microscopic dynamics of the Public Goods Game and its macroscopic behavior, strengthening the link between the field of Evolutionary Game Theory and statistical physics.Javarone, Marco AlbertoBattiston, FedericoMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08690https://cds.cern.ch/record/2156528['arXiv:1605.08690']arXiv:1605.08690High accuracy position response calibration method for a micro-channel plate ion detector
https://cds.cern.ch/record/2156527
We have developed a position response calibration method for a micro-channel plate (MCP) detector with a delay-line anode position readout scheme. Using an {\em in situ} calibration mask, an accuracy of 8~$\mu$m and a resolution of 85~$\mu$m (FWHM) have been achieved for MeV-scale $\alpha$ particles and ions with energies of $\sim$10~keV. For high statistics experiments, this method can be directly employed with the experimental data without any dedicated calibration runs. The improved performance of the MCP detector can find applications in many fields of AMO and nuclear physics. In our case, it helps reducing systematic uncertainties in a high-precision nuclear $\beta$-decay experiment.Hong, RanLeredde, ArnaudBagdasarova, YelenaFlechard, XavierGarcia, AlejandroMueller, PeterKnecht, AndreasLienard, EtienneKossin, MichaelSternberg, Matthew GSwanson, H EZumwalt, David WMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08686https://cds.cern.ch/record/2156527['arXiv:1605.08686']arXiv:1605.08686The Dose Makes The Cooperation
https://cds.cern.ch/record/2156526
Explaining cooperation is one of the greatest challenges for basic scientific research. We proposed an agent-based model to study co-evolution of memory and cooperation. In our model, reciprocal agents with limited memory size play Prisoner's Dilemma Game iteratively. The characteristic of the environment, whether it is threatening or not, is embedded in the payoff matrix. Our findings are as follows. (i) Memory plays a critical role in the protection of cooperation. (ii) In the absence of threat, subsequent generations loose their memory and are consequently invaded by defectors. (iii) In contrast, the presence of an appropriate level of threat triggers the emergence of a self-protection mechanism for cooperation within subsequent generations. On the evolutionary level, memory size acts like an immune response of the population against aggressive defection. (iv) Even more extreme threat results again in defection. Our findings boil down to the following: The dose of the threat makes the cooperation.Cetin, UzayBingol, Haluk OMon, 30 May 2016 05:28:55 GMT21 May 2016arXiv:1605.08682https://cds.cern.ch/record/2156526['arXiv:1605.08682']arXiv:1605.08682Silicon Photonics WDM Transceiver with SOA and Semiconductor Mode-Locked Laser
https://cds.cern.ch/record/2156525
We demonstrate a complete Silicon Photonics WDM link relying on a single section semiconductor mode-locked laser and a single SOA to support up to 12 multiplexed channels with a bit error rate of 1e-12 at serial data rates of 14 Gbps without channel pre-emphasis, equalization or forward error correction. Individual channels reach error free operation at 25 Gbps and multi-channel operation at 25 Gbps is shown to be compatible with standard 7% overhead hard decision forward error correction. Silicon Photonics transmitter and receiver chips are hybridly integrated with driver and receiver electronics. A detailed link model is derived and verified. Particular emphasis is placed on accurate system level modeling of laser RIN, SOA amplified spontaneous emission noise and receiver noise. The impact of the electrical receiver bandwidth and non-Gaussian statistics on level dependent amplified spontaneous emission noise are investigated in detail. The channel count scalability as limited by SOA saturation is further analyzed taking cross gain modulation and four wave mixing into account. While semiconductor mode-locked lasers have been identified as a potential light source for low cost Datacom WDM transceivers for some time, this is, to the best of our knowledge, the first comprehensive investigation of the overall link budget in a Silicon Photonics implementation showing this technology to be a credible contender for low latency datacenter interconnects.Moscoso-Mártir, AlvaroMüller, JulianaHauck, JohannesChimot, NicolasSetter, RonyBadihi, AvnerRasmussen, Daniel EGarreau, AlexandreNielsen, MadsIslamova, ElmiraRomero-García, SebastiánShen, BinSandomirsky, AnnaRockman, SylvieLi, ChaoAzadeh, Saeed SharifLo, Guo-QiangMentovich, EladMerget, FlorianLelarge, FrançoisWitzens, JeremyMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08668https://cds.cern.ch/record/2156525['arXiv:1605.08668']arXiv:1605.08668Statistical properties of the one-dimensional Burridge-Knopoff model of earthquakes obeying the rate and state dependent friction law
https://cds.cern.ch/record/2156524
Statistical properties of the homogeneous one-dimensional spring-block (Burridge-Knopoff) model of earthquakes obeying the rate and state dependent friction law are studied by extensive computer simulations. The quantities computed include the magnitude distribution, the rupture-length distribution, the mainshock recurrence-time distribution, the seismic time correlations before and after the mainshock, the mean slip amount and the mean stress drop at the mainshock, etc. Events of the model can be classified into two distinct categories. One tends to be unilateral with its epicenter located at the rim of the rupture zone of the preceding event, while the other tends to be bilateral with enhanced "characteristic" features resembling the so-called "asperity". For both types events, the distribution of the rupture length L_r exhibits an exponential behavior at larger sizes, exp[-L_r/L_0] with a characteristic "seismic correlation length" L_0. The continuum limit of the model is examined, where the model is found to exhibit pronounced characteristic features. In the continuum limit, the characteristic rupture length L_0 is estimated to be ~100 [km]. This means that, even in a hypothetical homogenous infinite fault, events cannot be indefinitely large, the upper limit being of order ~10^3 kilometers. The mean slip as well as the mean stress drop tends to be rupture-length (L_r) independent for larger events of L_r > 200[km]. Implications to real seismicity are discussed.Kawamura, HikaruUeda, YushiKakui, ShingoMorimoto, SyoujiYamamoto, TakumiMon, 30 May 2016 05:28:55 GMT27 May 2016arXiv:1605.08659https://cds.cern.ch/record/2156524['arXiv:1605.08659']arXiv:1605.08659Scale invariance and scaling law of Thomson backscatter spectra by electron moving in laser-magnetic resonance regime
https://cds.cern.ch/record/2156523
The Thomson scattering spectra by an electron moving in the laser-magnetic resonance acceleration regime are computed numerically and analytically. The dependence of fundamental frequency on the laser intensity and magnetic resonance parameter is examined carefully. By calculating the emission of a single electron in a circularly polarized plane-wave laser field and constant external magnetic field, the scale invariance of the radiation spectra is evident in terms of harmonic orders. The scaling law of backscattered spectra are exhibited remarkably for the laser intensity as well for the initial axial momentum of the electron when the cyclotron frequency of the electron approaches the laser frequency. The results indicate that the magnetic resonance parameter plays an important role on the strength of emission. And the rich features of scattering spectra found may be applicable to the radiation source tunability.Fu, Yi-JiaLv, ChongWan, FengSang, Hai-BoXie, Bai-SongMon, 30 May 2016 05:28:55 GMT25 May 2016arXiv:1605.08647https://cds.cern.ch/record/2156523['arXiv:1605.08647']arXiv:1605.08647Noise-induced standing waves in oscillatory systems with time-delayed feedback
https://cds.cern.ch/record/2156522
In oscillatory reaction-diffusion systems, time-delay feedback can lead to the instability of uniform oscillations with respect to formation of standing waves. Here, we investigate how the presence of additive, Gaussian white noise can induce the appearance of standing waves. Combining analytical solutions of the model with spatio-temporal simulations, we find that noise can promote standing waves in regimes where the deterministic uniform oscillatory modes are stabilized. As the deterministic phase boundary is approached, the spatio-temporal correlations become stronger, such that even small noise can induce standing waves in this parameter regime. With larger noise strengths, standing waves could be induced at finite distances from the (deterministic) phase boundary. The overall dynamics is defined through the interplay of noisy forcing with the inherent reaction-diffusion dynamics.Stich, MichaelChattopadhyay, Amit KMon, 30 May 2016 05:28:54 GMT27 May 2016arXiv:1605.08646https://cds.cern.ch/record/2156522['arXiv:1605.08646']arXiv:1605.08646Bright-dark vector soliton solutions for the coupled complex short pulse equations in nonlinear optics
https://cds.cern.ch/record/2156520
Under investigation in this paper are the coupled complex short pulse equations, which describe the propagation of ultra-short optical pulses in cubic nonlinear media.Through the Hirota method, bright-dark one- and two-soliton solutions are obtained. Interactions between two bright or two dark solitons are verified to be elastic through the asymptotic analysis. With different parameter conditions of the vector bright-dark two solitons, the oblique interactions, bound states of solitons and parallel solitons are analyzed.Guo, Bo-LingWang, Yu-FengMon, 30 May 2016 05:28:54 GMT25 Apr 2016arXiv:1605.08622https://cds.cern.ch/record/2156520['arXiv:1605.08622']arXiv:1605.08622