11,869 research outputs found
Anomaly Detection for Resonant New Physics with Machine Learning
Despite extensive theoretical motivation for physics beyond the Standard
Model (BSM) of particle physics, searches at the Large Hadron Collider (LHC)
have found no significant evidence for BSM physics. Therefore, it is essential
to broaden the sensitivity of the search program to include unexpected
scenarios. We present a new model-agnostic anomaly detection technique that
naturally benefits from modern machine learning algorithms. The only
requirement on the signal for this new procedure is that it is localized in at
least one known direction in phase space. Any other directions of phase space
that are uncorrelated with the localized one can be used to search for
unexpected features. This new method is applied to the dijet resonance search
to show that it can turn a modest 2 sigma excess into a 7 sigma excess for a
model with an intermediate BSM particle that is not currently targeted by a
dedicated search.Comment: Replaced with short PRL version. 7 pages, 2 figures. Revised long
version will be submitted separatel
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Methods of Studying False Memory
The study of memory is one of those domains in psychology which has clear practical relevance. Think, for example, about people with Alzheimer’s disease. Devastating dysfunction experienced by these patients makes it abundantly evident that our memory constitutes an overarching and critical role in our daily life. However, in the study of memory, there is another memory phenomenon that also carries with it enormous theoretical and practical implications, namely, memory illusions. That is, people frequently claim that they remember details or even an entire event that never actually happened. These false memories can have serious consequences when they appear in the testimony of witness, victims, or suspects in legal cases (Howe & Knott, 2015; Otgaar, De Ruiter, Howe, Hoetmer, & van Reekum, in press). A person, for example, might falsely remember that he/she was sexually abused when he/she was a child, and this memory illusion might lead to false accusations that may result in wrongful convictions
L-branes
The superembedding approach to -branes is used to study a class of
-branes which have linear multiplets on the worldvolume. We refer to these
branes as L-branes. Although linear multiplets are related to scalar multiplets
(with 4 or 8 supersymmetries) by dualising one of the scalars of the latter to
a -form field strength, in many geometrical situations it is the linear
multiplet version which arises naturally. Furthermore, in the case of 8
supersymmetries, the linear multiplet is off-shell in contrast to the scalar
multiplet. The dynamics of the L-branes are obtained by using a systematic
procedure for constructing the Green-Schwarz action from the superembedding
formalism. This action has a Dirac-Born-Infeld type structure for the -form.
In addition, a set of equations of motion is postulated directly in superspace,
and is shown to agree with the Green-Schwarz equations of motion.Comment: revised version, minor changes, references added, 22 pages, no
figures, LaTe
Solar Rotation Rate During the Cycle 24 Minimum in Activity
The minimum of solar cycle 24 is significantly different from most other
minima in terms of its duration as well as its abnormally low levels of
activity. Using available helioseismic data that cover epochs from the minimum
of cycle 23 to now, we study the differences in the nature of the solar
rotation between the minima of cycles 23 and 24. We find that there are
significant differences between the rotation rates during the two minima. There
are differences in the zonal-flow pattern too. We find that the band of fast
rotating region close to the equator bifurcated around 2005 and recombined by
2008. This behavior is different from that during the cycle 23 minimum. By
auto-correlating the zonal-flow pattern with a time shift, we find that in
terms of solar dynamics, solar cycle 23 lasted for a period of 11.7 years,
consistent with the result of Howe et al. (2009). The autocorrelation
coefficient also confirms that the zonal-flow pattern penetrates through the
convection zone.Comment: Accepted for publication in Ap
Believing Does Not Equal Remembering: The Effects of Social Feedback and Objective False Evidence on Belief in Occurrence, Belief in Accuracy, and Recollection
We examined the impact of social feedback and objective false evidence on belief in occurrence, belief in accuracy, and recollection of an autobiographical experience. Participants viewed six virtual scenes (e.g., park) and were tested on their belief/recollection. After 1-week, participants were randomly assigned to four groups. One group received social feedback that one scene was not experienced. A second group received objective false evidence that one of the scenes was not shown. A third group received both social feedback and objective false evidence and the control group did not receive any manipulation. Belief in occurrence dropped considerably in the social feedback group and in the combined group. Also, nonbelieved memories were most likely to occur in participants receiving both social feedback and objective false evidence. We show that social feedback and objective false evidence undermine belief in occurrence, but that they leave belief in accuracy and recollection unaffected
Multiplicity, Invariants and Tensor Product Decomposition of Tame Representations of U(\infty)
The structure of r-fold tensor products of irreducible tame representations
of the inductive limit U(\infty) of unitary groups U(n) are are described,
versions of contragredient representations and invariants are realized on
Bargmann-Segal-Fock spaces.Comment: 48 pages, LaTeX file, to appear in J. Math. Phy
Rotor eddy-current loss in permanent magnet brushless machines
This paper presents an analysis of the rotor eddy-current loss in modular and conventional topologies of permanent magnet brushless machine. The loss is evaluated both analytically and by time-stepped finite-element analysis, and it is shown that it can be significant in both machine topologies. It is also shown that the loss can be reduced significantly by segmenting the magnets
MIT solar wind plasma data from Explorer 33 and Explorer 35: July 1966 to September 1970
The plasma experiments on Explorer 33 and Explorer 35 have yielded large amounts of solar wind data. This report gives a brief review of the method used to obtain the data, provides a description of the plasma parameters, and describes in detail the format of the plots and tapes which are available from the Data Center. Hourly average plots of the data are included at the end of the report. From these plots, the availability and interest of the solar wind data for any period of time may be determined
Low-degree multi-spectral p-mode fitting
We combine unresolved-Sun velocity and intensity observations at multiple wavelengths from the Helioseismic and Magnetic Imager and Atmospheric Imaging Array onboard the Solar Dynamics Observatory to investigate the possibility of multi-spectral mode-frequency estimation at low spherical harmonic degree. We test a simple multi-spectral algorithm using a common line width and frequency for each mode and a separate amplitude, background and asymmetry parameter, and compare the results with those from fits to the individual spectra. The preliminary results suggest that this approach may provide a more stable fit than using the observables separately
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