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Related papers: Maximum Likelihood Compton Polarimetry with the Co…

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We report a high precision measurement of electron beam polarization using Compton polarimetry. The measurement was made in experimental Hall A at Jefferson Lab during the CREX experiment in 2020. A total uncertainty of dP/P=0.36% was…

Measurement of gamma-ray polarization can provide valuable insight in different areas of physics. A possible application is in Positron Emission Tomography, where annihilation quanta with orthogonal polarizations are emitted. Since…

Instrumentation and Detectors · Physics 2020-02-26 Mihael Makek , Damir Bosnar , Luka Pavelić , Pavla Šenjug , Petar Žugec

We develop two algorithms, based on maximum likelihood (ML) inference, for estimating the parameters of polarized radio sources which emit at a single rotation measure (RM), e.g., pulsars. These algorithms incorporate the flux density…

Instrumentation and Methods for Astrophysics · Physics 2017-10-25 D. H. F. M. Schnitzeler , K. J. Lee

A Compton camera is the most promising approach for gamma-ray detection in the energy region from several hundred keV to MeV, especially for application in high energy astrophysics. In order to obtain good angular resolution, semiconductor…

We describe an optimal signal extraction process for imaging X-ray polarimetry using an ensemble of deep neural networks. The initial photo-electron angle, used to recover the polarization, has errors following a von Mises distribution.…

Instrumentation and Methods for Astrophysics · Physics 2021-10-20 A. L. Peirson , R. W. Romani

Using the RHESSI satellite as a Compton polarimeter, a recent study claimed that the prompt emission of GRB021206 was almost fully linearly polarized. This was challenged by a subsequent reanalysis. We present an novel approach, applying…

Astrophysics · Physics 2008-04-22 C. Wigger , W. Hajdas , K. Arzner , M. Güdel , A. Zehnder

We present recent improvements in polarization analysis with the INTEGRAL SPI data. The SPI detector plane consists of 19 independent Ge crystals and can operate as a polarimeter. The anisotropy characteristics of Compton diffusions can…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 M. Chauvin , J. P. Roques , D. J. Clark , E. Jourdain

We have developed a maximum likelihood source detection method capable of detecting ultra-faint streaks with surface brightnesses approximately an order of magnitude fainter than the pixel level noise. Our maximum likelihood detection…

Instrumentation and Methods for Astrophysics · Physics 2016-09-26 William A. Dawson , Michael D. Schneider , Chandrika Kamath

For the 1994/95 run of the SLD experiment at SLAC, a Compton polarimeter measured the luminosity-weighted electron beam polarization to be (77.2 +- 0.5)%. This excellent accuracy is achieved by measuring the rate asymmetry of…

High Energy Physics - Experiment · Physics 2007-05-23 M. Woods , representing the SLD collaboration

The spectrometer aboard INTEGRAL, SPI, has the capability to detect the signature of polarised emission from a bright gamma-ray source. GRB 041219a is the most intense burst localised by INTEGRAL and is an ideal candidate for such a study.…

Astrophysics · Physics 2009-11-13 S. McGlynn , D. J. Clark , A. J. Dean , L. Hanlon , S. McBreen , D. R. Willis , B. McBreen , A. J. Bird , S. Foley

We examine the potential for gamma-ray conversion to electron-positron pairs, either in the field of a nucleus or of an electron of a detector, to measure the fraction P of linear polarization of cosmic gamma sources. For this purpose we…

Instrumentation and Methods for Astrophysics · Physics 2013-09-27 Denis Bernard

The nature of the prompt gamma-ray emission of Gamma-Ray Bursts (GRBs) is still far from being completely elucidated. The measure of linear polarization is a powerful tool that can be used to put further constraints on the content and…

High Energy Astrophysical Phenomena · Physics 2015-06-22 D. Gotz , P. Laurent , S. Antier , S. Covino , P. D'Avanzo , V. D'Elia , A. Melandri

We propose detecting dark photons (DP), a major candidate for wave dark matter, through polarimetry. The DP can modify Maxwell's equations due to its kinetic mixing with regular photons, inducing an oscillating component in the…

High Energy Physics - Phenomenology · Physics 2025-09-03 Fiesta Ting Yan Leung , Tao Liu , Sida Lu , Jing Ren , Cheuk Kan Kelvin Yue , Kaifeng Zheng

In this paper, we propose a maximum smoothed likelihood method to estimate the component density functions of mixture models, in which the mixing proportions are known and may differ among observations. The proposed estimates maximize a…

Methodology · Statistics 2014-07-14 Tao Yu , Pengfei Li , Jing Qin

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in…

Astrophysics · Physics 2009-11-07 M. P. Hobson , Klaus Maisinger

We report on the highest precision yet achieved in the measurement of the polarization of a low energy, $\mathcal{O}$(1 GeV), electron beam, accomplished using a new polarimeter based on electron-photon scattering, in Hall~C at Jefferson…

This paper explores methods for constructing low multipole temperature and polarisation likelihoods from maps of the cosmic microwave background anisotropies that have complex noise properties and partial sky coverage. We use Planck 2018…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-26 Roger de Belsunce , Steven Gratton , William Coulton , George Efstathiou

A long duration gamma-ray burst, GRB 160530A, was detected by the Compton Spectrometer and Imager (COSI) during the 2016 COSI Super Pressure Balloon campaign. As a Compton telescope, COSI is inherently sensitive to the polarization of…

We investigate the nonlinear Compton photon source for upcoming laser-particle experiments in the collision scenario of high-energy electron beams and relativistic laser pulses. The stronger laser field could not only improve the scattering…

High Energy Physics - Phenomenology · Physics 2025-05-23 Yu Xin , Zu-dong Zhao , Suo Tang