Author: Publisher: ISBN: Category : Languages : en Pages : 125
Book Description
MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. This proposal presents the MeV-GeV DM discovery potential for a $\sim$1 m$^3$ segmented CsI(Tl) scintillator detector placed downstream of the Hall A beam-dump at Jefferson Lab, receiving up to 10$^{22}$ electrons-on-target (EOT) in 285 days. This experiment (Beam-Dump eXperiment or BDX) would be sensitive to elastic DM-electron and to inelastic DM scattering at the level of 10 counts per year, reaching the limit of the neutrino irreducible background. The distinct signature of a DM interaction will be an electromagnetic shower of few hundreds of MeV, together with a reduced activity in the surrounding active veto counters. A detailed description of the DM particle $\chi$ production in the dump and subsequent interaction in the detector has been performed by means of Monte Carlo simulations. Different approaches have been used to evaluate the expected backgrounds: the cosmogenic background has been extrapolated from the results obtained with a prototype detector running at INFN-LNS (Italy), while the beam-related background has been evaluated by GEANT4 Monte Carlo simulations. The proposed experiment will be sensitive to large regions of DM parameter space, exceeding the discovery potential of existing and planned experiments in the MeV-GeV DM mass range by up to two orders of magnitude.
Author: Publisher: ISBN: Category : Languages : en Pages : 7
Book Description
The existence of MeV-GeV dark matter (DM) is theoretically well motivated but remarkably unexplored. The Beam Dump eXperiment (BDX) at Jefferson Laboratory aims to investigate this mass range. Dark matter particles will be detected through scattering on a segmented, plastic scintillator detector placed downstream of the beam-dump at one of the high intensity JLab experimental Halls. The experiment will collect up to 1022 electrons-on-target (EOT) in a one-year period. For these conditions, BDX is sensitive to the DM-nucleon elastic scattering at the level of a thousand counts per year, and is only limited by cosmogenic backgrounds. The experiment is also sensitive to DM-electron elastic and inelastic scattering, at the level of 10 counts/year. The foreseen signal for these channels is a high-energy (> 100 MeV) electromagnetic shower, with almost no background. The experiment has been presented in form of a Letter of Intent to the laboratory, receiving positive feedback, and is currently being designed.
Author: Marco Fabbrichesi Publisher: Springer Nature ISBN: 3030625192 Category : Science Languages : en Pages : 85
Book Description
This book is about the dark photon which is a new gauge boson whose existence has been conjectured. Due to its interaction with the ordinary, visible photon, such a particle can be experimentally detected via specific signatures. In this book, the authors review the physics of the dark photon from the theoretical and experimental point of view. They discuss the difference between the massive and the massless case, highlighting how the two phenomena arise from the same vector portal between the dark and the visible sector. A review of the cosmological and astrophysical observations is provided, together with the connection to dark matter physics. Then, a perspective on current and future experimental limits on the parameters of the massless and massive dark photon is given, as well as the related bounds on milli-charged fermions. The book is intended for graduate students and young researchers who are embarking on dark photon research, and offers them a clear and up-to-date introduction to the subject.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
A variety of Dark Matter particle candidates have been hypothesized by physics Beyond the Standard Model (BSM) in the very light (10−6 - 10−3 eV) range. In the past decade several international groups have conducted laboratory experiments designed to either produce such particles or extend the boundaries in parameter space. The LIght Pseudo-scalar and Scalar Search (LIPSS) Collaboration, using the 'Light Shining through a Wall' (LSW) technique, passes the high average power photon beam from Jefferson Lab's Free-Electron Laser through a magnetic field upstream from a mirror and optical beam dump. Light Neutral Bosons (LNBs), generated by coupling of photons with the magnetic field, pass through the mirror ('the Wall') into an identical magnetic field where they revert to detectable photons by the same coupling process. While no evidence of LNBs was evident, new scalar coupling boundaries were established. New constraints were also determined for hypothetical para-photons and for millicharged fermions. We will describe our experimental setup and results for LNBs, para-photons, and milli-charged fermions. Plans for chameleon particle searches are underway.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
Cosmological observations indicate that our universe contains dark matter (DM), yet we have no measurements of its microscopic properties. Whereas the gravitational interaction of DM is well understood, its interaction with the Standard Model is not. Direct detection experiments, the current standard, search for a nuclear recoil interaction and have a low-mass sensitivity edge of order 1 GeV. A path to detect DM with mass below 1 GeV is the use of accelerators producing boosted low-mass DM. Using neutrino detectors to search for low-mass DM is logical due to the similarity of the DM and neutrino signatures in the detector. The MiniBooNE experiment, located at Fermilab on the Booster Neutrino Beamline, has produced the first proton beam-dump light DM search results. Using dark matter scattering from nucleons 90% confidence limits were set over a large parameter space and, to allow tests of other theories, a model independent DM rate was extracted.
Author: Publisher: ISBN: Category : Languages : en Pages :
Book Description
The MiniBooNE-DM collaboration searched for vector-boson mediated production of dark matter using the Fermilab 8 GeV Booster proton beam in a dedicated run with $1.86 \times 10^{20}$ protons delivered to a steel beam dump. The MiniBooNE detector, 490~m downstream, is sensitive to dark matter via elastic scattering with nucleons in the detector mineral oil. Analysis methods developed for previous MiniBooNE scattering results were employed, and several constraining data sets were simultaneously analyzed to minimize systematic errors from neutrino flux and interaction rates. No excess of events over background was observed, leading to an 90\% confidence limit on the dark-matter cross section parameter, $Y=\epsilon^2\alpha^\prime(m_\chi/m_v)^4 \lesssim10^{-8}$, for $\alpha^\prime=0.5$ and for dark-matter masses of $0.01
Author: Georg G. Raffelt Publisher: University of Chicago Press ISBN: 9780226702728 Category : Science Languages : en Pages : 692
Book Description
Much of what we know about neutrinos is revealed by astronomical observations, and the same applies to the axion, a conjectured new particle that is a favored candidate for the main component of the dark matter of the universe.
Author: Iosif B. Khriplovich Publisher: Springer Science & Business Media ISBN: 3642608388 Category : Science Languages : en Pages : 241
Book Description
Electric dipole moments (EDMs) have interested physicists since 1950, when it was first suggested that there was no experimental evidence that nuclear forces are symmetric under parity (P) transformation. This question was regarded as speculative because the existence of an EDM, in addition to P violation, requires a violation of time-reversal (T) symmetry. In 1964 it was discovered that the invariance under CP transformation, which combines charge conjugation (C) with parity, is violated in K-meson decays. This provided a new incentive for EDM searches. Since the combined operations of CPT are expected to leave a system invariant, breakdown of CP invariance should be accompanied by a violation of time-reversal symmetry. Thus there is a reason to expect that EDMs should exist at some level. The original neutron EDM experiments were later supplemented with checks of T invariance in atoms and molecules. These investigations are pursued now by many groups. Over the years, the upper limit on the neutron EDM has been improved by seven orders of magnitude, and the upper limit on the electron EDM obtained in atomic experiments is even more strict.
Author: F.J.P. Soler Publisher: CRC Press ISBN: 142008240X Category : Science Languages : en Pages : 402
Book Description
Up to date and comprehensive in its coverage, Neutrinos in Particle Physics, Astrophysics and Cosmology reviews the whole landscape of neutrino physics, from state-of-the-art experiments to the latest phenomenological and theoretical developments to future advances.With contributions from internationally recognized leaders in the field, the book co
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Author: Marco Fabbrichesi
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Author: Georg G. Raffelt
Author: Iosif B. Khriplovich
Author: Argonne National Laboratory. Physics Division
Author: F.J.P. Soler