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Dark photon branch ratio

WebNov 10, 2014 · The presence of the dark photon would be indicated by the appearance of an unexpected peak in the total mass of its decay products above smooth backgrounds. Dark photons may be expected to decay in these ways if there are no lighter dark matter particles, but the researchers discovered no evidence for peaks in the energy range … WebApr 9, 2024 · For the branching ratio to this channel to be realistically observable at the LHC, there must exist new mediators that interact with both the standard model and the dark photon. In this paper, we study experimental and theoretical constraints on an extensive set of mediator models.

Search for the dark photon in B 0 → A′A′, A′ → e + e −, μ + μ −, …

WebMay 23, 2024 · We find that the branching ratio of the Higgs boson to a photon and a dark photon is constrained to be far smaller than the sensitivity of current collider searches, … The experiment has excluded dark photon candidates with mass centered around 24.86 μeV and by using a superconducting qubit to repeatedly measure the same photon. This has enabled a search speed up of over 1,000 as compared to the conventional linear amplification technique. See more The dark photon (also hidden, heavy, para-, or secluded photon) is a hypothetical hidden sector particle, proposed as a force carrier similar to the photon of electromagnetism but potentially connected to See more Adding a sector containing dark photons to the Lagrangian of the Standard Model can be done in a straightforward and minimal way by introducing a new U(1) gauge field. The specifics of the … See more • Dark radiation – Postulated type of radiation that mediates interactions of dark matter • Fifth force – Speculative fifth fundamental force • Dual photon – Hypothetical particle dual to the photon See more Observations of gravitational effects that cannot be explained by visible matter alone imply the existence of matter which does not or does only … See more Direct conversion A massive dark photon candidate with kinetic mixing strength $${\displaystyle \epsilon }$$ could spontaneously convert to a Standard Model photon. A cavity, with resonant frequency tuned to match the mass of a dark … See more images of small garden sheds https://dentistforhumanity.org

cosmology - Baryon / photon ratio - Physics Stack Exchange

Web128.84.4.18 http://128.84.4.18/pdf/2005.01515 WebApr 18, 2024 · Photon-Dark Photon Conversions in Background Electromagnetic Fields. The mixing of photons with light pseudoscalars in the presence of external … images of small grooming salons

SM + Dark Vector + Dark Higgs MadGraph5 Model

Category:Sensitivity of the SHiP experiment to dark photons ... - SpringerLink

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Dark photon branch ratio

A Toy Model for Dark Photon Compton Scattering - College …

Webwhen the dark photon decays to e+e ; (2) D and 4He over-production stemming from an increase in the n=p-ratio when the dark photon decays to ˇ+ˇ or K+K prior to NSE-freezeout, T>100keV; and (3) D over-production from an injection of neutrons facilitated by dark photon decay. Comparing the calculated yields of D, 3He, and 4He with the precision WebApr 1, 2024 · Abstract We consider a generic dark photon that arises from a hidden U (1) gauge symmetry imposed on right-handed neutrinos ( νR ν R ). Such a νR ν R -philic dark photon is naturally dark due to the absence of tree-level couplings to normal matter.

Dark photon branch ratio

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WebWe show that dark photons (A′) with masses ∼10−80MeV can be probed in the decay μ+→e+νe¯νμA′, A′→e+e−, with the upcoming Mu3e experiment at the Paul Scherrer Institute (PSI) in Switzerland. With an expected 1015 (5.5×1016) muon decays in 2015–2016 (2024 and beyond), Mu3e has the exciting opportunity to probe a substantial … WebAug 17, 2016 · The ratio of baryons to photons or the baryon abundance is defined as: n ≡ N b N γ ≃ 2.75 × 10 − 8 Ω b h 2 where N b is the number density of baryons, and N γ = 4.11 × 10 8 m − 3 is the number density of photons. Thus the primordial abundances of baryonic matter in the standard Big Bang nucleosynthesis scenario (BBN) is proportional to Ω b h 2.

WebWe present a search for the dark photon A′ in the B 0 → A′A′ decays, where A′ subsequently decays to e + e −, μ + μ −, and π + π −.The search is performed by analyzing 772 × 10 6 BB¯ events collected by the Belle detector at the KEKB e + e − energy-asymmetric collider at the ϒ(4S) resonance. [Figure not available: see fulltext.] WebSong Mao. Li Gang. Guo Jian-You. In this paper, we introduce the spinor helicity amplitude method. We provide the approaches to handle with massless fermions, massive spinors and polarization ...

http://insti.physics.sunysb.edu/~curtin/hahm_mg.html WebMay 25, 2024 · Dark photons are hypothetical massive vector particles that could mix with ordinary photons. The simplest theoretical model is fully characterised by only two …

WebS~, with gyromagnetic ratio g µ = 2. Quantum loop effects lead to a small calculable deviation from g µ = 2, parameterized by the anomalous magnetic moment a µ ≡ g µ −2 2. (1) That quantity can be accurately measured and, within the Standard Model (SM) framework, precisely predicted. Hence, comparison of experiment and theory tests the ...

WebSep 20, 2024 · As conventional dark matter scenarios have been probed extensively so far, the physics of a light dark matter charged under a new gauge group (dark gauge group) becomes one of new research... images of small groups of womenWebAs a point of reference, the minimum detection limit of the dark-adapted eye is approximately 40 times that (40 million photons/second). A properly designed fluorescence microscope typically yields 10e8 to 10e9 photons per second from the focal volume, or 100 to 1000 photons/pixel/second with the same 1-megapixel sensor. images of small herb gardensWeb• Interpretation depends on a number of assumptions – Light hidden fermion in addition to the dark photon – Higgs decay branching ratio 21 Current hidden photon limits at the LHC Remember : ATLAS limit relies on more assumptions ATLAS ArXiv:1511.05542 (2015), CMS arXiv:1506.00424 (2015) 22 LHCb list of books written by james a. michenerWebApr 20, 2024 · But in this new, exact measurement of the constant, evidence of the dark photon was nowhere to be found. Measuring the fine structure constant. Physicists use … images of small heartsWebBecause the dark current pulses are usually distributed in the lower pulse height region, setting the LLD level in the vicinity of the valley (L 1 ) of the distribution can effectively … images of small gardens with fountainsWebThe dark photon sees ordinary matter only through the e ect of operators 4 like the magnetic moment or the charge form factors (of dimension higher than four). This is the choice de ning the massless dark photon proper: L0= e0J0 A 0 + e0" p 1 "2 J0 + e p 1 "2 images of small heartWebMay 4, 2024 · We explain how the dark photon enters laboratory, astrophysical and cosmological observations as well as dark matter physics. We survey the current and … images of small home gyms