scholarly journals Constraints on the dark photon parameter space from leptonic rare kaon decays

2013 ◽  
Vol 87 (1) ◽  
Author(s):  
T. Beranek ◽  
M. Vanderhaeghen
Keyword(s):  
Parameter Space ◽  
Kaon Decays ◽  
Dark Photon ◽  
Photon Parameter

Kaon physics at the CERN-SPS

2015 ◽  
Vol 39 ◽  
pp. 1560100
Author(s):  
Mario Vormstein
Keyword(s):  
Kaon Physics ◽  
Current Status ◽  
Photon Mass ◽  
Kaon Decay ◽  
Kaon Decays ◽  
Preliminary Results ◽  
Dark Photon ◽  
Mixing Parameter ◽  
Upper Limits ◽  
Photon Signal

The NA48/2 and NA62 collaborations report on recent results, current status, and prospects of kaon physics at the CERN-SPS. The NA62 collaborations aims to measure the decay [Formula: see text] with an uncertainty of 10% or better. The NA62 detector and preliminary results from a pilot run in 2014 are presented. In addition, recent results of the NA48/2 collaboration are reported. A search for Dark Photons has been performed in [Formula: see text] decays via the kaon decays [Formula: see text] and [Formula: see text]. No dark photon signal was observed and new upper limits on the mixing parameter [Formula: see text] and the dark photon mass were computed. We also report the first observation of the kaon decay [Formula: see text].

scholarly journals Probing the dark axion portal with muon anomalous magnetic moment

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Shao-Feng Ge ◽  
Xiao-Dong Ma ◽  
Pedro Pasquini
Keyword(s):  
Parameter Space ◽  
Magnetic Moment ◽  
Anomalous Magnetic Moment ◽  
Muon Anomalous Magnetic Moment ◽  
Negative Contribution ◽  
Dark Photon ◽  
Loop Level

AbstractWe propose a new scenario of using the dark axion portal at one-loop level to explain the recently observed muon anomalous magnetic moment by the Fermilab Muon g-2 experiment. Both axion/axion-like particle (ALP) and dark photon are involved in the same vertex with photon. Although ALP or dark photon alone cannot explain muon $$g-2$$ g - 2 , since the former provides only negative contribution while the latter has very much constrained parameter space, dark axion portal can save the situation and significantly extend the allowed parameter space. The observed muon anomalous magnetic moment provides a robust probe of the dark axion portal scenario.

scholarly journals Dark photon from light scalar boson decays at FASER

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
T. Araki ◽  
K. Asai ◽  
H. Otono ◽  
T. Shimomura ◽  
Y. Takubo
Keyword(s):  
Gauge Symmetry ◽  
Standard Model ◽  
Parameter Space ◽  
Beyond The Standard Model ◽  
Scalar Boson ◽  
Dark Photon ◽  
The Standard Model ◽  
Light Scalar ◽  
Sizable Number

Abstract FASER is one of the promising experiments which search for long-lived particles beyond the Standard Model. In this paper, we focus on dark photon associating with an additional U(1) gauge symmetry, and also a scalar boson breaking this U(1) gauge symmetry. We study the sensitivity to the dark photon originated from U(1)-breaking scalar decays. We find that a sizable number of dark photon signatures can be expected in wider parameter space than previous studies.

scholarly journals Kaon decays shedding light on massless dark photons

2020 ◽  
Vol 80 (9) ◽  
Author(s):  
Jhih-Ying Su ◽  
Jusak Tandean
Keyword(s):  
Branching Fractions ◽  
Neutral Kaon ◽  
Charged Kaon ◽  
Missing Energy ◽  
Kaon Decays ◽  
Final State ◽  
Dark Photon ◽  
Flavor Changing ◽  
Model Independent

AbstractWe explore kaon decays with missing energy carried away by a massless dark photon, $${{\overline{\gamma }}}$$ γ ¯ , assumed to have flavor-changing dipole-type couplings to the d and s quarks. We consider in particular the neutral-kaon modes $$K_L\rightarrow \gamma {{\overline{\gamma }}}$$ K L → γ γ ¯ and $$K_L\rightarrow \pi ^0\gamma {{\overline{\gamma }}}$$ K L → π 0 γ γ ¯ and their $$K_S$$ K S counterparts, as well as the charged-kaon channel $$K^+\rightarrow \pi ^+\gamma {{\overline{\gamma }}}$$ K + → π + γ γ ¯ , each of which also has an ordinary photon, $$\gamma $$ γ , in the final state. In addition, we look at $$K_{L,S}\rightarrow \pi ^+\pi ^-{{\overline{\gamma }}}$$ K L , S → π + π - γ ¯ and $$K^+\rightarrow \pi ^+\pi ^0{{\overline{\gamma }}}$$ K + → π + π 0 γ ¯ . Interestingly, the same $$ds{{\overline{\gamma }}}$$ d s γ ¯ interactions give rise to the flavor-changing two-body decays of hyperons with missing energy and are subject to model-independent constraints that can be inferred from the existing hyperon data. Taking this into account, we obtain branching fractions $${{{\mathcal {B}}}}(K_L\rightarrow \gamma {{\overline{\gamma }}})$$ B ( K L → γ γ ¯ ) and $$\mathcal{B}(K_L\rightarrow \pi ^0\gamma {{\overline{\gamma }}})$$ B ( K L → π 0 γ γ ¯ ) which can be as high as $$10^{-3}$$ 10 - 3 and $$10^{-6}$$ 10 - 6 , respectively, one or both of which may be within the sensitivity reach of the KOTO experiment. Furthermore, we find that $${{{\mathcal {B}}}}(K^+\rightarrow \pi ^+\gamma {{\overline{\gamma }}})$$ B ( K + → π + γ γ ¯ ) and $$\mathcal{B}(K^+\rightarrow \pi ^+\pi ^0{{\overline{\gamma }}})$$ B ( K + → π + π 0 γ ¯ ) are allowed to be maximally of order $$10^{-6}$$ 10 - 6 as well, which may be probed by NA62. Complementarily, the hyperon modes can have rates which are potentially accessible by BESIII. Thus, these ongoing experiments could soon be able to offer significant tests on the existence of the massless dark photon.

scholarly journals A Sub-GeV Low Mass Hidden Dark Sector of SU(2)H × U(1)X

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Raymundo Ramos ◽  
Van Que Tran ◽  
Tzu-Chiang Yuan
Keyword(s):  
Dark Matter ◽  
Gauge Group ◽  
Parameter Space ◽  
Scalar Potential ◽  
Indirect Detection ◽  
Tree Level ◽  
Dark Matter Candidate ◽  
Dark Photon ◽  
Relic Density ◽  
Low Mass

Abstract We present a detailed study of the non-abelian vector dark matter candidate Wt with a MeV–GeV low mass range, accompanied by a dark photon A′ and a dark Z′ of similar masses, in the context of a gauged two-Higgs-doublet model with the hidden gauge group that has the same structure as the Standard Model electroweak gauge group. The stability of dark matter is protected by an accidental discrete Z2 symmetry (h-parity) which was usually imposed ad hoc by hand. We examine the model by taking into account various experimental constraints including dark photon searches at NA48, NA64, E141, ν-CAL, BaBar and LHCb experiments, electroweak precision data from LEP, relic density from Planck satellite, direct (indirect) detection of dark matter from CRESST-III, DarkSide-50, XENON1T (Fermi-LAT), and collider physics from the LHC. The theoretical requirements of bounded from below of the scalar potential and tree level perturbative unitarity of the scalar sector are also imposed. The viable parameter space of the model consistent with all the constraints is exhibited. While a dark Z′ can be the dominant contribution in the relic density due to resonant annihilation of dark matter, a dark photon is crucial to dark matter direct detection. We also demonstrate that the parameter space can be further probed by various sub-GeV direct dark matter experimental searches at CDEX, NEWS-G and SuperCDMS in the near future.

scholarly journals Dark photon production via $$\gamma \gamma \rightarrow \gamma A'$$

2021 ◽  
Vol 81 (5) ◽  
Author(s):  
Xiaorui Wong ◽  
Yongsheng Huang
Keyword(s):  
Light Scattering ◽  
Gauge Symmetry ◽  
Cross Section ◽  
Photon Production ◽  
Photon Mass ◽  
Production Mechanism ◽  
Time Intervals ◽  
Dark Photon ◽  
Mixing Parameter ◽  
Photon Parameter

AbstractThe dark photon is a new gauge boson which arises from an extra $$U'(1)$$ U ′ ( 1 ) gauge symmetry. In this paper, a novel dark photon production mechanism based on MeV-scale $$\gamma $$ γ –$$\gamma $$ γ collider is considered: $$\gamma \gamma \rightarrow \gamma A'$$ γ γ → γ A ′ . With the aid of PACKAGE-X, differential cross section of $$\gamma \gamma \rightarrow \gamma A'$$ γ γ → γ A ′ is obtained, as a function of the kinetic mixing parameter $$\varepsilon $$ ε and dark photon mass $$m_{A'}$$ m A ′ . Taking the light-by-light scattering as background, the constraints on the dark photon parameter space for different time intervals in a MeV-scale $$\gamma $$ γ –$$\gamma $$ γ collider are also given.

scholarly journals Dark photon dark matter and fast radio bursts

2020 ◽  
Vol 80 (10) ◽  
Author(s):  
Ricardo G. Landim
Keyword(s):  
Dark Matter ◽  
Time Delay ◽  
Parameter Space ◽  
Gamma Ray ◽  
Gamma Ray Bursts ◽  
Radio Bursts ◽  
Free Electrons ◽  
Weak Equivalence Principle ◽  
Dark Photon ◽  
The Standard Model

AbstractThe nature of dark matter (DM) is still a mystery that may indicate the necessity for extensions of the Standard Model (SM). Light dark photons (DP) may comprise partially or entirely the observed DM density and existing limits for the DP DM parameter space arise from several cosmological and astrophysical sources. In the present work we investigate DP DM using cosmic transients, specifically fast radio bursts (FRBs). The observed time delay of radio photons with different energies have been used to constrain the photon mass or the Weak Equivalence Principle, for example. Due to the mixing between the visible and the DP, the time delay of photons from these cosmic transients, caused by free electrons in the intergalactic medium, can change and impact those constraints from FRBs. We use five detected FRBs and two associations of FRBs with gamma-ray bursts to investigate the correspondent variation on the time delay caused by the presence of DP DM. The result is virtually independent of the FRB used and this variation is very small, considering the still allowed DP DM parameter space, not jeopardizing current bounds on other contributions of the observed time delay.

scholarly journals Probing Scalar and Pseudoscalar Solutions to the g−2 Anomaly

2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Fayez Abu-Ajamieh
Keyword(s):  
Parameter Space ◽  
Mass Range ◽  
The Other ◽  
Scalar Case ◽  
Horizontal Branch ◽  
Beam Dump ◽  
Yukawa Couplings ◽  
Dark Photon ◽  
Cosmological Observations ◽  
Open Window

I investigate a class of models with scalar and pseudoscalar solutions to the g−2 anomaly for both the muon and the electron over the mass range of perturbativity (mϕ≲50 GeV), with Yukawa couplings proportional to the lepton’s mass. In particular, I investigate the constraints from BaBar, beam dump experiments, Z decay measured quantities, LEP mono-γ searches, ee⟶ττγ searches, and solar and horizontal branch (HB) star bounds. For a pseudoscalar, I find that no region in the parameter space can simultaneously provide a solution for both the electron and the muon anomalies while maintaining the required form of the couplings, and therefore, the pseudoscalar solution is disfavored. On the other hand, I find for the scalar case that there is an open window above ~30 MeV in the allowed region, but with significant tension with experiment for the region mϕ≳10 GeV. In addition, there is a smaller window between ~350 KeV and 1 MeV that is not ruled out by cosmological observations. Part of the first open window is expected to be covered by the proposed NA64 experiment. Similar analysis can be readily applied to other proposed solutions to the anomaly, such as solutions with Z′ or with the dark photon.

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