scholarly journals Proposal to Search for a Dark Photon in Positron on Target Collisions at DAΦNE Linac

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Mauro Raggi ◽  
Venelin Kozhuharov

Photon-like particles are predicted in many extensions of the Standard Model. They have interactions similar to the photon, are vector bosons, and can be produced together with photons. The present paper proposes a search for such particles in thee+e-→Uγprocess in a positron-on-target experiment, exploiting the positron beam of the DAΦNE linac at the Laboratori Nazionali di Frascati, INFN. In one year of running a sensitivity in the relative interaction strength down to ~10−6is achievable, in the mass region from 2.5 MeV<MU<20 MeV. The proposed experimental setup and the analysis technique are discussed.

2015 ◽  
Vol 30 (18) ◽  
pp. 1550089 ◽  
Author(s):  
A. L. dos Santos ◽  
D. Hadjimichef

An extension of the Standard Model (SM) is studied, in which two new vector bosons are introduced, a first boson Z' coupled to the SM by the usual minimal coupling, producing an enlarged gauge sector in the SM. The second boson A' field, in the dark sector of the model, remains massless and originates a dark photon γ'. A hybrid mixing scenario is considered based on a combined Higgs and Stueckelberg mechanisms. In a Compton-like process, a photon scattered by a weakly interacting massive particles (WIMP) is converted into a dark photon. This process is studied, in an astrophysical application obtaining an estimate of the impact on stellar cooling of white dwarfs and neutron stars.


2021 ◽  
Author(s):  
Federica Oliva

Abstract PADME (Positron Annihilation into Dark Matter Experiment) is a fixed target experiment located at the Beam Test Facility (BTF) at the Laboratori Nazionali di Frascati (LNF) designed to search for a massive dark photon A' in the process e+e- into γA', using a positron beam of energy up to 550 MeV.


2017 ◽  
Vol 26 (03) ◽  
pp. 1730007 ◽  
Author(s):  
Nick E. Mavromatos ◽  
Carlos R. Argüelles ◽  
Remo Ruffini ◽  
Jorge A. Rueda

Self-interacting dark matter (SIDM) is a hypothetical form of dark matter (DM), characterized by relatively strong (compared to the weak interaction strength) self-interactions (SIs), which has been proposed to resolve a number of issues concerning tensions between simulations and observations at the galactic or smaller scales. We review here some recent developments discussed at the 14th Marcel Grossmann Meeting (MG14), paying particular attention to restrictions on the SIDM (total) cross-section from using novel observables in merging galactic structures, as well as the rôle of SIDM on the Milky Way halo and its central region. We report on some interesting particle-physics inspired SIDM models that were discussed at MG14, namely the glueball DM, and a right-handed neutrino DM (with mass of a few tens of keV, that may exist in minimal extensions of the standard model (SM)), interacting among themselves via vector bosons mediators in the dark sector. A detailed phenomenology of the latter model on galactic scales, as well as the potential role of the right handed neutrinos in alleviating some of the small-scale cosmology problems, namely the discrepancies between observations and numerical simulations within standard [Formula: see text]CDM and [Formula: see text]WDM cosmologies are reported.


2017 ◽  
Vol 32 (23n24) ◽  
pp. 1750138 ◽  
Author(s):  
Min He ◽  
Xiao-Gang He ◽  
Cheng-Kai Huang

One of the interesting portals linking a dark sector and the Standard Model (SM) is the kinetic mixing between the SM [Formula: see text] field with a new dark photon [Formula: see text] from a [Formula: see text] gauge interaction. Stringent limits have been obtained for the kinetic mixing parameter [Formula: see text] through various processes. In this work, we study the possibility of searching for a dark photon interaction at a circular [Formula: see text] collider through the process [Formula: see text]. We find that the constraint on [Formula: see text] for dark photon mass in the few tens of GeV range, assuming that the [Formula: see text] invariant mass can be measured to an accuracy of 0.5% [Formula: see text], can be better than [Formula: see text] for the proposed CEPC with a 10-year running at [Formula: see text] (statistic) level, and better than [Formula: see text] for FCC-ee with even just one-year running at [Formula: see text], better than the LHCb, ATLAS, CMS experiments and other facilities can do in a similar dark photon mass range. For FCC-ee, running at [Formula: see text], the constraint can be even better.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Henning Bahl ◽  
Philip Bechtle ◽  
Sven Heinemeyer ◽  
Judith Katzy ◽  
Tobias Klingl ◽  
...  

Abstract The $$ \mathcal{CP} $$ CP structure of the Higgs boson in its coupling to the particles of the Standard Model is amongst the most important Higgs boson properties which have not yet been constrained with high precision. In this study, all relevant inclusive and differential Higgs boson measurements from the ATLAS and CMS experiments are used to constrain the $$ \mathcal{CP} $$ CP -nature of the top-Yukawa interaction. The model dependence of the constraints is studied by successively allowing for new physics contributions to the couplings of the Higgs boson to massive vector bosons, to photons, and to gluons. In the most general case, we find that the current data still permits a significant $$ \mathcal{CP} $$ CP -odd component in the top-Yukawa coupling. Furthermore, we explore the prospects to further constrain the $$ \mathcal{CP} $$ CP properties of this coupling with future LHC data by determining tH production rates independently from possible accompanying variations of the $$ t\overline{t}H $$ t t ¯ H rate. This is achieved via a careful selection of discriminating observables. At the HL-LHC, we find that evidence for tH production at the Standard Model rate can be achieved in the Higgs to diphoton decay channel alone.


2018 ◽  
Vol 46 ◽  
pp. 1860046 ◽  
Author(s):  
Dayong Wang

Many models beyond the Standard Model, motivated by the recent astrophysical anomalies, predict a new type of weak-interacting degrees of freedom. Typical models include the possibility of the low-mass dark gauge bosons of a few GeV and thus making them accessible at the BESIII experiment running at the tau-charm region. The BESIII has recently searched such dark bosons in several decay modes using the high statistics data set collected at charmonium resonaces. This talk will summarize the recent BESIII results of these dark photon searches and related new physics studies.


2019 ◽  
Vol 17 (1) ◽  
pp. 22
Author(s):  
Muhammad Taufik S Gunawan ◽  
Sumiyati Sumiyati ◽  
Masharyono Masharyono

Objective of this research is to determine the effect of burnout and work discipline on employee performance. This research was conducted in a span of less than one year, so the research design used was a cross-sectional method. This study uses a descriptive and verification approach with explanatory survey methods. A total of 100 respondents were selected as samples using probability sampling. The research questionnaire is used as a research instrument to collect data from respondents, and the data analysis technique used is multiple linear regression. The findings of this research is work fatigue (burnout) and work discipline have a significant influence on employee performance.  Differences found in objects and research methods, population and research samples, research periods, measurement tools and research results, and sources of theory from foreign journals and foreign books


2021 ◽  
Vol 71 (1) ◽  
pp. 279-313
Author(s):  
Gaia Lanfranchi ◽  
Maxim Pospelov ◽  
Philip Schuster

At the dawn of a new decade, particle physics faces the challenge of explaining the mystery of dark matter, the origin of matter over antimatter in the Universe, the apparent fine-tuning of the electroweak scale, and many other aspects of fundamental physics. Perhaps the most striking frontier to emerge in the search for answers involves New Physics at mass scales comparable to that of familiar matter—below the GeV scale but with very feeble interaction strength. New theoretical ideas to address dark matter and other fundamental questions predict such feebly interacting particles (FIPs) at these scales, and existing data may even provide hints of this possibility. Emboldened by the lessons of the LHC, a vibrant experimental program to discover such physics is underway, guided by a systematic theoretical approach that is firmly grounded in the underlying principles of the Standard Model. We give an overview of these efforts, their motivations, and the decadal goals that animate the community involved in the search for FIPs, and we focus in particular on accelerator-based experiments.


2018 ◽  
Vol 170 ◽  
pp. 01007 ◽  
Author(s):  
Paola Gianotti

The PADME experiment, by using the positron beam of the Frascati laboratory, aims at searching for signals of a dark photon, A′ . It will evaluate the final state missing mass of the process e+ e- → A′ γ by knowing the beam energy and measuring the four-momentum of the ordinary recoil photon. The precise determination of this quantity, and the capability to reject background events, are the key points for the success of the experiment. In this paper a description of each component of the PADME detector is given.


2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Emidio Gabrielli ◽  
Marco Palmiotto

Abstract In this work we evaluate the long-distance QED contributions, induced by the magnetic-dipole corrections to the final charged leptons, on the B meson decay widths B → (K, K*)ℓ+ℓ− and ratios RK,K* = Γ(B → (K, K*)μ+μ−)/Γ(B → (K, K*)e+e−), as well as on $$ {R}_{K,K\ast}^{\tau } $$ R K , K ∗ τ (with μ replaced by the τ lepton). QED long-distance contributions induced by the Coulomb potential corrections (Fermi-Sommerfeld factors) were also included. Corresponding corrections to the inclusive decay widths of B → Xsℓ+ℓ−, with ℓ = e, μ, τ, are also analyzed for completeness. The magnetic-dipole corrections, which are manifestly Lepton Flavor Universality violating and gauge-invariant, are expected to be particularly enhanced in RK* for the dilepton mass region close to the threshold. However, we find that the largest contribution of all these corrections to the RK,K* observables do not exceed a few per mille effect, thus reinforcing the validity of previous estimates about the leading QED corrections to RK,K*. Finally, viable new physics contributions to RK,K* induced by the exchange of a massless dark-photon via magnetic-dipole interactions, which provide the leading contribution to the corresponding B → (K, K*)ℓ+ℓ− amplitudes in this scenario, are analyzed in light of the present RK,K* anomalies.


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