Related papers: Probing millicharged particles with NA64 experimen…
The search for experimental signatures of the critical point (CP) of strongly interacting matter is one of the main objectives of the NA61/SHINE experiment at CERN SPS. In the course of the experiment, a beam momentum and system size scan…
If new physics manifests itself in the existence of very weakly coupled particles of MeV-GeV mass-scale, fixed-target experiments can be an excellent instrument to discover it. In these proceedings, we review especially the sensitivity of…
We propose to search for millicharged particles at the BESIII detector which is operated at the Beijing Electron Positron Collider. We compute the monophoton signal events at the BESIII detector due to millicharged particle production, as…
We identify potentially the world's most sensitive location to search for millicharged particles in the 10 MeV to 100 GeV mass range: the forward region at the LHC. We propose constructing a scintillator-based experiment, FORward…
Mirror matter from the dark hidden sector with the same particle content and gauge interactions as in the standard model is still an interesting candidate for dark matter. Several experiments on search for positronium and neutron…
NA64 is a fixed-target experiment at the CERN SPS designed to search for Light particle Dark Matter (LDM) candidates with masses in the sub-GeV range. During the 2016-2022 runs, the experiment obtained the world-leading constraints, leaving…
A search is performed for a new sub-GeV vector boson ($A'$) mediated production of Dark Matter ($\chi$) in the fixed-target experiment, NA64, at the CERN SPS. The $A'$, called dark photon, could be generated in the reaction $ e^- Z \to e^-…
Fixed target missing-momentum experiments such as LDMX and M$^3$ are powerful probes of light dark matter and other light, weakly coupled particles beyond the Standard Model (SM). Such experiments involve $\sim$ 10 GeV beam particles whose…
Particles with electric charge 10^(-12)e in bulk mass are not excluded by present experiments. In the present letter we provide a feasible scheme to measure the millicharged particles via the optical cavity coupled to a levitated…
AMBER (NA66) is a fixed-target facility at the M2 beam line of CERN SPS, which performs worldwide unique research on the internal structure and the excitation spectrum of hadrons. The approved first phase of the experiment focuses on three…
Sub-GeV light dark matter often requires new light mediators, such as a dark $Z$ boson in the $L_\mu - L_\tau$ gauge theory. We study the search potential for such a $Z^\prime$ boson via the process $\mu e^- \to \mu e^- X$, with $X$…
A search for dark matter particles is performed using events with a pair of W bosons and large missing transverse momentum. Candidate events are selected by requiring one or two leptons ($\ell =$ electrons or muons). The analysis is based…
The results of a search for $\pi^0$ decays to a photon and an invisible massive dark photon at the NA62 experiment at the CERN SPS are reported. From a total of $4.12\times10^8$ tagged $\pi^0$ mesons, no signal is observed. Assuming a…
A search for lightly ionizing particles has been performed with the MACRO detector. This search was sensitive to particles with charges between $\fractional{5}$$e$ and close to the charge of an electron, with $\beta$ between approximately…
The RICH detector of the NA62 experiment at CERN SPS is required to suppress $\mu^+$ contamination in $K^+ \to \pi^+ \nu \bar\nu$ candidate events by a factor at least 100 between 15 and 35 GeV/c momentum, to measure the pion arrival time…
The NA60 experiment has studied low-mass muon pair production in proton-nucleus collisions with a system of Be, Cu, In, W, Pb and U targets using a 400 GeV/$c$ proton beam at the CERN SPS. The mass spectrum is well described by the…
Using (10087$\pm$44)$\times$10$^{6}$ $J/\psi$ events collected with the BESIII detector at the BEPCII collider at the center-of-mass energy of $\sqrt{s}=3.097~\rm{GeV}$, we report the first search for $\eta\to\pi^0S\to\pi^0\chi\bar{\chi}$…
The NA61/SHINE experiment performs a detailed study of the onset of deconfinement and search for critical point of hadronic matter by colliding nuclei of different sizes at various beam momenta from 13A to 158A GeV/c. Experimental setup and…
We report the results of a search for a light pseudoscalar particle $a$ that couples to electrons and decays to $e^+e^-$ performed using the high-energy CERN SPS H4 electron beam. If such pseudoscalar with a mass $\simeq 17$ MeV exists, it…
We present the performance of multiplexed XY resistive Micromegas detectors tested in the CERN SPS 100 GeV/c electron beam at intensities up to 3.3 $\times$ 10$^5$ e$^- $/(s$\cdot$cm$^2$). So far, all studies with multiplexed Micromegas…