Related papers: Probing millicharged particles with NA64 experimen…
We propose a new channel to search for millicharged particles at the future Super Tau Charm Facility (STCF) via mono-$\pi^0$ signature. For the first time, we compute the mono-$\pi^0$ signal events at the future STCF due to millicharged…
Since its approval in 2016, NA64 has pioneered light dark matter (LDM) searches with electron, positron, muon, and hadron beams. The experiment has successfully met its primary objectives, as outlined in the EPPS input (2018), and even…
We test a novel idea of using a $\pi^-$ beam in the fixed-target experiments to search for New Physics in the events with missing energy. Bounds for invisible vector $\rho$ meson decay were derived, analyzed, and compared with the current…
New sub-GeV gauge forces ("dark photons") that kinetically mix with the photon provide a promising scenario for MeV-GeV dark matter, and are the subject of a program of searches at fixed-target and collider facilities around the world. In…
We consider nuclear gamma decays and $\gamma$-emitting reactions that can be an efficient source of hypothetical millicharged particles ($\chi$). In particular, we revisit the production of millicharged particles in nuclear reactor…
We studied the feasibility of an experiment searching for sub-millicharged particles ($\chi$s) using 30 GeV proton fixed-target collisions at J-PARC. The detector is composed of two layers of stacked scintillator bars and PMTs and is…
Millicharged particles appear in several extensions of the Standard Model, but have not yet been detected. These hypothetical particles could be produced by an intense proton beam striking a fixed target. We use data collected in 2020 by…
We report on a search for elementary particles with charges much smaller than the electron charge using a data sample of proton-proton collisions provided by the CERN Large Hadron Collider in 2018, corresponding to an integrated luminosity…
The milliQan Collaboration has proposed to search for millicharged particles by looking for very weakly ionizing tracks in a detector installed in a cavern near the CMS experiment at the LHC. We note that another form of exotica can also…
A search for a new $Z'$ gauge boson associated with (un)broken B-L symmetry in the keV-GeV mass range is carried out for the first time using the missing-energy technique in the NA64 experiment at the CERN SPS. From the analysis of the data…
The NA64 experiment consists of two detectors which are planned to be located at the electron (NA64e) and muon (NA64$\mu$) beams of the CERN SPS and start operation after the LHC long-stop 2 in 2021. Its main goals include searches for dark…
Dark sector models present a rich phenomenology that requires high-intensity beams and precision detectors for thorough exploration. The NA62 experiment has already published several constraints on dark sector models, leveraging proton beam…
Charge quantization has always been enigmatic. Theoretically, Millicharged particles can be an answer. The use of existing detectors, without affecting their initial mandate, is a very promising low cost new physics detector for…
We report the first results on a direct search for a new 16.7 MeV boson (X) which could explain the anomalous excess of e+e- pairs observed in the excited Be-8 nucleus decays. Due to its coupling to electrons, the X could be produced in the…
We present the first results from a proof-of-concept search for dark sectors via invisible decays of pseudoscalar $\eta$ and $\eta'$ mesons in the NA64h experiment at the CERN SPS. Our novel technique uses the charge-exchange reaction of 50…
The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 $\mathrm{\small GeV/c}$ proton beam offers a unique opportunity to explore the Hidden Sector. The proposed experiment is an intensity…
A search for millicharged particles, a simple extension of the standard model, has been performed with the ArgoNeuT detector exposed to the Neutrinos at the Main Injector beam at Fermilab. The ArgoNeuT Liquid Argon Time Projection Chamber…
We propose to search for millicharged particles produced in high-intensity electron beam dumps using small ultralow-threshold sensors. As a concrete example, we consider a Skipper-CCD placed behind the beam dump in Hall A at Jefferson Lab.…
It has been recently suggested that the vacuum magnetic dichroism observed by the PVLAS experiment could be explained by the pair production of a new light, m ~0.1 eV, millicharged, q ~ 3 10^{-6} e, fermions. In addition, it has been…
Atomic electron motion is responsible for well-studied effects observed in low-energy (MeV-scale) processes. Recently, interest in this phenomenon has also emerged within the high-energy physics community, due to its potential to increase…