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Wojtsekhowski, Bogdan

Publications and source records attributed to Wojtsekhowski, Bogdan.

Status of the Proton EDM Experiment (pEDM)

The Proton EDM Experiment (pEDM) is the first direct search for the proton electric dipole moment (EDM) with the aim of being the first experiment to probe the Standard Model (SM) prediction of any particle EDM. Phase-I of pEDM will achieve $10^{-29} e\cdot$cm, improving current indirect limits by four orders of magnitude. This will establish a new standard of precision in nucleon EDM searches and offer a unique sensitivity to better understand the Strong CP problem. The experiment is ideally positioned to explore physics beyond the Standard Model (BSM), with sensitivity to axionic dark matter via the signal of an oscillating proton EDM and across a wide mass range of BSM models from $\mathcal{O}(1\text{GeV})$ to $\mathcal{O}(10^3\text{TeV})$. Utilizing the frozen-spin technique in a highly symmetric storage ring that leverages existing infrastructure at Brookhaven National Laboratory (BNL), pEDM builds upon the technological foundation and experimental expertise of the highly successful Muon $g$$-$$2$ Experiments. With significant R&D and prototyping already underway, pEDM is preparing a conceptual design report (CDR) to offer a cost-effective, high-impact path to discovering new sources of CP violation and advancing our understanding of fundamental physics. It will play a vital role in complementing the physics goals of the next-generation collider while simultaneously contributing to sustaining particle physics research and training early-career researchers during gaps between major collider operations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Polarized internal target experiments based on EIC beams

The Electron-Ion Collider is under construction at BNL. It will have high-energy high-intensity polarized beams of electrons and hadrons. These beams will allow a high accuracy investigation of nucleon structure in the low- to very-low-x DIS regime. At the same time, similar to the realization at HERA, these beams could be used with an internal target for a very productive investigation of medium- to high-x nucleon structure. Due to a novel regime of electron beam operation and its high polarization and intensity, the Figure-of-Merit of an internal target experiment at EIC will be 500+ times higher than was obtained by HERMES.

Wojtsekhowski, Bogdan↗

Spinning Hall Probe magnetic compass

In a large range of physics and space experiments, the direction of the magnetic field needs to be determined with an accuracy on the level of one milli radian or better. We have proposed a new type of magnetic compass - a rotation-based one, which provides an alternating signal from the Hall probe proportional to the value of the magnetic field transverse to the axis of rotation. The spinning Hall probe device has been realized. Alignment of the spinning axis for a minimum (zero) value of the signal allows us to find the direction of the magnetic field. The device does not require calibration and is free of any drift problems. The measurement of the rotation axis direction was accomplished by means of a laser and a flat mirror attached to the rotor. The constructed prototype achieved an accuracy for the magnetic field direction in the experiment with the polarized He-3 target on the level of one milli radian.

Wojtsekhowski, Bogdan↗

A possible low-energy positron source at Jefferson Lab

Jefferson Lab is interested in the production of positrons for nuclear physics applications but also has the capability of producing low energy positrons that could be used for positron annihilation studies. Using the LERF accelerator at the Thomas Jefferson National Accelerator Facility, it is possible to produce a high brightness source of very low-energy positrons. The accelerator requirements are well within the capabilities of the installed hardware. For these experiments, we only need run at up to 100 MeV. A challenge is the production of the positrons. The gamma converter must be able to absorb the 50 kW of beam power that the linac delivers. At this low an energy, the converter, though challenging, is feasible. The transport of the low energy positrons from the production target to the next stage, where the energy is reduced even further, must have a very large acceptance to be able to efficiently transport the flux of positrons from the positron production target to the moderator. We propose to accomplish such a transport by means of a guiding solenoidal field with a novel endcap design. Finally, it is in principle possible to produce a spin polarized beam by filtering the positrons at low energy. The layout of the proposed device will be described in this presentation.

Benson, Stephen↗

Opportunities and challenges of a low-energy positron source in the LERF

Though there are many applications of low energy positrons, many experiments are source limited. Using the LERF accelerator at the Thomas Jefferson National Accelerator Facility, it is possible to build a high brightness source of very low-energy positrons. The accelerator requirements are well within the capabilities of the installed hardware. The accelerator can produce 120 kW of beam with a beam energy of up to 170 MeV. For these experiments, we only need run at up to 120 MeV. The gamma-to-positron converter must be able to absorb 20% of the beam power that the linac delivers. At this low an energy the converter, though challenging, is possible. The transport of the low energy positrons from the production target to the next stage, where the energy is reduced even further, must have a very large acceptance to be able to efficiently transport the flux of positrons from the positron production target to the moderator. In this paper, we propose to accomplish such a transport by means of a guiding solenoidal field with a novel endcap design. Finally, in this presentation, we will present the proposed schemes necessary to realize such a high brightness positron source.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Overview of SIDIS results from Hall B at Jefferson Lab

Though there are many applications of low energy positrons, many experiments are source limited. Using the LERF accelerator at the Thomas Jefferson National Accelerator Facility, it is possible to produce a high brightness source of very low-energy positrons. The accelerator requirements are well within the capabilities of the installed hardware. The accelerator can easily produce 50 kW of beam with a beam energy of up to 170 MeV. For these experiments, we only need run at up to 100 MeV. The gamma converter must be able to absorb the 50 kW of beam power that the linac delivers. At this low an energy the converter, though challenging, is possible. The transport of the low energy positrons from the production target to the next stage, where the energy is reduced even further, must have a very large acceptance to be able to efficiently transport the flux of positrons from the positron production target to the moderator. We propose to accomplish such a transport by means of a guiding solenoidal field with a novel end-cap design. In this presentation, we will present the proposed schemes necessary to realize such a high brightness positron source.

Benson, Stephen↗

Study of the one-way speed of light anisotropy with particle beams

Concepts of high precision studies of the one-way speed of light anisotropy are discussed. The high energy particle beam allows measurement of a one-way speed of light anisotropy (SOLA) via analysis of the beam momentum variation with sidereal phase without the use of synchronized clocks. High precision beam position monitors could provide accurate monitoring of the beam orbit and determination of the particle beam momentum with relative accuracy on the level of 10^-10, which corresponds to a limit on SOLA of 10^-18 with existing storage rings. A few additional versions of the experiment are also presented.

Wojtsekhowski, Bogdan B.↗

Proposed measurement of tagged deep inelastic scattering in Hall A of Jefferson lab

A tagged deep inelastic scattering (TDIS) experiment is planned for Hall A of Jefferson Lab, which will probe the mesonic content of the nucleon directly. Low momentum recoiling (and spectator) protons will be measured in coincidence with electrons scattered in a deep inelastic regime from hydrogen (and deuterium) targets, covering kinematics of 8 < W2 < 18 GeV2, 1 < Q2 < 3 (GeV/c)2 and 0:05 < x < 0:2. The tagging technique will help identify scattering from partons in the meson cloud and provide access to the pion structure function via the Sullivan process. The experiment will yield the first TDIS results in the valence regime, for both proton and neutron targets. We present here an overview of the experiment.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗