The main goal of the AEgIS experiment at CERN is to test the weak equivalence principle for antimatter. AEgIS will measure the free-fall of an antihydrogen beam traversing a moir'e deflectometer. The goal is to determine the gravitational acceleration ḡ with an initial relative accuracy of 1% by using an emulsion detector combined with a silicon μ-strip detector to measure the time of flight. Nuclear emulsions can measure the annihilation vertex of antihydrogen atoms with a precision of ∼ 1–2 μm r.m.s. We present here results for emulsion detectors operated in vacuum using low energy antiprotons from the CERN antiproton decelerator. We compare with Monte Carlo simulations, and discuss the impact on the AEgIS project.

The goal of the AEḡIS experiment at the Antiproton Decelerator (AD) at CERN, is to measure directly the Earth's gravitational acceleration on antimatter by measuring the free fall of a pulsed, cold antihydrogen beam. The final position of the falling antihydrogen will be detected by a position sensitive detector. This detector will consist of an active silicon part, where the annihilations take place, followed by an emulsion part. Together, they allow to achieve 1% precision on the measurement ofḡ with about 600 reconstructed and time tagged annihilations. We present here the prospects for the development of the AEḡIS silicon position sentive detector and the results from the first beam tests on a monolithic silicon pixel sensor, along with a comparison to Monte Carlo simulations.-2 -2 antimatter by measuring the Earth's gravitational acceleration g for antihydrogen. Several attempts 3 have been made in the past to measure the gravitational constant for antimatter, both for charged 4 [2, 3] and neutral antiparticles [4, 5, 6]. However, none of these experiments brought to conclusive 5 results. Recently, a study from the ALPHA collaboration [7] sets limits to the ratio of gravitational 6 mass to the inertial mass of antimatter but is yet far from testing the equivalence principle. Another 7 experiment, GBAR, [8] has been proposed but not yet built. 8 Cold antihydrogen (100 mK) in Rydberg states will be produced through the charge exchange 9 reaction between Rydberg positronium and cold antiprotons stored in a Penning trap [9]. Applying 10 an appropriate electric field will accelerate the formed antihydrogen in a horizontal beam, with a 11 typical axial velocity distribution spanning a few 100 m/s [10]. 12Some of the trajectories will be selected through a moiré deflectometer [11], which will consist 13 of two vertical gratings producing a fringe pattern on a downstream annihilation plane (see fig. 2). 14 This plane will be the first layer of the position sensitive detector where the antihydrogen will 15 impinge with energies of the order of meV and annihilate. The vertical deflection of the pattern 16 is proportional to the gravitational constant to be measured. Over a flight path of ∼ 1 m, the 17 deflection is expected in the order of ∼ 20 µm for a 1 g vertical acceleration [1]. A vertical 18 resolution better than 10 µm is required to meet the goal of 1% precision on theḡ measurement 19 with 600 reconstructed and time tagged annihilations [12]. 20According to the current design, the position sensitive detector will be a hybrid detector con-21 sisting of an active silicon part, where the annihilation takes place, followed by an emulsion part 22 65 the fragmentation of excited hadronic systems into individual hadrons, whereas the FTFP model 66 [23] relies on a string model to describe the interactions between quarks. 67The CHIPS and FTFP models differ in the production rate and in the composition of the 68 annihilation products. CHIPS produces heavy nuclear fragments in only 20 % of the events while 69 FTFP...

A design study, named $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB for European Spallation Source neutrino Super Beam, has been carried out during the years 2018–2022 of how the 5 MW proton linear accelerator of the European Spallation Source under construction in Lund, Sweden, can be used to produce the world’s most intense long-baseline neutrino beam. The high beam intensity will allow for measuring the neutrino oscillations near the second oscillation maximum at which the CP violation signal is close to three times higher than at the first maximum, where other experiments measure. This will enable CP violation discovery in the leptonic sector for a wider range of values of the CP violating phase $$\delta _{{\mathrm{CP}}}$$ δ CP and, in particular, a higher precision measurement of $$\delta _{{\mathrm{CP}}}$$ δ CP . The present Conceptual Design Report describes the results of the design study of the required upgrade of the ESS linac, of the accumulator ring used to compress the linac pulses from 2.86 ms to 1.2 μs, and of the target station, where the 5 MW proton beam is used to produce the intense neutrino beam. It also presents the design of the near detector, which is used to monitor the neutrino beam as well as to measure neutrino cross sections, and of the large underground far detector located 360 km from ESS, where the magnitude of the oscillation appearance of $$\nu _{e }$$ ν e from $$\nu _{\mu }$$ ν μ is measured. The physics performance of the $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB research facility has been evaluated demonstrating that after 10 years of data-taking, leptonic CP violation can be detected with more than 5 standard deviation significance over 70% of the range of values that the CP violation phase angle $$\delta _{{\mathrm{CP}}}$$ δ CP can take and that $$\delta _{{\mathrm{CP}}}$$ δ CP can be measured with a standard error less than 8° irrespective of the measured value of $$\delta _{{\mathrm{CP}}}$$ δ CP . These results demonstrate the uniquely high physics performance of the proposed $${\text {ESS}}\nu {\text {SB}}$$ ESS ν SB research facility.

We present here a new application of silicon sensors aimed at the direct detection of antinucleons annihilations taking place inside the sensor׳s volume. Such detectors are interesting particularly for the measurement of antimatter properties and will be used as part of the gravity measurement module in the AEg¯IS experiment at the CERN Antiproton Decelerator. One of the goals of the AEg¯IS experiment is to measure the gravitational acceleration of antihydrogen with 1% precision. Three different silicon sensor geometries have been tested with an antiproton beam to investigate their properties as annihilation detection devices: strip planar, 3D pixels and monolithic pixel planar. In all cases we were successfully detecting annihilations taking place in the sensor and we were able to make a first characterization of the clusters and tracks

The proton linac of the European Spallation Source, under construction in Lund, Sweden, had beam commissioning of its ion source (IS) and the following low energy beam transport (LEBT) at their final locations from September 2018 to July 2019. This was first of several beam commissioning stages for the linac of ESS, towards the start of the user program in 2023. This paper presents highlights of characterizations of the IS and LEBT from the aforementioned beam commissioning period, including behavioral change of the IS against its parameters, error source identifications of the beam trajectory in the LEBT, and preliminary characterization of the LEBT output beam against solenoid strengths in LEBT. K: Ion sources (positive ions, negative ions, electron cyclotron resonance (ECR), electron beam (EBIS)); Beam-line instrumentation (beam position and profile monitors; beam-intensity monitors; bunch length monitors); Beam dynamics 1Corresponding author.