268 research outputs found

    A Feasibility Experiment of a W-powder Target

    Get PDF
    The¬†development of high‚Äźpowertargetsremains a key R&D actvity for future facilities presently under study like the Neutrino Factory, Muon Collider or upgraded high‚Äźpower¬†super beams for long‚Äźbaseline neutrino experiments. The choice of materials to sustain the beam power ranging up to MW levels is not trivial.Granular solid targets¬†have¬†been¬†proposed¬†and¬†are¬†being¬†studied¬†as¬†a¬†candidate¬†for¬†such¬†high-power¬†target¬†systems.¬†In¬†the¬†recently¬†commissioned¬†HiRadMat¬†facility¬†at¬†CERN,¬†a¬†feasibility¬†experiment¬†of¬†a¬†tungsten¬†powder¬†target¬†was¬†performed.¬†The¬†experiment¬†was¬†designed¬†to¬†explore¬†for¬†Ô¨Ārst¬†time¬†the¬†impact¬†of¬†a¬†high‚Äźpower¬†proton¬†beam¬†on¬†a¬†static¬†W powder¬†target¬†in¬†a¬†thimble¬†conÔ¨Āguration.¬†The¬†diagnostics¬†of¬†the¬†experiment¬†were¬†based¬†on¬†remote¬†high‚Äźspeed¬†photography¬†as¬†well¬†as¬†on¬†laser‚Äźdoppler¬†vibration¬†measurements¬†of¬†the¬†target¬†containers.¬†Results¬†from¬†the¬†experimental¬†Ô¨Āndings¬†are¬†presented¬†in¬†this¬†poster

    Physics Beyond Colliders:The Conventional Beams Working Group

    Get PDF
    The Physics Beyond Colliders initiative aims to exploit the full scientific potential of the CERN accelerator complex and its scientific infrastructure for particle physics studies, complementary to current and future collider experiments. Several experiments have been proposed to fully utilize and further advance the beam options for the existing fixed target experiments present in the North and East Experimental Areas of the CERN SPS and PS accelerators. We report on progress with the RF-separated beam option for the AMBER experiment, following a recent workshop on this topic. In addition we cover the status of studies for ion beams for the NA‚Ā∂‚Āį‚Āļ experiment, as well as of those for high intensity beams for Kaon physics and feebly interacting particle searches. With first beams available in 2021 after a CERN-wide long shutdown, several muon beam options were already tested for the NA64mu, MUonE and AMBER experiments

    Search for Axionlike and Scalar Particles with the NA64 Experiment

    Get PDF
    We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as shielding, and would be observed either through their a(s)‚Üíő≥ő≥a(s)\to\gamma \gamma decay in the rest of the HCAL detector or as events with large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84√ó10112.84\times10^{11} electrons on target allowing to set new limits on the a(s)ő≥ő≥a(s)\gamma\gamma-coupling strength for a(s) masses below 55 MeV.Comment: This publication is dedicated to the memory of our colleague Danila Tlisov. 7 pages, 5 figures, revised version accepted for publication in Phys. Rev. Let

    FIRST YEAR OF OPERATIONS IN THE HIRADMAT IRRADIATION FACILITY AT CERN

    Get PDF
    HiRadMat (High Irradiation to Materials) is a new facility at CERN constructed in 2011, designed to provide high-intensity pulsed beams to an irradiation area where material samples as well as accelerator component assemblies can be tested. The facility uses a 440 GeV proton beam extracted from the CERN SPS with a pulse length of up to 7.2 s, to a maximum pulse energy of 3.4 MJ. For 2012, the first year of operations of the facility, nine experiments were scheduled and completed data-taking successfully. The experience gained in operating this unique facility, along with highlights of the experiments and the instrumentation developed for online measurements are reported

    Search for Axionlike and Scalar Particles with the NA64 Experiment

    Get PDF
    Indexaci√≥n: Scopus.We carried out a model-independent search for light scalar (s) and pseudoscalar axionlike (a) particles that couple to two photons by using the high-energy CERN SPS H4 electron beam. The new particles, if they exist, could be produced through the Primakoff effect in interactions of hard bremsstrahlung photons generated by 100 GeV electrons in the NA64 active dump with virtual photons provided by the nuclei of the dump. The a(s) would penetrate the downstream HCAL module, serving as a shield, and would be observed either through their a(s)‚Üíő≥ő≥ decay in the rest of the HCAL detector, or as events with a large missing energy if the a(s) decays downstream of the HCAL. This method allows for the probing of the a(s) parameter space, including those from generic axion models, inaccessible to previous experiments. No evidence of such processes has been found from the analysis of the data corresponding to 2.84√ó1011 electrons on target, allowing us to set new limits on the a(s)ő≥ő≥-coupling strength for a(s) masses below 55 MeV. ¬© 2020 authors. Published by the American Physical Society. Funded by SCOAP3.https://journals-aps-org.recursosbiblioteca.unab.cl/prl/abstract/10.1103/PhysRevLett.125.08180

    The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines

    Get PDF
    The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of ‚ąľ20\sim 20 kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 700 kW of power. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the L/EL/E behaviour, and distinguishing effects arising from őīCP\delta_{CP} and matter. In this paper we show how this comprehensive physics case can be further enhanced and complemented if a neutrino beam produced at the Protvino IHEP accelerator complex, at a distance of 1160 km, and with modest power of 450 kW is aimed towards the same far detectors. We show that the coupling of two independent sub-MW conventional neutrino and antineutrino beams at different baselines from CERN and Protvino will allow to measure CP violation in the leptonic sector at a confidence level of at least 3ŌÉ3\sigma for 50\% of the true values of őīCP\delta_{CP} with a 20 kton detector. With a far detector of 70 kton, the combination allows a 3ŌÉ3\sigma sensitivity for 75\% of the true values of őīCP\delta_{CP} after 10 years of running. Running two independent neutrino beams, each at a power below 1 MW, is more within today's state of the art than the long-term operation of a new single high-energy multi-MW facility, which has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure

    Constraints on New Physics in the Electron g-2 from a Search for Invisible Decays of a Scalar, Pseudoscalar, Vector, and Axial Vector

    Get PDF
    We performed a search for a new generic XX boson, which could be a scalar (SS), pseudoscalar (PP), vector (VV) or an axial vector (AA) particle produced in the 100 GeV electron scattering off nuclei, e‚ąíZ‚Üíe‚ąíZXe^- Z \to e^- Z X, followed by its invisible decay in the NA64 experiment at CERN. No evidence for such process was found in the full NA64 data set of 2.84√ó10112.84\times 10^{11} electrons on target. We place new bounds on the S,P,V,AS, P, V, A coupling strengths to electrons, and set constraints on their contributions to the electron anomalous magnetic moment aea_e, ‚ą£őĒaX‚ą£‚Č≤10‚ąí15‚ąí10‚ąí13|\Delta a_{X}| \lesssim 10^{-15} - 10^{-13} for the XX mass region mX‚Č≤1m_X\lesssim 1 GeV. These results are an order of magnitude more sensitive compared to the current accuracy on aea_e from the electron g‚ąí2g-2 experiments and recent high-precision determination of the fine structure constant.Comment: 6 pages, 4 figure

    Hunting down the X17 boson at the CERN SPS

    Get PDF
    Recently, the ATOMKI experiment has reported new evidence for the excess of e+e‚ąíe^+ e^- events with a mass ‚ąľ\sim17 MeV in the nuclear transitions of 4^4He, that they previously observed in measurements with 8^8Be. These observations could be explained by the existence of a new vector X17X17 boson. So far, the search for the decay X17‚Üíe+e‚ąíX17 \rightarrow e^+ e^- with the NA64 experiment at the CERN SPS gave negative results. Here, we present a new technique that could be implemented in NA64 aiming to improve the sensitivity and to cover the remaining X17X17 parameter space. If a signal-like event is detected, an unambiguous observation is achieved by reconstructing the invariant mass of the X17X17 decay with the proposed method. To reach this goal an optimization of the X17X17 production target, as well as an efficient and accurate reconstruction of two close decay tracks, is required. A dedicated analysis of the available experimental data making use of the trackers information is presented. This method provides independent confirmation of the NA64 published results [Phys. Rev. D101, 071101 (2020)], validating the tracking procedure. The detailed Monte Carlo study of the proposed setup and the background estimate shows that the goal of the proposed search is feasible
    • ‚Ķ
    corecore