47 research outputs found
Limits on the effective quark radius from inclusive scattering at HERA
The high-precision HERA data allows searches up to TeV scales for Beyond the
Standard Model contributions to electron-quark scattering. Combined
measurements of the inclusive deep inelastic cross sections in neutral and
charged current scattering corresponding to a luminosity of around 1
fb have been used in this analysis. A new approach to the beyond the
Standard Model analysis of the inclusive data is presented; simultaneous
fits of parton distribution functions together with contributions of "new
physics" processes were performed. Results are presented considering a finite
radius of quarks within the quark form-factor model. The resulting 95% C.L.
upper limit on the effective quark radius is cm.Comment: 10 pages, 4 figures, accepted by Phys. Lett.
The SHiP experiment at the proposed CERN SPS Beam Dump Facility
The Search for Hidden Particles (SHiP) Collaboration has proposed a general-purpose experimental facility operating in beam-dump mode at the CERN SPS accelerator to search for light, feebly interacting particles. In the baseline configuration, the SHiP experiment incorporates two complementary detectors. The upstream detector is designed for recoil signatures of light dark matter (LDM) scattering and for neutrino physics, in particular with tau neutrinos. It consists of a spectrometer magnet housing a layered detector system with high-density LDM/neutrino target plates, emulsion-film technology and electronic high-precision tracking. The total detector target mass amounts to about eight tonnes. The downstream detector system aims at measuring visible decays of feebly interacting particles to both fully reconstructed final states and to partially reconstructed final states with neutrinos, in a nearly background-free environment. The detector consists of a 50 m long decay volume under vacuum followed by a spectrometer and particle identification system with a rectangular acceptance of 5 m in width and 10 m in height. Using the high-intensity beam of 400 GeV protons, the experiment aims at profiting from the 4 x 10(19) protons per year that are currently unexploited at the SPS, over a period of 5-10 years. This allows probing dark photons, dark scalars and pseudo-scalars, and heavy neutral leptons with GeV-scale masses in the direct searches at sensitivities that largely exceed those of existing and projected experiments. The sensitivity to light dark matter through scattering reaches well below the dark matter relic density limits in the range from a few MeV/c(2) up to 100 MeV-scale masses, and it will be possible to study tau neutrino interactions with unprecedented statistics. This paper describes the SHiP experiment baseline setup and the detector systems, together with performance results from prototypes in test beams, as it was prepared for the 2020 Update of the European Strategy for Particle Physics. The expected detector performance from simulation is summarised at the end
Fast simulation of muons produced at the SHiP experiment using generative adversarial networks
This paper presents a fast approach to simulating muons produced in interactions of the SPS proton beams with the target of the SHiP experiment. The SHiP experiment will be able to search for new long-lived particles produced in a 400 GeV/c SPS proton beam dump and which travel distances between fifty metres and tens of kilometers. The SHiP detector needs to operate under ultra-low background conditions and requires large simulated samples of muon induced background processes. Through the use of Generative Adversarial Networks it is possible to emulate the simulation of the interaction of 400 GeV/c proton beams with the SHiP target, an otherwise computationally intensive process. For the simulation requirements of the SHiP experiment, generative networks are capable of approximating the full simulation of the dense fixed target, offering a speed increase by a factor of Script O(106). To evaluate the performance of such an approach, comparisons of the distributions of reconstructed muon momenta in SHiP's spectrometer between samples using the full simulation and samples produced through generative models are presented. The methods discussed in this paper can be generalised and applied to modelling any non-discrete multi-dimensional distribution
The experimental facility for the Search for Hidden Particles at the CERN SPS
The International School for Advanced Studies (SISSA) logo The International School for Advanced Studies (SISSA) logo The following article is OPEN ACCESS The experimental facility for the Search for Hidden Particles at the CERN SPS C. Ahdida44, R. Albanese14,a, A. Alexandrov14, A. Anokhina39, S. Aoki18, G. Arduini44, E. Atkin38, N. Azorskiy29, J.J. Back54, A. Bagulya32Show full author list Published 25 March 2019 • © 2019 CERN Journal of Instrumentation, Volume 14, March 2019 Download Article PDF References Download PDF 543 Total downloads 7 7 total citations on Dimensions. Article has an altmetric score of 1 Turn on MathJax Share this article Share this content via email Share on Facebook Share on Twitter Share on Google+ Share on Mendeley Article information Abstract The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 GeV/c proton beam offers a unique opportunity to explore the Hidden Sector [1–3]. The proposed experiment is an intensity frontier experiment which is capable of searching for hidden particles through both visible decays and through scattering signatures from recoil of electrons or nuclei. The high-intensity experimental facility developed by the SHiP Collaboration is based on a number of key features and developments which provide the possibility of probing a large part of the parameter space for a wide range of models with light long-lived super-weakly interacting particles with masses up to Script O(10) GeV/c2 in an environment of extremely clean background conditions. This paper describes the proposal for the experimental facility together with the most important feasibility studies. The paper focuses on the challenging new ideas behind the beam extraction and beam delivery, the proton beam dump, and the suppression of beam-induced background
Measurement of the muon flux from 400 GeV/c protons interacting in a thick molybdenum/tungsten target
The SHiP experiment is proposed to search for very weakly interacting particles beyond the Standard Model which are produced in a 400 GeV/c proton beam dump at the CERN SPS. About 1011 muons per spill will be produced in the dump. To design the experiment such that the muon-induced background is minimized, a precise knowledge of the muon spectrum is required. To validate the muon flux generated by our Pythia and GEANT4 based Monte Carlo simulation (FairShip), we have measured the muon flux emanating from a SHiP-like target at the SPS. This target, consisting of 13 interaction lengths of slabs of molybdenum and tungsten, followed by a 2.4 m iron hadron absorber was placed in the H4 400 GeV/c proton beam line. To identify muons and to measure the momentum spectrum, a spectrometer instrumented with drift tubes and a muon tagger were used. During a 3-week period a dataset for analysis corresponding to (3.27±0.07) × 1011 protons on target was recorded. This amounts to approximatively 1% of a SHiP spill
Track reconstruction and matching between emulsion and silicon pixel detectors for the SHiP-charm experiment
In July 2018 an optimization run for the proposed charm cross section measurement for SHiP was performed at the CERN SPS. A heavy, moving target instrumented with nuclear emulsion films followed by a silicon pixel tracker was installed in front of the Goliath magnet at the H4 proton beam-line. Behind the magnet, scintillating-fibre, drift-tube and RPC detectors were placed. The purpose of this run was to validate the measurement's feasibility, to develop the required analysis tools and fine-tune the detector layout. In this paper, we present the track reconstruction in the pixel tracker and the track matching with the moving emulsion detector. The pixel detector performed as expected and it is shown that, after proper alignment, a vertex matching rate of 87% is achieved
Анестезіологія в Одесі: історія розвитку і нові перспективи
The article below summarizes the development of the anesthesiology service in
Odessa and, in particular, the participation of the Department of Anesthesiology
in this process. The article will be interesting to colleagues who are interested in
history, chronographs, historians and local historians of Odessa and the Odessa
region.У статті, що наведена нижче, викладені короткі відомості про розвиток анестезіологічної служби в Одесі і, зокрема, участі у цьому процесі кафедри анестезіології. Стаття буде цікава колегам, які цікавляться історією, хронографам,
історикам і краєзнавцям Одеси та одеського регіону
Study of low multiplicity electron source LEETECH with diamond detector
International audienceIn this paper, we present experimental and numerical studies of the calibration of low-multiplicity electron source using signals from electrons incident on a diamond detector. The experiments were performed at the newly commissioned versatile LEETECH platform at the PHIL photoinjector facility at LAL. We show that with a single crystal CVD diamonds of 500 micrometers thickness, the energy losses from the first three electrons of 2.5–3 MeV are clearly resolved. The described technique can be used as a complementary approach for calibration of diamond detectors as well as for diagnostics of accelerated beam halos in a regime down to a few particles