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

Surgical management of genital lymphoedema: experience and critical considerations from a tri-center study

Aim: Genital lymphoedema (GL) is a chronic and debilitating disease, which can severely affect the patient's quality of life with significant socio-economic impact. Nowadays, no gold standard algorithm exists for GL from diagnosis to treatment. This study proposes our therapeutic flowchart based on the three senior consultants' experience in lymphatic surgery. Methods: A retrospective investigation was conducted on a prospectively maintained database (2018-2022). Inclusion criteria involved all patients who underwent surgical procedures for treating GL in three plastic surgery departments (Lausanne, Bari, and Genova). Outcomes were assessed in terms of oedema reduction, stage regression, and functional reported outcomes. Results: 16 patients with GL were included: 50% underwent debulking surgery, 18.8% microsurgery, and 31.2% debulking + microsurgery. We recorded a significant regression of the GL stage: 62.5% shifted from stage II/III to postoperative stage I. Similarly, we found an infection recurrency resolution in 50%, a scrotal oedema reduction in 62.5%, and a scrotal oedema resolution in 37.5% of the patients treated. While almost half of the patients (53.3%) with associated penile oedema described persistent postoperative penile oedema, only two patients complained of persistent lymphorrhea. Conclusion: According to our clinical experience, preoperative and postoperative physical functional therapy is always recommended. For stages I and IIA, after the failure of the conservative treatment, lymph -venous shunts and lymph node transplantation surgery are proposed at the early time. When GL is already diagnosed at stages IIB and III, the debulking surgery, together with functional procedures, represents our first approach

Front-line therapy for elderly chronic lymphocytic leukemia patients: bendamustine plus rituximab or chlorambucil plus rituximab? Real-life retrospective multicenter study in the Lazio region

Previous studies investigated the efficacy and the safety of bendamustine (B) vs. chlorambucil (Chl) associated with rituximab (R) in fludarabine-ineligible patients with treated and untreated chronic lymphocytic leukemia (CLL). We conducted a retrospective multicenter study in the Lazio region to further evaluate and compare the efficacy and the toxicity of Chl-R and B-R regimen in CLL patients over the age of 65. We enrolled 192 untreated CLL patients: 111 treated with B-R and 81 with Chl-R. The overall response rates (ORR; 93.6% in B-R and 86.5% in Chl-R) were not statistically different between the two groups, such as progression-free survival (PFS), time to retreatment (TTR), and overall survival (OS). The B-R group showed a higher hematological (p = 0.007) and extra-hematological (p = 0.008) toxicity. When comparing the toxicities according to age, we noted that the extra-hematological toxicity was higher in patients over the age of 75 who were treated with B-R than those treated with Chl-R (p = 0.03). This retrospective study confirms the feasibility of B-R and Chl-R in elderly untreated CLL patients. Currently, patients who are over 75 and unfit are usually treated with Chl-R. This scheme allows achieving the same ORR, PFS, TTR, and OS when compared with B-R because of hematological and extra-hematological toxicities due to B, in which a greater dose reduction has been shown in comparison to Chl

Coexisting conditions and concomitant medications do not affect venetoclax management and survival in chronic lymphocytic leukemia

The question of which parameters may be informative on venetoclax outcome in chronic lymphocytic leukemia (CLL) is still unclear. Furthermore, the choice to treat with venetoclax can be challenging in patients with baseline characteristics or comorbidities that may potentially favor some specific adverse events