high luminosity
Recently Published Documents


TOTAL DOCUMENTS

1100
(FIVE YEARS 249)

H-INDEX

43
(FIVE YEARS 6)

2022 ◽  
Author(s):  
Abhishek Sharma ◽  
Phil Allport ◽  
Ignacio Asensi ◽  
Ivan Berdalović ◽  
Daniela Bortoletto ◽  
...  
Keyword(s):  

2022 ◽  
Vol 2022 (1) ◽  
Author(s):  
Rebeca Beltrán ◽  
Giovanna Cottin ◽  
Juan Carlos Helo ◽  
Martin Hirsch ◽  
Arsenii Titov ◽  
...  

Abstract Interest in searches for heavy neutral leptons (HNLs) at the LHC has increased considerably in the past few years. In the minimal scenario, HNLs are produced and decay via their mixing with active neutrinos in the Standard Model (SM) spectrum. However, many SM extensions with HNLs have been discussed in the literature, which sometimes change expectations for LHC sensitivities drastically. In the NRSMEFT, one extends the SM effective field theory with operators including SM singlet fermions, which allows to study HNL phenomenology in a “model independent” way. In this paper, we study the sensitivity of ATLAS to HNLs in the NRSMEFT for four-fermion operators with a single HNL. These operators might dominate both production and decay of HNLs, and we find that new physics scales in excess of 20 TeV could be probed at the high-luminosity LHC.


2022 ◽  
Vol 17 (01) ◽  
pp. C01011
Author(s):  
A. Samalan ◽  
M. Tytgat ◽  
G.A. Alves ◽  
F. Marujo ◽  
F. Torres Da Silva De Araujo ◽  
...  

Abstract During the upcoming High Luminosity phase of the Large Hadron Collider (HL-LHC), the integrated luminosity of the accelerator will increase to 3000 fb−1. The expected experimental conditions in that period in terms of background rates, event pileup, and the probable aging of the current detectors present a challenge for all the existing experiments at the LHC, including the Compact Muon Solenoid (CMS) experiment. To ensure a highly performing muon system for this period, several upgrades of the Resistive Plate Chamber (RPC) system of the CMS are currently being implemented. These include the replacement of the readout system for the present system, and the installation of two new RPC stations with improved chamber and front-end electronics designs. The current overall status of this CMS RPC upgrade project is presented.


2022 ◽  
Vol 137 (1) ◽  
Author(s):  
Alain Blondel ◽  
Patrick Janot

AbstractWith its high luminosity, its clean experimental conditions, and a range of energies that cover the four heaviest particles known today, FCC-ee offers a wealth of physics possibilities, with high potential for discoveries. The FCC-ee is an essential and complementary step towards a 100 TeV hadron collider, and as such offers a uniquely powerful combined physics program. This vision is the backbone of the 2020 European Strategy for Particle Physics. One of the main challenges is now to design experimental systems that can, demonstrably, fully exploit these extraordinary opportunities.


2022 ◽  
Vol 17 (01) ◽  
pp. C01004
Author(s):  
Jelena Mijuskovic

Abstract The electromagnetic calorimeter (ECAL) of the CMS detector has played an important role in the physics program of the experiment, delivering outstanding performance throughout data taking. The high-luminosity LHC will pose new challenges. The four to five-fold increase of the number of interactions per bunch crossing will require superior time resolution and noise rejection capabilities. For these reasons the electronics readout has been completely redesigned. A dual gain trans-impedance amplifier and an ASIC providing two 160 MHz ADC channels, gain selection, and data compression will be used in the new readout electronics. The trigger decision will be moved off-detector and will be performed by powerful and flexible FPGA processors, allowing for more sophisticated trigger algorithms to be applied. The upgraded ECAL will be capable of high-precision energy measurements throughout HL-LHC and will greatly improve the time resolution for photons and electrons above 10 GeV.


2021 ◽  
Vol 137 (1) ◽  
Author(s):  
D. Mirarchi ◽  
R. B. Appleby ◽  
R. Bruce ◽  
M. Giovannozzi ◽  
A. Mereghetti ◽  
...  

AbstractThe design stored beam energy in the CERN high-luminosity large hadron collider (HL-LHC) upgrade is about 700 MJ, with about 36 MJ in the beam tails, according to estimates based on scaling considerations from measurements at the LHC. Such a large amount of stored energy in the beam tails poses serious challenges on its control and safe disposal. In particular, orbit jitters can cause significant losses on primary collimators, which can lead to accidental beam dumps, magnet quenches, or even permanent damage to collimators and other accelerator elements. Thus, active control of the diffusion speed of halo particles is necessary and the use of hollow electron lenses (HELs) represents the most promising approach to handle overpopulated tails at the HL-LHC. HEL is a very powerful and advanced tool that can be used for controlled depletion of beam tails, thus enhancing the performance of beam halo collimation. For these reasons, HELs have been recently included in the HL-LHC baseline. In this paper, we present detailed beam dynamics calculations performed with the goal of defining HEL specifications and operational scenarios for HL-LHC. The prospects for effective halo control in HL-LHC are presented.


2021 ◽  
Vol 16 (12) ◽  
pp. P12014
Author(s):  
W. Adam ◽  
T. Bergauer ◽  
D. Blöch ◽  
M. Dragicevic ◽  
R. Frühwirth ◽  
...  

Abstract The CMS Inner Tracker, made of silicon pixel modules, will be entirely replaced prior to the start of the High Luminosity LHC period. One of the crucial components of the new Inner Tracker system is the readout chip, being developed by the RD53 Collaboration, and in particular its analogue front-end, which receives the signal from the sensor and digitizes it. Three different analogue front-ends (Synchronous, Linear, and Differential) were designed and implemented in the RD53A demonstrator chip. A dedicated evaluation program was carried out to select the most suitable design to build a radiation tolerant pixel detector able to sustain high particle rates with high efficiency and a small fraction of spurious pixel hits. The test results showed that all three analogue front-ends presented strong points, but also limitations. The Differential front-end demonstrated very low noise, but the threshold tuning became problematic after irradiation. Moreover, a saturation in the preamplifier feedback loop affected the return of the signal to baseline and thus increased the dead time. The Synchronous front-end showed very good timing performance, but also higher noise. For the Linear front-end all of the parameters were within specification, although this design had the largest time walk. This limitation was addressed and mitigated in an improved design. The analysis of the advantages and disadvantages of the three front-ends in the context of the CMS Inner Tracker operation requirements led to the selection of the improved design Linear front-end for integration in the final CMS readout chip.


2021 ◽  
Vol 16 (12) ◽  
pp. C12009
Author(s):  
N. Trevisani

Abstract This contribution presents an update on the Analytical Method (AM) algorithm for trigger primitive (TP) generation in the CMS Drift Tube (DT) chambers during the High Luminosity LHC operation (HL-LHC or LHC phase 2). The algorithm has been developed and validated both in software with an emulation approach, and through hardware implementation tests. The algorithm is mainly divided into the following steps: a grouping (pattern recognition) step that finds the path of a given muon, a fitting step to extract the track parameters (position and bending angle), and a correlation step that matches the information from the different super-layers and with signal from the resistive plate chambers. Agreement between the software emulation and the firmware implementation has been verified using different data samples, including a sample of real muons collected during 2016 data taking. In this contribution, an update of the grouping step using a pseudo-Bayes classifier will be discussed.


2021 ◽  
Vol 16 (12) ◽  
pp. P12025
Author(s):  
V.I. Telnov

Abstract Superconducting technology makes it possible to build a high energy e+e- linear collider with energy recovery (ERLC) and reusable beams. To avoid parasitic collisions inside the linacs, a twin (dual) LC is proposed. In this article, I consider the principle scheme of the collider and estimate the achievable luminosity, which is limited by collision effects and available power. Such a collider can operate in a duty cycle (DC) and in a continuous (CW) modes, if sufficient power. With current SC Nb technology (T = 1.8 K, f RF = 1.3 GHz, used for ILC) and with power P = 100 MW, a luminosity L ∼ 0.33 × 1036 cm-2 s-1 is possible at the Higgs factory with 2E 0 = 250 GeV. Using superconductors operating at 4.5 K with high Q 0 values, such as Nb3Sn, and f RF = 0.65 GHz, the luminosity can reach L ∼ 1.4 × 1036 cm-2 s-1 at 2EE0 = 250 GeV (with P = 100 MW) and L ∼ 0.8 × 1036 cm-2 s-1 at 2E 0 = 500 GeV (with P = 150 MW), which is almost two orders of magnitude greater than at the ILC, where the beams are used only once. This technology requires additional efforts to obtain the required parameters and reliably operation. Such a collider would be the best machine for precision Higgs studies, including the measurement of Higgs self-coupling.


2021 ◽  
Vol 81 (12) ◽  
Author(s):  
John M. Campbell ◽  
Stefan Höche ◽  
Christian T. Preuss

AbstractThe evaluation of one-loop matrix elements is one of the main bottlenecks in precision calculations for the high-luminosity phase of the Large Hadron Collider. To alleviate this problem, a new C++ interface to the "Image missing" parton-level Monte Carlo is introduced, giving access to an extensive library of analytic results for one-loop amplitudes. Timing comparisons are presented for a large set of Standard Model processes. These are relevant for high-statistics event simulation in the context of experimental analyses and precision fixed-order computations.


Sign in / Sign up

Export Citation Format

Share Document