Performance of the CMS RPC upgrade using 2D fast timing readout system Shchablo, K.; Laktineh, I.; Gouzevitch, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
Odprti dostop
We present a new generation of Resistive Plate Chambers (RPC) that are able to withstand high particle fluxes (up to 2 kHz cm−2). These chambers will be instrumented with a precise timing readout ...electronics and they are proposed to equip two of the four high eta stations of the CMS muon system.
Two-gap RPC detectors, with each gap made of two 1.4 mm High Pressure Laminate (HPL) electrodes and separated by a gas gap of the same thickness, are proposed. The new scheme reduces the amount of the avalanche charge produced by the passage of a charged particle through the detector. This improves the RPC rate capability by reducing the needed time to absorb this charge. To keep the RPC efficiency high a sensitive, low-noise and high time resolution Front-End Electronics Board (FEB) is needed to cope with the low charge signal. An ASIC called PETIROC that has all these characteristics is proposed to read out the new chambers.
A thin (0.6 mm) Printed Circuit Board (PCB), 165 cm long, equipped with pickup strips of average pitch of 0.75 cm is inserted between the two RPC gaps. The strips are read out from both ends and the arrival time difference of the two signals is used to determine the particle position along the strip (η position). The absolute time measurement will also be used to reduce the data ambiguity due to the expected high pileup at the High-Luminosity phase of the Large Hadron Collider (HL-LHC).
The radiation pattern within high energy quark- and gluon-initiated jets (jet substructure) is used extensively as a precision probe of the strong force as well as an environment for optimizing event ...generators with numerous applications in high energy particle and nuclear physics. Looking at electron-proton collisions is of particular interest as many of the complications present at hadron colliders are absent. A detailed study of modern jet substructure observables, jet angularities, in electron-proton collisions is presented using data recorded using the H1 detector at HERA. The measurement is unbinned and multi-dimensional, using machine learning to correct for detector effects. All of the available reconstructed object information of the respective jets is interpreted by a graph neural network, achieving superior precision on a selected set of jet angularities. Training these networks was enabled by the use of a large number of GPUs in the Perlmutter supercomputer at Berkeley Lab. The particle jets are reconstructed in the laboratory frame, using the kT jet clustering algorithm. Results are reported at high transverse momentum transfer Q2>150GeV2, and inelasticity 0.2<y<0.7. The analysis is also performed in sub-regions of Q2, thus probing scale dependencies of the substructure variables. The data are compared with a variety of predictions and point towards possible improvements of such models.
The inclusive jet cross section in deep-inelastic scattering (DIS) and dijet cross-section in photo-production and DIS have been measured at s√ 320 GeV at the electron-proton collider HERA by the H1 ...and ZEUS collaborations using data taken in 1998-2000 (HERA I) and in 2004-2007 (HERA II). Cross-sections are presented as a function of relevant kinematical variables such as boson virtuality Q2, proton (photon) momentum fraction carried by the interacting parton xp (xγ) or transverse energy ET of the jets. The data are compared to perturbative QCD (pQCD) predictions at next-to-leading order (NLO) and are in general in good agreement within the estimated theory error which exceeds the typical experimental uncertainty in most regions of phase-space. The sensitivity of these high-precision jet observables to QCD parameters such as the strong coupling αS and parameterisations of the parton density functions (PDF) of the proton and the photon are discussed.
Since 2013, Muon Tomography technology has been developed at Tsinghua University. We have built up a prototype system named THUMTY (Tsinghua University cosmic ray Muon tomography facility) to do ...elementary research. Our research is focused on developing a muon NDT (Non Destructive Testing) system that will be used in homeland security operations such as custom inspections, airport security and so on. This muon NDT system is based on the MRPC (Multi-gap Resistive Plate Chamber) technology, thus the impact of the ambient temperature must be considered. In this paper, the performance of the MRPC with Freon/SF6/isobutene mixture and pure Freon gas at different temperatures (-15ˆC, -10ˆC, -5ˆC, 5ˆC, 15ˆC and 25ˆC) were studied. This study is important to develop a widely used stable cosmic ray detection system.
High-sensitivity double-gap phenolic resistive plate chambers (RPCs) are studied for the Phase-2 upgrade of the Compact Muon Solenoid (CMS) muon system at high pseudorapidity
η
. Whereas the present ...CMS RPCs have a gas gap thickness of 2 mm, we propose to use thinner gas gaps, which will improve the performance of these RPCs. To validate this proposal, we constructed double-gap RPCs with two different gap thicknesses of 1.2 and 1.4 mm by using high-pressure laminated plates having a mean resistivity of about 5 × 10
10
Ω-cm. This paper presents test results using cosmic muons and
137
Cs gamma rays. The rate capabilities of these thin-gap RPCs measured with the gamma source exceed the maximum rate expected in the new high-
η
endcap RPCs planned for future Phase-2 runs of the Large Hadron Collider (LHC).
A first measurement is presented of exclusive photoproduction of $\rho^0$ mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years $2006$ and $2007$ at a ...centre-of-mass energy of $\sqrt{s}=319$ GeV and correspond to an integrated luminosity of $1.16$ pb$^{-1}$. The $\rho^0$ mesons with transverse momenta $p_T<1$ GeV are reconstructed from their decays to charged pions, while leading neutrons carrying a large fraction of the incoming proton momentum, $x_L>0.35$, are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality $Q^2 < 2$ GeV$^2$, the total energy of the photon-proton system $20 < W_{\gamma p} < 100$ GeV and the polar angle of the leading neutron $\theta_n < 0.75$ mrad. The cross section of the reaction $\gamma p \to \rho^0 n \pi^+$ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a $\rho^0$ meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, $\sigma^{\rm el}(\gamma\pi^+ \to \rho^0\pi^+)$, is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction $\gamma p\to\rho^0 n \pi^+$.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A
bstract
We study resonant pair production of heavy particles in fully hadronic final states by means of jet substructure techniques. We propose a new resonance tagging strategy that smoothly ...interpolates between the highly boosted and fully resolved regimes, leading to uniform signal efficiencies and background rejection rates across a broad range of masses. Our method makes it possible to efficiently replace independent experimental searches, based on different final state topologies, with a single common analysis. As a case study, we apply our technique to pair production of Higgs bosons decaying into
pairs in generic New Physics scenarios. We adopt as benchmark models radion and massive KK graviton production in warped extra dimensions. We find that despite the overwhelming QCD background, the 4
b
final state has enough sensitivity to provide a complementary handle in searches for enhanced Higgs pair production at the LHC.
The accurate determination of the parton distribution functions (PDFs) of the proton is an essential ingredient of the Large Hadron Collider (LHC) program. PDF uncertainties impact a wide range of ...processes, from Higgs boson characterization and precision Standard Model measurements to new physics searches. A major recent development in modern PDF analyses has been to exploit the wealth of new information contained in precision measurements from the LHC Run I, as well as progress in tools and methods to include these data in PDF fits. In this report we summarize the information that PDF-sensitive measurements at the LHC have provided so far, and review the prospects for further constraining PDFs with data from the recently started Run II. This document aims to provide useful input to the LHC collaborations to prioritize their PDF-sensitive measurements at Run II, as well as a comprehensive reference for the PDF-fitting collaborations.
Performance of the CMS RPC upgrade using 2D fast timing readout system Shchablo, K.; Laktineh, I.; Gouzevitch, M. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2019, Letnik:
958
Journal Article
Recenzirano
Odprti dostop
Here, we present a new generation of Resistive Plate Chambers (RPC) that are able to withstand high particle fluxes (up to 2 kHz cm -2 ). These chambers will be instrumented with a precise timing ...readout electronics and they are proposed to equip two of the four high eta stations of the CMS muon system.Two-gap RPC detectors, with each gap made of two 1.4 mm High Pressure Laminate (HPL) electrodes and separated by a gas gap of the same thickness, are proposed. The new scheme reduces the amount of the avalanche charge produced by the passage of a charged particle through the detector. This improves the RPC rate capability by reducing the needed time to absorb this charge. To keep the RPC efficiency high a sensitive, low-noise and high time resolution Front-End Electronics Board (FEB) is needed to cope with the low charge signal. An ASIC called PETIROC that has all these characteristics is proposed to read out the new chambers. A thin (0.6 mm) Printed Circuit Board (PCB), 165 cm long, equipped with pickup strips of average pitch of 0.75 cm is inserted between the two RPC gaps. The strips are read out from both ends and the arrival time difference of the two signals is used to determine the particle position along the strip ( η position). The absolute time measurement will also be used to reduce the data ambiguity due to the expected high pileup at the High-Luminosity phase of the Large Hadron Collider (HL-LHC).
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