scholarly journals Feasibility study of TPC tracker detector for the circular collider

2020 ◽  
Vol 35 (15n16) ◽  
pp. 2041014 ◽  
Author(s):  
Zhiyang Yuan ◽  
Huirong Qi ◽  
Haiyun Wang ◽  
Hongliang Dai ◽  
Yuanbo Chen ◽  
...  

The discovery of a SM Higgs boson at the LHC brought about great opportunity to investigate the feasibility of a Circular Electron Positron Collider (CEPC) operating at center-of-mass energy of 240 GeV, as a Higgs factory, with designed luminosity of about [Formula: see text]. The CEPC provides a much cleaner collision environment than the LHC, it is ideally suited for studying the properties of Higgs boson with greater precision. Another advantage of the CEPC over the LHC is that the Higgs boson can be detected through the recoil mass method by only reconstructing [Formula: see text] boson decay without examining the Higgs decays. In Concept Design Report (CDR), the circumference of CEPC is 100 km, with two interaction points available for exploring different detector design scenarios and technologies. The baseline design of CEPC detector is an ILD-like concept, with a superconducting solenoid of 3.0 Tesla surrounding the inner silicon detector, TPC tracker detector and the calorimetry system. Time Projection Chambers (TPCs) have been extensively studied and used in many fields, especially in particle physics experiments, including STAR and ALICE. The TPC detector will operate in continuous mode on the circular machine. To fulfill the physics goals of the future circular collider and meet Higgs/[Formula: see text] run, a TPC with excellent performance is required. We have proposed and investigated the ions controlling performance of a novel configuration detector module. The aim of this study is to suppress ion backflow (IBF) continually. In this paper, some update results of the feasibility and limitation on TPC detector technology R&D will be given using the hybrid gaseous detector module.

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
M. Chiesa ◽  
F. Maltoni ◽  
L. Mantani ◽  
B. Mele ◽  
F. Piccinini ◽  
...  

Abstract Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 1035cm−2s−1, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
◽  
A. Tumasyan ◽  
W. Adam ◽  
J. W. Andrejkovic ◽  
T. Bergauer ◽  
...  

Abstract A search for a heavy Higgs boson H decaying into the observed Higgs boson h with a mass of 125 GeV and another Higgs boson hS is presented. The h and hS bosons are required to decay into a pair of tau leptons and a pair of b quarks, respectively. The search uses a sample of proton-proton collisions collected with the CMS detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 137 fb−1. Mass ranges of 240–3000 GeV for mH and 60–2800 GeV for $$ {m}_{{\mathrm{h}}_{\mathrm{S}}} $$ m h S are explored in the search. No signal has been observed. Model independent 95% confidence level upper limits on the product of the production cross section and the branching fractions of the signal process are set with a sensitivity ranging from 125 fb (for mH = 240 GeV) to 2.7 fb (for mH = 1000 GeV). These limits are compared to maximally allowed products of the production cross section and the branching fractions of the signal process in the next-to-minimal supersymmetric extension of the standard model.


2018 ◽  
Vol 182 ◽  
pp. 02052
Author(s):  
Asma Hadef

The Higgs boson was discovered on the 4th of July 2012 with a mass around 125 GeV by ATLAS and CMS experiments at LHC. Determining the Higgs properties (production and decay modes, couplings,...) is an important part of the high-energy physics programme in this decade. A search for the Higgs boson production in association with a top quark pair (tt̄H) at ATLAS [1] is summarized in this paper at an unexplored center-of-mass energy of 13 TeV, which could allow a first direct measurement of the top quark Yukawa coupling and could reveal new physics. The tt̄H analysis in ATLAS is divided into 3 channels according to the Higgs decay modes: H → Hadrons, H → Leptons and H → Photons. The best-fit value of the ratio of observed and Standard Model cross sections of tt̄H production process, using 2015-2016 data and combining all tt̄H final states, is 1:8±0:7, corresponds to 2:8σ (1:8σ) observed (expected) significance.


2020 ◽  
pp. 2141003
Author(s):  
Joon-Bin Lee ◽  
Jehyun Lee

We present the implementation in the MadAnalysis 5 framework of the CMS-HIG-18-011 search for exotic decays of the Standard Model Higgs boson, in which the Higgs boson is assumed to decay into a pair of light pseudoscalar [Formula: see text], that then further decay into a di-muon and di-[Formula: see text]-jet final state. This analysis considers proton-proton collisions at a center-of-mass energy of 13 TeV and data collected by the CMS experiment in 2016, with an integrated luminosity of 35.9 fb[Formula: see text]. We present a selection of recast predictions, obtained with MadAnalysis 5 and Delphes 3, that include a few differential distributions, yields, and efficiencies. We show that they agree at a level of a few percent with public CMS results.


Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 28
Author(s):  
Saranya Ghosh ◽  
on behalf of the CMS Collaboration

The highlights of the recent activities and physics results leading up to the summer of 2018 from the Compact Muon Solenoid (CMS) experiment at the CERN Large Hadron Collider (LHC) are presented here. The CMS experiment has a very wide-ranging physics program, and only a very limited subset of the physics analyses being performed at CMS are discussed here, consisting of several important results from the analysis of proton-proton collision data at center-of-mass energy of 13 TeV. These include important analyses of Higgs boson physics, with the highlight being the first observation of the t t ¯ H production of the Higgs boson, along with analyses pertaining to precision standard model measurements, top quark physics, with the single top production cross-section measurement, and flavor physics, with the important observation of χ b (3P) states. Additionally, important searches for physics beyond the standard model are also presented.


2009 ◽  
Vol 24 (16n17) ◽  
pp. 2899-3037 ◽  
Author(s):  
MARC-ANDRÉ PLEIER

This review summarizes the program in the physics of the top quark being pursued at Fermilab's Tevatron proton–antiproton collider at a center-of-mass energy of 1.96 TeV. More than a decade after the discovery of the top quark at the two collider detectors CDF and D0, the Tevatron has been the only accelerator to produce top quarks and to study them directly.The Tevatron's increased luminosity and center-of-mass energy offer the possibility to scrutinize the properties of this heaviest fundamental particle through new measurements that were not feasible before, such as the first evidence for electroweak production of top quarks and the resulting direct constraints on the involved couplings. Better measurements of top quark properties provide more stringent tests of predictions from the SM of elementary particle physics. In particular, the improvement in measurements of the mass of the top quark, with the latest uncertainty of 0.7% marking the most precisely measured quark mass to date, further constrains the prediction of the mass of the still to be discovered Higgs boson.


2019 ◽  
Vol 69 (1) ◽  
pp. 389-415 ◽  
Author(s):  
M. Benedikt ◽  
A. Blondel ◽  
P. Janot ◽  
M. Klein ◽  
M. Mangano ◽  
...  

After 10 years of physics at the Large Hadron Collider (LHC), the particle physics landscape has greatly evolved. Today, a staged Future Circular Collider (FCC), consisting of a luminosity-frontier highest-energy electron–positron collider (FCC-ee) followed by an energy-frontier hadron collider (FCC-hh), promises the most far-reaching physics program for the post-LHC era. FCC-ee will be a precision instrument used to study the Z, W, Higgs, and top particles, and will offer unprecedented sensitivity to signs of new physics. Most of the FCC-ee infrastructure could be reused for FCC-hh, which will provide proton–proton collisions at a center-of-mass energy of 100 TeV and could directly produce new particles with masses of up to several tens of TeV. This collider will also measure the Higgs self-coupling and explore the dynamics of electroweak symmetry breaking. Thermal dark matter candidates will be either discovered or conclusively ruled out by FCC-hh. Heavy-ion and electron–proton collisions (FCC-eh) will further contribute to the breadth of the overall FCC program. The integrated FCC infrastructure will serve the particle physics community through the end of the twenty-first century. This review combines key contents from the first three volumes of the FCC Conceptual Design Report.


2019 ◽  
Vol 34 (13n14) ◽  
pp. 1940016 ◽  
Author(s):  
Haiyun Wang ◽  
Huirong Qi

The Circular Electron Positron Collider (CEPC) has been proposed as a Higgs/[Formula: see text] factory, which would allow precision measurements of the Higgs boson properties, as well as of [Formula: see text] and [Formula: see text] bosons. The baseline design of CEPC tracking system consists of a vertex detector with three concentric double-sided pixel layers, a high precision (about 100 [Formula: see text]m) large volume time projection chamber (TPC) and a silicon tracker on both barrel and end-cap regions. The tracking system has similar performance requirements to the ILD detector in ILC detectors but without power-pulsing, which leads to significantly additional constrains on detector specifications, especially for the case of machine operating at [Formula: see text]-pole energy region with high luminosity. In this paper, we will give an overview of the CEPC TPC detector, the requirements and challenges for the detector with possible technologies. The on-going R&D activities of the TPC detector module and prototype will also be reported.


2019 ◽  
Vol 34 (18) ◽  
pp. 1950094 ◽  
Author(s):  
Satendra Kumar ◽  
Poulose Poulose ◽  
Rafiqul Rahaman ◽  
Ritesh K. Singh

The recent discovery of a Higgs boson at LHC, while establishing the Higgs mechanism as the way of electroweak symmetry breaking, started an era of precision measurements involving the Higgs boson. In an effective Lagrangian framework, we consider the [Formula: see text] process, at an ILC running at a center-of-mass energy of 500 GeV to investigate the effect of the [Formula: see text] and [Formula: see text] couplings on the sensitivity of [Formula: see text] coupling on this process. Our results show that the sensitivity of the trilinear Higgs self-couplings on this process has somewhat strong dependence on the Higgs-gauge boson couplings. Single- and two-parameter reaches of ILC with integrated luminosity of 1000 fb[Formula: see text] are obtained on all the effective couplings indicating how these limits are affected by the presence of anomalous [Formula: see text] and [Formula: see text] couplings. The kinematic distributions studied to understand the effect of the anomalous couplings, again, show strong influence of [Formula: see text]–[Formula: see text] couplings on the dependence of these distributions on [Formula: see text] coupling. Similar results are indicated in the case of the process, [Formula: see text], considered at a center-of-mass energy of 2 TeV, where the cross-section is large enough. The effect of [Formula: see text] and [Formula: see text] couplings on the sensitivity of [Formula: see text] coupling is clearly established through our analyses in this process.


2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Ernesto Arganda ◽  
Leandro Da Rold ◽  
Daniel A. Díaz ◽  
Anibal D. Medina

Abstract Since the discovery in 2012 of the Higgs boson at the LHC, as the last missing piece of the Standard Model of particle physics, any hint of new physics has been intensively searched for, with no confirmation to date. There are however slight deviations from the SM that are worth investigating. The CMS collaboration has reported, in a search for heavy resonances decaying in t$$ \overline{t} $$ t ¯ with a 13-TeV center-of-mass energy and a luminosity of 35.9 fb−1, deviations from the SM predictions at the 3.5σ level locally (1.9σ after the look-elsewhere effect). In addition, in the ditau final state search performed by the ATLAS collaboration at $$ \sqrt{s} $$ s = 13 TeV and $$ \mathcal{L} $$ L = 139 fb−1, deviations from the SM at the 2σ level have been also observed. Interestingly, both slight excesses are compatible with a new pseudoscalar boson with a mass around 400 GeV that couples at least to fermions of the third generation and gluons. Starting from a purely phenomenological perspective, we inspect the possibility that a 400-GeV pseudoscalar can account for these deviations and at the same time satisfy the constraints on the rest of the channels that it gives contributions to and that are analyzed by the ATLAS and CMS experiments. After obtaining the range of effective couplings compatible with all experimental measurements, we study the gauge invariant UV completions that can give rise to this type of pseudoscalar resonance, which can be accommodated in an SO(6)/SO(5) model with consistency at the 1σ level and in a SO(5) × U(1)P × U(1)X/SO(4) × U(1)X at the 2σ level, while exceedingly large quartic couplings would be necessary to account for it in a general two Higgs doublet model.


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