scholarly journals Measurement of the Higgs Boson Mass in the H → ZZ∗→ 4ℓ and H → γγ Channels with s = 13TeV pp Collisions Using the ATLAS Detector

2018 ◽  
Vol 46 ◽  
pp. 1860052
Author(s):  
N. Bruscino
Keyword(s):  
Higgs Boson ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Atlas Detector ◽  
Boson Mass ◽  
Proton Collision ◽  
Proton Proton ◽  
Decay Channels ◽  
Mass Distributions ◽  
Center Of Mass Energy

The mass of the Higgs boson is measured in the [Formula: see text] and in the [Formula: see text] decay channels with [Formula: see text]fb[Formula: see text] of proton-proton collision data from the Large Hadron Collider at a center-of-mass energy of [Formula: see text] TeV recorded by the ATLAS detector in 2015 and 2016. The measured value in the [Formula: see text] channel is [Formula: see text]GeV, while the measured value in the [Formula: see text] channel is [Formula: see text]GeV. The two results have a compatibility of [Formula: see text]. The combined measurement from a simultaneous fit to the invariant mass distributions in the two channels is [Formula: see text]GeV.

scholarly journals Measurement of cross sections and couplings of the Higgs boson in fermionic decay modes with the ATLAS detector

2018 ◽  
Vol 182 ◽  
pp. 02119
Author(s):  
Liaoshan Shi
Keyword(s):  
Higgs Boson ◽  
Large Hadron Collider ◽  
Cross Sections ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Proton Collision ◽  
Proton Proton ◽  
Decay Modes ◽  
Proton Proton Collision ◽  
The Cross

In this report, we present the latest ATLAS results on the measurement of the cross sections and couplings of the Higgs boson in the fermionic decay modes, H → μ+μ-, H → τ+τ- and H → bb. The searches are performed with proton-proton collision data delivered by the Large Hadron Collider during Run 1 and the first two years of Run 2 at √s = 7, 8 and 13 TeV.

scholarly journals Highlights from the Compact Muon Solenoid (CMS) Experiment

Universe ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 28
Author(s):  
Saranya Ghosh ◽  
on behalf of the CMS Collaboration
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Top Quark ◽  
Compact Muon Solenoid ◽  
Production Cross ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Proton Collision ◽  
Center Of Mass Energy ◽  
Cms Experiment

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.

scholarly journals SEARCHES FOR SUPERSYMMETRY WITH THE ATLAS DETECTOR

2012 ◽  
Vol 27 (32) ◽  
pp. 1230033 ◽  
Author(s):  
G. REDLINGER
Keyword(s):  
Large Hadron Collider ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Atlas Detector ◽  
Mass Energy ◽  
Future Directions ◽  
Proton Proton ◽  
Proton Collisions ◽  
Center Of Mass Energy ◽  
Proton Proton Collisions

This is a review of searches for supersymmetry (SUSY) with the ATLAS detector in proton–proton collisions at a center-of-mass energy of 7 TeV at the Large Hadron Collider (LHC) at CERN. The review covers results that have been published, or submitted for publication, up to September 2012, many of which cover the full 7 TeV data-taking period. No evidence for SUSY has been seen; some possibilities for future directions are discussed.

scholarly journals Collider Searches for Dark Matter (ATLAS + CMS)

Universe ◽  
2018 ◽  
Vol 4 (11) ◽  
pp. 131 ◽  
Author(s):  
Nicolò Trevisani
Keyword(s):  
Dark Matter ◽  
Standard Model ◽  
Direct Detection ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Interaction Cross Section ◽  
Proton Proton ◽  
Mass Distributions ◽  
Center Of Mass Energy ◽  
Proton Proton Collisions

Several searches for dark matter have been performed by the CMS and ATLAS collaborations, using proton-proton collisions with a center-of-mass energy of 13 TeV produced by the Large Hadron Collider. Different signatures may highlight the presence of dark matter: the imbalance in the transverse momentum in an event due to the presence of undetectable dark matter particles, produced together with one Standard Model particle, a bump in the di-jet or di-lepton invariant mass distributions, or an excess of events in the di-jet angular distribution, produced by a dark matter mediator. No significant discrepancies with respect to the Standard Model predictions have been found in data, so that limits on the dark matter couplings to ordinary matter, or limits on the dark matter particles and mediators masses have been set. The results are also re-interpreted as limits on the dark matter interaction cross-section with baryonic matter, so that a comparison with direct detection experiments is allowed.

scholarly journals Measuring the quartic Higgs self-coupling at a multi-TeV muon collider

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
M. Chiesa ◽  
F. Maltoni ◽  
L. Mantani ◽  
B. Mele ◽  
F. Piccinini ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Mass Energy ◽  
Simple Analysis ◽  
Proton Proton ◽  
Coupling Interaction ◽  
Center Of Mass Energy ◽  
Muon Collider ◽  
Better Than

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.

scholarly journals Search for decays of the 125 GeV Higgs boson into a Z boson and a ρ or ϕ meson

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Z Boson ◽  
Branching Fractions ◽  
Proton Collision ◽  
Data Set ◽  
Proton Proton ◽  
Decay Channels ◽  
Decay Products ◽  
Upper Limits ◽  
Z Boson Decays

Abstract Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at $$ \sqrt{s} $$ s = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb−1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04–1.31% and 0.31–0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740–940 and 730–950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.

scholarly journals TOP AND HIGGS PHYSICS AT THE HADRON COLLIDERS

2013 ◽  
Vol 28 (26) ◽  
pp. 1330038 ◽  
Author(s):  
SHABNAM JABEEN
Keyword(s):  
Top Quark ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Charge Asymmetry ◽  
Mass Energy ◽  
Top Quark Mass ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
Single Top

This review summarizes the recent results for top quark and Higgs boson measurements from experiments at Tevatron, a proton–antiproton collider at a center-of-mass energy of [Formula: see text], and the Large Hadron Collider, a proton–proton collider at a center-of-mass energy of [Formula: see text]. These results include the discovery of a Higgs-like boson and measurement of its various properties, and measurements in the top quark sector, e.g. top quark mass, spin, charge asymmetry and production of single top quark.

scholarly journals Collider searches for nonperturbative low-scale gravity states

2015 ◽  
Vol 30 (34) ◽  
pp. 1530061 ◽  
Author(s):  
Douglas M. Gingrich
Keyword(s):  
Large Hadron Collider ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Mass Energy ◽  
Personal View ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
8 Tev

The possibility of producing nonperturbative low-scale gravity states in collider experiments was first discussed in about 1998. The ATLAS and CMS experiments have searched for nonperturbative low-scale gravity states using the Large Hadron Collider with a proton–proton center-of-mass energy of 8 TeV. These experiments have now seriously confronted the possibility of producing nonperturbative low-scale gravity states which were proposed over 17 years ago. I will summarize the results of the searches, give a personal view of what they mean, and make some predictions for 13 TeV center-of-mass energy. I will also discuss early ATLAS 13 TeV center-of-mass energy results.

Modeling charged-particle multiplicity distributions at LHC

2020 ◽  
Vol 35 (36) ◽  
pp. 2050302
Author(s):  
Amr Radi
Keyword(s):  
High Energy Physics ◽  
Hadron Collider ◽  
Center Of Mass ◽  
Charged Particles ◽  
High Energy ◽  
Particle Multiplicity ◽  
Charged Particle Multiplicity ◽  
Proton Proton ◽  
Center Of Mass Energy ◽  
8 Tev

With many applications in high-energy physics, Deep Learning or Deep Neural Network (DNN) has become noticeable and practical in recent years. In this article, a new technique is presented for modeling the charged particles multiplicity distribution [Formula: see text] of Proton-Proton [Formula: see text] collisions using an efficient DNN model. The charged particles multiplicity n, the total center of mass energy [Formula: see text], and the pseudorapidity [Formula: see text] used as input in DNN model and the desired output is [Formula: see text]. DNN was trained to build a function, which studies the relationship between [Formula: see text]. The DNN model showed a high degree of consistency in matching the data distributions. The DNN model is used to predict with [Formula: see text] not included in the training set. The expected [Formula: see text] had effectively merged the experimental data and the values expected indicate a strong agreement with Large Hadron Collider (LHC) for ATLAS measurement at [Formula: see text], 7 and 8 TeV.

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