scholarly journals Discovery of the bound state of three gluons - odderon

2021 ◽  
Vol 22 (1) ◽  
pp. 5-9
Author(s):  
V.E. Aushev ◽  
Keyword(s):  
Cross Section ◽  
Hadron Collider ◽  
Bound State ◽  
High Energy ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Strong Force ◽  
Independent Analysis ◽  
Theoretical Predictions ◽  
Proton Data

The TOTEM collaboration at the Large Hadron Collider, together with the D0 collaboration at the Tevatron collider at Fermilab, have announced the discovery of the odderon – a bound state of three gluons that was predicted about 50 years ago. The result was presented at CERN on March 5 and follows the joint submission in December 2020 of a CERN and Fermilab preprints by TOTEM and D0 reporting this observation. States comprising several gluons are usually called “glueballs”, and are peculiar objects made only of the carriers of the strong force. The advent of quantum chromodynamics led theorists to predict the existence of the odderon, C-odd gluonic compound. Proving its existence in high-energy collisions at Tevatron and LHC has been a major experimental challenge. The work is based on a model-independent analysis of data at medium-range momentum transfer. The TOTEM and D0 teams compared proton-proton data (recorded at collision energies of 2.76, 7, 8, and 13 TeV and extrapolated to 1.96 TeV), with Tevatron proton-antiproton data measured at 1.96 TeV. In agreement with theoretical predictions, the proton-proton cross-section exhibits a deeper dip and stays below the proton-antiproton cross-section until the bump region, thus evidence of odderon was found.

Proton–Proton and Proton–Antiproton Colliders

2014 ◽  
Vol 07 ◽  
pp. 9-33 ◽  
Author(s):  
Walter Scandale
Keyword(s):  
High Energy Physics ◽  
Hadron Collider ◽  
High Energy ◽  
Accelerator Physics ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Ion Collisions ◽  
Polarized Protons ◽  
Part Time ◽  
Energy Physics

In the last five decades, proton–proton and proton–antiproton colliders have been the most powerful tools for high energy physics investigations. They have also deeply catalyzed innovation in accelerator physics and technology. Among the large number of proposed colliders, only four have really succeeded in becoming operational: the ISR, the SppbarS, the Tevatron and the LHC. Another hadron collider, RHIC, originally conceived for ion–ion collisions, has also been operated part-time with polarized protons. Although a vast literature documenting them is available, this paper is intended to provide a quick synthesis of their main features and key performance.

scholarly journals Measurements of the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson at $$\sqrt{s} = 13$$ TeV with the ATLAS detector

2021 ◽  
Vol 81 (8) ◽  
Author(s):  
◽  
G. Aad ◽  
B. Abbott ◽  
D. C. Abbott ◽  
A. Abed Abud ◽  
...  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Top Quark ◽  
Production Cross ◽  
Hadron Collider ◽  
Inclusive Cross Section ◽  
Atlas Detector ◽  
Proton Collision ◽  
Proton Proton ◽  
Theoretical Predictions

AbstractMeasurements of both the inclusive and differential production cross sections of a top-quark–antiquark pair in association with a Z boson ($$t{\bar{t}}Z$$ t t ¯ Z ) are presented. The measurements are performed by targeting final states with three or four isolated leptons (electrons or muons) and are based on $$\sqrt{s} = 13$$ s = 13  TeV proton–proton collision data with an integrated luminosity of 139 $$\hbox {fb}^{-1}$$ fb - 1 , recorded from 2015 to 2018 with the ATLAS detector at the CERN Large Hadron Collider. The inclusive cross section is measured to be $$\sigma _{t{\bar{t}}Z} = 0.99 \pm 0.05$$ σ t t ¯ Z = 0.99 ± 0.05  (stat.) $$\pm \, 0.08$$ ± 0.08  (syst.) pb, in agreement with the most precise theoretical predictions. The differential measurements are presented as a function of a number of kinematic variables which probe the kinematics of the $$t{\bar{t}}Z$$ t t ¯ Z system. Both absolute and normalised differential cross-section measurements are performed at particle and parton levels for specific fiducial volumes and are compared with theoretical predictions at different levels of precision, based on a $$\chi ^{2}/$$ χ 2 / ndf and p value computation. Overall, good agreement is observed between the unfolded data and the predictions.

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.

Diffraction and photon exchange processes at the LHC and parton saturation

2020 ◽  
Vol 35 (08) ◽  
pp. 2030004 ◽  
Author(s):  
Christophe Royon ◽  
Cristian Baldenegro
Keyword(s):  
New York ◽  
Degrees Of Freedom ◽  
National Laboratory ◽  
Hadron Collider ◽  
Brookhaven National Laboratory ◽  
Forward Physics ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Proton Structure ◽  
Exchange Processes

We present a review of the recent theoretical and experimental developments related to the field of diffraction, parton saturation, and forward physics. We first discuss our present understanding of the proton structure in terms of quarks and gluons, the degrees of freedom of quantum chromodynamics. We then focus on some of the main results on diffraction at the HERA electron–proton collider in DESY, Germany, at the Tevatron proton–antiproton collider at Fermilab, Batavia, US, and at the CERN Large Hadron Collider (LHC) proton–proton and nucleus–nucleus collider, which is located in Geneva, Switzerland. We also present a selected amount of results on diffraction and photon exchanges that can be done at the LHC experiments and at a future Electron Ion Collider (EIC) to be built in the US at Brookhaven National Laboratory, New York.

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.

scholarly journals Energy Dependence of Slope Parameter in Elastic Nucleon-Nucleon Scattering

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
V. A. Okorokov
Keyword(s):  
Experimental Data ◽  
Energy Dependence ◽  
Nucleon Nucleon ◽  
High Energy ◽  
Slope Parameter ◽  
Proton Antiproton ◽  
Proton Proton ◽  
Elastic Proton ◽  
Energy Domain ◽  
Very High Energy

The diffraction slope parameter is investigated for elastic proton-proton and proton-antiproton scattering based on all the available experimental data at low and intermediate momentum transfer values. Energy dependence of the elastic diffraction slope is approximated by various analytic functions. The expanded “standard” logarithmic approximations with minimum number of free parameters allow description of the experimental slopes in all the available energy range reasonably. The estimations of asymptotic shrinkage parameterαP′are obtained for various|t|domains based on all the available experimental data. Various approximations differ from each other both in the low energy and very high energy domains. Predictions for diffraction slope parameter are obtained for elastic proton-proton scattering from NICA up to future collider (FCC/VLHC) energies, for proton-antiproton elastic reaction in FAIR energy domain for various approximation functions.

scholarly journals Magnetic Field in Nuclear Collisions at Ultra High Energies

Physics ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 183-193
Author(s):  
Vitalii A. Okorokov
Keyword(s):  
Magnetic Field ◽  
Hard Sphere ◽  
W Boson ◽  
Hadron Collider ◽  
High Energy ◽  
Hard Sphere Model ◽  
Heavy Nuclei ◽  
Proton Proton ◽  
High Energies ◽  
The Magnetic Field

The magnetic field created in proton–proton and nucleus–nucleus collisions at ultra-high energies are studied with models of point-like charges and hard sphere for distribution of the constituents for vacuum conditions. The various beam ions are considered from light to heavy nuclei at energies corresponding to the nominal energies of the proton beam within the projects of further accelerator facilities high-energy Large Hadron Collider (HE-LHC) and Future Circular Collider (FCC). The magnetic-field strength immediately after collisions reaches the value tens of GeV 2 , while in the approach with point-like charges, some overestimate the amplitude of the field in comparison with more realistic hard-sphere model. The absolute value of the magnetic field rapidly decreases with time and increases with growth of atomic number. The amplitude for e B is estimated at level 100 GeV 2 to provide magnitude for quark–quark collisions at energies corresponding to the nominal energies of proton beams. These estimations are close to the range for onset of W boson condensation.

TIME MACHINE AT THE LHC

2008 ◽  
Vol 05 (04) ◽  
pp. 641-651 ◽  
Author(s):  
I. YA. AREF'EVA ◽  
I. V. VOLOVICH
Keyword(s):  
Black Hole ◽  
Cross Section ◽  
Production Cross ◽  
Hadron Collider ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Time Machine ◽  
Proton Proton ◽  
Traversable Wormhole ◽  
Time Machines

Recently, black hole and brane production at CERN's Large Hadron Collider (LHC) has been widely discussed. We suggest that there is a possibility to test causality at the LHC. We argue that if the scale of quantum gravity is of the order of few TeVs, proton-proton collisions at the LHC could lead to the formation of time machines (spacetime regions with closed timelike curves) which violate causality. One model for the time machine is a traversable wormhole. We argue that the traversable wormhole production cross section at the LHC is of the same order as the cross section for the black hole production. Traversable wormholes assume violation of the null energy condition (NEC) and an exotic matter similar to the dark energy is required. Decay of the wormholes/time machines and signatures of time machine events at the LHC are discussed.

Proton-proton scattering at the C. E. R. N. Intersecting Storage Rings

1973 ◽  
Vol 335 (1603) ◽  
pp. 431-452 ◽  
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
High Energy ◽  
Storage Rings ◽  
The Other ◽  
Proton Scattering ◽  
High Energy Proton ◽  
Proton Proton ◽  
Total Cross Sections ◽  
Energy Proton

The main features of the C. E. R. N. Intersecting Storage Rings (I. S. R.) are reviewed, together with results obtained in 1971 and 1972 on elastic scattering and total cross-sections. The main result is a 10% increase of the total proton-proton cross-section in the I. S. R. energy range. The simplest picture of high energy proton-proton scattering which emerges from this and the other data, is briefly discussed.

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