Search results for "Hadron"
showing 10 items of 3505 documents
"Table 97" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2019
$|y^{t}|$ normalized differential cross-section at parton level. The parton level phase-space is limited to the region $p_T^{t,1} > 500~$GeV, $p_T^{t,2} > 350~$GeV.
"Table 86" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2019
$|{y}^{t,2}|$ absolute differential cross-section at parton level. The parton level phase-space is limited to the region $p_T^{t,1} > 500~$GeV, $p_T^{t,2} > 350~$GeV.
"Table 92" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ coll…
2019
$|{p_{out}}^{t\bar{t}}|$ absolute differential cross-section at parton level. The parton level phase-space is limited to the region $p_T^{t,1} > 500~$GeV, $p_T^{t,2} > 350~$GeV.
"Table 172" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…
2019
Statistical correlation matrix for the normalized differential cross-section of all 15 variables at parton level. The observables are arranged as follows: random top pT - ${p_{{T}}}^{t}$ [bins 1-8], random top rapidity - $|y^{t}|$ [bins 9-16], leading top pT - ${p_{{T}}}^{t,1}$ [bins 17-24], leading top rapidity - $|y^{t,1}|$ [bins 25-32], subleading top pT - ${p_{{T}}}^{t,2}$ [bins 33-39], subleading top rapidity - $|y^{t,2}|$ [bins 40-46], ttbar mass - $m^{t\bar{t}}$ [bins 48-57], ttbar pT - ${p_{{T}}}^{t\bar{t}}$ [bins 58-63], ttbar rapidity - $|y^{t\bar{t}}|$ [bins 66-71], chi ttbar ${\chi}^{t\bar{t}}$ - [bins 74-80], delta phi ttbar - ${\Delta\phi}(t_1,t_2)$ [bins 81-84], ttbar out of …
"Table 171" of "Measurements of $t\bar{t}$ differential cross-sections of highly boosted top quarks decaying to all-hadronic final states in $pp$ col…
2019
Statistical correlation matrix for the absolute differential cross-section of all 15 variables at parton level. The observables are arranged as follows: random top pT - ${p_{{T}}}^{t}$ [bins 1-8], random top rapidity - $|y^{t}|$ [bins 9-16], leading top pT - ${p_{{T}}}^{t,1}$ [bins 17-24], leading top rapidity - $|y^{t,1}|$ [bins 25-32], subleading top pT - ${p_{{T}}}^{t,2}$ [bins 33-39], subleading top rapidity - $|y^{t,2}|$ [bins 40-46], ttbar mass - $m^{t\bar{t}}$ [bins 48-57], ttbar pT - ${p_{{T}}}^{t\bar{t}}$ [bins 58-63], ttbar rapidity - $|y^{t\bar{t}}|$ [bins 66-71], chi ttbar ${\chi}^{t\bar{t}}$ - [bins 74-80], delta phi ttbar - ${\Delta\phi}(t_1,t_2)$ [bins 81-84], ttbar out of pl…
Beyond the standard model via extended symmetries and dark matter
2015
In this thesis, we discuss ideas of how to go beyond the Standard Model (SM) of particle physics to incorporate the cosmological observations of dark matter and matter–antimatter asymmetry, and to address the theoretical problems related to the scalar sector of the SM. Although the SM has proven to be an excellent description of the interactions of elementary particles, there is both experimental and theoretical evidence that this description cannot be complete. Most notably, the cosmological observations of dark matter (DM) and the matter–antimatter asymmetry in the universe cannot be explained within the SM. We have studied simple singlet extensions of the SM. We found out that these DM a…
Pion photo- and electroproduction on nucleons in relativistic chiral perturbation theory
2022
En esta tesis, hemos estudiado la producción de piones mediante pruebas electromagnéticas en nucleones. Para cada uno de los estudios realizados aquí, nos enfocamos en la Teoría Quiral de Perturbaciones (ChPT) relativista para hadrones ligeros: nucleones, piones y los grados de libertad explícitos Delta. Para preservar la covariancia de la teoría, se implementó el método de renormalización en el esquema Extended On Mass Shell (EOMS). En este caso, las divergencias y los términos que violan el conteo de potencias se absorben en las constantes de baja energía (LECs) del Lagrangiano efectivo. El presente trabajo se desarrolló dentro de tres estudios principales relacionados con la producción d…
Measurement of an Excess in the Yield of J/ψ at Very Low pT in Pb-Pb Collisions at √sNN = 2.76 TeV
2016
We report on the first measurement of an excess in the yield of J=ψ at very low transverse momentum (pT < 0.3 GeV=c) in peripheral hadronic Pb-Pb collisions at √sNN=2.76 TeV, performed by ALICE at the CERN LHC. Remarkably, the measured nuclear modification factor of J=ψ in the rapidity range 2.5 <y< 4 reaches about 7 (2) in the pT range 0–0.3 GeV=c in the 70%–90% (50%–70%) centrality class. The J=ψ production cross section associated with the observed excess is obtained under the hypothesis that coherent photoproduction of J=ψ is the underlying physics mechanism. If confirmed, the observation of J=ψ coherent photoproduction in Pb-Pb collisions at impact parameters smaller than twice the nu…
Measurement of ψ(2S) production as a function of charged-particle pseudorapidity density in pp collisions at √s = 13 TeV and p–Pb collisions at √sNN …
2023
Production of inclusive charmonia in pp collisions at center-of-mass energy of √ s = 13 TeV and p–Pb collisions at center-of-mass energy per nucleon pair of √ sNN = 8.16 TeV is studied as a function of charged-particle pseudorapidity density with ALICE. Ground and excited charmonium states (J/ψ, ψ(2S)) are measured from their dimuon decays in the interval of rapidity in the center-of-mass frame 2.5 < ycms < 4.0 for pp collisions, and 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96 for p–Pb collisions. The charged-particle pseudorapidity density is measured around midrapidity (|η| < 1.0). In pp collisions, the measured charged-particle multiplicity extends to about six times the average value, w…
Review of proton and nuclear shape fluctuations at high energy
2020
Determining the inner structure of protons and nuclei in terms of their fundamental constituents has been one of the main tasks of high energy nuclear and particle physics experiments. This quest started as a mapping of the (average) parton densities as a function of longitudinal momentum fraction and resolution scale. Recently, the field has progressed to more differential imaging, where one important development is the description of the event-by-event quantum fluctuations in the wave function of the colliding hadron. In this Review, recent developments on the extraction of proton and nuclear transverse geometry with event-by-event fluctuations from collider experiments at high energy is …