| 1. |
- Abazov, V. M., et al.
(författare)
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Odderon Exchange from Elastic Scattering Differences between pp and p(p)over-bar Data at 1.96 TeV and from pp Forward Scattering Measurements
- 2021
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 127:6
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Tidskriftsartikel (refereegranskat)abstract
- We describe an analysis comparing the p (p) over bar elastic cross section as measured by the D0 Collaboration at a center-of-mass energy of 1.96 TeV to that in pp collisions as measured by the TOTEM Collaboration at 2.76, 7, 8, and 13 TeVusing a model-independent approach. The TOTEM cross sections, extrapolated to a center-of-mass energy of root s = 1.96 TeV, are compared with the D0 measurement in the region of the diffractive minimum and the second maximum of the pp cross section. The two data sets disagree at the 3.4s level and thus provide evidence for the t-channel exchange of a colorless, C-odd gluonic compound, also known as the odderon. We combine these results with a TOTEM analysis of the same C-odd exchange based on the total cross section and the ratio of the real to imaginary parts of the forward elastic strong interaction scattering amplitude in pp scattering for which the significance is between 3.4s and 4.6s. The combined significance is larger than 5 sigma and is interpreted as the first observation of the exchange of a colorless, C-odd gluonic compound.
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| 2. |
- Abazov, V. M., et al.
(författare)
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Studies of X(3872) and psi(2S) production in p(p)over-bar collisions at 1.96 TeV
- 2020
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Ingår i: Physical Review D. - : AMER PHYSICAL SOC. - 1550-7998 .- 1550-2368. ; 102:7
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Tidskriftsartikel (refereegranskat)abstract
- We present various properties of the production of the X(3872) and psi(2S) states based on 10.4 fb(-1) collected by the D0 experiment in Tevatron p (p) over bar collisions at root s = 1.96 TeV. For both states, we measure the nonprompt fraction f(NP) of the inclusive production rate due to decays of b-flavored hadrons. We find the f(NP) values systematically below those obtained at the LHC. The f(NP) fraction for psi(2S) increases with transverse momentum, whereas for the X(3872) it is constant within large uncertainties, in agreement with the LHC results. The ratio of prompt to nonprompt psi(2S) production, ( 1 - f(NP))/f(NP), decreases only slightly going from the Tevatron to the LHC, but for the X(3872), this ratio decreases by a factor of about 3. We test the soft-pion signature of the X(3872) modeled as a weakly bound charm-meson pair by studying the production of the X(3872) as a function of the kinetic energy of the X(3872) and the pion in the X(3872)pi center-of-mass frame. For a subsample consistent with prompt production, the results are incompatible with a strong enhancement in the production of the X(3872) at the small kinetic energy of the X(3872) and the pi in the X(3872)pi center-of-mass frame expected for the X + soft-pion production mechanism. For events consistent with being due to decays of b hadrons, there is no significant evidence for the soft-pion effect, but its presence at the level expected for the binding energy of 0.17 MeV and the momentum scale Lambda = M(pi) is not ruled out.
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| 3. |
- Abazov, V. M., et al.
(författare)
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Study of the normalized transverse momentum distribution of W bosons produced in p(p)over-bar collisions at root s=1.96 TeV
- 2021
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Ingår i: Physical Review D. - : American Physical Society. - 2470-0010 .- 2470-0029. ; 103:1
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Tidskriftsartikel (refereegranskat)abstract
- We present a study of the normalized transverse momentum distribution of W bosons produced in p (p) over bar collisions, using data corresponding to an integrated luminosity of 4.35 fb(-1) collected with the D0 detector at the Fermilab Tevatron collider at root s = 1.96 TeV. The measurement focuses on the transverse momentum region below 15 GeV, which is of special interest for electroweak precision measurements; it relies on the same detector calibration methods which were used for the precision measurement of the W boson mass. The measured distribution is compared to different QCD predictions and a procedure is given to allow the comparison of any further theoretical models to the D0 data.
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