Date

Test of low-energy theorems for p(gamma(pol.),pi0)p in the threshold region.

Schmidt, A. ; Achenbach, P. ; Ahrens, J. ; et al.
Phys.Rev.Lett. 87 (2001) 232501, 2001.
Inspire Record 556802 DOI 10.17182/hepdata.31362

The photon asymmetry in the reaction p(\vec{\gamma},\pi^{0})p close to threshold has been measured for the first time with the photon spectrometer TAPS using linearly polarized photons from the tagged-photon facility at the Mainz Microtron MAMI. The total and differential cross sections were also measured simultaneously with the photon asymmetry. This allowed determination of the S-wave and all three P-wave amplitudes. The low-energy theorems based on the parameter-free third-order calculations of heavy-baryon chiral perturbation theory for P1 and P2 agree with the experimental values.

1 data table match query

Polarized photon beam.


Version 2
Evidence for the charge asymmetry in $pp \rightarrow t\bar{t}$ production at $\sqrt{s}= 13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, G. ; Abbott, B. ; Abbott, D.C. ; et al.
JHEP 08 (2023) 077, 2023.
Inspire Record 2141752 DOI 10.17182/hepdata.132116

Inclusive and differential measurements of the top-antitop ($t\bar{t}$) charge asymmetry $A_\text{C}^{t\bar{t}}$ and the leptonic asymmetry $A_\text{C}^{\ell\bar{\ell}}$ are presented in proton-proton collisions at $\sqrt{s} = 13$ TeV recorded by the ATLAS experiment at the CERN Large Hadron Collider. The measurement uses the complete Run 2 dataset, corresponding to an integrated luminosity of 139 fb$^{-1}$, combines data in the single-lepton and dilepton channels, and employs reconstruction techniques adapted to both the resolved and boosted topologies. A Bayesian unfolding procedure is performed to correct for detector resolution and acceptance effects. The combined inclusive $t\bar{t}$ charge asymmetry is measured to be $A_\text{C}^{t\bar{t}} = 0.0068 \pm 0.0015$, which differs from zero by 4.7 standard deviations. Differential measurements are performed as a function of the invariant mass, transverse momentum and longitudinal boost of the $t\bar{t}$ system. Both the inclusive and differential measurements are found to be compatible with the Standard Model predictions, at next-to-next-to-leading order in quantum chromodynamics perturbation theory with next-to-leading-order electroweak corrections. The measurements are interpreted in the framework of the Standard Model effective field theory, placing competitive bounds on several Wilson coefficients.

49 data tables match query

The unfolded inclusive charge asymmetry. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.

The unfolded differential charge asymmetry as a function of the invariant mass of the top pair system. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed, and the impact of the linear term of the Wilson coefficient on the $A_C^{t\bar{t}}$ prediction is shown for two different values. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.

The unfolded differential charge asymmetry as a function of the transverse momentum of the top pair system. The measured values are given with statistical and systematic uncertainties. The SM theory predictions calculated at NNLO in QCD and NLO in EW theory are listed. The scale uncertainty is obtained by varying renormalisation and factorisation scales independently by a factor of 2 or 0.5 around $\mu_0$ to calculate the maximum and minimum value of the asymmetry, respectively. The nominal value $\mu_0$ is chosen as $H_T/4$. The variations in which one scale is multiplied by 2 while the other scale is divided by 2 are excluded. Finally, the scale and MC integration uncertainties are added in quadrature.

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Vector Meson Production in $\pi^- p$ Interactions at 360-{GeV}/$c$

The LEBC-EHS collaboration Aguilar-Benitez, M. ; Bailly, J.L. ; Batalov, A.A. ; et al.
Z.Phys.C 44 (1989) 531, 1989.
Inspire Record 278763 DOI 10.17182/hepdata.15359

The inclusive production of vector mesons (charged ρ(770), ω(783), ϕ(1020) and neutralK*(892)) in π−p interactions at 360 GeV/c is studied. The data are based on 160 000 reconstructed events recorded in the NA 27 Experiment using the LEBC-EHS facility at CERN. The production cross sections in the forward hemisphere in c.m.s. and the longitudinal momentum distributions are determined. The results are compared with data obtained at lower energies.

17 data tables match query

No description provided.

Upper limits of cross sections.

Cross sections extrapolated to x > 0.

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Strange and Nonstrange Baryon Production in $\pi^+ p$ and $K^+ p$ Interactions at 250-{GeV}/$c$

The EHS/NA22 collaboration Ajinenko, I.V. ; Atayan, M.R. ; Belokopytov, Yu. A. ; et al.
Z.Phys.C 44 (1989) 573, 1989.
Inspire Record 283744 DOI 10.17182/hepdata.15338

We present data on the production of the baryons Λ,\(\bar \Lambda \),p and of the baryon resonances Σ*+ (1385) and Δ++ (1232) inK+p and π+p interactions at 250 GeV/c. Results are given on total and semi-inclusive cross sections, Feynman-x spectra, transverse momentum distributions and Λ polarization. The data are compared with measurements at lower energies, with deep inclastic lepton nucleon data and with predictions of quark-parton models. The models underestimate Λ production in the central c.m. region, a feature also seen in recent heavy-ion data. This failure can be cured in JETSET 6.3 by adjustment of the di-quark break-up probability.

30 data tables match query

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A STUDY OF FOUR AND SIX BODY REACTIONS IN K+ p AND pi+ p INTERACTIONS AT 250-GeV/c

The EHS/NA22 collaboration Ajinenko, I.V. ; Belokopytov, Yu. A. ; Bialkowska, H. ; et al.
Z.Phys.C 43 (1989) 15, 1989.
Inspire Record 279065 DOI 10.17182/hepdata.15471

Data on the reactions (K+/π+)p→(K+/π+)pπ+π- and (K+/π+)p→(K+/π+)p2π+2π-, obtained with the European Hybrid Spectrometer, are presented and compared with data at lower energies. The contribution of beam and target diffractive dissociation and double Pomeron exchange, and porperties of these reactions are discussed.

7 data tables match query

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Observation of Puzzling A-dependence of Symmetric Hadron Pairs at High $p_T$

Abramov, V.V. ; Baldin, B.Yu. ; Buzulutskov, A.F. ; et al.
Z.Phys.C 27 (1985) 491, 1985.
Inspire Record 203789 DOI 10.17182/hepdata.16051

Symmetric hadron pair production cross section (π+ π+, π+K+, π+p,K+p, andpp) were measured in the range 0.48≦P⊥≦2.29 GeV/c from Be, Cu, and Pb targets bombarded by 70 GeV protons. TheA-dependence exponent as a function ofP⊥ differs for varios pairs.A steep drop of α for meson pairs atP⊥>1.5 GeV/c is observed.

7 data tables match query
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MEASUREMENT OF THE FORM-FACTOR FOR THE DECAY K- ---> PI0 E- ANTI-NEUTRINO

Bolotov, V.N. ; Gninenko, S.N. ; Dzhilkibaev, R.M. ; et al.
JETP Lett. 47 (1988) 7-11, 1988.
Inspire Record 271435 DOI 10.17182/hepdata.16819

None

1 data table match query

No description provided.


Measurement of Asymmetry of Photoproduction of Positive Pions on Protons by Linearly Polarized Photons in 250-MeV-500-MeV Energy Range

Ganenko, V.B. ; Gorbenko, V.G. ; Derkach, L.M. ; et al.
Yad.Fiz. 23 (1976) 100-106, 1976.
Inspire Record 113097 DOI 10.17182/hepdata.19093

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12 data tables match query

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Real part of spinless p p-scattering amplitude at zero angle in the energy region from 0.135 to 1.700 gev/c

Amirkhanov, I.V. ; Bystritskii, V.M. ; Vertogradov, L.S. ; et al.
Yad.Fiz. 17 (1973) 1222-1224, 1973.
Inspire Record 85077 DOI 10.17182/hepdata.19177

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1 data table match query

FORWARD AMPLITUDE DEDUCED FROM D(SIG)/DOMEGA IN COULOMB-NUCLEAR INTERFERENCE REGION.


Study of 4pi system in the rho-prime(1710) meson mass region in the reaction pi- p ---> p pi+ pi- pi- pi0 at 4.5 gev/c momentum.

Kliger, G.K. ; Beketov, G.V. ; Grechko, V.E. ; et al.
Yad.Fiz. 19 (1974) 839-848, 1974.
Inspire Record 95146 DOI 10.17182/hepdata.19145

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2 data tables match query

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