Date

First measurement of the spin transfer parameter K(n00n) in the anti-p p ---> anti-n n reaction at 875-MeV/c

Ahmidouch, A. ; Bertini, R. ; Birsa, R. ; et al.
Phys.Lett.B 380 (1996) 235-240, 1996.
Inspire Record 429760 DOI 10.17182/hepdata.5745

The spin-transfer parameter K n 00 n of the p p↑ → n ↑n charge exchange reaction has been measured for the first time at the CERN Low Energy Antiproton Ring (LEAR), at 875 MeV/ c p momentum, in the centre-of-mass scattering-angle range from 45° to 78°. To measure the transverse polarisation of the n 's, a thick scintillator counter hodoscope was used as live target, and the elastic n p scattering on the hydrogen of the scintillator was used as analysing reaction of the n transverse polarisation. Its so far unmeasured analysing power is taken as linear in momentum transfer, A n p = α·q , and results are given for α · K n 00 n . The values one obtains for K n 00 n , estimating α from N N potential models, are less than 0.25, in agreement with the predictions.

2 data tables match query

Polarized beam. CONST is overall normalization unknown factor.

No description provided.


Antiproton-proton elastic scattering at 4 GeV/c and derivation of diffraction slope at infinite energy

Czyzewski, O. ; Escoubes, B. ; Goldscmidt-Clermont, Y. ; et al.
Phys.Lett. 15 (1965) 188-191, 1965.
Inspire Record 1392865 DOI 10.17182/hepdata.837

None

4 data tables match query

'1'. '2'.

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ANTI-P P TOTAL CROSS-SECTIONS BELOW 420-MEV/C

Bugg, D.V. ; Hall, J. ; Clough, A.S. ; et al.
Phys.Lett.B 194 (1987) 563-567, 1987.
Inspire Record 253124 DOI 10.17182/hepdata.30120

p̄p total cross sections have been measured from 220 to 413 MeV/ c in small (⩽ 10 MeV/ c ) steps of momentum with statistics of ± 0.5 %. There is no evidence for structure in the cross section, and a limit of 8 mb MeV/ c 2 is set with 90% confidence on the strength of any narrow resonance down to 250 MeV/ c .

2 data tables match query

Data taken with long target.

Data taken with short target.


First measurement of D (0n 0n) in anti-p p elastic scattering

Kunne, R.A. ; Beard, C.I. ; Birsa, R. ; et al.
Phys.Lett.B 261 (1991) 191-196, 1991.
Inspire Record 316076 DOI 10.17182/hepdata.29400

The depolarization parameter D onon in p p elastic scattering has been measured at LEAR for thirteen momenta between 679 and 1550 MeV/c in the backward angular region. Striking disagreement with theoretical models is observed.

10 data tables match query

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Measurement of $d \sigma / d \Omega$ and A(on) in $\bar{p} p$ Elastic Scattering Between 497-{MeV}/$c$ and 1550-{MeV}/$c$

Kunne, R.A. ; Beard, C.I. ; Birsa, R. ; et al.
Nucl.Phys.B 323 (1989) 1-36, 1989.
Inspire Record 267175 DOI 10.17182/hepdata.48676

Measurements have been made of the differential cross section and asymmetry A on for p p elastic scattering at 15 incident momenta between 497 MeV/ c and 1550 MeV/ c . The angular range where both particles have enough energy to traverse target and setup has been covered. The results are compared with predictions of various N N potential models. None of these models fully explains the present results, although the general trend of the data is predicted correctly.

16 data tables match query

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A High statistics measurement of the anti-p p ---> anti-n n charge exchange reaction at 875-MeV/c

Lamanna, M. ; Ahmidouch, A. ; Birsa, R. ; et al.
Nucl.Phys.B 434 (1995) 479-502, 1995.
Inspire Record 379991 DOI 10.17182/hepdata.48341

A new measurement of the differential cross section and of the analysing power A 0 n of the charge-exchange reaction p − p → n − n at 875 MeV/ c is presented. The A 0 n data cover the entire angular range and constitute a considerable improvement over previously published data, both in the forward and in the backward hemisphere. The cross-section data cover only the backward region, but are unique at this energy. A careful study of the long-term drifts of the apparatus has allowed to fully exploit the good statistics of the data.

3 data tables match query

Forward hemisphere measurement. Additional systematic error of 4 pct due to target polarization uncertainty.

Backward hemisphere measurement. Additional systematic error of 15 pct.

Differential cross section in the backward hemisphere. Additional systematic error of 15 pct.


Measurement of the nuclear modification factor for muons from charm and bottom hadrons in Pb+Pb collisions at 5.02 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Dale ; et al.
Phys.Lett.B 829 (2022) 137077, 2022.
Inspire Record 1914582 DOI 10.17182/hepdata.111123

Heavy-flavour hadron production provides information about the transport properties and microscopic structure of the quark-gluon plasma created in ultra-relativistic heavy-ion collisions. A measurement of the muons from semileptonic decays of charm and bottom hadrons produced in Pb+Pb and $pp$ collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV with the ATLAS detector at the Large Hadron Collider is presented. The Pb+Pb data were collected in 2015 and 2018 with sampled integrated luminosities of $208~\mathrm{\mu b}^{-1}$ and $38~\mathrm{\mu b^{-1}}$, respectively, and $pp$ data with a sampled integrated luminosity of $1.17~\mathrm{pb}^{-1}$ were collected in 2017. Muons from heavy-flavour semileptonic decays are separated from the light-flavour hadronic background using the momentum imbalance between the inner detector and muon spectrometer measurements, and muons originating from charm and bottom decays are further separated via the muon track's transverse impact parameter. Differential yields in Pb+Pb collisions and differential cross sections in $pp$ collisions for such muons are measured as a function of muon transverse momentum from 4 GeV to 30 GeV in the absolute pseudorapidity interval $|\eta| < 2$. Nuclear modification factors for charm and bottom muons are presented as a function of muon transverse momentum in intervals of Pb+Pb collision centrality. The measured nuclear modification factors quantify a significant suppression of the yields of muons from decays of charm and bottom hadrons, with stronger effects for muons from charm hadron decays.

6 data tables match query

Summary of charm muon double differential cross section in pp collisions at 5.02 TeV as a function of pT. Uncertainties are statistical and systematic, respectively.

Summary of charm muon per-event invariant yields in Pb+Pb collisions at 5.02 TeV as a function of pT for five different centrality intervals. Uncertainties are statistical and systematic, respectively.

Summary of bottom muon per-event invariant yields in Pb+Pb collisions at 5.02 TeV as a function of pT for five different centrality intervals. Uncertainties are statistical and systematic, respectively.

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Search for Higgs boson production in association with a high-energy photon via vector-boson fusion with decay into bottom quark pairs at $\sqrt{s}$=13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Brad ; et al.
JHEP 03 (2021) 268, 2021.
Inspire Record 1826521 DOI 10.17182/hepdata.100160

A search is presented for the production of the Standard Model Higgs boson in association with a high-energy photon. With a focus on the vector-boson fusion process and the dominant Higgs boson decay into $b$-quark pairs, the search benefits from a large reduction of multijet background compared to more inclusive searches. Results are reported from the analysis of 132 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}$=13 TeV collected with the ATLAS detector at the LHC. The measured Higgs boson signal yield in this final-state signature is $1.3 \pm 1.0$ times the Standard Model prediction. The observed significance of the Higgs boson signal above the background is 1.3 standard deviations, compared to an expected significance of 1.0 standard deviations.

13 data tables match query

Comparisons of data and simulated event distributions of the BDT input variable \(\Delta \eta_{jj}\) in the two \(m_{bb}\) sidebands after kinematic reweighting of the non-resonant \(b\bar{b}\gamma jj\) background. The data are shown as black points, and the background contributions are stacked in coloured histograms. The Higgs boson signal contribution is scaled up and represented by the dashed red line. The bottom panel in each plot shows the ratio of the data to the SM prediction, where the uncertainty band corresponds to the statistical uncertainty only.

Comparisons of data and simulated event distributions of the BDT input variable \(p_{\text{T}}^{\text{balance}}\) in the two \(m_{bb}\) sidebands after kinematic reweighting of the non-resonant \(b\bar{b}\gamma jj\) background. The data are shown as black points, and the background contributions are stacked in coloured histograms. The Higgs boson signal contribution is scaled up and represented by the dashed red line. The bottom panel in each plot shows the ratio of the data to the SM prediction, where the uncertainty band corresponds to the statistical uncertainty only.

The \(m_{bb}\) distributions in the HighBDT categories, overlaid with contributions from the \(H\gamma jj\) signal as well as the resonant \(Z\gamma jj\) and non-resonant \(b\bar{b} \gamma jj\) background fits. The combined \(\chi^2\) per degree of freedom is \(45.2/45\). The bottom panel in each plot presents the significance of the Higgs boson signal relative to the non-resonant \(b\bar{b} \gamma jj\) background in each bin.

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Version 2
Search for trilepton resonances from chargino and neutralino pair production in $\sqrt{s}$ = 13 TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Abbott, Braden Keim ; Abbott, Brad ; et al.
Phys.Rev.D 103 (2021) 112003, 2021.
Inspire Record 1831992 DOI 10.17182/hepdata.99806

A search is performed for the electroweak pair production of charginos and associated production of a chargino and neutralino, each of which decays through an $R$-parity-violating coupling into a lepton and a $W$, $Z$, or Higgs boson. The trilepton invariant-mass spectrum is constructed from events with three or more leptons, targeting chargino decays that include an electron or muon and a leptonically decaying $Z$ boson. The analyzed dataset corresponds to an integrated luminosity of 139 fb$^{-1}$ of proton-proton collision data produced by the Large Hadron Collider at a center-of-mass energy of $\sqrt{s}$ = 13 TeV and collected by the ATLAS experiment between 2015 and 2018. The data are found to be consistent with predictions from the Standard Model. The results are interpreted as limits at 95% confidence level on model-independent cross sections for processes beyond the Standard Model. Limits are also set on the production of charginos and neutralinos for a Minimal Supersymmetric Standard Model with an approximate $B$-$L$ symmetry. Charginos and neutralinos with masses between 100 GeV and 1100 GeV are excluded depending on the assumed decay branching fractions into a lepton (electron, muon, or $\tau$-lepton) plus a boson ($W$, $Z$, or Higgs).

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The observed data and the SM background expectation in the CRs (pre-fit) and VRs (post-fit). The ''Other'' category mostly consists of tW Z, ttW, and tZ processes. The hatched bands indicate the combined theoretical, experimental, and MC statistical uncertainties. The bottom panel shows the fractional difference between the observed data and expected yields for the CRs and the significance of the difference for the VRs, computed following the profile likelihood method described in Ref. [arXiv: physics/0702156].

The observed data and the SM background expectation in the CRs (pre-fit) and VRs (post-fit). The ''Other'' category mostly consists of tW Z, ttW, and tZ processes. The hatched bands indicate the combined theoretical, experimental, and MC statistical uncertainties. The bottom panel shows the fractional difference between the observed data and expected yields for the CRs and the significance of the difference for the VRs, computed following the profile likelihood method described in Ref. [arXiv: physics/0702156].

The observed yields and post-fit background expectations in SRFR, SR4$\ell$, and SR3$\ell$, shown inclusively and when the direct lepton from a $\tilde\chi^{\pm}_{1}/\tilde\chi^{0}_{1}$ decay is required to be an electron or muon. The Other category mostly consists of $tWZ$, $t\bar{t}W$, and $tZ$ processes. Uncertainties on the background expectation include combined statistical and systematic uncertainties. The individual uncertainties may be correlated and do not necessarily add in quadrature to equal the total background uncertainty.

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MEASUREMENT OF THE SPIN CORRELATION PARAMETER A(00NN) AND OF THE ANALYZING POWER FOR P P ELASTIC SCATTERING IN THE ENERGY RANGE FROM 0.5-GEV TO 0.8-GEV

Bystricky, J. ; Chaumette, P. ; Deregel, J. ; et al.
Nucl.Phys.B 262 (1985) 727-743, 1985.
Inspire Record 227731 DOI 10.17182/hepdata.33710

The spin correlation parameter A oonn and the analyzing powers A oono and A ooon were measured simultaneously, in the energy range 0.5–0.8 GeV and in the angular region 40°–80° CM. The experiment used the polarized proton beam of SATURNE II and the Saclay frozen spin polarized target.

15 data tables match query

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