Version 2
Precision measurement of forward $Z$ boson production in proton-proton collisions at $\sqrt{s} = 13$ TeV

The LHCb collaboration Aaij, R. ; Abdelmotteleb, A.S.W. ; Abellán Beteta, C. ; et al.
JHEP 07 (2022) 026, 2022.
Inspire Record 1990313 DOI 10.17182/hepdata.132011

A precision measurement of the $Z$ boson production cross-section at $\sqrt{s} = 13$ TeV in the forward region is presented, using $pp$ collision data collected by the LHCb detector, corresponding to an integrated luminosity of 5.1 fb$^{-1}$. The production cross-section is measured using $Z\rightarrow\mu^+\mu^-$ events within the fiducial region defined as pseudorapidity $2.0<\eta<4.5$ and transverse momentum $p_{T}>20$ GeV/$c$ for both muons and dimuon invariant mass $60<M_{\mu\mu}<120$ GeV/$c^2$. The integrated cross-section is determined to be $\sigma (Z \rightarrow \mu^+ \mu^-)$ = 196.4 $\pm$ 0.2 $\pm$ 1.6 $\pm$ 3.9~pb, where the first uncertainty is statistical, the second is systematic, and the third is due to the luminosity determination. The measured results are in agreement with theoretical predictions within uncertainties.

27 data tables

Relative uncertainty for the integrated $Z -> \mu^{+} \mu^{-}$ cross-section measurement. The total uncertainty is the quadratic sum of uncertainties from statistical, systematic and luminosity contributions.

Final state radiation correction used in the $y^{Z}$ cross-section measurement. The first uncertainty is statistical and the second is systematic.

Final state radiation correction used in the $p_{T}^{Z}$ cross-section measurement. The first uncertainty is statistical and the second is systematic.

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Measurement of $J/\psi$ production cross-sections in $pp$ collisions at $\sqrt{s}=5$ TeV

The LHCb collaboration Aaij, R. ; Abdelmotteleb, A.S.W. ; Beteta, C. Abellán ; et al.
JHEP 11 (2021) 181, 2021.
Inspire Record 1915030 DOI 10.17182/hepdata.115512

The production cross-sections of $J/\psi$ mesons in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=5$ TeV are measured using a data sample corresponding to an integrated luminosity of $9.13\pm0.18~\text{pb}^{-1}$, collected by the LHCb experiment. The cross-sections are measured differentially as a function of transverse momentum, $p_{\text{T}}$, and rapidity, $y$, and separately for $J/\psi$ mesons produced promptly and from beauty hadron decays (nonprompt). With the assumption of unpolarised $J/\psi$ mesons, the production cross-sections integrated over the kinematic range $0<p_{\text{T}}<20~\text{GeV}/c$ and $2.0<y<4.5$ are $8.154\pm0.010\pm0.283~\mu\text{b}$ for prompt $J/\psi$ mesons and $0.820\pm0.003\pm0.034~\mu\text{b}$ for nonprompt $J/\psi$ mesons, where the first uncertainties are statistical and the second systematic. These cross-sections are compared with those at $\sqrt{s}=8$ TeV and $13$ TeV, and are used to update the measurement of the nuclear modification factor in proton-lead collisions for $J/\psi$ mesons at a centre-of-mass energy per nucleon pair of $\sqrt{s_{\text{NN}}}=5$ TeV. The results are compared with theoretical predictions.

20 data tables

Double-differential production cross-sections for prompt $J/\psi$ mesons in ($p_\text{T},y$) intervals. The first uncertainties are statistical, the second are correlated systematic uncertainties shared between intervals, the third are uncorrelated systematic uncertainties, and the last are correlated between $p_\text{T}$ intervals and uncorrelated between $y$ intervals.

Double-differential production cross-sections for nonprompt $J/\psi$ mesons in ($p_\text{T},y$) intervals. The first uncertainties are statistical, the second are correlated systematic uncertainties shared between intervals, the third are uncorrelated systematic uncertainties, and the last are correlated between $p_\text{T}$ intervals and uncorrelated between $y$ intervals.

Single-differential production cross-sections for prompt $J/\psi$ mesons as a function of $p_\text{T}$. The first uncertainties are statistical, the second are correlated systematic uncertainties shared between intervals, and the last are uncorrelated systematic uncertainties.

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Measurement of Exclusive $\pi^{+}\pi^{-}$ and $\rho^0$ Meson Photoproduction at HERA

The H1 collaboration Andreev, V. ; Baghdasaryan, A. ; Baty, A. ; et al.
Eur.Phys.J.C 80 (2020) 1189, 2020.
Inspire Record 1798511 DOI 10.17182/hepdata.102569

Exclusive photoproduction of $\rho^0(770)$ mesons is studied using the H1 detector at the $ep$ collider HERA. A sample of about 900000 events is used to measure single- and double-differential cross sections for the reaction $\gamma p \to \pi^{+}\pi^{-}Y$. Reactions where the proton stays intact (${m_Y{=}m_p}$) are statistically separated from those where the proton dissociates to a low-mass hadronic system ($m_p{<}m_Y{<}10$ GeV). The double-differential cross sections are measured as a function of the invariant mass $m_{\pi\pi}$ of the decay pions and the squared $4$-momentum transfer $t$ at the proton vertex. The measurements are presented in various bins of the photon-proton collision energy $W_{\gamma p}$. The phase space restrictions are $0.5 < m_{\pi\pi} < 2.2$ GeV, ${\vert t\vert < 1.5}$ GeV${}^2$, and ${20 < W_{\gamma p} < 80}$ GeV. Cross section measurements are presented for both elastic and proton-dissociative scattering. The observed cross section dependencies are described by analytic functions. Parametrising the $m_{\pi\pi}$ dependence with resonant and non-resonant contributions added at the amplitude level leads to a measurement of the $\rho^{0}(770)$ meson mass and width at $m_\rho = 770.8\ {}^{+2.6}_{-2.7}$ (tot) MeV and $\Gamma_\rho = 151.3\ {}^{+2.7}_{-3.6}$ (tot) MeV, respectively. The model is used to extract the $\rho^0(770)$ contribution to the $\pi^{+}\pi^{-}$ cross sections and measure it as a function of $t$ and $W_{\gamma p}$. In a Regge asymptotic limit in which one Regge trajectory $\alpha(t)$ dominates, the intercept $\alpha(t{=}0) = 1.0654\ {}^{+0.0098}_{-0.0067}$ (tot) and the slope $\alpha^\prime(t{=}0) = 0.233\ {}^{+0.067 }_{-0.074 }$ (tot) GeV${}^{-2}$ of the $t$ dependence are extracted for the case $m_Y{=}m_p$.

28 data tables

Elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction off protons, differential in the dipion mass. The tabulated cross sections are $\gamma p$ cross sections but can be converted to $ep$ cross sections using the effective photon flux $\Phi_{\gamma/e}$.

Elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction off protons, differential in the dipion mass --- statistical correlations coefficients $\rho_{ij}$ only. Only one half of the (symmetric) matrix is stored. Bins are identified by their global bin number.

Fit of elastic ($m_Y=m_p$) and proton-dissociative ($1<m_Y<10$ GeV) $\pi^{+}\pi^{-}$ photoproduction cross section off protons with a Soeding-inspired analytic function including $\rho$ and $\omega$ meson resonant contributions as well as a continuum background which interfere at the amplitude level. Parameters with subscript "el" and "pd" correspond to elastic and proton-dissociative cross sections, respectively.

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Forward peak in $\pi^+$ photoproduction

Buschhorn, G. ; Heide, P. ; Kötz, U. ; et al.
Phys.Lett.B 25 (1967) 622-623, 1967.
Inspire Record 1392927 DOI 10.17182/hepdata.29549

The π+—photoproduction cross section is found to have a peak in the forward direction in disagreement with simple Regge pole models.

1 data table

No description provided.


$K^+$ nucleon elastic scattering at 180° between 1.0 and 1.5 GeV/c incident momentum

Adams, U. ; Carter, R.S. ; Cook, V. ; et al.
Nucl.Phys.B 87 (1975) 41-51, 1975.
Inspire Record 1392682 DOI 10.17182/hepdata.32061

We have measured the cross section at 180° for K + p and K + n elastic scattering in the momentum range 1.0 to 1.5 GeV/ c . The K + n cross section was measured on deuterium and the K + p on hydrogen and deuterium. We were thus able to measure directly the difference between free nucleon (proton) scattering and bound nucleon (proton) scattering at large angles. This difference was found to be small and within our experimental accuracy the K + p(n) cross section should be equal to the K + p (free) cross section at 180°. We found no evidence for an s -channel resonance Z ∗ in either the K + p or K + n system. A comparison of our data and those of other groups with theoretical predictions is given.

2 data tables

DEUTERIUM TARGET. U IS ABOUT 0.1 GEV**2.

HYDROGEN AND DEUTERIUM TARGET DATA ARE IN GOOD AGREEMENT. THESE CROSS SECTIONS ARE A WEIGHTED AVERAGE.


Study of $\pi^0$ pair production in single-tag two-photon collisions

The Belle collaboration Masuda, M. ; Uehara, S. ; Watanabe, Y. ; et al.
Phys.Rev.D 93 (2016) 032003, 2016.
Inspire Record 1390112 DOI 10.17182/hepdata.71443

We report a measurement of the differential cross section of $\pi^0$ pair production in single-tag two-photon collisions, $\gamma^* \gamma \to \pi^0 \pi^0$, in $e^+ e^-$ scattering. The cross section is measured for $Q^2$ up to 30 GeV$^2$, where $Q^2$ is the negative of the invariant mass squared of the tagged photon, in the kinematic range 0.5 GeV < W < 2.1 GeV and $|\cos \theta^*|$ < 1.0 for the total energy and pion scattering angle, respectively, in the $\gamma^* \gamma$ center-of-mass system. The results are based on a data sample of 759 fb$^{-1}$ collected with the Belle detector at the KEKB asymmetric-energy $e^+ e^-$ collider. The transition form factor of the $f_0(980)$ and that of the $f_2(1270)$ with the helicity-0, -1, and -2 components separately are measured for the first time and are compared with theoretical calculations.

10 data tables

$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=3.45 GeV$^2$.

$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=4.46 GeV$^2$.

$W$ dependence of the differential cross section ${\rm d}\sigma/{\rm d}|\cos\theta^*|$ in five $|\cos\theta^*|$ bins for $Q^2$=5.47 GeV$^2$.

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$K^+ n$ charge exchange reaction at 3 GeV/c

Goldschmidt-Clermont, Y. ; Henri, V.P. ; Jongejans, B. ; et al.
Phys.Lett.B 27 (1968) 602-604, 1968.
Inspire Record 1389631 DOI 10.17182/hepdata.29205

About 100 000 pictures, with an average of ∼12K + per picture, taken in the 81 cm Saclay deuterium bubble chamber exposed to a separated 3 GeV/c K + beam have been analysed for the reaction K + d→K 0 pp in the 1-prong V 0 and 2-prong V 0 topologies. 214 such events have been found allowing a determination of the differential cross-section. A comparison with the prediction of Rarita and Schwarzschild yields reasonable agreement; in particular a large real part is inferred for the amplitude for the reaction K + n→K 0 p.

2 data tables

The errors are statistical only.

The errors are statistical only. To evaluate the cross section on neutron thE data are divided on (1-FORMFACTOR(C=DEUT). For definition of the formfactor see L. Durand, Phys. Rev. 115 (1959) 1020.


Study of the reaction pi- p --> omega n at 3, 8, 6 and 8 GeV/c

Apel, W.D. ; Ausländer, J. ; Müller, H. ; et al.
Phys.Lett.B 55 (1975) 111-116, 1975.
Inspire Record 1388800 DOI 10.17182/hepdata.27881

Results are given for the production differential cross sections and the ω decay angular distribution in terms of the ω spin density matrix elements.

3 data tables

PAPER ALSO GIVES OFF-DIAGONAL ELEMENTS OF THE ERROR COVARIANCE MATRIX.

PAPER ALSO GIVES OFF-DIAGONAL ELEMENTS OF THE ERROR COVARIANCE MATRIX.

No description provided.


Photoproduction of $\omega$ mesons off protons and neutrons

The CBELSA/TAPS collaboration Dietz, F. ; Metag, V. ; Anisovich, A.V. ; et al.
Eur.Phys.J.A 51 (2015) 6, 2015.
Inspire Record 1340913 DOI 10.17182/hepdata.69767

ω photoproduction off hydrogen and deuterium has been studied with the tagged photon beam of the ELSA accelerator in Bonn for photon energies up to 2.0 GeV. The ω meson has been identified via the ω → π$^{0}$ γ → γγγ decay mode, using the combined setup of the Crystal Barrel/TAPS detector systems. Both inclusive and exclusive analyses have been carried out. Differential and total cross-sections have been derived for ω mesons produced off free protons and off protons and neutrons bound in deuterium. The cross-section for the production off the bound neutron is found to be a factor of ≈ 1.3 larger than the one off the bound proton in the incident beam energy region 1.2 GeV < E$_{γ}$ < 1.6 GeV. For higher incident beam energies this factor goes down to ≈ 1.1 at 2.0 GeV. The cross-sections of this work have been used as normalization for transparency ratio measurements.

85 data tables

Differential cross-sections of $\omega$ mesons produced off the free proton versus $\cos(\theta^\omega_{\mathrm{c.m.}})$ and versus the momentum transfer to the nucleon, $t$, for incident photon energy $E_\gamma$ = 1.125-1.150 GeV.

Differential cross-sections of $\omega$ mesons produced off the free proton versus $\cos(\theta^\omega_{\mathrm{c.m.}})$ and versus the momentum transfer to the nucleon, $t$, for incident photon energy $E_\gamma$ = 1.150-1.175 GeV.

Differential cross-sections of $\omega$ mesons produced off the free proton versus $\cos(\theta^\omega_{\mathrm{c.m.}})$ and versus the momentum transfer to the nucleon, $t$, for incident photon energy $E_\gamma$ = 1.175-1.200 GeV.

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The Charge Form Factor of the Proton at a Momentum Transfer of 75 F$^-^2$

Bartel, W. ; Dudelzak, B. ; Krehbiel, H. ; et al.
Phys.Lett.B 25 (1967) 236-237, 1967.
Inspire Record 1333753 DOI 10.17182/hepdata.29448

The proton form factors GE(q2) and GM(q2) are determined at q2 = 75fm−2.

2 data tables

No description provided.

No description provided.