Measurement of antiproton production in ${\rm p He}$ collisions at $\sqrt{s_{NN}}=110$ GeV

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
No Journal Information, 2018.
Inspire Record 1688924 DOI 10.17182/hepdata.84584

The cross-section for prompt antiproton production in collisions of protons with an energy of $6.5$ TeV incident on helium nuclei at rest is measured with the LHCb experiment from a data set corresponding to an integrated luminosity of $0.5\,nb^{-1}$. The target is provided by injecting helium gas into the LHC beam line at the LHCb interaction point. The reported results, covering antiproton momenta between $12$ and $110\,\mathrm{GeV/}c$, represent the first direct determination of the antiproton production cross-section in ${\rm p He}$ collisions, and impact the interpretation of recent results on antiproton cosmic rays from space-borne experiments.

1 data table

Double-differential cross-section in antiproton momentum and transverse momentum for antiproton production in collisions of 6.5 TeV protons on He nuclei at rest. The antiproton momentum is defined in the laboratory frame. Results are averaged over the given kinematic range of each bin. The uncertainty is split into an uncertainty delta_uncorr, uncorrelated among the kinematic bins, and an uncertainty delta_corr, fully correlated among the kinematic bins. For both uncertainties, the systematic uncertainty, dominant for most bins, and the statistical uncertainty, are added in quadrature. The average value within each bin is also reported for the antiproton momentum, the transverse momentum, and x-Feynman xF=2 p_Z*/SQRT(S), where p_Z* is the longitudinal antiproton momentum in the center-of-mass system and SQRT(S) the nucleon-nucleon center-of-mass energy. These average values are obtained from simulation (based on EPOS LHC), to avoid biases from reconstruction effects and given the good agreement with data observed for the simulated kinematic spectra.


Measurement of forward $W$ and $Z$ boson production in association with jets in proton-proton collisions at $\sqrt{s}=8$ TeV

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1605 (2016) 131, 2016.
Inspire Record 1454404 DOI 10.17182/hepdata.78541

The production of W and Z bosons in association with jets is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 ± 0.02 fb$^{−1}$. The W boson is identified using its decay to a muon and a neutrino, while the Z boson is identified through its decay to a muon pair. Total cross-sections are measured and combined into charge ratios, asymmetries, and ratios of W +jet and Z+jet production cross-sections. Differential measurements are also performed as a function of both boson and jet kinematic variables. All results are in agreement with Standard Model predictions.

22 data tables

The total cross sections for $Wj$ and $Zj$ production, obtained by summing over the measured cross-sections in bins of $\eta^{\mathrm{jet}}$.

The ratios of the $Wj$, $W^+j$ and $W^-j$ cross-sections to the $Zj$ cross-section, and the ratio of the $W^+j$ to $W^-j$ cross-sections.

The asymmetry of $W^+j$ and $W^-j$ production, given by $A(Wj)\equiv (\sigma_{W^+j}-\sigma_{W^-j})/(\sigma_{W^+j}+\sigma_{W^-j})$.

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Angular analysis of the $B^{0} \to K^{*0} \mu^{+} \mu^{-}$ decay using 3 fb$^{-1}$ of integrated luminosity

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1602 (2016) 104, 2016.
Inspire Record 1409497 DOI 10.17182/hepdata.74247

An angular analysis of the B$^{0}$ → K$^{*0}$(→ K$^{+}$ π$^{−}$)μ$^{+}$ μ$^{−}$ decay is presented. The dataset corresponds to an integrated luminosity of 3.0 fb$^{−1}$ of pp collision data collected at the LHCb experiment. The complete angular information from the decay is used to determine CP-averaged observables and CP asymmetries, taking account of possible contamination from decays with the K$^{+}$ π$^{−}$ system in an S-wave configuration. The angular observables and their correlations are reported in bins of q$^{2}$, the invariant mass squared of the dimuon system. The observables are determined both from an unbinned maximum likelihood fit and by using the principal moments of the angular distribution. In addition, by fitting for q$^{2}$-dependent decay amplitudes in the region 1.1 < q$^{2}$ < 6.0 GeV$^{2}$/c$^{4}$, the zero-crossing points of several angular observables are computed. A global fit is performed to the complete set of CP-averaged observables obtained from the maximum likelihood fit. This fit indicates differences with predictions based on the Standard Model at the level of 3.4 standard deviations. These differences could be explained by contributions from physics beyond the Standard Model, or by an unexpectedly large hadronic effect that is not accounted for in the Standard Model predictions.

83 data tables

CP-averaged angular observables evaluated by the unbinned maximum likelihood fit.

CP-averaged angular observables evaluated by the unbinned maximum likelihood fit. The first uncertainties are statistical and the second systematic.

CP-asymmetric angular observables evaluated by the unbinned maximum likelihood fit. The first uncertainties are statistical and the second systematic.

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Measurement of forward W and Z boson production in $pp$ collisions at $ \sqrt{s}=8 $ TeV

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1601 (2016) 155, 2016.
Inspire Record 1406555 DOI 10.17182/hepdata.71419

Measurements are presented of electroweak boson production using data from pp collisions at a centre-of-mass energy of $ \sqrt{s}=8 $ TeV. The analysis is based on an integrated luminosity of 2.0 fb$^{−1}$ recorded with the LHCb detector. The bosons are identified in the W → μν and Z → μ$^{+}$ μ$^{−}$ decay channels. The cross-sections are measured for muons in the pseudorapidity range 2.0 < η < 4.5, with transverse momenta p$_{T}$ > 20 GeV/c and, in the case of the Z boson, a dimuon mass within $ 60 < {M}_{\mu }{{{}_{{}^{+}}}_{\mu}}_{{}^{-}}<120 $ GeV/c$^{2}$. The results are $ {\sigma}_W{{}_{{}^{+}}}_{\to \mu }{{}_{{}^{+}}}_{\nu }=1093.6\pm 2.1\pm 7.2\pm 10.9\pm 12.7\ \mathrm{p}\mathrm{b}, $ $ {\sigma}_W{{}_{{}^{-}}}_{\to \mu }{{}_{{}^{-}}}_{\overline{\nu}}=818.4\pm 1.9\pm 5.0\pm 7.0\pm 9.5\ \mathrm{p}\mathrm{b}, $ $ {\sigma}_{\mathrm{Z}\to \mu }{{{}_{{}^{+}}}_{\mu}}_{{}^{-}}=95.0\pm 0.3\pm 0.7\pm 1.1\pm 1.1\ \mathrm{p}\mathrm{b}, $ $ {\sigma}_{Z\to \mu }{{{}_{{}^{+}}}_{\mu}}_{{}^{-}}=95.0\pm 0.3\pm 0.7\pm 1.1\pm 1.1\ \mathrm{p}\mathrm{b}, $ where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. The evolution of the W and Z boson cross-sections with centre-of-mass energy is studied using previously reported measurements with 1.0 fb$^{−1}$ of data at 7 TeV. Differential distributions are also presented. Results are in good agreement with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics.

23 data tables

Inclusive cross-section for $W^+$ and $W^-$ boson production in bins of muon pseudorapidity. The uncertainties are statistical, systematic, beam and luminosity.

Inclusive cross-section for $Z$ boson production in bins of rapidity. The uncertainties are statistical, systematic, beam and luminosity.

Inclusive cross-section for $Z$ boson production in bins of transverse momentum. The uncertainties are statistical, systematic, beam and luminosity.

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Production of associated Y and open charm hadrons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV via double parton scattering

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1607 (2016) 052, 2016.
Inspire Record 1399056 DOI 10.17182/hepdata.73583

Associated production of bottomonia and open charm hadrons in pp collisions at $ \sqrt{s}=7 $ and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb$^{−1}$ accumulated with the LHCb detector. The observation of five combinations, Y(1S)D$^{0}$, Y(2S)D$^{0}$, Y(1S)D$^{+}$, Y(2S)D$^{+}$ and Y(1S)D$_{s}^{+}$ , is reported. Production crosssections are measured for Y(1S)D$^{0}$ and Y(1S)D$^{+}$ pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism.

20 data tables

Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^0)}{\mathrm{d} p_T(\Upsilon(1S))}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^0)<4.5$, $p_T(D^0)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.

Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^+)}{\mathrm{d} p_T(\Upsilon(1S))}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^+)<4.5$, $p_T(D^+)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.

Normalized differential cross-section $\frac{1}{\sigma}\frac{ \mathrm{d}\sigma(\Upsilon(1S)D^0)}{\mathrm{d} p_T(D^0)}$ for $2<y(\Upsilon(1S))<4.5$, $2<y(D^0)<4.5$, $p_T(D^0)>1$ GeV/$c$. Only statistical uncertainties are quoted as systematic uncertainties are found to be negligible. The distribution is normalized to unity.

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Version 2
Measurements of prompt charm production cross-sections in $pp$ collisions at $ \sqrt{s}=13 $ TeV

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
JHEP 1603 (2016) 159, 2016.
Inspire Record 1396331 DOI 10.17182/hepdata.73066

Production cross-sections of prompt charm mesons are measured with the first data from $pp$ collisions at the LHC at a centre-of-mass energy of $13\,\mathrm{TeV}$. The data sample corresponds to an integrated luminosity of $4.98 \pm 0.19\,\mathrm{pb}^{-1}$ collected by the LHCb experiment. The production cross-sections of $D^{0}$, $D^{+}$, $D_{s}^{+}$, and $D^{*+}$ mesons are measured in bins of charm meson transverse momentum, $p_{\mathrm{T}}$, and rapidity, $y$, and cover the range $0 < p_{\mathrm{T}} < 15\,\mathrm{GeV}/c$ and $2.0 < y < 4.5$. The inclusive cross-sections for the four mesons, including charge conjugation, within the range of $1 < p_{\mathrm{T}} < 8\,\mathrm{GeV}/c$ are found to be \begin{align*} \begin{array}{lcr} \sigma(pp \to D^{0} X) &=& 2460 \pm \phantom{1}3 \pm 130\,\mu\mathrm{b} \\ \sigma(pp \to D^{+} X) &=& 1000 \pm \phantom{1}3 \pm 110\,\mu\mathrm{b} \\ \sigma(pp \to D_{s}^{+} X) &=& 460 \pm 13 \pm 100\,\mu\mathrm{b} \\ \sigma(pp \to D^{*+} X) &=& 880 \pm \phantom{1}5 \pm 140\,\mu\mathrm{b} \end{array} \end{align*} where the uncertainties are due to statistical and systematic uncertainties, respectively.

14 data tables

Differential production cross-sections in for prompt $D^{0} + \bar{D}^{0}$ mesons in bins of $(p_{\mathrm{T}}, y)$. The first uncertainty is statistical, and the second is the total systematic.

Differential production cross-sections in for prompt $D^{+} + D^{-}$ mesons in bins of $(p_{\mathrm{T}}, y)$. The first uncertainty is statistical, and the second is the total systematic.

Differential production cross-sections in for prompt $D_{s}^{+} + D_{s}^{-}$ mesons in bins of $(p_{\mathrm{T}}, y)$. The first uncertainty is statistical, and the second is the total systematic.

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Measurement of the $\eta_c (1S)$ production cross-section in proton-proton collisions via the decay $\eta_c (1S) \rightarrow p \bar{p}$

The LHCb collaboration Aaij, Roel ; Abellán Beteta, Carlos ; Adeva, Bernardo ; et al.
Eur.Phys.J. C75 (2015) 311, 2015.
Inspire Record 1316329 DOI 10.17182/hepdata.75251

The production of the $\eta _c (1S)$ state in proton-proton collisions is probed via its decay to the $p\overline{p}$ final state with the LHCb detector, in the rapidity range $2.0 < y < 4.5$ and in the meson transverse-momentum range $p_\mathrm{T} > 6.5 \mathrm{{\,GeV/}{ c}} $ . The cross-section for prompt production of $\eta _c (1S)$ mesons relative to the prompt ${{ J}}/{\psi } $ cross-section is measured, for the first time, to be $\sigma _{\eta _c (1S)}/\sigma _{{{{ J}}/{\psi }}} = 1.74\, \pm \,0.29\, \pm \, 0.28\, \pm \,0.18 _{{\mathcal{B}}}$ at a centre-of-mass energy ${\sqrt{s}} = 7 {~\mathrm{TeV}}$ using data corresponding to an integrated luminosity of 0.7 fb$^{-1}$ , and $\sigma _{\eta _c (1S)}/\sigma _{{{{ J}}/{\psi }}} = 1.60 \pm 0.29 \pm 0.25 \pm 0.17 _{{\mathcal{B}}}$ at ${\sqrt{s}} = 8 {~\mathrm{TeV}}$ using 2.0 fb$^{-1}$ . The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the $\eta _c (1S)$ and ${{ J}}/{\psi } $ decays to the $p\overline{p}$ final state. In addition, the inclusive branching fraction of ${b} $ -hadron decays into $\eta _c (1S)$ mesons is measured, for the first time, to be ${\mathcal{B}}( b {\rightarrow } \eta _c X ) = (4.88\, \pm \,0.64\, \pm \,0.29\, \pm \, 0.67 _{{\mathcal{B}}}) \times 10^{-3}$ , where the third uncertainty includes also the uncertainty on the ${{ J}}/{\psi } $ inclusive branching fraction from ${b} $ -hadron decays. The difference between the ${{ J}}/{\psi } $ and $\eta _c (1S)$ meson masses is determined to be $114.7 \pm 1.5 \pm 0.1 {\mathrm {\,MeV\!/}c^2} $ .

4 data tables

Differential cross-section for $\eta_c(1S)$ prompt production for $p_T > 6.5$ [GeV/$c$] and $2.0 < y < 4.5$. The reported uncertainties are total errors.

Differential cross-section for $\eta_c(1S)$ prompt production for $p_T > 6.5$ [GeV/$c$] and $2.0 < y < 4.5$. The reported uncertainties are total errors.

Differential cross-section for $\eta_c(1S)$ from inclusive charmonium production in b-hadrons decays for $p_T > 6.5$ [GeV/$c$] and $2.0 < y < 4.5$. The reported uncertainties are total errors.

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