Measurement of energy flow, cross section and average inelasticity of forward neutrons produced in $\mathrm{\sqrt{s} = 13 TeV}$ proton-proton collisions with the LHCf Arm2 detector

The LHCf collaboration Adriani, O. ; Berti, E. ; Bonechi, L. ; et al.
JHEP 07 (2020) 016, 2020.
Inspire Record 1783943 DOI 10.17182/hepdata.130268

In this paper, we report the measurement of the energy flow, the cross section and the average inelasticity of forward neutrons (+ antineutrons) produced in $\sqrt{s} = 13$ TeV proton-proton collisions. These quantities are obtained from the inclusive differential production cross section, measured using the LHCf Arm2 detector at the CERN Large Hadron Collider. The measurements are performed in six pseudorapidity regions: three of them ($\eta > 10.75$, $8.99 < \eta < 9.21$ and $8.80 < \eta < 8.99$), albeit with smaller acceptance and larger uncertainties, were already published in a previous work, whereas the remaining three ($10.06 < \eta < 10.75$, $9.65 < \eta < 10.06$ and $8.65 < \eta < 8.80$) are presented here for the first time. The analysis was carried out using a data set acquired in June 2015 with a corresponding integrated luminosity of $\mathrm{0.194~nb^{-1}}$. Comparing the experimental measurements with the expectations of several hadronic interaction models used to simulate cosmic ray air showers, none of these generators resulted to have a satisfactory agreement in all the phase space selected for the analysis. The inclusive differential production cross section for $\eta > 10.75$ is not reproduced by any model, whereas the results still indicate a significant but less serious deviation at lower pseudorapidities. Depending on the pseudorapidity region, the generators showing the best overall agreement with data are either SIBYLL 2.3 or EPOS-LHC. Furthermore, apart from the most forward region, the derived energy flow and cross section distributions are best reproduced by EPOS-LHC. Finally, even if none of the models describe the elasticity distribution in a satisfactory way, the extracted average inelasticity is consistent with the QGSJET II-04 value, while most of the other generators give values that lie just outside the experimental uncertainties.

9 data tables match query

Neutron (and antineutron) inclusive differential production cross section in $\eta > 10.75$

Neutron (and antineutron) inclusive differential production cross section in $10.06 < \eta < 10.75$

Neutron (and antineutron) inclusive differential production cross section in $9.65 < \eta < 10.06$

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Measurement of inclusive forward neutron production cross section in proton-proton collisions at $\mathrm{\sqrt{s} = 13~TeV}$ with the LHCf Arm2 detector

The LHCf collaboration Adriani, O. ; Berti, E. ; Bonechi, L. ; et al.
JHEP 11 (2018) 073, 2018.
Inspire Record 1692008 DOI 10.17182/hepdata.87099

In this paper, we report the measurement relative to the production of forward neutrons in proton-proton collisions at $\mathrm{\sqrt{s} = 13~TeV}$ obtained using the LHCf Arm2 detector at the Large Hadron Collider. The results for the inclusive differential production cross section are presented as a function of energy in three different pseudorapidity regions: $\eta > 10.76$, $8.99 < \eta < 9.22$ and $8.81 < \eta < 8.99$. The analysis was performed using a data set acquired in June 2015 that corresponds to an integrated luminosity of $\mathrm{0.194~nb^{-1}}$. The measurements were compared with the predictions of several hadronic interaction models used to simulate air showers generated by Ultra High Energy Cosmic Rays. None of these generators showed good agreement with the data for all pseudorapidity intervals. For $\eta > 10.76$, no model is able to reproduce the observed peak structure at around $\mathrm{5~TeV}$ and all models underestimate the total production cross section: among them, QGSJET II-04 shows the smallest deficit with respect to data for the whole energy range. For $8.99 < \eta < 9.22$ and $8.81 < \eta < 8.99$, the models having the best overall agreement with data are SIBYLL 2.3 and EPOS-LHC, respectively: in particular, in both regions SIBYLL 2.3 is able to reproduce the observed peak structure at around $\mathrm{1.5-2.5~TeV}$.

3 data tables match query

Inclusive neutron (and antineutron) production cross section in $\eta > 10.76$

Inclusive neutron (and antineutron) production cross section in $8.99 < \eta < 9.22$

Inclusive neutron (and antineutron) production cross section in $8.81 < \eta < 8.99$


Measurement of forward photon production cross-section in proton–proton collisions at $\sqrt{s}$ = 13 TeV with the LHCf detector

The LHCf collaboration Adriani, O. ; Berti, E. ; Bonechi, L. ; et al.
Phys.Lett.B 780 (2018) 233-239, 2018.
Inspire Record 1518782 DOI 10.17182/hepdata.86566

In this paper, we report the production cross-section of forward photons in the pseudorapidity regions of $\eta\,&gt;\,10.94$ and $8.99\,&gt;\,\eta\,&gt;\,8.81$, measured by the LHCf experiment with proton--proton collisions at $\sqrt{s}$ = 13 TeV. The results from the analysis of 0.191 $\mathrm{nb^{-1}}$ of data obtained in June 2015 are compared to the predictions of several hadronic interaction models that are used in air-shower simulations for ultra-high-energy cosmic rays. Although none of the models agree perfectly with the data, EPOS-LHC shows the best agreement with the experimental data among the models.

2 data tables match query

Inclusive photon production cross section in $\eta > 10.94$

Inclusive photon production cross section in $8.81<\eta<8.99$


Measurement of the forward-backward asymmetry of $\Lambda$ and $\bar{\Lambda}$ production in $p \bar{p}$ collisions

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.D 93 (2016) 032002, 2016.
Inspire Record 1404885 DOI 10.17182/hepdata.76972

We study $\Lambda$ and $\bar{\Lambda}$ production asymmetries in $p \bar{p} \rightarrow \Lambda (\bar{\Lambda}) X$, $p \bar{p} \rightarrow J/\psi \Lambda (\bar{\Lambda}) X$, and $p \bar{p} \rightarrow \mu^\pm \Lambda (\bar{\Lambda}) X$ events recorded by the D0 detector at the Fermilab Tevatron collider at $\sqrt{s} = 1.96$ TeV. We find an excess of $\Lambda$'s ($\bar{\Lambda}$'s) produced in the proton (antiproton) direction. This forward-backward asymmetry is measured as a function of rapidity. We confirm that the $\bar{\Lambda}/\Lambda$ production ratio, measured by several experiments with various targets and a wide range of energies, is a universal function of "rapidity loss", i.e., the rapidity difference of the beam proton and the lambda.

2 data tables match query

Forward-backward asymmetry $A_{FB}$ of $\Lambda$ and $\bar{\Lambda}$ with $p_T > 2.0$ GeV in minimum bias events $p \bar{p} \rightarrow \Lambda (\bar{\Lambda}) X$, events $p \bar{p} \rightarrow J/\psi \Lambda (\bar{\Lambda}) X$, and events $p \bar{p} \rightarrow \mu^\pm \Lambda (\bar{\Lambda}) X$.

Forward-backward asymmetry $A_{FB}$ of $\Lambda$ and $\bar{\Lambda}$ in bins of $p_T$ in events $p \bar{p} \rightarrow \mu^\pm \Lambda (\bar{\Lambda}) X$.


Measurements of longitudinal and transverse momentum distributions for neutral pions in the forward-rapidity region with the LHCf detector

The LHCf collaboration Adriani, O. ; Berti, E. ; Bonechi, L. ; et al.
Phys.Rev.D 94 (2016) 032007, 2016.
Inspire Record 1385877 DOI 10.17182/hepdata.74066

The differential cross sections for inclusive neutral pions as a function of transverse and longitudinal momentum in the very forward rapidity region have been measured at the Large Hadron Collider (LHC) with the Large Hadron Collider forward detector (LHCf) in proton-proton collisions at $\sqrt{s}=$ 2.76 and 7 TeV and in proton-lead collisions at nucleon-nucleon center-of-mass energies of $\sqrt{s_\text{NN}}=$ 5.02 TeV. Such differential cross sections in proton-proton collisions are compatible with the hypotheses of limiting fragmentation and Feynman scaling. Comparing proton-proton with proton-lead collisions, we find a sizable suppression of the production of neutral pions in the differential cross sections after subtraction of ultra-peripheral proton-lead collisions. This suppression corresponds to the nuclear modification factor value of about 0.1-0.3. The experimental measurements presented in this paper provide a benchmark for the hadronic interaction Monte Carlo simulation codes that are used for the simulation of cosmic ray air showers.

20 data tables match query

The average $\pi^{0}$ transverse momenta for the rapidity range $8.8<y<10.6$ in $p+p$ collisions at $\sqrt{s}=2.76$ and 7 TeV and for the rapidity range $-8.8>y_\rm{lab}>-10.6$ in $p+\rm{Pb}$ collisions at $\sqrt{s_\rm{NN}}=5.02$ TeV. The rapidity values for $p+\rm{Pb}$ collisions are in the detector reference frame and must be multiplied by -1.

Production rate for the $\pi^{0}$ production in the rapidity range $8.8 < y < 9.0$ in $p+p$ collisions and in the rapidity range $-8.8 > y_\rm{lab} > -9.0$ in $p+\rm{Pb}$ collisions.

Production rate for the $\pi^{0}$ production in the rapidity range $9.0 < y < 9.2$ in $p+p$ collisions and in the rapidity range $-9.0 > y_\rm{lab} > -9.2$ in $p+\rm{Pb}$ collisions.

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Measurement of the forward-backward asymmetry in $\Lambda_b^0$ and $\overline \Lambda_b^0$ baryon production in $p \overline p$ collisions at $\sqrt s =1.96$ TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.D 91 (2015) 072008, 2015.
Inspire Record 1352125 DOI 10.17182/hepdata.73327

We measure the forward-backward asymmetry in the production of $\Lambda_b^0$ and $\overline \Lambda_b^0$ baryons as a function of rapidity in $p \overline p $ collisions at $\sqrt s =1.96$ TeV using $10.4$ fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron collider. The asymmetry is determined by the preference of $\Lambda_b^0$ or $\overline \Lambda_b^0$ particles to be produced in the direction of the beam protons or antiprotons, respectively. The measured asymmetry integrated over rapidity $y$ in the range $0.1<|y|<2$ is $A=0.04 \pm 0.07 {\rm (stat)} \pm 0.02 {\rm (syst)}$.

1 data table match query

Efficiencies $\epsilon$, averaged values of background-subtracted transverse momenta $\left< p_T\right>$, backward and forward fitted yields for the signal $N(B)$ and $N(F)$, forward-backward asymmetries $A$, and cross-section ratios $R$ in four intervals of rapidity. Uncertainties on $\left< p_T\right>$, $N(B)$ and $N(F)$ are statistical only. Uncertainties on $\epsilon$ arise from the statistical precision of the simulated event samples.


Measurement of very forward neutron energy spectra for 7 TeV proton--proton collisions at the Large Hadron Collider

The LHCf collaboration Adriani, O. ; Berti, E. ; Bonechi, L. ; et al.
Phys.Lett.B 750 (2015) 360-366, 2015.
Inspire Record 1351909 DOI 10.17182/hepdata.73320

The Large Hadron Collider forward (LHCf) experiment is designed to use the LHC to verify the hadronic-interaction models used in cosmic-ray physics. Forward baryon production is one of the crucial points to understand the development of cosmic-ray showers. We report the neutron-energy spectra for LHC $\sqrt{s}$ = 7 TeV proton--proton collisions with the pseudo-rapidity $\eta$ ranging from 8.81 to 8.99, from 8.99 to 9.22, and from 10.76 to infinity. The measured energy spectra obtained from the two independent calorimeters of Arm1 and Arm2 show the same characteristic feature before unfolding the difference in the detector responses. We unfolded the measured spectra by using the multidimensional unfolding method based on Bayesian theory, and the unfolded spectra were compared with current hadronic-interaction models. The QGSJET II-03 model predicts a high neutron production rate at the highest pseudo-rapidity range similar to our results and the DPMJET 3.04 model describes our results well at the lower pseudo-rapidity ranges. However no model perfectly explains the experimental results in the whole pseudo-rapidity range. The experimental data indicate the most abundant neutron production rate relative to the photon production, which does not agree with predictions of the models.

1 data table match query

Differential neutron production rate d$\sigma_{n}$/dE [mb/GeV] for each rapidity range.


Measurement of the $W+b$-jet and $W+c$-jet differential production cross sections in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Lett.B 743 (2015) 6-14, 2015.
Inspire Record 1334689 DOI 10.17182/hepdata.73191

We present a measurement of the cross sections for the associated production of a $W$ boson with at least one heavy quark jet, $b$ or $c$, in proton-antiproton collisions. Data corresponding to an integrated luminosity of 8.7 fb$^{-1}$ recorded with the D0 detector at the Fermilab Tevatron \ppbar Collider at $\sqrt{s}=1.96$ TeV are used to measure the cross sections differentially as a function of the jet transverse momenta in the range 20 to 150 GeV. These results are compared to calculations of perturbative QCD theory as well as predictions from Monte Carlo generators.

3 data tables match query

The $W + b$-jet production cross sections times $W \to \mu\nu$ branching fraction, ${\rm d}\sigma/{\rm d}p_T^{\rm jet}$.

The $W + c$-jet production cross sections times $W \to \mu\nu$ branching fraction, ${\rm d}\sigma/{\rm d}p_T^{\rm jet}$.

The $\sigma(W+c)/\sigma(W+b)$ cross section ratio in bins of $c(b)$-jet $p_T$.


Measurement of the electron charge asymmetry in $\boldsymbol{p\bar{p}\rightarrow W+X \rightarrow e\nu +X}$ decays in $\boldsymbol{p\bar{p}}$ collisions at $\boldsymbol{\sqrt{s}=1.96}$ TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.D 91 (2015) 032007, 2015.
Inspire Record 1333394 DOI 10.17182/hepdata.73177

We present a measurement of the electron charge asymmetry in $p\bar{p}\rightarrow W+X \rightarrow e\nu +X$ events at a center-of-mass energy of 1.96 TeV, using data corresponding to 9.7~fb$^{-1}$ of integrated luminosity collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron pseudorapidity and is presented in five kinematic bins based on the electron transverse energy and the missing transverse energy in the event. The measured asymmetry is compared with next-to-leading-order predictions in perturbative quantum chromodynamics and provides accurate information for the determination of parton distribution functions of the proton. This is the most precise lepton charge asymmetry measurement to date.

3 data tables match query

CP-folded electron charge asymmetry for data with $E_T^{e} > 25$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.

CP-folded electron charge asymmetry for data with $25 < E_T^{e} < 35$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.

CP-folded electron charge asymmetry for data with $E_T^{e} > 35$ GeV multiplied by 100. $\langle|\eta^e|\rangle$ is the cross section weighted average of electron pseudorapidity in each bin from RESBOS with PHOTOS.


Measurement of the ratio of differential cross sections {\sigma}(ppbar -> Z + b jet)/{\sigma}(ppbar -> Z + jet) in ppbar collisions at sqrt(s)=1.96 TeV

The D0 collaboration Abazov, Victor Mukhamedovich ; Abbott, Braden Keim ; Acharya, Bannanje Sripath ; et al.
Phys.Rev.D 87 (2013) 092010, 2013.
Inspire Record 1210034 DOI 10.17182/hepdata.61314

We measure the ratio of cross sections, {\sigma}(ppbar -> Z + b jet)/{\sigma}(ppbar -> Z + jet), for associated production of a Z boson with at least one jet. The ratio is also measured as a function of the jet transverse momentum, jet pseudorapidity, Z boson transverse momentum, and the azimuthal angle between the Z boson and the closest jet for events with at least one b jet. These measurements use data collected by the D0 experiment in Run II of Fermilab's Tevatron ppbar Collider at a center-of-mass energy of 1.96 TeV, and correspond to an integrated luminosity of 9.7 fb$^{-1}$. The results are compared to predictions from next-to-leading order calculations and various Monte Carlo event generators.

4 data tables match query

The ratio of (BJET + Z0)/(JET + Z0) production as a function of the jet transverse momentum.

The ratio of (BJET + Z0)/(JET + Z0) production as a function of the Z0 transverse momentum.

The ratio of (BJET + Z0)/(JET + Z0) production as a function of the JET pseudorapidity.

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