Plots from Rivet analyses

Charged particle production in deep-inelastic ep scattering at H1 (H1_2013_I1217865)

Inspire | HepData | Analysis reference | Eur.Phys.J. C73 (2013) 2406, | arXiv:1302.1321

Charged particle production in deep-inelastic ep scattering is measured with the H1 detector at HERA. The kinematic range of the analysis covers low photon virtualities, 5 < Q2 < 100 GeV2 and small values of Bjorken-x, 10**-2 < x < 10**-2. The analysis is performed in the hadronic centre-of-mass system. The charged particle densities are measured as a function of pseudorapidity eta* and transverse momentum pT* in the range 0 <eta* <5 and 0 < pT* < 10 GeV in bins of x and Q2.

Strangeness Production at low $Q^2$ in Deep-Inelastic $ep$ Scattering at HERA (H1_2009_I810046)

The production of neutral strange hadrons is investigated using deep-inelastic scattering events measured with the H1 detector at HERA. The measurements are made in the phase space defined by the negative four-momentum transfer squared of the photon $2 < Q^2 < 100 GeV^2$ and the inelasticity $0.1 < y < 0.6$. The $K_s$ and $\Lambda$ production cross sections and their ratios are determined. $K_s$ production is compared to the production of charged particles in the same region of phase space. The $\Lambda$ - anti-$\Lambda$ asymmetry is also measured and found to be consistent with zero. Predictions of leading order Monte Carlo programs are compared to the data.

Measurement of inclusive production of D* mesons both with and without dijet production in DIS collisions (H1) (H1_2007_I736052)

Inclusive $D^*$ production is measured in deep-inelastic $ep$ scattering at HERA with the H1 detector. In addition, the production of dijets in events with a $D^*$ meson is investigated. The analysis covers values of photon virtuality $2< Q^2 \leq 100$ GeV$^2$ and of inelasticity $0.05 \leq y \leq 0.7$. Differential cross sections are measured as a function of $Q^2$ and $x$ and of various $D^*$ meson and jet observables.

Measurement of Event Shape Variables in Deep-Inelastic Scattering at HERA (H1_2006_I699835)

Deep-inelastic ep scattering data taken with the H1 detector at HERA and corresponding to an integrated luminosity of $106 pb^{-1}$ are used to study the differential distributions of event shape variables. These include thrust, jet broadening, jet mass and the C-parameter. The four-momentum transfer Q is taken to be the relevant energy scale and ranges between 14 GeV and 200 GeV.

Measurement of beauty production at HERA using events with muons and jets (H1) (H1_2005_I676166)

A measurement of the beauty production cross section in $ep$ collisions at a centre-of-mass energy of 319 GeV is presented. The data were collected with the H1 detector at the HERA collider in the years 1999-2000. Events are selected by requiring the presence of jets and muons in the final state. Both the long lifetime and the large mass of b-flavoured hadrons are exploited to identify events containing beauty quarks. Differential cross sections are measured in photoproduction, with photon virtualities $Q^2 < 1$ GeV$^2$, and in deep inelastic scattering, where $2 < Q^2 < 100$ GeV$^2$.

Measurement of $D^{*\pm}$ meson production in deep inelastic scattering at HERA (H1_2002_I561885)

Inspire | HepData | Analysis reference

The inclusive production of $D^{*\pm}$ (2010) mesons in deep-inelastic scattering is studied with the H1 detector at HERA. In the kinematic region $1 < Q^2 < 100 $ GeV$^2$ and $0.05 < y < 0.7$ in $e^+ p$ cross section for inclusive $D^{*\pm}$ meson production is measured in the visible range $p_{T}^{D*} > 1.5$ GeV and $|\eta^{D*}| < 1.5 $.

H1 energy flow in DIS (H1_2000_S4129130)

Measurements of transverse energy flow for neutral current deep- inelastic scattering events produced in positron-proton collisions at HERA. The kinematic range covers squared momentum transfers $Q^2$ from 3.2 to 2200 GeV$^2$; the Bjorken scaling variable $x$ from $8 \times 10^{-5}$ to 0.11 and the hadronic mass $W$ from 66 to 233 GeV. The transverse energy flow is measured in the hadronic centre of mass frame and is studied as a function of $Q^2$, $x$, $W$ and pseudorapidity. The behaviour of the mean transverse energy in the central pseudorapidity region and an interval corresponding to the photon fragmentation region are analysed as a function of $Q^2$ and $W$. This analysis is useful for exploring the effect of photon PDFs and for tuning models of parton evolution and treatment of fragmentation and the proton remnant in DIS.

Forward pi0 meson production at HERA (H1_1999_I504022)

High transverse momentum $\pi^0$ mesons have been measured with the H1 detector at HERA in deep-inelastic ep scattering events at low Bjorken-x, down to $x \approx 4 \cdot 10^{-5}$ .The measurement is performed in a region of small angles with respect to the proton remnant in the laboratory frame of reference, namely the forward region, and corresponds to central rapidity in the centre of mass system of the virtual photon and proton. This region is expected to be particularly sensitive to QCD effects in hadronic final states. Differential cross-sections for inclusive $\pi^0$ meson production are presented as a function of Bjorken-x and the four-momentum transfer $Q^2$, and as a function of transverse momentum and pseudorapidity.

Measurement of D* meson cross-sections at HERA and determination of the gluon density in the proton using NLO QCD (H1_1999_I481112)

With the H1 detector at the $ep$ collider HERA, $D^*$ meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers $Q^2>2$ GeV$^2$ and in photoproduction at energies around $W_{\gamma p} \sim 88$ GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, $x_g g(x_g)$, has been extracted in the momentum fraction range $7.5 \times 10^{-4}< x_g <4 \times 10^{-2}$ at average scales $mu^2 =25$ to 50 GeV$^2$. The gluon momentum fraction $x_g$ has been obtained from the measured kinematics of the scattered electron and the $D^*$ meson in the final state.

Evolution of e p fragmentation and multiplicity distributions in the Breit frame (H1_1997_I445116)

Low x deep-inelastic ep scattering data, taken in 1994 at the H1 detector at HERA, are analysed in the Breit frame of reference. The evolution of the peak and width of the current hemisphere fragmentation function is presented as a function of Q.

Transverse momentum spectra of charged particles in DIS (H1 1996) (H1_1996_I424463)

Transverse momentum spectra of charged particles produced in deep inelastic scattering are measured as a function of the kinematic variables x and Q2 using the H1 detector at the epcollider HERA. The data are compared to different patton emission models, either with or without ordering of the emissions in transverse momentum. The data provide evidence for a relatively large amount of patton radiation between the current and the remnant systems.

Charged particle multiplicities in deep inelastic scattering at HERA (H1_1996_I422230)

Using the H1 detector at HERA, charged particle multiplicity distributions in deep inelastic ep scattering have been measured over a large kinematical region. The evolution with W and Q2 of the multiplicity distribution and of the multiplicity moments in pseudorapidity domains of varying size is studied in the current fragmentation region of the hadronic centre-of-mass frame. Data on multiplicity as well as the various moments of the distribution are given in a variety of psuedorapidity regions. The moments are the generalised dispersions (D), the factorial moments (R), the Muller moments (K) and the C factors (C).

Inclusive D0 and D*+- production in deep inelastic e p scattering at HERA (H1_1996_I421105)

First results on inclusive D0 and D* production in deep inelastic ep scattering are reported using data collected by the H1 experiment at HERA in 1994.

A Study of the Fragmentation of Quarks in ep Collisions at HERA (H1_1995_I394793)

Deep inelastic scattering (DIS) events, selected from 1993 data taken by the H1 experiment at HERA, are studied in the Breit frame of reference. It is shown that certain aspects of the quarks emerging from within the proton in $ep$ interactions are essentially the same as those of quarks pair-created from the vacuum in $e^+e^-$ annihilation.

H1 energy flow and charged particle spectra in DIS (H1_1994_S2919893)

Inspire | HepData | Analysis reference | Z.Phys.C63:377-390,1994 | doi:10.1007/BF01580319

Global properties of the hadronic final state in deep inelastic scattering events at HERA are investigated. The data are corrected for detector effects. Energy flows in both the laboratory frame and the hadronic centre of mass system, and energy-energy correlations in the laboratory frame are presented. Historically, the Ariadne colour dipole model provided the only satisfactory description of this data, hence making it a useful 'target' analysis for MC shower models.

Measurement of sigma_red (F2) of H1 and ZEUS at different beam energies (HERA_2015_I1377206)

Inspire | HepData | Analysis reference | Eur.Phys.J. C75 (2015), 580, | arXiv:1506.06042

A combination is presented of all inclusive deep inelastic cross sections previously published by the H1 and ZEUS collaborations at HERA for neutral and charged current ep scattering for zero beam polarisation. The data were taken at proton beam energies of 920, 820, 575 and 460 GeV and an electron beam energy of 27.5GeV. The data correspond to an integrated luminosity of about 1 fb^-1 and span six orders of magnitude in negative four-momentum-transfer squared, Q2, and Bjorken x . The correlations of the systematic uncertainties were evaluated and taken into account for the combination. The combined cross sections were input to QCD analyses at leading order, next-to-leading order and at next-to-next-to-leading order, providing a new set of parton distribution functions, called HERAPDF2.0.. The energy and beam options need to be specified when using rivet-merge.