13 research outputs found

    Diffractive Dijet Production with a Leading Proton in ep Collisions at HERA

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    The cross section of the diffractive process e^+p -> e^+Xp is measured at a centre-of-mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q^2 <2 GeV^2 and in deep-inelastic scattering with 4 GeV^2<Q^2<80 GeV^2. The results are compared to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering

    Colombeau generalized functions on manifolds

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    Eduard NigschZsfassung in dt. SpracheWien, Techn. Univ. u. Univ., Dipl.-Arb., 2006OeBB(VLID)161012

    Erratum to: Measurement of jet production cross sections in deep-inelastic ep scattering at HERA

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    The measurement of the jet cross sections by the H1 collaboration had been compared to various predictions including the next-to-next-to-leading order (NNLO) QCD calculations which are corrected in this erratum for an implementation error in one of the components of the NNLO calculations. The jet data and the other predictions remain unchanged. Eight figures, one table and conclusions are adapted accordingly, exhibiting even better agreement between the corrected NNLO predictions and the jet data

    Measurement of lepton-jet correlation in deep-inelastic scattering with the H1 detector using machine learning for unfolding

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    The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm OmniFold, which considers eight observables simultaneously in this first application. The unfolded cross sections are compared to calculations performed within the context of collinear or transverse-momentum-dependent (TMD) factorization in Quantum Chromodynamics (QCD) as well as Monte Carlo event generators. The measurement probes a wide range of QCD phenomena, including TMD parton distribution functions and their evolution with energy in so far unexplored kinematic regions

    Measurement of Jet Production Cross Sections in Deep-inelastic ep Scattering at HERA

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    A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities 5.5<Q2<80GeV25.5<Q^2<80\,{\rm GeV}^2 and inelasticities 0.2<y<0.60.2<y<0.6 is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290pb1290\,{\rm pb}^{-1}. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of Q2Q^2. Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective Q2Q^2-interval are also determined. Previous results of inclusive jet cross sections in the range 150<Q2<15000GeV2150<Q^2<15\,000\,{\rm GeV}^2 are extended to low transverse jet momenta 5<PTjet<7GeV5<P_{T}^{\rm jet}<7\,{\rm GeV}. The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of Q2Q^2, the strong coupling constant αs(MZ)\alpha_s(M_Z) is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities 5.5<Q2<80GeV25.5<Q^2<80\,{\rm GeV}^2 and inelasticities 0.2<y<0.60.2<y<0.6 is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290pb1290\,{\rm pb}^{-1}. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of Q2Q^2. Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective Q2Q^2-interval are also determined. Previous results of inclusive jet cross sections in the range 150<Q2<15000GeV2150<Q^2<15\,000\,{\rm GeV}^2 are extended to low transverse jet momenta 5<PTjet<7GeV5<P_{T}^{\rm jet}<7\,{\rm GeV}. The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of Q2Q^2, the strong coupling constant αs(MZ)\alpha_s(M_Z) is determined in next-to-leading order.A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities 5.5<Q2<80GeV25.5<Q^2 <80\,\mathrm {GeV}^2 and inelasticities 0.2<y<0.60.2<y<0.6 is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290pb1290\,\mathrm {pb}^{-1} . Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and are presented as a function of jet transverse momentum observables and as a function of Q2Q^2 . Jet cross sections normalised to the inclusive neutral current DIS cross section in the respective Q2Q^2 -interval are also determined. Previous results of inclusive jet cross sections in the range 150<Q2<15,000GeV2150<Q^2 <15{,}000\,\mathrm {GeV}^2 are extended to low transverse jet momenta 5<PTjet<7GeV5<P_\mathrm{T}^\mathrm{jet} <7\,\mathrm {GeV} . The data are compared to predictions from perturbative QCD in next-to-leading order in the strong coupling, in approximate next-to-next-to-leading order and in full next-to-next-to-leading order. Using also the recently published H1 jet data at high values of Q2Q^2 , the strong coupling constant αs(MZ)\alpha _s(M_Z) is determined in next-to-leading order

    Measurement of jet production cross sections in deep-inelastic ep scattering at HERA

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    Exclusive ρ0\rho^0 Meson Photoproduction with a Leading Neutron at HERA

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    A first measurement is presented of exclusive photoproduction of ρ0\rho^0 mesons associated with leading neutrons at HERA. The data were taken with the H1 detector in the years 20062006 and 20072007 at a centre-of-mass energy of s=319\sqrt{s}=319 GeV and correspond to an integrated luminosity of 1.161.16 pb1^{-1}. The ρ0\rho^0 mesons with transverse momenta pT0.35p_T0.35, are detected in the Forward Neutron Calorimeter. The phase space of the measurement is defined by the photon virtuality Q2<2Q^2 < 2 GeV2^2, the total energy of the photon-proton system 20<Wγp<10020 < W_{\gamma p} < 100 GeV and the polar angle of the leading neutron θn<0.75\theta_n < 0.75 mrad. The cross section of the reaction γpρ0nπ+\gamma p \to \rho^0 n \pi^+ is measured as a function of several variables. The data are interpreted in terms of a double peripheral process, involving pion exchange at the proton vertex followed by elastic photoproduction of a ρ0\rho^0 meson on the virtual pion. In the framework of one-pion-exchange dominance the elastic cross section of photon-pion scattering, σel(γπ+ρ0π+)\sigma^{\rm el}(\gamma\pi^+ \to \rho^0\pi^+), is extracted. The value of this cross section indicates significant absorptive corrections for the exclusive reaction γpρ0nπ+\gamma p\to\rho^0 n \pi^+

    Measurement of Dijet Production in Diffractive Deep-Inelastic ep Scattering at HERA

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    A measurement is presented of single- and double-differential dijet cross sections in diffractive deep-inelastic epep scattering at HERA using data collected by the H1 experiment corresponding to an integrated luminosity of 290 pb^{-1}. The investigated phase space is spanned by the photon virtuality in the range of 4<Q^{2}<100 GeV^{2} and by the fractional proton longitudinal momentum loss x_pom<0.03. The resulting cross sections are compared with next-to-leading order QCD predictions based on diffractive parton distribution functions and the value of the strong coupling constant is extracted

    Diffractive Dijet Production with a Leading Proton in ep\it ep Collisions at HERA

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    The cross section of the diffractive process e+pe+Xp\it e^{+}p → e^{+}X p is measured at a centre-of- mass energy of 318 GeV, where the system X contains at least two jets and the leading final state proton p\it p is detected in the H1 Very Forward Proton Spectrometer. The measurement is performed in photoproduction with photon virtualities Q2<2GeV2\it Q^{2} < 2 GeV^{2} and in deep-inelastic scattering with 4GeV2<Q2<80GeV2\it 4 GeV^{2} < Q^{2} < 80 GeV^{2}. The results are compared to next-to-leading order QCD calculations based on diffractive parton distribution functions as extracted from measurements of inclusive cross sections in diffractive deep-inelastic scattering
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