arXiv subjects

Paul R. Newman

Publications and source records attributed to Paul R. Newman.

8 recordsLinked to original sources

arXiv2026

Inclusive electron-proton measurement prospects in the Electron-Ion Collider early science stage

We explore the potential for extracting proton structure functions, proton parton density functions (PDFs), and the strong coupling $α_s(M_z^2)$, using early science data from the future Electron-Ion Collider (EIC), both standalone, and in combination with HERA data. Different scenarios are considered in which samples with modest luminosity are collected at either two or three EIC beam energy configurations. The Rosenbluth separation method is used to extract the proton structure functions $F_2$ and $F_L$ from simulated data in a model-independent manner, showing that $F_L$ can be extracted significantly more precisely with three centre of mass energies than with two, whilst also obtaining $F_2$ to higher precision than has been achieved previously. The inclusion of a third beam configuration is also beneficial in the extraction of the strong coupling $α_s(M_z^2)$ that is obtainable with unprecedented experimental precision with the early EIC data. Additionally, the precision of the proton PDFs is improved when adding these data, especially for large values of Bjorken-$x$, for both two and three EIC beam energy configurations. These studies show that EIC data will already be a highly competitive probe of perturbative Quantum Chromodynamics within the first five years of data taking.

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arXiv2024

Prospects for measurements of the longitudinal proton structure function $F_L$ at the Electron Ion Collider

We explore the potential for extracting the longitudinal proton structure function $F_{L}$ at the future Electron-Ion Collider (EIC) through a Rosenbluth separation method. The impacts of differing assumptions on sample sizes, systematic uncertainties and beam energy scenarios are investigated. With a sufficiently large number of centre of mass energy configurations and well-controlled systematics, the EIC will measure $F_{L}$ to an unprecedented precision, even with relatively modest luminosities. The accessible kinematic range complements both fixed target and HERA data. In the most optimistic scenarios, the EIC data will be a highly competitive direct probe of the proton gluon density.

hep-ph↗

arXiv2024

Extracting the partonic structure of colorless exchanges at the Electron Ion Collider

We investigate the determination of the partonic structure of colorless exchanges in deep inelastic diffractive $ep$ scattering at the Electron Ion Collider, using the standard decomposition into Pomeron and Reggeon contributions. We perform fits to simulated diffractive cross section pseudodata in four variables, including the momentum transfer $t$, to estimate the achievable precision on the Pomeron and Reggeon quark and gluon distributions. We analyze the influence of different cuts in the kinematic variables, beam energy configurations and luminosities, including a `first year' scenario. We conclude that the EIC will be able to constrain the partonic structure of the sub-leading Reggeon exchange with a precision comparable to that of the leading Pomeron exchange.

hep-ph↗

arXiv2023

Extraction of the strong coupling with HERA and EIC inclusive data

Sensitivity to the strong coupling $α_S(M^2_Z)$ is investigated using existing Deep Inelastic Scattering data from HERA in combination with projected future measurements from the Electron Ion Collider (EIC) in a next-to-next-to-leading order QCD analysis. A potentially world-leading level of precision is achievable when combining simulated inclusive neutral current EIC data with inclusive charged and neutral current measurements from HERA, with or without the addition of HERA inclusive jet and dijet data. The result can be obtained with substantially less than one year of projected EIC data at the lower end of the EIC centre-of-mass energy range. Some questions remain over the magnitude of uncertainties due to missing higher orders in the theoretical framework.

hep-ph↗

arXiv2022

Diffractive longitudinal structure function at the Electron Ion Collider

Possibilities for the measurement of the longitudinal structure function in diffraction $F_\mathrm{L}^\mathrm{D}$ at the future US Electron Ion Collider are investigated. The sensitivity to $F_\mathrm{L}^\mathrm{D}$ arises from the variation of the reduced diffractive cross section with centre-of-mass energy. Simulations are performed with various sets of beam energy combinations and for different assumptions on the precision of the diffractive cross section measurements. Scenarios compatible with current EIC performance expectations lead to an unprecedented precision on $F_\mathrm{L}^\mathrm{D}$ at the 5-10 % level in the best measured regions. While scenarios with data at a larger number of centre-of-mass energies allow the extraction of $F_\mathrm{L}^\mathrm{D}$ in the widest kinematic domain and with the smallest uncertainties, even the more conservative assumptions lead to precise measurements. The ratio $R^\mathrm{D}$ of photoabsorption cross sections for longitudinally to transversely polarised photons can also be obtained with high precision using a separate extraction method.

hep-ph↗

arXiv2022

Opportunities for inclusive diffraction at EIC

The possibilities for inclusive diffraction in the Electron Ion Collider, EIC, in the US, are analyzed. We find that thanks to the excellent forward proton tagging, the EIC will be able to access a wider kinematical range of longitudinal momentum fraction and momentum transfer of the leading proton than at HERA. This opens up the possibility to measure subleading diffractive exchanges. The extended $t$-range would allow the precise extraction of 4-dimensional reduced cross section in diffraction. In addition, the varying beam energy setups at the EIC would allow for precise measurements of the longitudinal diffractive structure function.

hep-ph↗

arXiv2020

Inclusive diffraction in future electron-proton and electron-ion colliders

We analyse the possibilities for the study of inclusive diffraction offered by future electron--proton/nucleus colliders in the TeV regime, the Large Hadron-electron Collider as an upgrade of the HL-LHC and the Future Circular Collider in electron-hadron mode. Compared to $ep$ collisions at HERA, we find an extension of the available kinematic range in $x$ by a factor of order $20$ and of the maximum $Q^2$ by a factor of order $100$ for LHeC, while the FCC version would extend the coverage by a further order of magnitude both in $x$ and $Q^2$. This translates into a range of available momentum fraction of the diffractive exchange with respect to the hadron ($ξ$), down to $10^{-4}-10^{-5}$ for a wide range of the momentum fraction of the parton with respect to the diffractive exchange ($β$). Using the same framework and methodology employed in previous studies at HERA, considering only the experimental uncertainties and not those stemming from the functional form of the initial conditions or other ones of theoretical origin, and under very conservative assumptions for the luminosities and systematic errors, we find an improvement in the extraction of diffractive parton densities from fits to reduced cross sections for inclusive coherent diffraction in $ep$ by about an order of magnitude. For $eA$, we also perform the simulations for the Electron Ion Collider. We find that an extraction of the currently unmeasured nuclear diffractive parton densities is possible with similar accuracy to that in $ep$.

hep-ph↗

arXiv2008

What HERA may provide ?

More than 100 people participated in a discussion session at the DIS08 workshop on the topic What HERA may provide. A summary of the discussion with a structured outlook and list of desirable measurements and theory calculations is given.

hep-ph↗