Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 1207.0480

Single Perturbative Splitting Diagrams in Double Parton Scattering

Jonathan R. Gaunt
View original source ↗Read source document ↗Export metadata ↓

Abstract

We present a detailed study of a specific class of graph that can potentially contribute to the proton-proton double parton scattering (DPS) cross section. These are the `2v1' or `single perturbative splitting' graphs, in which two `nonperturbatively generated' (NP) ladders interact with two ladders that have been generated via a perturbative 1->2 branching process. Using a detailed calculation, we confirm the result first written down by Ryskin and Snigirev, that 2v1 graphs in which the two NP ladders do not interact with one another do contribute to the LO proton-proton DPS cross section, albeit with a different geometrical prefactor to the one that applies to the `2v2'/`zero perturbative splitting' graphs. We then show that 2v1 graphs in which the NP ladders exchange partons with one another also contribute to the LO proton-proton DPS cross section, provided that this `crosstalk' occurs at a lower scale than the 1->2 branching on the other side of the graph. Due to the preference in the 2v1 graphs for the x value at which the branching occurs/crosstalk ceases to be much larger than x values at the hard scale, the effect of crosstalk interactions is likely to be a decrease in the 2v1 cross section except at very small x values (< 10^-6). At moderate x values ~10^-3 - 10^-2, the x value at the splitting is in the region ~10^-1 where PDFs do not change much with scale, and crosstalk effects are likely to be small. We give an explicit formula for the contribution from the 2v1 graphs to the DPS cross section, and combine this with the suggestion that `double perturbative splitting'/`1v1' graphs should be removed from this cross section made in a previous publication, to obtain a formula for the DPS cross section. We point out that there are two potentially concerning features in this equation, that might indicate that our prescription for handling the 1v1 graphs is not quite correct.

Explore related subjects

hep-ph

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jonathan R. Gaunt. 2012-12-06. Single Perturbative Splitting Diagrams in Double Parton Scattering. https://doi.org/10.1007/jhep01(2013)042

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

First constraints on QCD axion dark matter using James Webb Space Telescope observations

We present the first constraints on QCD axion dark matter using measurements from the James Webb Space Telescope. By utilizing publicly available MIRI and NIRSpec blank-sky observations, originally collected for sky subtraction purposes, we derive strong limits on the axion-photon coupling constant $g_{a γγ}$ in the mass range 0.1-4 eV. This analysis underscores the potential of blank-sky observations as a powerful tool for constraining dark matter models and demonstrates how astrophysical missions can be repurposed for particle physics research.

hep-ph↗
arXiv2026

Interplay between Electroweak Symmetry Breaking and Higgs Portal Dark Matter

Models of Dark Matter must contend with the fact that the presence of electroweak symmetry breaking along the thermal evolution of the Universe modifies the masses, interactions and, thus, the thermally averaged cross sections. We study in detail the impact of taking (not taking) the presence of the electroweak symmetry breaking into account in the calculations of the Dark Matter relic density in Higgs portal models, providing a model-independent measure of such differences. By focusing on a particular model, we show that ignoring this effect can lead to the inclusion (exclusion) of wrong (viable) regions of parameter space.

hep-ph↗
arXiv2026

Sensitivity Analysis of Singlet Vector-Like B Quarks via Photon-Induced and Z-Initiated Processes at FCC-$μp$

This study presents a systematic sensitivity analysis of singlet-type vector-like $B$ quark production at an FCC--$μp$ collider with a centre-of-mass energy of $\sqrt{s}=24.5~\mathrm{TeV}$ through photon- and $Z$-initiated production mechanisms. The analysis focuses on the $B\to Zb$ decay channel, considering the leptonic decay of the $Z$ boson and the hadronic decay of the accompanying $W$ boson, leading to the final state $\ell^+\ell^-bjj$. Detector-resolution effects are incorporated through a simplified Gaussian smearing procedure, and the discovery and exclusion sensitivities are evaluated using an Asimov-based statistical framework. For the photon-induced channel, the most favourable sensitivity is obtained for $R_L=0.05$ and $\mathcal{L}=1000~\mathrm{fb^{-1}}$. Over the mass range $M_B=2$--$3~\mathrm{TeV}$, the expected $5σ$ discovery reach is approximately $g^\ast\simeq0.263$--$0.328$, while the $95\%$ C.L. exclusion sensitivity extends to $g^\ast\simeq0.162$--$0.197$. On the other hand, the $Z$-initiated channel provides a substantially stronger sensitivity and extends the investigated mass range up to $M_B=4.5~\mathrm{TeV}$. For $R_L=0.05$ and $\mathcal{L}=500~\mathrm{fb^{-1}}$, the $5σ$ discovery reach is approximately $g^\ast\simeq0.038$--$0.056$, while the corresponding $95\%$ C.L. exclusion sensitivity reaches $g^\ast\simeq0.021$--$0.032$. These results demonstrate that photon- and $Z$-initiated single production at an FCC--$μp$ collider provide complementary probes of heavy vector-like $B$ quarks. Moreover, the $Z$-initiated channel offers particularly strong sensitivity to small effective couplings in the multi-TeV mass region beyond the present direct LHC reach.

hep-ph↗