Nuclear Theory·nucl-th

Monday·July 11, 2022

8 papers—5 primary·3 cross-listed

06
[Submitted on 7 Jul 2022] (cross-list from hep-ph)
Radiative corrections to the forward-backward asymmetry in $e^{+} e^{-} \to π^{+} π^{-}$
Gilberto Colangelo🇨🇭 · Martin Hoferichter🇨🇭 · Joachim Monnard🇨🇭 · Jacobo Ruiz de Elvira🇨🇭
We present a calculation of the $C$ -odd radiative corrections to $e^{+} e^{-} \to π^{+} π^{-}$ in a dispersive formalism, concentrating on the leading pion-pole contribution in the virtual box diagrams. In particular, we show how the effect of a general pion vector form factor in the loop integral can be incorporated in a model-independent way and how the cancellation of infrared singularities proceeds in this case. The numerical results, dominated by the infrared enhanced contributions, indicate significant corrections beyond scalar QED, essentially confirming recent findings in generalized vector-meson-dominance models.
Comments:
16 pages, 3 figures; numerical results for the corrections included as supplemental material; corrected treatment of endpoint singularity, including mixed term in real part
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2207.03495 [pdf]
JHEP(2022)·49 citations
07
[Submitted on 7 Jul 2022] (cross-list from hep-ph)
One-Loop Corrections to Dihadron Production in DIS at Small $x$
Filip Bergabo🇺🇸 · Jamal Jalilian-Marian🇺🇸
We calculate the one-loop corrections to dihadron production in Deep Inelastic Scattering (DIS) at small x using the Color Glass Condensate formalism. We show that all UV and soft singularities cancel while the collinear divergences are absorbed into quark and anti quark-hadron fragmentation functions. Rapidity divergences lead to JIMWLK evolution of dipoles and quadrupoles describing multiple-scatterings of the quark anti-quark dipole on the target proton/nucleus. The resulting cross section is finite and can be used for phenomenological studies of dihadron angular correlations at small x in a future Electron-Ion Collider (EIC).
Comments:
28 pages, 3 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.03606 [pdf]
PRD(2022)·55 citations
08
[Submitted on 8 Jul 2022] (cross-list from hep-ph)
Nuclear geometry at high energy from exclusive vector meson production
Heikki Mäntysaari🇫🇮 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸
We show that when saturation effects are included one obtains a good description of the exclusive $J / ψ$ production spectra in ultra peripheral lead-lead collisions as recently measured by the ALICE Collaboration at the LHC. As exclusive spectra are sensitive to the spatial distribution of nuclear matter at small Bjorken- $x$ , this implies that gluon saturation effects modify the impact parameter profile of the target as we move towards small $x$ . In addition to saturation effects, we find a preference for larger nuclear strong-interaction radii compared to the typical charge radius. We demonstrate the role of finite photon transverse momentum and the interference between the cases for which the role of photon emitter and target are switched between the nuclei. We show that these effects are comparable to the experimental precision for $p_{T}$ -differential cross sections and as such need to be included when comparing to LHC data. Finally, the integrated $J / ψ$ production cross sections from the LHC and preliminary transverse momentum spectra from RHIC are shown to prefer calculations with fluctuating nucleon substructure, although these datasets would require even stronger saturation effects than predicted from our framework.
Comments:
20 pages, 19 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2207.03712 [pdf]
PRD(2022)·81 citations

Affiliations

first authorsco-authorsvia INSPIRE

Radiative corrections to the forward-backward asymmetry in e+e−→π+π−

One-Loop Corrections to Dihadron Production in DIS at Small x

Nuclear geometry at high energy from exclusive vector meson production

Affiliations

Radiative corrections to the forward-backward asymmetry in $e^{+} e^{-} \to π^{+} π^{-}$

One-Loop Corrections to Dihadron Production in DIS at Small $x$