Parton Distribution Functions (PDFs) at large Bjorken-$x$ are mostly constrained by high-energy measurements, and thus risk to absorb the energy-growing effects of unaccounted new physics (NP) if it were present in the high-energy tails of hadron-collider observables used in global PDF fits. If undetected, such contamination biases the resulting PDFs and can potentially hide the absorbed NP signals from subsequent searches. We illustrate this effect in a Standard Model Effective Field Theory (SMEFT) risk-assessment scenario affecting high-mass Drell-Yan production at the High-Luminosity LHC, and compare two strategies to obtain robust PDFs and SMEFT bounds: conservative fits that exclude data above an energy cut, and simultaneous fits of PDFs and Wilson coefficients performed with the {\tt SIMUnet} tool. Both approaches are shown to successfully recover the injected new physics that is otherwise absorbed and hidden by the PDFs.
High-mass Drell-Yan dilepton production provides one of the most sensitive probes of semileptonic four-fermion operators in the Standard Model Effective Field Theory (SMEFT), thanks to the energy growth of the corresponding contributions. At the same time, these measurements also constrain parton distribution functions...
We present a global two-channel Flatt\'e amplitude analysis of the hidden-charm pentaquark candidates observed by the LHCb collaboration in the J/{\psi}p invariant-mass spectrum using the Run 1+2 dataset. We simultaneously fit the three pentaquark amplitudes to the full spectrum, including a polynomial background and c...
A. Likéné, P. Hebbar, A. F. Rothen et al.· 0 citations
Electroweak precision observables (EWPO) remain among the most powerful indirect probes of physics beyond the Standard Model (BSM), and future $e^+ e^-$ colliders are expected to substantially enhance their sensitivity. Within the framework of the Standard Model Effective Field Theory (SMEFT), we show how EWPO predicti...
Based on the combined Deep-Inelastic Scattering (DIS) data from HERA and the exclusive $J/\psi$ and $\Upsilon$ cross sections measured at the LHC, we investigate the role of absorptive corrections on the low-$x$ behaviour of parton distribution functions (PDFs) at low and moderate scales. Using $\texttt{xFitter}$, we s...
V. Bertone, C. Flett, A. D. Martin et al.· 0 citations
We present a next-to-next-to-leading order (NNLO) QCD analysis of polarized parton distribution functions (PDFs) based on the world data set of inclusive polarized deep-inelastic scattering (DIS). The resulting PDF set, denoted as \texttt{KLS26}, includes a consistent treatment of target-mass corrections (TMCs), higher...
Javad Shahrzad, Elliot Leader, A. Khorramian· 0 citations
We present a next-to-leading order (NLO) and next-to-next-to-leading order (NNLO) QCD analysis of the non-singlet structure function $xF_3$, utilizing a Gegenbauer-polynomial representation for the input parton distribution functions (PDFs). The main objective is to assess how this flexible parameterization improves th...
Shahin Atashbar Tehrani, J. Sheibani, E. Astaraki· 0 citations
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