Date

Search for lepton-number-violating $B^-\to D^{(*)+}μ^-μ^-$ decays

The LHCb collaboration Aaij, Roel ; Abdelmotteleb, Ahmed Sameh Wagih ; Abellan Beteta, Carlos ; et al.
LHCb-PAPER-2025-033, 2026.
Inspire Record 3103133 DOI 10.17182/hepdata.167818

A search is performed for lepton-number-violating $B^-\to D^{(*)+}μ^-μ^-$ decays, using data collected by the LHCb experiment in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb$^{-1}$. No significant signal is observed, and upper limits are set on the branching fractions, ${\cal B}(B^-\to D^{+}μ^-μ^-) < 4.6 \times 10^{-8}$ and ${\cal B}(B^-\to D^{*+}μ^-μ^-) < 5.9 \times 10^{-8}$, at the 95% confidence level.

2 data tables

Binned efficiencies across the Dalitz plane for $B^- \to D^{+} \mu^- \mu^-$ decay. Here $\mu_1^-$ and $\mu_2^-$ represent the two muons produced in the decay, and the index specifies their ordering in transverse momentum. Efficiencies are normalized to the average over the full simulated sample.

Binned efficiencies across the Dalitz plane for $B^- \to D^{*+} \mu^- \mu^-$ decay. Here $\mu_1^-$ and $\mu_2^-$ represent the two muons produced in the decay, and the index specifies their ordering in transverse momentum. Efficiencies are normalized to the average over the full simulated sample.


Measurement of differential $t$-channel single top (anti)quark production cross-sections at 13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-286, 2026.
Inspire Record 3098996 DOI 10.17182/hepdata.167734

The production of single top quarks and top antiquarks via the $t$-channel exchange of a virtual $W$ boson is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV at the Large Hadron Collider. The full Run 2 data sample recorded with the ATLAS detector in the years 2015-2018 is used, corresponding to an integrated luminosity of 140 fb$^{-1}$. The absolute and normalised production cross-sections are measured differentially as a function of the transverse momentum and absolute rapidity of the top quark and top antiquark. In addition, the ratio of top quark to top antiquark production cross-sections is measured. The measured distributions are compared with next-to-leading-order quantum chromodynamics predictions obtained with different combinations of matrix-element generators, parton-shower programs and proton parton distribution functions, as well as to next-to-next-to-leading-order calculations. Overall, good agreement is observed between the measurements and the theoretical predictions. For most measured distributions, the sensitivity to differences between the predictions is limited by the systematic uncertainties in the measurement. The measured differential distributions are also interpreted in an effective field theory approach to constrain the Wilson-Coefficient $C_{Qq}^{3,1}$ associated with a four-quark operator. The interpretation accounts for the effect of the selection efficiency, which is altered significantly by non-zero contributions from $C_{Qq}^{3,1}$.

81 data tables

------- Overview of the HEPData record ------- Event selection on detector level: one charged lepton with $p_\text{T}(\ell) > 28$ GeV two jets with $p_\text{T}(j) > 30$ GeV and $|\eta(j)|<4\text{.}5$ one b-tag (DL1r, 60% WP) $E_\text{T}^{miss} > 30$ GeV $m_\text{T}(W) > 50$ GeV $p_\text{T}(\ell) > 40$ GeV $\cdot\frac{|\Delta\Phi(j_1,\ell)|}{\pi}$ $m(\ell b) < 160$ GeV ------- The criteria above define the $\ell^{\pm}$ selection ------- $D_{nn}\geq0\text{.}93$ ------- The criteria above define the signal regions $\ell^{\pm}$ SRs ------- Data/MC comparisons: <ul> <li> $\ell^+$ selection (<a href="167734?version=1&table=Figure%202a">Figure 2a</a> ) <li> $\ell^-$ selection (<a href="167734?version=1&table=Figure%202b">Figure 2b</a> ) Variables in the $\ell^{\pm}$ SRs: <li> $p_T(\ell^+\nu b)$ (<a href="167734?version=1&table=Figure%203a">Figure 3a</a> ) <li> $p_T(\ell^-\nu b)$ (<a href="167734?version=1&table=Figure%203b">Figure 3b</a> ) <li> $|y(\ell^+\nu b)|$ (<a href="167734?version=1&table=Figure%203c">Figure 3c</a> ) <li> $|y(\ell^-\nu b)|$ (<a href="167734?version=1&table=Figure%203d">Figure 3d</a> ) Yields in the $\ell^{\pm}$ SRs: <a href="167734?version=1&table=Table%203">Table 3</a> Uncertainy breakdown into categories: Absolute cross sections: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%204a">Figure 4a</a> ) <li> $p_T(t)$ (<a href="167734?version=1&table=Table%206">Table 6</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%204b">Figure 4b</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Table%207">Table 7</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Figure%204c">Figure 4c</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Table%208">Table 8</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Figure%204d">Figure 4d</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Table%209">Table 9</a> ) <li> $p_T(t \text{ or }\bar{t})$ (<a href="167734?version=1&table=Figure%204e">Figure 4e</a> ) <li> $p_T(t \text{ or }\bar{t})$ (<a href="167734?version=1&table=Table%2010">Table 10</a> ) <li> $|y(t \text{ or }\bar{t})|$ (<a href="167734?version=1&table=Figure%204f">Figure 4f</a> ) <li> $|y(t \text{ or }\bar{t})|$ (<a href="167734?version=1&table=Table%2011">Table 11</a> ) Normalised cross sections: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%205a">Figure 5a</a> ) <li> $p_T(t)$ (<a href="167734?version=1&table=Table%2012">Table 12</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%205b">Figure 5b</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Table%2013">Table 13</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Figure%205c">Figure 5c</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Table%2014">Table 14</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Figure%205d">Figure 5d</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Table%2015">Table 15</a> ) Parton-level cross-sections with full breakdown of uncertainties and theoretical predictions: Absolute cross sections: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%206a">Figure 6a</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%206b">Figure 6b</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Figure%206c">Figure 6c</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Figure%206d">Figure 6d</a> ) <li> $p_T(t \text{ or }\bar{t})$ (<a href="167734?version=1&table=Figure%206e">Figure 6e</a> ) <li> $|y(t \text{ or }\bar{t})|$ (<a href="167734?version=1&table=Figure%206f">Figure 6f</a> ) Normalised cross sections: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%207a">Figure 7a</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%207b">Figure 7b</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Figure%207c">Figure 7c</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Figure%207d">Figure 7d</a> ) $\chi^2$ probabilities for the theoretical predictions: <li> $p_T$ distributions (<a href="167734?version=1&table=Table%204">Table 4</a> ) <li> $|y|$ distributions (<a href="167734?version=1&table=Table%205">Table 5</a> ) Selection efficiencies of the MC EFT signal samples: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%2014a">Figure 14a</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%2014b">Figure 14b</a> ) Best fits for cross-section dependence on $C_{Qq}^{3,1}$: <a href="167734?version=1&table=Table%2022">Table 22</a> Migration matrices: <li> $p_T(t)$ (<a href="167734?version=1&table=Figure%2016a">Figure 3a</a> ) <li> $p_T(\bar{t})$ (<a href="167734?version=1&table=Figure%2016b">Figure 3b</a> ) <li> $|y(t)|$ (<a href="167734?version=1&table=Figure%2016c">Figure 3c</a> ) <li> $|y(\bar{t})|$ (<a href="167734?version=1&table=Figure%2016d">Figure 3d</a> ) Additional material (in order of entries): Unscaled event yields in both SRs: <li> (<a href="167734?version=1&table=Event%20yields%20%24%5Cell%5E%2B%24%20SR%20no%20SFs"> $\ell^+$ SR </a> ) <li> (<a href="167734?version=1&table=Event%20yields%20%24%5Cell%5E-%24%20SR%20no%20SFs"> $\ell^-$ SR </a> ) Statistical covariance matrices for all measurements: Absolute cross sections: <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24p_%5Ctext%7BT%7D(t)%24%20absolute"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20absolute"> $p_T(\bar{t})$</a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24%7Cy(t)%7C%24%20absolute"> $|y(t)|$</a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20absolute"> $|y(\bar{t})|$</a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24p_%5Ctext%7BT%7D(t%20%5C%2C%20%5Ctext%7Bor%7D%5C%2C%20%20%5Cbar%7Bt%7D)%24"> $p_T(t \text{ or }\bar{t})$</a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24%7Cy(t%20%5C%2C%20%5Ctext%7Bor%7D%5C%2C%20%20%5Cbar%7Bt%7D)%7C%24"> $|y(t \text{ or }\bar{t})|$</a> ) Normalised cross sections: <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24p_%5Ctext%7BT%7D(t)%24%20normalised"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20normalised" > $p_T(\bar{t})$ </a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24%7Cy(t)%7C%24%20normalised"> $|y(t)|$ </a> ) <li> (<a href="167734?version=1&table=Statistical%20covariance%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20normalised"> $|y(\bar{t})|$ </a> ) Statistical cross-correlation between variables: Absolute cross sections: <li> (<a href="167734?version=1&table=Cross%20correlation%20%24tq%24%20absolute"> $tq$ </a> ) <li> (<a href="167734?version=1&table=Cross%20correlation%20%24%5Cbar%7Bt%7Dq%24%20absolute"> $\bar{t}q$</a> ) Normalised cross sections: <li> (<a href="167734?version=1&table=Cross%20correlation%20%24tq%24%20normalised"> $tq$ </a> ) <li> (<a href="167734?version=1&table=Cross%20correlation%20%24%5Cbar%7Bt%7Dq%24%20normalised"> $\bar{t}q$ </a> ) Full covariance matrices for all measurements: Absolute cross sections: <li> (<a href="167734?version=1&table=Covariance%20%24p_%5Ctext%7BT%7D(t)%24%20absolute"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Covariance%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20absolute"> $p_T(\bar{t})$</a> ) <li> (<a href="167734?version=1&table=Covariance%20%24%7Cy(t)%7C%24%20absolute"> $|y(t)|$</a> ) <li> (<a href="167734?version=1&table=Covariance%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20absolute"> $|y(\bar{t})|$</a> ) <li> (<a href="167734?version=1&table=Covariance%20%24p_%5Ctext%7BT%7D(t%20%5C%2C%20%5Ctext%7Bor%7D%5C%2C%20%20%5Cbar%7Bt%7D)%24"> $p_T(t \text{ or }\bar{t})$</a> ) <li> (<a href="167734?version=1&table=Covariance%20%24%7Cy(t%20%5C%2C%20%5Ctext%7Bor%7D%5C%2C%20%20%5Cbar%7Bt%7D)%7C%24"> $|y(t \text{ or }\bar{t})|$</a> ) Normalised cross sections: <li> (<a href="167734?version=1&table=Covariance%20%24p_%5Ctext%7BT%7D(t)%24%20normalised"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Covariance%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20normalised"> $p_T(\bar{t})$ </a> ) <li> (<a href="167734?version=1&table=Covariance%20%24%7Cy(t)%7C%24%20normalised"> $|y(t)|$ </a> ) <li> (<a href="167734?version=1&table=Covariance%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20normalised"> $|y(\bar{t})|$ </a> ) Statistical uncertainty on systematic uncertainties evaluated with the bootstrap method: Absolute cross sections: <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24p_%5Ctext%7BT%7D(t)%24%20absolute"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20absolute"> $p_T(\bar{t})$</a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24%7Cy(t)%7C%24%20absolute"> $|y(t)|$</a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20absolute"> $|y(\bar{t})|$</a> ) Normalised cross sections: <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24p_%5Ctext%7BT%7D(t)%24%20normalised"> $p_T(t)$ </a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24p_%5Ctext%7BT%7D(%5Cbar%7Bt%7D)%24%20normalised"> $p_T(\bar{t})$ </a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24%7Cy(t)%7C%24%20normalised"> $|y(t)|$ </a> ) <li> (<a href="167734?version=1&table=Bootstrap%20systematics%20%24%7Cy(%5Cbar%7Bt%7D)%7C%24%20normalised"> $|y(\bar{t})|$ </a> )

Post-fit agreement between data and the expected distributions in events containing a positively charged lepton. The experimental, background-related and MC statistical uncertainties are incorporated in the uncertainty bands. The region $D_{nn} > 0.93$ is excluded from the fit.

Post-fit agreement between data and the expected distributions in events containing a negatively charged lepton. The experimental, background-related and MC statistical uncertainties are incorporated in the uncertainty bands. The region $D_{nn} > 0.93$ is excluded from the fit.

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Search for ttbar resonances in final states with exactly one or two leptons using 140 fb$^{-1}$ of pp collision data at $\sqrt{s}=13$ TeV with the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-281, 2025.
Inspire Record 3094414 DOI 10.17182/hepdata.168229

A search for heavy spin-1 and spin-2 resonances decaying into a top-antitop-quark pair has been performed with 140 fb$^{-1}$ of proton-proton collision data collected by the ATLAS experiment at the Large Hadron Collider at a centre-of-mass energy of $\sqrt{s}=13$ TeV. Final states with either exactly one electron or muon, or exactly two leptons ($ee$, $μμ$ or $eμ$), large missing transverse momentum, and two jets, at least one of which must be identified as likely containing a b-hadron decay, are considered. The search targets resonances with both narrow and broad widths relative to the detector resolution, and with masses in the range of 0.4-5.0 TeV. No significant deviation from the Standard Model prediction is observed. Exclusion limits are set on the production cross-section times branching ratio for hypothetical $Z'$ bosons, Kaluza-Klein gravitons, and Kaluza-Klein gluons that decay into top-quark pairs.

21 data tables

Selection efficiency times acceptance (Eff x Acc) for the ljets final state as a function of the tt&#772; invariant mass at the parton level before the emission of FSR, for the (a) Z', (b) G<sub>KK</sub>, and (c) g<sub>KK</sub> signals. The selections in the resolved topology only (short-dashed magenta), the merged topology only (dashed blue) and the inclusive topology (solid black) are shown. The error bars correspond to the statistical uncertainty. All tt&#772; decay modes are considered.

Selection efficiency times acceptance (Eff x Acc) for the ljets final state as a function of the tt&#772; invariant mass at the parton level before the emission of FSR, for the (a) Z', (b) G<sub>KK</sub>, and (c) g<sub>KK</sub> signals. The selections in the resolved topology only (short-dashed magenta), the merged topology only (dashed blue) and the inclusive topology (solid black) are shown. The error bars correspond to the statistical uncertainty. All tt&#772; decay modes are considered.

Selection efficiency times acceptance (Eff x Acc) for the ljets final state as a function of the tt&#772; invariant mass at the parton level before the emission of FSR, for the (a) Z', (b) G<sub>KK</sub>, and (c) g<sub>KK</sub> signals. The selections in the resolved topology only (short-dashed magenta), the merged topology only (dashed blue) and the inclusive topology (solid black) are shown. The error bars correspond to the statistical uncertainty. All tt&#772; decay modes are considered.

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Measurement of the top-quark mass using decays with a $J/ψ$ meson at $\sqrt{s}=$13 TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-249, 2025.
Inspire Record 3087833 DOI 10.17182/hepdata.167264

The top-quark mass is measured using top-quark decays producing an isolated lepton and $J/ψ$ meson reconstructed in its $μ^+μ^-$ decay mode. The data sample was recorded with the ATLAS detector in proton-proton collisions at a centre-of-mass energy of $\sqrt{s}=13$ TeV during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. The measurement is based on the invariant mass $m(\ell μ^+μ^-)$ of the system made of the isolated lepton $\ell$ from the $W$ boson decay and the non-isolated $μ^+μ^-$ pair from a $J/ψ$ decay of a $b$-hadron, exploiting its sensitivity to the top-quark mass. An unbinned maximum-likelihood fit to the $m(\ell μ^+μ^-)$ distribution is performed to extract the top-quark mass. The top-quark mass is measured to be $m_{top} = 172.17 \pm 0.80 (stat) \pm 0.81 (syst) \pm 1.07 (recoil)$ GeV, with a total uncertainty of 1.56 GeV. The third uncertainty arises from changing the dipole parton shower gluon-recoil scheme used in top-quark decays.

4 data tables

Top mass measurement result.

Number of selected events in data after the final selection. Also shown are the expected numbers of $t\bar{t}$ and single-top-quark events, assuming a top-quark mass of $m_{top} = 172.5$ GeV, broken down into contributions with and without the $b\rightarrow J/\psi\rightarrow\mu^+\mu^-$ decay, and other background events, corresponding to the integrated luminosity of the data. The last two rows show the expected background fraction and the ratio of observed to expected events. The total uncertainty includes both statistical and systematic components, combined in quadrature.

Impact of sources of uncertainty in $m_{top}$. Each row of the table corresponds to a group of individual systematic variations. Uncertainties related to tt and single-top-quark processes are shown separately and are considered uncorrelated. For each systematic uncertainty listed, the first value corresponds to the uncertainty in $m_{top}$, and the second to the statistical precision of this uncertainty. The total systematic uncertainty and the corresponding statistical precision are calculated as discussed in Section 6. The total uncertainty is the sum in quadrature of the statistical and systematic uncertainties.

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Search for emerging jets in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS experiment

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-225, 2025.
Inspire Record 3069355 DOI 10.17182/hepdata.167179

A search is presented for emerging jets using 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s} = 13$ TeV, collected by the ATLAS experiment between 2015 and 2018. The search looks for the existence of a dark sector with symmetries similar to those in quantum chromodynamics. This dark sector is populated with dark quarks, which undergo showering similar to quarks in the Standard Model, leading to a high multiplicity of long-lived dark hadrons within a dark jet. These dark hadrons subsequently decay to Standard Model particles via a new heavy scalar mediating particle $ϕ$. This results in jets which contain multiple displaced vertices, known as emerging jets. This analysis targets four-jet topologies, with two emerging jets and two Standard Model jets, resulting from the decay of pair-produced scalar mediators. No significant excess above the Standard Model background is observed. For dark pion proper decay lengths of 20 mm, mediator masses are excluded between 1 TeV and 2 TeV assuming a dark pion mass of 20 GeV.

63 data tables

Comparison of the data with N<sub>DV</sub> &gt; 1 and the estimated background in the SR using the modified ABCD method. The division between the SR and CR is shown by the vertical dashed line. In the final fit, the bins with R &gt; 0.4 are combined into a single bin. Three selected signal samples are included for comparison.

95&percnt; CL upper limits as a function of (left) c&tau;<sub>&pi;<sub>d</sub></sub> and (right) M<sub>&phi;</sub>. The upper plots show the expected and observed limits on &sigma;(pp &rarr;&phi;<sup>&dagger;</sup>&phi;) for m<sub>&pi;<sub>d</sub></sub> = 20&nbsp;GeV: (a) using M<sub>&phi;</sub> = 1.6&nbsp;TeV and (b) using c&tau;<sub>&pi;<sub>d</sub></sub> = 20&nbsp;mm. The lower plots show a comparison of the observed limits for all three dark pion masses: (c) using M<sub>&phi;</sub> = 1.4&nbsp;TeV, and (d) using c&tau;<sub>&pi;<sub>d</sub></sub> = 1&nbsp;mm. The mediator mass-dependent theoretical cross-section is given with the band corresponding to the uncertainty from NNLL-Fast.

95&percnt; CL upper limits as a function of (left) c&tau;<sub>&pi;<sub>d</sub></sub> and (right) M<sub>&phi;</sub>. The upper plots show the expected and observed limits on &sigma;(pp &rarr;&phi;<sup>&dagger;</sup>&phi;) for m<sub>&pi;<sub>d</sub></sub> = 20&nbsp;GeV: (a) using M<sub>&phi;</sub> = 1.6&nbsp;TeV and (b) using c&tau;<sub>&pi;<sub>d</sub></sub> = 20&nbsp;mm. The lower plots show a comparison of the observed limits for all three dark pion masses: (c) using M<sub>&phi;</sub> = 1.4&nbsp;TeV, and (d) using c&tau;<sub>&pi;<sub>d</sub></sub> = 1&nbsp;mm. The mediator mass-dependent theoretical cross-section is given with the band corresponding to the uncertainty from NNLL-Fast.

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Measurement of the $W \to μν_μ$ cross-sections as a function of the muon transverse momentum in $pp$ collisions at 5.02 TeV

The LHCb collaboration Aaij, Roel ; Abdelmotteleb, Ahmed Sameh Wagih ; Abellan Beteta, Carlos ; et al.
LHCb-PAPER-2025-031, 2025.
Inspire Record 2972386 DOI 10.17182/hepdata.165429

The $pp \to W^{\pm} (\to μ^{\pm} ν_μ) X$ cross-sections are measured at a proton-proton centre-of-mass energy $\sqrt{s} = 5.02$ TeV using a dataset corresponding to an integrated luminosity of 100 pb$^{-1}$ recorded by the LHCb experiment. Considering muons in the pseudorapidity range $2.2 < η< 4.4$, the cross-sections are measured differentially in twelve intervals of muon transverse momentum between $28 < p_\mathrm{T} < 52$ GeV. Integrated over $p_\mathrm{T}$, the measured cross-sections are \begin{align*} σ_{W^+ \to μ^+ ν_μ} &= 300.9 \pm 2.4 \pm 3.8 \pm 6.0~\text{pb}, \\ σ_{W^- \to μ^- \barν_μ} &= 236.9 \pm 2.1 \pm 2.7 \pm 4.7~\text{pb}, \end{align*} where the first uncertainties are statistical, the second are systematic, and the third are associated with the luminosity calibration. These integrated results are consistent with theoretical predictions. This analysis introduces a new method to determine the $W$-boson mass using the measured differential cross-sections corrected for detector effects. The measurement is performed on this statistically limited dataset as a proof of principle and yields \begin{align*} m_W = 80369 \pm 130 \pm 33~\text{MeV}, \end{align*} where the first uncertainty is experimental and the second is theoretical.

5 data tables

The measured differential cross sections ($d\sigma/dp_T$) for $W^+$. The first systematic uncertainty is statistical and the second is systematic.

The measured differential cross sections ($d\sigma/dp_T$) for $W^-$. The first systematic uncertainty is statistical and the second is systematic.

The correlation matrix corresponding to the statistical uncertainties on the differential cross-section ($d\sigma/dp_T$) fit results for $W^+$. To combine with $W^-$, use the rows and columns ordered as $W^+$ and then $W^-$. Assume no correlation in the statistical uncertainties between $W^+$ and $W^-$ (zero entries in the off-diagonal blocks).

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Precise measurement of the $t\bar{t}$ production cross-section and lepton differential distributions in $eμ$ dilepton events from $\sqrt{s}=13$ TeV $pp$ collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-211, 2025.
Inspire Record 2971071 DOI 10.17182/hepdata.165857

The inclusive top quark pair ($t\bar{t}$) cross-section $σ_{t\bar{t}}$ has been measured in $\sqrt{s}=13$ TeV proton-proton collisions, using 140 fb$^{-1}$ of data collected by the ATLAS experiment at the Large Hadron Collider. Using events with an opposite-charge $eμ$ pair and $b$-tagged jets, the cross-section is measured to be: $\begin{equation}\nonumber σ_{t\bar{t}} = 829.3 \pm 1.3\,\mathrm{(stat)}\ \pm 8.0\,\mathrm{(syst)}\ \pm 7.3\,\mathrm{(lumi)}\ \pm 1.9\,\mathrm{(beam)}\,\mathrm{pb}, \end{equation}$ where the uncertainties reflect the limited size of the data sample, experimental and theoretical systematic effects, the integrated luminosity, and the proton beam energy, giving a total uncertainty of 1.3%. The result is used to determine the top quark pole mass via the dependence of the predicted cross-section on $m_t^\mathrm{pole}$, giving $m_t^\mathrm{pole}=172.8^{+1.5}_{-1.7}$ GeV. The same event sample is used to measure absolute and normalised differential cross-sections for the $t\bar{t}\rightarrow eμν\barνb\bar{b}$ process as a function of single-lepton and dilepton kinematic variables. Complementary measurements of $eμb\bar{b}$ production, treating both $t\bar{t}$ and $Wt$ events as signal, are also provided. Both sets of differential cross-sections are compared to the predictions of various Monte Carlo event generators, demonstrating that the state-of-the-art generators Powheg MiNNLO and Powheg $bb4l$ describe the data better than Powheg hvq. The sensitivity of some of the measured differential distributions to quasi-bound-state formation near the $t\bar{t}$ threshold is investigated in an addendum.

250 data tables

Absolute differential cross-section in the fiducial region as a function of lepton pT. The first column gives the tt->em cross-section including contributions from leptonic tau decays, and the second gives the tt->em cross-section without including the leptonic tau contributions. Columns three and four give the corresponding results for the embb cross-sections. Systematic uncertainties are given for ttbar modelling (ttmod), lepton calibration (lept), jet and b-tagging calibration (jet), backgrounds (bkg) and integrated luminosity and beam energy (leb). The last bin includes overflow beyond the upper bin boundary. The corresponding correlation matrices are given in Tables 27 to 30 and the covariance matrices in Tables 131 to 134

Absolute differential cross-section in the fiducial region as a function of lepton |eta|. The first column gives the tt->em cross-section including contributions from leptonic tau decays, and the second gives the tt->em cross-section without including the leptonic tau contributions. Columns three and four give the corresponding results for the embb cross-sections. Systematic uncertainties are given for ttbar modelling (ttmod), lepton calibration (lept), jet and b-tagging calibration (jet), backgrounds (bkg) and integrated luminosity and beam energy (leb). The corresponding correlation matrices are given in Tables 31 to 34 and the covariance matrices in Tables 135 to 138

Absolute differential cross-section in the fiducial region as a function of dilepton pT. The first column gives the tt->em cross-section including contributions from leptonic tau decays, and the second gives the tt->em cross-section without including the leptonic tau contributions. Columns three and four give the corresponding results for the embb cross-sections. Systematic uncertainties are given for ttbar modelling (ttmod), lepton calibration (lept), jet and b-tagging calibration (jet), backgrounds (bkg) and integrated luminosity and beam energy (leb). The last bin includes overflow beyond the upper bin boundary. The corresponding correlation matrices are given in Tables 35 to 38 and the covariance matrices in Tables 139 to 142

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Measurement of the $W$-boson angular coefficients and transverse momentum in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-188, 2025.
Inspire Record 2970689 DOI 10.17182/hepdata.166079

The angular distributions of Drell-Yan lepton pairs provide sensitive probes of the underlying dynamics of quantum chromodynamics (QCD) effects in vector-boson production. This paper presents for the first time the measurement of the full set of angular coefficients together with the differential cross-section as a function of the transverse momentum of the $W$ boson, in the full phase space of the decay leptons. The measurements are performed separately for the $W^-$ and $W^+$ channels. The analysis uses proton-proton collision data recorded by the ATLAS experiment at the Large Hadron Collider in 2017 and 2018, during special low-luminosity runs with a reduced number of interactions per bunch crossings (pile-up). The data correspond to an integrated luminosity of $338$ pb$^{-1}$ at a centre-of-mass energy of $\sqrt{s} = 13$ TeV. The low pile-up conditions enable an optimised reconstruction of the $W$ boson transverse momentum. All results agree with theory predictions incorporating finite-order QCD corrections up to next-to-next-to-leading-order in the strong coupling constant, $α_S$.

6 data tables

The measured angular coefficients for $W^-$ in bins of the $p_T$ of the W.

The measured angular coefficients for $W^+$ in bins of the $p_T$ of the W.

The measured differential cross-section for $W^-$ in bins of the $p_T$ of the $W$.

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Measurement of the azimuthal anisotropy of charged particles in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV $^{16}$O$+^{16}$O and $^{20}$Ne$+^{20}$Ne collisions with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-200, 2025.
Inspire Record 2967110 DOI 10.17182/hepdata.168010

This paper presents the first measurements of the azimuthal anisotropy coefficients $v_{n}$, which quantify the $n^{\mathrm{th}}$-order Fourier modulation of charged-particle azimuthal distributions, for $n=2$-4 in $\sqrt{s_{\mathrm{NN}}}=5.36$ TeV $\mathrm{^{16}O}+\mathrm{^{16}O}$ and $\mathrm{^{20}Ne}+\mathrm{^{20}Ne}$ collisions recorded with the ATLAS detector at the Large Hadron Collider in 2025. The $v_{n}$ coefficients are measured as a function of transverse momentum ($p_{\mathrm{T}}$), collision centrality, and event multiplicity. They are extracted using two complementary methods: two-particle correlations with a template-fit subtraction of short-range non-flow contributions, and four-particle subevent cumulants, which intrinsically suppress non-flow effects and provide sensitivity to flow fluctuations. The results show a clear hierarchy $v_{2} > v_{3} > v_{4}$ and a non-monotonic dependence on $p_{\mathrm{T}}$, reaching a maximum around 2 GeV, consistent with trends observed in heavy-ion collisions. Detailed comparisons between the two collision systems reveal an enhanced $v_{2}$ in central $\mathrm{^{20}Ne}+\mathrm{^{20}Ne}$ collisions, consistent with theory expectations based on the predicted prolate deformation of neon nuclei, in contrast to the slightly tetrahedral structure predicted for oxygen. The four-particle cumulant results highlight strong event-by-event fluctuations and provide the greatest sensitivity to nuclear shape effects. These measurements can place new constraints on the initial geometry and the hydrodynamic response in light-ion collisions, offering valuable input for models of nuclear structure.

67 data tables

The ΣE<sub>T</sub><sup>FCal</sup> distribution in minimum-bias events, together with the thresholds for a few centrality intervals, for (a) O+O collisions and (b) Ne+Ne collisions. (c) Comparison to Xe+Xe collisions&nbsp;, where the ΣE<sub>T</sub><sup>FCal</sup> of the Xe+Xe and Ne+Ne systems are scaled by the relative number of nucleons to oxygen. The Ne+Ne and Xe+Xe distributions in panel (c) are normalized to have the same integral as the O+O distribution above 30&nbsp;GeV.

The ΣE<sub>T</sub><sup>FCal</sup> distribution in minimum-bias events, together with the thresholds for a few centrality intervals, for (a) O+O collisions and (b) Ne+Ne collisions. (c) Comparison to Xe+Xe collisions&nbsp;, where the ΣE<sub>T</sub><sup>FCal</sup> of the Xe+Xe and Ne+Ne systems are scaled by the relative number of nucleons to oxygen. The Ne+Ne and Xe+Xe distributions in panel (c) are normalized to have the same integral as the O+O distribution above 30&nbsp;GeV.

The ΣE<sub>T</sub><sup>FCal</sup> distribution in minimum-bias events, together with the thresholds for a few centrality intervals, for (a) O+O collisions and (b) Ne+Ne collisions. (c) Comparison to Xe+Xe collisions&nbsp;, where the ΣE<sub>T</sub><sup>FCal</sup> of the Xe+Xe and Ne+Ne systems are scaled by the relative number of nucleons to oxygen. The Ne+Ne and Xe+Xe distributions in panel (c) are normalized to have the same integral as the O+O distribution above 30&nbsp;GeV.

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Measurement of coherent exclusive $J/ψ\toμ^+μ^-$ production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{\textrm{NN}}}=5.36$ TeV with the ATLAS detector

The ATLAS collaboration Aad, Georges ; Aakvaag, Erlend ; Abbott, Braden Keim ; et al.
CERN-EP-2025-180, 2025.
Inspire Record 2966819 DOI 10.17182/hepdata.169183

The ATLAS experiment has performed a measurement of coherent exclusive $J/ψ\toμ^+μ^-$ production in ultraperipheral Pb+Pb collisions at $\sqrt{s_{\textrm{NN}}}=5.36$ TeV. The data was recorded at the Large Hadron Collider (LHC) during 2023, and corresponds to an integrated luminosity of 78 $μ$b$^{-1}$. Exclusive $J/ψ$ candidates were selected with a dedicated track-sensitive trigger based on the ATLAS transition radiation tracker. The analysis involves reconstruction of the dimuon invariant mass based on muon tracks from the inner detector, as the muon transverse momentum range of interest precludes the use of the standard muon reconstruction and identification algorithms. Differential cross sections are measured as a function of $J/ψ$ rapidity and are compared with theoretical predictions. After extrapolation to $\sqrt{s_{\textrm{NN}}}=5.02$ TeV, they are also compared with previous measurements performed by other experiments using data from LHC Run 2. While the results agree reasonably well with theoretical predictions, they are in tension with previous Run-2 results for the central rapidity region.

2 data tables

Differential cross section dσ/dy for coherent exclusive J/ψ production in ultraperipheral Pb+Pb collisions at sqrt(s_NN)=5.36 TeV as a function of J/ψ rapidity.

Differential cross section dσ/dy for coherent exclusive J/ψ production in ultraperipheral Pb+Pb collisions extrapolated to sqrt(s_NN)=5.02 TeV as a function of J/ψ rapidity.