Meriem Boubdir

activity

20142026

most citedObservation of a narrow pentaquark state,

P_{c} (4312)^{+}

, and of two-peak structure of the

P_{c} (4450)^{+}

738 citations · 8.5k across the 150 of their papers we have counts for

collaborators

153 papers

cs.CL2026

Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

NVIDIA, :, Aaron Blakeman +572

We introduce Nemotron 3 Ultra, a 550 billion total and 55 billion active parameter Mixture-of-Experts Hybrid Mamba-Attention language model. We pre-trained Nemotron 3 Ultra on 20 t…

cs.CL2025

Detecting Data Contamination in LLMs via In-Context Learning

Michał Zawalski, Meriem Boubdir, Klaudia Bałazy +2

We present Contamination Detection via Context (CoDeC), a practical and accurate method to detect and quantify training data contamination in large language models. CoDeC distingui…

cs.CL2025

NVIDIA Nemotron Nano 2: An Accurate and Efficient Hybrid Mamba-Transformer Reasoning Model

NVIDIA, :, Aarti Basant +214

We introduce Nemotron-Nano-9B-v2, a hybrid Mamba-Transformer language model designed to increase throughput for reasoning workloads while achieving state-of-the-art accuracy compar…

cs.CL2023★ 5 cited

Elo Uncovered: Robustness and Best Practices in Language Model Evaluation

Meriem Boubdir, Edward Kim, Beyza Ermis +2

In Natural Language Processing (NLP), the Elo rating system, originally designed for ranking players in dynamic games such as chess, is increasingly being used to evaluate Large La…

cs.CL2023★ 4 cited

Which Prompts Make The Difference? Data Prioritization For Efficient Human LLM Evaluation

Meriem Boubdir, Edward Kim, Beyza Ermis +2

Human evaluation is increasingly critical for assessing large language models, capturing linguistic nuances, and reflecting user preferences more accurately than traditional automa…

hep-ex2020★ 29 cited

Search for $C P$ violation in $Ξ_{c}^{+} \to p K^{-} π^{+}$ decays using model-independent techniques

LHCb collaboration, R. Aaij, C. Abellán Beteta +950

A first search for $C P$ violation in the Cabibbo-suppressed $Ξ_{c}^{+} \to p K^{-} π^{+}$ decay is performed using both a binned and an unbinned model-independent technique in the Dal…

hep-ex2019★ 31 cited

Determination of quantum numbers for several excited charmed mesons observed in $B^{-} \to D^{*+} π^{-} π^{-}$ decays

LHCb collaboration, R. Aaij, C. Abellán Beteta +907

A four-body amplitude analysis of the $B^{-} \to D^{*+} π^{-} π^{-}$ decay is performed, where fractions and relative phases of the various resonances contributing to the decay are measu…

hep-ex2019★ 37 cited

Measurement of the $η_{c} (1 S)$ production cross-section in $pp$ collisions at $s = 13$ TeV

LHCb collaboration, R. Aaij, C. Abellán Beteta +913

Using a data sample corresponding to an integrated luminosity of $2.0 f b^{- 1}$ , collected by the LHCb experiment, the production of the $η_{c} (1 S)$ state in proton-proton collisions…

hep-ex2019★ 28 cited

Search for the lepton-flavour violating decays $B^{+} \to K^{+} μ^{\pm} e^{\mp}$

LHCb collaboration, R. Aaij, C. Abellán Beteta +895

A search for the lepton-flavour violating decays $B^{+} \to K^{+} μ^{\pm} e^{\mp}$ is performed using a sample of proton-proton collision data, collected with the LHCb experiment at ce…

hep-ex2019★ 75 cited

Amplitude analysis of the $B^{+} \to π^{+} π^{+} π^{-}$ decay

LHCb collaboration, R. Aaij, C. Abellán Beteta +868

The results of an amplitude analysis of the charmless three-body decay $B^{+} \to π^{+} π^{+} π^{-}$ , in which $C P$ -violation effects are taken into account, are reported. The anal…

hep-ex2019★ 13 cited

Measurement of the electron reconstruction efficiency at LHCb

LHCb collaboration, R. Aaij, C. Abellán Beteta +910

The single electron track-reconstruction efficiency is calibrated using a sample corresponding to $1.3 fb^{- 1}$ of $pp$ collision data recorded with the LHCb detector in 20…

hep-ex2019★ 35 cited

Precision measurement of the $Λ_{c}^{+}$ , $Ξ_{c}^{+}$ and $Ξ_{c}^{0}$ baryon lifetimes

LHCb collaboration, R. Aaij, C. Abellán Beteta +847

We report measurements of the lifetimes of the $Λ_{c}^{+}$ , $Ξ_{c}^{+}$ and $Ξ_{c}^{0}$ charm baryons using proton-proton collision data at center-of-mass energies of 7 and 8\tev, correspondin…

hep-ex2019★ 18 cited

Measurement of psi(2S) production cross-sections in proton-proton collisions at 7 and 13 TeV

LHCb collaboration, R. Aaij, C. Abellán Beteta +842

The cross-sections of $ψ (2 S)$ meson production in proton-proton collisions at $s = 13 TeV$ are measured with a data sample collected by the LHCb detector correspondin…

hep-ex2019★ 16 cited

Measurement of CP violation in the $B_{s}^{0} \to ϕϕ$ decay and search for the $B^{0} \to ϕϕ$ decay

LHCb collaboration, R. Aaij, C. Abellán Beteta +868

A measurement of the time-dependent CP-violating asymmetry in $B_{s}^{0} \to ϕϕ$ decays is presented. Using a sample of proton-proton collision data corresponding to an integrate…

hep-ex2019★ 14 cited

Observation of the $Λ_{b}^{0} \to χ_{c 1} (3872) p K^{-}$ decay

LHCb collaboration, R. Aaij, C. Abellán Beteta +903

Using proton-proton collision data, collected with the LHCb detector and corresponding to 1.0, 2.0 and 1.9fb $^{- 1}$ of integrated luminosity at the centre-of-mass energies of 7, 8,…

hep-ex2019★ 46 cited

Updated measurement of time-dependent $C P$ -violating observables in $B_{s}^{0} \to J / ψ K^{+} K^{-}$ decays

LHCb collaboration, R. Aaij, C. Abellán Beteta +910

The decay-time-dependent $C P$ asymmetry in $B_{s}^{0} \to J / ψ K^{+} K^{-}$ decays is measured using proton-proton collision data, corresponding to an integrated luminosity of $1.9\,\…

hep-ex2019★ 738 cited

Observation of a narrow pentaquark state, $P_{c} (4312)^{+}$ , and of two-peak structure of the $P_{c} (4450)^{+}$

LHCb collaboration, R. Aaij, C. Abellán Beteta +866

A narrow pentaquark state, $P_{c} (4312)^{+}$ , decaying to $J / ψ p$ is discovered with a statistical significance of $7.3 σ$ in a data sample of $Λ_{b}^{0} \to J / ψ p K^{-}$ decays which is an or…

hep-ex2019★ 15 cited

Amplitude analysis of the $B_{(s)} \to K^{* 0} K^{* 0}$ decays and measurement of the branching fraction of the $B \to K^{* 0} K^{* 0}$ decay

LHCb Collaboration, R. Aaij, C. Abellán Beteta +844

The $B^{0} \to K^{* 0} K^{* 0}$ and $B_{s}^{0} \to K^{* 0} K^{* 0}$ decays are studied using proton-proton collision data corresponding to an integrated luminosity of 3…

hep-ex2019★ 52 cited

Search for the lepton-flavour-violating decays $B_{s}^{0} \to τ^{\pm} μ^{\mp}$ and $B^{0} \to τ^{\pm} μ^{\mp}$

LHCb collaboration, R. Aaij, C. Abellán Beteta +863

A search for $B_{s}^{0} \to τ^{\pm} μ^{\mp}$ and $B^{0} \to τ^{\pm} μ^{\mp}$ decays is performed using data corresponding to an integrated luminosity of 3 fb $^{- 1}$ of proton-proton coll…

hep-ex2019★ 17 cited

A search for $Ξ_{cc}^{++} \to D^{+} p K^{-} π^{+}$ decays

LHCb Collaboration, R. Aaij, C. Abellán Beteta +848

A search for the $Ξ_{cc}^{++}$ baryon through the $Ξ_{cc}^{++} \to D^{+} p K^{-} π^{+}$ decay is performed with a data sample corresponding to an integrated luminosit…

hep-ex2019★ 32 cited

First observation of the radiative decay $Λ_{b}^{0} \to Λ γ$

LHCb Collaboration, R. Aaij, C. Abellán Beteta +848

The radiative decay $Λ_{b}^{0} \to Λ γ$ is observed for the first time using a data sample of proton-proton collisions corresponding to an integrated luminosity of $1.7 f b^{- 1}$ co…

hep-ex2019★ 6 cited

Measurement of the ratio of branching fractions of the decays $Λ_{b}^{0} \to ψ (2 S) Λ$ and $Λ_{b}^{0} \to J / ψ Λ$

LHCb Collaboration, R. Aaij, B. Adeva +799

Using $pp$ collisions corresponding to 3 $fb^{- 1}$ integrated luminosity, recorded by the LHCb experiment at centre-of-mass energies of 7 and 8 $TeV$ , the ratio of…

hep-ex2019★ 41 cited

Measurement of $B^{+}$ , $B^{0}$ and $Λ_{b}^{0}$ production in $p Pb$ collisions at $s_{NN} = 8.16 TeV$

LHCb Collaboration, R. Aaij, C. Abellán Beteta +842

The production of $B^{+}$ , $B^{0}$ and $Λ_{b}^{0}$ hadrons is studied in proton-lead collisions at a centre-of-mass energy per nucleon pair of $s_{NN} = 8.16 TeV$ record…

hep-ex2019★ 55 cited

Near-threshold $D D ˉ$ spectroscopy and observation of a new charmonium state

LHCb Collaboration, R. Aaij, C. Abellán Beteta +846

Using proton-proton collision data, corresponding to an integrated luminosity of 9 $f b^{- 1}$ , collected with the~LHCb detector between 2011 and 2018, a new narrow charmonium state,…

Nemotron 3 Ultra: Open, Efficient Mixture-of-Experts Hybrid Mamba-Transformer Model for Agentic Reasoning

Detecting Data Contamination in LLMs via In-Context Learning

NVIDIA Nemotron Nano 2: An Accurate and Efficient Hybrid Mamba-Transformer Reasoning Model

Elo Uncovered: Robustness and Best Practices in Language Model Evaluation

Which Prompts Make The Difference? Data Prioritization For Efficient Human LLM Evaluation

Search for CP violation in Ξc+​→pK−π+ decays using model-independent techniques

Determination of quantum numbers for several excited charmed mesons observed in B−→D∗+π−π− decays

Measurement of the ηc​(1S) production cross-section in pp collisions at s​=13 TeV

Search for the lepton-flavour violating decays B+→K+μ±e∓

Amplitude analysis of the B+→π+π+π− decay

Measurement of the electron reconstruction efficiency at LHCb

Precision measurement of the Λc+​, Ξc+​ and Ξc0​ baryon lifetimes

Measurement of psi(2S) production cross-sections in proton-proton collisions at 7 and 13 TeV

Measurement of CP violation in the Bs0​→ϕϕ decay and search for the B0→ϕϕ decay

Observation of the Λb0​→χc1​(3872)pK− decay

Updated measurement of time-dependent CP-violating observables in Bs0​→J/ψK+K− decays

Observation of a narrow pentaquark state, Pc​(4312)+, and of two-peak structure of the Pc​(4450)+

Amplitude analysis of the B(s)​→K∗0K∗0 decays and measurement of the branching fraction of the B→K∗0K∗0 decay

Search for the lepton-flavour-violating decays Bs0​→τ±μ∓ and B0→τ±μ∓

A search for Ξcc++​→D+pK−π+ decays

First observation of the radiative decay Λb0​→Λγ

Measurement of the ratio of branching fractions of the decays Λb0​→ψ(2S)Λ and Λb0​→J/ψΛ

Measurement of B+, B0 and Λb0​ production in pPb collisions at sNN​​=8.16TeV

Near-threshold DDˉ spectroscopy and observation of a new charmonium state