2025-09-18
04:02 |
Notice détaillée
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2025-09-15
17:27 |
Branching fractions of $\eta$ and $\eta’(958)$ anomalous decays at LHCb
/LHCb Collaboration
Branching fractions of $\eta$ and $\eta’(958)$ anomalous decays are measured using $pp$ collision data at a center-of-mass energy of $\sqrt{s}=13\,\mathrm{TeV}$ collected by the LHCb experiment and corresponding to an integrated luminosity of $5.4\,\mathrm{fb^{-1}}$. The measured values and upper limits at the 90% confidence level are \begin{equation} \mathcal{B}(\eta\to\mu^+\mu^-) = (5.30\pm0.14_{\text{(stat)}}\pm0.18_{\text{(syst)}}\pm0.26_{\phi})\times10^{-6} \nonumber, \end{equation} \begin{equation} \mathcal{B}(\eta’(958)\to\mu^+\mu^-)<1.94\times10^{-7} \nonumber, \end{equation} \begin{equation} \mathcal{B}(\eta\to\pi^+\pi^-\mu^+\mu^-)<6\times10^{-7} \nonumber, \end{equation} \begin{equation} \mathcal{B}(\eta’(958)\to\pi^+\pi^-\mu^+\mu^-) = (2.80\pm0.14_{\text{(stat)}}\pm0.13_{\text{(syst)}}\pm0.14_{\phi})\times10^{-5} \nonumber, \end{equation} where the first uncertainty is statistical, the second is systematic, and the third is the uncertainty associated with the branching fraction of the $\phi\to\mu^+ \mu^-$ decay which is used for normalization. [...]
LHCb-CONF-2025-002; CERN-LHCb-CONF-2025-002.-
Geneva : CERN, 2025
Fulltext: LHCb-CONF-2025-002 - PDF; LHCb-CONF-2025-002_Figures - ZIP;
In : 13th International Workshop on the CKM Unitarity Triangle, Cagliari, It, 15 - 19 Sep 2025
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2025-04-04
10:35 |
Notice détaillée
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2024-07-30
17:34 |
Antihelium production in $\overline{\it \Lambda}_b^0$ decays
/LHCb Collaboration
Decays of $\overline{\Lambda}^{0}_{b}$ baryons produced in dark matter annihilating into $b\overline b$ pairs could enhance the abundance of antihelium in cosmic rays. The LHCb collaboration provides in this paper the first experimental limits on related branching fractions: \begin{align*} \mathcal B({\overline{\it \Lambda}_b^0\to{}^3{\rm\overline He}p p})&<1.9\times10^{-9}\text{ at 90% CL,}\\ \mathcal B({\overline{\it \Lambda}_b^0\to{}^3{\rm\overline He}pp X})&<1.6\times10^{-8}\text{ at 90% CL,}\\ \mathcal B({\overline{\it \Lambda}_b^0\to{}^3{\rm \overline He}pX})&<3.6\times10^{-8}\text{ at 90% CL,} \end{align*} where $X$ denotes one or several particles. [...]
LHCb-CONF-2024-005; CERN-LHCb-CONF-2024-005.-
Geneva : CERN, 2024 - 19.
- Published in : PoS: ICHEP2024 (2025) , pp. 676
Fulltext: LHCb-CONF-2024-005-figures - ZIP; LHCb-CONF-2024-005 - PDF; ICHEP2024_676 - PDF;
In : 42nd International Conference on High Energy Physics (ICHEP 2024), Prague, Czech Republic, 18 - 24 Jul 2024, pp.676
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2024-07-26
14:09 |
Notice détaillée
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2024-06-06
16:32 |
Notice détaillée
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2024-06-06
11:11 |
Observation of the $\Sigma^+ \to p \mu^+ \mu^-$ rare decay at LHCb
/LHCb Collaboration
The first observation of the $\Sigma^+ \to p \mu^+ \mu^-$ decay is reported with high significance using proton-proton collision data, corresponding to an integrated luminosity of $5.4\,fb^{-1}$, collected with the LHCb detector at a centre-of-mass energy of 13 TeV. A yield of $279 \pm 19 $ $\Sigma^+ \to p \mu^+ \mu^-$ decays is observed. [...]
LHCb-CONF-2024-002; CERN-LHCb-CONF-2024-002.-
Geneva : CERN, 2024 - 16.
Fulltext: LHCb-CONF-2024-002 - PDF; LHCb-CONF-2024-002-figures - ZIP;
In : The XV International Conference on Beauty, Charm, Hyperons in Hadronic Interactions (BEACH 2024) , Charleston, Sc, Us, 3 - 7 Jun 2024
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2024-04-02
18:14 |
Observation of the rare decay $J\mskip -3mu/\mskip -2mu\psi \to \mu^+\mu^-\mu^+\mu^-$
/LHCb Collaboration
The rare electromagnetic decay $J\mskip -3mu/\mskip -2mu\psi \to \mu^+\mu^-\mu^+\mu^-$ is observed with significance greatly exceeding the discovery threshold, using the proton-proton collision data collected by the LHCb experiment in 2016-2018 at a center-of-mass energy of 13 $\textrm{TeV}$, corresponding to an integrated luminosity of 5.4 $\text{fb}^{-1}$. The rate of this decay is measured relative to that of $J\mskip -3mu/\mskip -2mu\psi \to \mu^+\mu^-$ mode. [...]
LHCb-CONF-2024-001; CERN-LHCb-CONF-2024-001.-
Geneva : CERN, 2024 - 17.
Fulltext: LHCb-CONF-2024-001 - PDF; LHCb-CONF-2024-001_Figures - ZIP;
In : 58th Rencontres de Moriond on QCD and High Energy Interactions, La Thuile, Italy, 31 Mar - 7 Apr 2024
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2023-10-24
09:25 |
Notice détaillée
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2023-10-04
14:36 |
Measurement of $CP$ asymmetry in $B^0_s \rightarrow D^{\mp}_s K^{\pm}$ decays
/LHCb Collaboration
A measurement of the $CP$-violating parameters in $B^0_s \rightarrow > D^{\mp}_s K^{\pm}$ decays obtained from $pp$ collisions is reported, using a data set corresponding to an integrated luminosity of $6\,\textrm{fb}^{-1}$ at a centre-of-mass energy of ${\sqrt{s}=13 \,\textrm{TeV}}$ recorded with the LHCb detector between 2015 and 2018. The measured values are: > \begin{align*} C_f &= \phantom{+}0.791 \pm 0.061 \pm 0.022 \, , \\ A_f^{\Delta \Gamma} &= -0.051 \pm 0.134 \pm 0.037\, , \\ A_{\bar{f}}^{\Delta \Gamma} &= -0.303 \pm 0.125 \pm 0.036\, , \\ S_f &= -0.571 \pm 0.084 \pm 0.023\, , \\ S_{\bar{f}} &= -0.503 \pm 0.084 \pm 0.025 \, , \end{align*} where the uncertainties are statistical and systematic, respectively. [...]
LHCb-CONF-2023-004; CERN-LHCb-CONF-2023-004.-
Geneva : CERN, 2023 - 25.
Fulltext: LHCb-CONF-2023-004-Fig-Supplementary - ZIP; LHCb-CONF-2023-004 - PDF; LHCb-CONF-2023-004_final_typofix - PDF; LHCb-CONF-2023-004-Fig - ZIP;
In : 12th International Workshop on the CKM Unitarity Triangle (CKM 2023), Santiago De Compostela, Spain, 18 - 22 Sep 2023
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