CERN Accelerating science

LHCb Note
Report number	LHCb-CONF-2024-005 ; CERN-LHCb-CONF-2024-005
Title	Antihelium production in $\overline{\it \Lambda}_b^0$ decays
Corporate author(s)	The LHCb Collaboration
Collaboration	LHCb Collaboration
To be published in:	PoS
Submitted to	42nd International Conference on High Energy Physics (ICHEP 2024), Prague, Czech Republic, 18 - 24 Jul 2024, pp.676
Submitted by	lhcb.secretariat@cern.ch on 30 Jul 2024
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; LHCb
Free keywords	QCD ; experimental result
Abstract	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. The $\mathcal B({\overline{\it \Lambda}_b^0\to{}^3{\rm He}\overline p\overline pX})$ limit is extrapolated to the fully inclusive branching fraction $\mathcal B(\overline{\it \Lambda}_b^0\to{}^3{\rm \overline He}X)$. The obtained result significantly restricts the aforementioned scenario for antihelium production.

Corresponding record in: Inspire
Email contact(s) : Lhcb.Secretariat@cern.ch