Search for Pcs(4459) and Pcs(4338) in Upsilon(1S,2S) inclusive decays at Belle

2025/02/14 by I. Adachi, Adachi, I., L. Aggarwal +807 · 1 voice · 3 citations
#hep-ex

paper · pdf · doi:10.48550/arxiv.2502.09951

Abstract

Using data samples of 102 million Upsilon(1S) events and 158 million Upsilon(2S) events collected by the Belle detector at the KEKB asymmetric-energy e⁺e^- collider, we search for [udsccbar] pentaquark states decaying to Jpsi Lambda. Using the first observations of Upsilon(1S, 2S) inclusive decays to Jpsi Lambda, we find evidence of the P_ccbars(4459)0 state with a local significance of 3.3 standard deviations, including statistical and systematic uncertainties. We measure the mass and width of the Pccbars(4459)0 to be (4471.7 +- 4.8 +- 0.6) MeV/c2 and (21.9 +- 13.1 +- 2.7) MeV, respectively. The branching fractions for P_ccbars(4459)0 production are measured to be B[Upsilon(1S) -> P_ccbars(4459)0/ Pbar_ccbars(4459)0 + anything] = (3.5 +- 2.0 +- 0.2)*10-6 and B[Upsilin(2S) -> P_ccbars(4459)0/ Pbar_ccbars(4459)0 +anything] = (2.9 +- 1.7 +- 0.4)*10-6. The inclusive branching fractions of Upsilon(1S, 2S) -> Jpsi Lambda/Lambdabar are measured to be B[Upsilin(1S) -> Jpsi Lambda/Lambdabar + anything] = (36.9 +- 5.3 +- 2.4)*10-6 and B[Upsilon(2S) -> Jpsi Lambda/Lambdabar + anything] = (22.3 +- 5.7 +- 3.1)*10-6. We measure the visible cross section σ(e⁺e^- → J/psi Λ/Λ + anything) = (90 +- 14 +- 6) fb for the continuum production at √(s) = 10.52 GeV. In all cases, the first uncertainties are statistical and the second are systematic.

Cited by

• ALP production in Lepton Flavour Violating meson, tau and gauge boson decays
• Analytic electromagnetic signatures of compact pentaquark structure: A multicurrent QCD light-cone sum rules analysis of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msubsup> <mml:mi>P</mml:mi> <mml:mrow> <mml:mi>ψ</mml:mi> <mml:mi>s</mml:mi> </mml:mrow> <mml:mi mathvariant="normal">Λ</mml:mi> </mml:msubsup> </mml:math> states
• Electromagnetic tomography of spin-(3)/(2) hidden-charm strange pentaquarks

Discussions

• Exciting! The Belle experiment sees evidence for a charmonium strange pentaquark that was seen by LHCb in baryon decays. They see it in Y(2S) decays, do not in weak decays of the b quark. A very diffe [bsky, 28 points, 0 comments]

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