Details

Autor(en) / Beteiligte

• Aaij, R.
• Adlarson, Patrik
• Eklund, Lars
• Kupsc, Andrzej
• Zunica, G.

Titel

Observation of a J /ΨΛ Resonance Consistent with a Strange Pentaquark Candidate in B - →†’ J /ψΛ( p )over-bar Decays

Ist Teil von

• Physical review letters, 2023-07, Vol.131 (3)

Erscheinungsjahr

2023

Link zum Volltext

Quelle

American Physical Society Journals

Beschreibungen/Notizen

• An amplitude analysis of B- -> J/psi Lambda(p) over bar decays is performed using 4400 signal candidates selected on a data sample of pp collisions recorded at center-of-mass energies of 7, 8, and 13 TeV with the LHCb detector, corresponding to an integrated luminosity of 9 fb(-1). A narrow resonance in the J/psi Lambda system, consistent with a pentaquark candidate with strangeness, is observed with high significance. The mass and the width of this new state are measured to be 4338.2 +/- 0.7 +/- 0.4 MeV and 7.0 +/- 1.2 +/- 1.3 MeV, where the first uncertainty is statistical and the second systematic. The spin is determined to be 1/2 and negative parity is preferred. Because of the small Q-value of the reaction, the most precise single measurement of the B- mass to date, 5279.44 +/- 0.05 +/- 0.07 MeV, is obtained.