Тяжёлые адроны ФИАН / 9
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Upper limit on X(5568)
ρX is a fraction of Bs mesons produced from X(5568) decays |
https://inspirehep.net/literature/1643829 |
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https://inspirehep.net/literature/1653453 |
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https://inspirehep.net/literature/1645421 |
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https://inspirehep.net/literature/1478792 |
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https://inspirehep.net/literature/1645240 |
An upper limit is ρX < 1.1 % at 95% C.L.
All the procedure is repeated with pT(B0s )>15GeV, yielding the limit ρX < 1.0 % @ 95% C.L.
Comparison with the results of other collaborations:
The obtained limits are the strongest and contradict to the D0 collaboration result, thus not confirming a tetraquark candidate X(5568)
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Open heavy flavor multiquark states: X(2900)
LHCb 2020 https://arxiv.org/abs/2009.00026 Amplitude analysis
States decaying into DDbar: to be discussed later, some exotic some not (?) …
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Open heavy flavor multiquark states: X(2900)
Lots of theory models for X(2900)
rescattering
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Doubly open charm Tetraquark T(3875)
LHCb 2021 https://arxiv.org/abs/2109.01038 |
Charged partner of X(3872)? |
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Open heavy flavor multiquark states: T(2900)
https://indico.cern.ch/event/1176505/ LHCb 2022
https://arxiv.org/abs/2212.02716
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New open charm strange tetraquark! T(2900)
https://arxiv.org/abs/2212.02716 Dec
https://indico.cern.ch/event/1176505/ LHCb 2022
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X(3872) mass and quantum numbers
Starting with X(3872)
Observed by Belle 2003
Decaying into J/ψππ
http://dx.doi.org/10.1103/PhysRevD.92.011102
LHCb measured quantum numbers JPC = 1++
~1000 signal
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X(3872) width and isospin violation
Starting with X(3872),, JPC = 1++ →PDG lists it as χc1(3872)
The first hints of the isospin-violating nature of X(3872) come from the observation of both
the ππJ/ψ and also the πππJ/ψ [87] final states, with the pions resonating in ρ and ω states respectively, with similar branching fractions
https://inspirehep.net/literature/856587
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X(3872) radiative decays
https://arxiv.org/abs/1404.0275
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X(3872) in PbPb
Production of X(3872): |
Phys. Rev. Lett. 128 (2022) 032001 |
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In b decays, promptly in pp collisions and e-e+ collisions → not a molecule ?
Excited states production is known to be suppressed in heavy ion collisions
CMS finds a first evidence for X(3872) production in PbPb collisions
~4σ |
Ratio of efficiency-corrected yields X/ψ(2S) |
Phys. Lett. B 790 (2019) 270 |
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after non-prompt subtraction |
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RX/ψ = 1.10 ± 0.51 ± 0.53 |
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Same ratio in pp |
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collisions is 0.1 |
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X(3872) production enhanced w.r.t. ψ(2S) in PbPb collisions, |
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additional hint/constraint on X(3872) nature ? |
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