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LHCb Collaboration(Aaij, R. et al), Jaimes Elles, S. J., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Rebollo De Miguel, M., et al. (2024). Prompt and nonprompt ψ(2S) production in pPb collisions at √sNN = 8.16 TeV. J. High Energy Phys., 04(4), 111–52pp.
Abstract: The production of psi(2S) mesons in proton-lead collisions at a centre-of-mass energy per nucleon pair of root s(NN) = 8.16TeV is studied with the LHCb detector using data corresponding to an integrated luminosity of 34 nb(-1). The prompt and nonprompt psi(2S) production cross-sections and the ratio of the psi(2S) to J/psi cross-section are measured as a function of the meson transverse momentum and rapidity in the nucleon-nucleon centre-of-mass frame, together with forward-to-backward ratios and nuclear modification factors. The production of prompt psi(2S) is observed to be more suppressed compared to pp collisions than the prompt J/psi production, while the nonprompt productions have similar suppression factors.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2019). Prompt Lambda+c production in pPb collisions at root s(NN)=5.02 TeV. J. High Energy Phys., 02(2), 102–26pp.
Abstract: The prompt production of +c baryons is studied in proton- lead collisions collected with the LHCb detector at the LHC. The data sample corresponds to an integrated luminosity of 1 : 58 nb recorded at a nucleon- nucleon centre- of- mass energy of p sNN = 5 : 02TeV. Measurements of the di ff erential cross- section and the forwardbackward production ratio are reported for +c baryons with transverse momenta in the range 2 < pT < 10 GeV =c and rapidities in the ranges 1 : 5 < y < 4 : 0 and 4 : 5 < y < 2 : 5 in the nucleon- nucleon centre- of- mass system. The ratio of cross- sections of +c baryons and D0 mesons is also reported. The results are compared with next- to- leading order calculations that use nuclear parton distribution functions.
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LHCb Collaboration(Aaij, R. et al), Garcia Martin, L. M., Henry, L., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2018). Search for beautiful tetraquarks in the Î¥(1S)(+-) invariant-mass spectrum. J. High Energy Phys., 10(10), 086–22pp.
Abstract: The Υ(1 S) invariant-mass distribution is investigated for a possible exotic meson state composed of two b quarks and two b quarks, X bbbb. The analysis is based on a data sample of pp collisions recorded with the LHCb detector at centre-of-mass energies s = 7, 8 and 13 TeV, corresponding to an integrated luminosity of 6.3 fb. No signi fi cant excess is found, and upper limits are set on the product of the production cross-section and the branching fraction as functions of the mass of the X bbbb state. The limits are set in the fi ducial volume where all muons have pseudorapidity in the range [2 : 0; 5 : 0], and the X bbbb state has rapidity in the range [2 : 0; 4 : 5] and transverse momentum less than 15 GeV/c.
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ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Castillo, F. L., Castillo Gimenez, V., et al. (2020). Search for t(t)over-bar resonances in fully hadronic final states in pp collisions at root s=13 TeV with the ATLAS detector. J. High Energy Phys., 10(10), 061–43pp.
Abstract: This paper presents a search for new heavy particles decaying into a pair of top quarks using 139 fb(-1) of proton-proton collision data recorded at a centre-of-mass energy of root s = 13TeV with the ATLAS detector at the Large Hadron Collider. The search is performed using events consistent with pair production of high-transverse-momentum top quarks and their subsequent decays into the fully hadronic final states. The analysis is optimized for resonances decaying into a t (t) over bar pair with mass above 1.4TeV, exploiting a dedicated multivariate technique with jet substructure to identify hadronically decaying top quarks using large-radius jets and evaluating the background expectation from data. No significant deviation from the background prediction is observed. Limits are set on the production cross-section times branching fraction for the new Z' boson in a topcolor-assisted-technicolor model. The Z0 boson masses below 3.9 and 4.7TeV are excluded at 95% confidence level for the decay widths of 1% and 3%, respectively.
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LHCb Collaboration(Aaij, R. et al), Henry, L., Jashal, B. K., Martinez-Vidal, F., Oyanguren, A., Remon Alepuz, C., et al. (2021). Search for the doubly heavy baryons Omega(0)(bc) and Xi(0)(bc) decaying to Lambda(+)(c)pi(-) and Xi(+)(c)pi-. Chin. Phys. C, 45(9), 093002–12pp.
Abstract: The first search for the doubly heavy Omega(0)(bc) baryon and a search for the Xi(0)(bc) baryon are performed using collision data collected via the experiment from 2016 to 2018 at a centre-of-mass energy of, corresponding to an integrated luminosity of 5.2 fb(-1). The baryons are reconstructed via their decays to Lambda(+)(-)(c)(pi) and Xi(+)(c)pi(-). No significant excess is found for invariant masses between 6700 and 7300 MeV/c(2), in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 MeV/c. Upper limits are set on the ratio of the Omega(0)(bc) and Xi(0)(bc) production cross-section times the branching fraction to Lambda(+)(c)pi(-)(Xi(+)(c)pi(-)) relative to that of the Lambda(0)(b)(Xi(0)(b)) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from 0.5x10(-4) to 2.5x10(-4) for the Omega(0)(bc) -> Lambda(+)(c)pi(-) (Xi(0)(bc) -> Lambda(+)(c)pi(-)) decay, pending on the considered mass and lifetime of the Omega(0)(bc) (Xi(0)(bc)) baryon.
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