Measurement of branching ratios and estimate of the phase of the strong decay amplitude

1998 ◽  
Vol 444 (1-2) ◽  
pp. 111-118 ◽  
Author(s):  
R Baldini ◽  
M Bertani ◽  
C Bini ◽  
R Calabrese ◽  
A De Falco ◽  
...  
Author(s):  
Hua-Xing Chen

AbstractWe systematically study hidden-charm pentaquark currents with the quark configurations $$[\bar{c} u][u d c]$$ [ c ¯ u ] [ u d c ] , $$[\bar{c} d][u u c]$$ [ c ¯ d ] [ u u c ] , and $$[\bar{c} c][u u d]$$ [ c ¯ c ] [ u u d ] . Some of their relations are derived using the Fierz rearrangement of the Dirac and color indices, and the obtained results are used to study strong decay properties of $$P_c$$ P c states as $$\bar{D}^{(*)} \varSigma _c$$ D ¯ ( ∗ ) Σ c hadronic molecules. We calculate their relative branching ratios for the $$J/\psi p$$ J / ψ p , $$\eta _c p$$ η c p , $$\chi _{c0} p$$ χ c 0 p , $$\chi _{c1} p$$ χ c 1 p , $$\bar{D}^{(*)0} \varLambda _c^+$$ D ¯ ( ∗ ) 0 Λ c + , $$\bar{D}^{0} \varSigma _c^{+}$$ D ¯ 0 Σ c + , and $$\bar{D}^{-} \varSigma _c^{++}$$ D ¯ - Σ c + + decay channels. We propose to search for the $$P_c(4312)$$ P c ( 4312 ) in the $$\eta _c p$$ η c p channel and the $$P_c(4440)/P_c(4457)$$ P c ( 4440 ) / P c ( 4457 ) in the $$\bar{D}^{0} \varLambda _c^+$$ D ¯ 0 Λ c + channel.


1997 ◽  
Vol 62 (2) ◽  
pp. 154-171 ◽  
Author(s):  
Jan Vojtík ◽  
Richard Kotal

An analysis of the degree of convergence of theoretical pictures of the dynamics of the autoionization event He(23S)-D2(v" = 0) -> [He...D2+(v')] + e is presented for a number of batches of Monte Carlo calculations differing in the number of the trajectories run. The treatment of the dynamics consists in 2D classical trajectory calculations based on static characteristics which include a quantum mechanical treatment of the perturbed D2(v" = 0) and D2+(v') vibrational motion. The vibrational populations are dynamical averages over the local widths of the He(23S)-D2(v" = 0) state with respect to autoionization to D2+(...He) in its v'th vibrational level and the Penning electron energies are related to the local differences between the energies of the corresponding perturbed D2(v" = 0)(...He*) and D2+(v')(...He) vibrational states. Special attention is paid to the connection between the requirements on the degree of convergence of the classical trajectory picture of the event and the purpose of the calculations. Information is obtained regarding a scale of the trajectory calculations required for physically sensible applications of the model to an interpretation of different type of experiments on the system: total ionization cross section measurements, Penning ionization electron spectra, subsequent 3D classical trajectory calculations of branching ratios of the products of the postionization collision process, and interpretation of electron ion coincidence measurements of the product branching ratios for individual vibrational levels of the nascent Penning ion.


2019 ◽  
Vol 199 ◽  
pp. 01014
Author(s):  
K. Piscicchia ◽  
M. Bazzi ◽  
G. Belloti ◽  
A. M. Bragadireanu ◽  
D. Bosnar ◽  
...  

The AMADEUS experiment at the DAΦNE collider of LNF-INFN deals with the investigation of the at-rest, or low-momentum, K− interactions in light nuclear targets, with the aim to constrain the low energy QCD models in the strangeness sector. The 0 step of the experiment consisted in the reanalysis of the 2004/2005 KLOE data, exploiting K− absorptions in H, 4He, 9Be and 12C, leading to the first invariant mass spectroscopic study with very low momentum (about 100 MeV) in-flight K− captures. With AMADEUS step 1 a dedicated pure Carbon target was implemented in the central region of the KLOE detector, providing a high statistic sample of pure at-rest K− nuclear interaction. The first measurement of the non-resonant transition amplitude $\left| {{A_{{K^ - }n \to \Lambda {\pi ^ - }}}} \right|$ at $\sqrt s = 33\,MeV$ below the K̄N threshold is presented, in relation with the Λ(1405) properties studies. The analysis procedure adopted in the serarch for K− multi-nucleon absorption cross sections and Branching Ratios will be also described.


1974 ◽  
Vol 52 (23) ◽  
pp. 2329-2342 ◽  
Author(s):  
R. W. Ollerhead ◽  
D. C. Kean ◽  
R. M. Gorman ◽  
M. B. Thomson

All levels below 5.2 MeV in 25Mg have been studied using the reaction 25Mg(p, p′γ). In-elastically scattered protons were detected in an annular surface barrier detector located at 180°; coincidence gamma-ray spectra were obtained at Ge (Li) detector angles of 90°, 45°, and 135°. Level energies were determined from unshifted gamma-ray energies recorded in the 90° spectra. Lifetimes were obtained from the attenuated Doppler shift of gamma-ray energies recorded in spectra taken at forward and backward angles. Branching ratios were deduced from the combined data of all three angles. The identification of levels as members of rotational bands is discussed, and transition strengths deduced from the present measurements are compared with predictions of the simple rotational model.


2017 ◽  
Vol 19 (7) ◽  
pp. 5519-5524 ◽  
Author(s):  
Yufeng Gao ◽  
Mingjie Wan

The feasibility of laser cooling of the AlBr molecule is investigated usingab initioquantum chemistry.


2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Aoife Bharucha ◽  
Diogo Boito ◽  
Cédric Méaux

Abstract In this paper we consider the decay D+ → π+ℓ+ℓ−, addressing in particular the resonance contributions as well as the relatively large contributions from the weak annihilation diagrams. For the weak annihilation diagrams we include known results from QCD factorisation at low q2 and at high q2, adapting the existing calculation for B decays in the Operator Product Expansion. The hadronic resonance contributions are obtained through a dispersion relation, modelling the spectral functions as towers of Regge-like resonances in each channel, as suggested by Shifman, imposing the partonic behaviour in the deep Euclidean. The parameters of the model are extracted using e+e− → (hadrons) and τ → (hadrons) + ντ data as well as the branching ratios for the resonant decays D+ → π+R(R → ℓ+ℓ−), with R = ρ, ω, and ϕ. We perform a thorough error analysis, and present our results for the Standard Model differential branching ratio as a function of q2. Focusing then on the observables FH and AFB, we consider the sensitivity of this channel to effects of physics beyond the Standard Model, both in a model independent way and for the case of leptoquarks.


2020 ◽  
Vol 1643 ◽  
pp. 012155
Author(s):  
S. Pirrie ◽  
C. Wheldon ◽  
Tz. Kokalova ◽  
J. Bishop ◽  
R. Hertenberger ◽  
...  

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