Search results for "bound state"
showing 10 items of 235 documents
Reanalysis of thee+e−→(D*D¯*)±π∓reaction and the claim for theZc(4025)resonance
2014
In this paper we study the reaction ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{({D}^{*}{\overline{D}}^{*})}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\pi}}^{\ensuremath{\mp}}$ in which the BESIII collaboration has claimed the existence of a ${1}^{+}$ resonance, named ${Z}_{c}(4025)$, in the ${D}^{*}{\overline{D}}^{*}$ invariant mass spectrum with a mass around 4026 MeV and width close to 26 MeV . We determine the ${D}^{*}{\overline{D}}^{*}$ invariant mass distribution and find that although the explanation considered by the BESIII collaboration is plausible, there are others which are equally possible, like a ${2}^{+}$ resonance or a bound state. Even more, we find that the data …
Study ofBB¯*andB*B¯*interactions inI=1and relationship to theZb(10610),Zb(10650)states
2015
We use the local hidden gauge approach in order to study the $B{\overline{B}}^{*}$ and ${B}^{*}{\overline{B}}^{*}$ interactions for isospin $I=1$. We show that both interactions via one light meson exchange are not allowed by the Okubo-Zweig-Iizuka rule and, for that reason, we calculate the contributions due to the exchange of two pions, interacting and noninteracting among themselves, and also due to the heavy vector mesons. Then, to compare all these contributions, we use the potential related to the heavy vector exchange as an effective potential corrected by a factor which takes into account the contribution of the other light meson exchanges. In order to look for poles, this effective…
ΛNNandΣNNsystems at threshold
2007
We calculate the hypertriton binding energy and the $\ensuremath{\Lambda}d$ and $\ensuremath{\Sigma}d$ scattering lengths using baryon-baryon interactions obtained from a chiral constituent quark model. We study consistently the $\ensuremath{\Lambda}\mathit{NN}$ and $\ensuremath{\Sigma}\mathit{NN}$ systems by analyzing the effect of the $\ensuremath{\Sigma}\ensuremath{\leftrightarrow}\ensuremath{\Lambda}$ conversion. Our interactions correctly predict the hypertriton binding energy. The $(I,J)=(0,3/2)$ $\ensuremath{\Lambda}\mathit{NN}$ channel is also attractive and it might have a bound state. From the condition of nonexistence of a (0,3/2) $\ensuremath{\Lambda}\mathit{NN}$ bound state, an…
Critical view on the deeply boundK−ppsystem
2006
We briefly review the situation around the claimed deeply bound ${K}^{\ensuremath{-}}$ states in different recent experiments and concentrate particularly on the state ${K}^{\ensuremath{-}}\mathit{pp}$ advocated by the FINUDA collaboration in nuclear ${K}^{\ensuremath{-}}$ absorption. We perform a theoretical simulation of the process and show that the peak in the $\ensuremath{\Lambda}p$ spectrum that was interpreted as a deep ${K}^{\ensuremath{-}}\mathit{pp}$ bound state corresponds mostly to the process ${K}^{\ensuremath{-}}pp\ensuremath{\rightarrow}\ensuremath{\Lambda}p$ followed by final-state interactions of the produced particles with the daughter nucleus.
Isospin 0 and 1 resonances fromπΣphotoproduction data
2013
Recently we presented a successful strategy to extract the position of the two $\ensuremath{\Lambda}(1405)$ poles from experimental photoproduction data on the $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{0}{\ensuremath{\Sigma}}^{0}$ reaction at Jefferson Lab. Following a similar strategy, we extend the previous method to incorporate also the isospin 1 component which allows us to consider in addition the experimental data on $\ensuremath{\gamma}p\ensuremath{\rightarrow}{K}^{+}{\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}{\ensuremath{\Sigma}}^{\ensuremath{\mp}}$. The idea is based on considering a production mechanism as model independent as possible and imple…
Plausible explanation for theΔ5/2+(2000)puzzle
2011
From a Faddeev calculation for the $\ensuremath{\pi}$-$(\ensuremath{\Delta}\ensuremath{\rho}){}_{{N}_{5/{2}^{\ensuremath{-}}}(1675)}$ system we show the plausible existence of three dynamically generated $I({J}^{P})=3/2(5/{2}^{+})$ baryon states below 2.3 GeV, whereas only two resonances, ${\ensuremath{\Delta}}_{5/{2}^{+}}(1905)(****)$ and ${\ensuremath{\Delta}}_{5/{2}^{+}}(2000)(**),$ are cataloged in the Particle Data Book Review. Our results give theoretical support to data analyses extracting two distinctive resonances, ${\ensuremath{\Delta}}_{5/{2}^{+}}(~$1740) and ${\ensuremath{\Delta}}_{5/{2}^{+}}(~$2200), from which the mass of ${\ensuremath{\Delta}}_{5/{2}^{+}}(2000)(**)$ is estima…
S-waveKK*interactions in a finite volume and thef1(1285)
2015
Lattice QCD simulations provide a promising way to disentangle different interpretations of hadronic resonances, which might be of particular relevance to understand the nature of the so-called XY Z particles. Recent studies have shown that in addition to the well-established naive quark model picture, the axial-vector meson f1(1285) can also be understood as a dynamically generated state built upon the KK ∗ interaction. In this work, we calculate the energy levels of the KK ∗ system in the f1(1285) channel in finite volume using the chiral unitary approach. We propose to calculate the loop function in the dimensional regularization scheme, which is equivalent to the hybrid approach adopted…
Bound-state dark matter with Majorana neutrinos
2019
We propose a simple scenario in which dark matter (DM) emerges as a stable neutral hadronic thermal relics, its stability following from an exact $\operatorname{U}(1)_D$ symmetry. Neutrinos pick up radiatively induced Majorana masses from the exchange of colored DM constituents. There is a common origin for both dark matter and neutrino mass, with a lower bound for neutrinoless double beta decay. Direct DM searches at nuclear recoil experiments will test the proposal, which may also lead to other phenomenological signals at future hadron collider and lepton flavour violation experiments.
Formation of Heavy Meson Bound States by Two Nucleon Pick-up Reactions
2011
We develop a model to evaluate the formation rate of the heavy mesic nuclei in the two nucleon pick-up reactions, and apply it to the $^6$Li target cases for the formation of heavy meson-$\alpha$ bound states, as examples. The existence of the quasi-deuteron in the target nucleus is assumed in this model. It is found that the mesic nuclei formation in the recoilless kinematics is possible even for heavier mesons than nucleon in the two nucleon pick-up reactions. We find the formation rate of the meson-$\alpha$ bound states can be around half of the elementary cross sections at the recoilless kinematics with small distortions.
Y(3940),Z(3930), and theX(4160)as dynamically generated resonances from the vector-vector interaction
2009
We apply a unitary approach together with a set of hidden‐gauge Lagrangians to study the vector‐vector interaction. Concretely, we focus on the sector with quantum numbers charm C = 0 and strangeness S = 0 in the region around 4000 MeV. We get five poles, three of which could be identified with the Y(3940), Z(3930) and X(4160). These poles appear with quantum numbers I = 0 and JPC = 0++,2++ and 2++, respectively, and can be considered as hadronic molecules made of D*D*, Ds*Ds*, decaying to a pair of light vectors, light‐heavy vector or pseudoscalar‐pseudoscalar.