scholarly journals Resonance Y(4660) as a vector tetraquark and its strong decay channels

2018 ◽  
Vol 98 (5) ◽  
Author(s):  
H. Sundu ◽  
S. S. Agaev ◽  
K. Azizi
Keyword(s):  
2014 ◽  
Vol 29 ◽  
pp. 1460234
Author(s):  
Yan-Rui Liu

The newly observed exotic mesons above [Formula: see text] threshold were widely discussed in the molecular picture. To understand deeper their structures, we here discuss the spin ([Formula: see text]) of a heavy quark-antiquark pair in an S-wave meson-antimeson system by constructing explicitly the spin wave function. One finds two selection rules for [Formula: see text] (a) the total angular momentum J is larger than the maximum angular momentum of the light degree of freedom or smaller than the minimum one; (b) JC = 1+, 2-, 3+, ⋯ if the two mesons are different but belong to the same doublet. This feature may be used to constrain possible strong decay channels.


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.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Linda M. Carpenter ◽  
Taylor Murphy ◽  
Matthew J. Smylie

Abstract In this work we study the collider phenomenology of color-octet scalars (sgluons) in minimal supersymmetric models endowed with a global continuous R symmetry. We systematically catalog the significant decay channels of scalar and pseudoscalar sgluons and identify novel features that are natural in these models. These include decays in nonstandard diboson channels, such as to a gluon and a photon; three-body decays with considerable branching fractions; and long-lived particles with displaced vertex signatures. We also discuss the single and pair production of these particles and show that they can evade existing constraints from the Large Hadron Collider, to varying extents, in large regions of reasonable parameter space. We find, for instance, that a 725 GeV scalar and a 350 GeV or lighter pseudoscalar can still be accommodated in realistic scenarios.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Lucien Heurtier ◽  
Hao-Lin Li ◽  
Huayang Song ◽  
Shufang Su ◽  
Wei Su ◽  
...  

AbstractThe Higgs sector in neutral naturalness models provides a portal to the hidden sectors, and thus measurements of Higgs couplings at current and future colliders play a central role in constraining the parameter space of the model. We investigate a class of neutral naturalness models, in which the Higgs boson is a pseudo-Goldstone boson from the universal SO(N)/SO(N −1) coset structure. Integrating out the radial mode from the spontaneous global symmetry breaking, we obtain various dimension-six operators in the Standard Model effective field theory, and calculate the low energy Higgs effective potential with radiative corrections included. We perform aχ2fit to the Higgs coupling precision measurements at current and future colliders and show that the new physics scale could be explored up to 2.3 (2.4) TeV without (with) the Higgs invisible decay channels at future Higgs factories. The limits are comparable to the indirect constraints obtained via electroweak precision measurements.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ulrich Haisch ◽  
Amando Hala

Abstract We estimate the form factors that parametrise the hadronic matrix elements of proton-to-pion transitions with the help of light-cone sum rules. These form factors are relevant for semi-leptonic proton decay channels induced by baryon-number violating dimension-six operators, as typically studied in the context of grand unified theories. We calculate the form factors in a kinematical regime where the momentum transfer from the proton to the pion is space-like and extrapolate our final results to the regime that is relevant for proton decay. In this way, we obtain estimates for the form factors that show agreement with the state-of-the-art calculations in lattice QCD, if systematic uncertainties are taken into account. Our work is a first step towards calculating more involved proton decay channels where lattice QCD results are not available at present.


2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
A. M. Sirunyan ◽  
◽  
A. Tumasyan ◽  
W. Adam ◽  
F. Ambrogi ◽  
...  

Abstract Decays of the 125 GeV Higgs boson into a Z boson and a ρ0(770) or ϕ(1020) meson are searched for using proton-proton collision data collected by the CMS experiment at the LHC at $$ \sqrt{s} $$ s = 13 TeV. The analysed data set corresponds to an integrated luminosity of 137 fb−1. Events are selected in which the Z boson decays into a pair of electrons or a pair of muons, and the ρ and ϕ mesons decay into pairs of pions and kaons, respectively. No significant excess above the background model is observed. As different polarization states are possible for the decay products of the Z boson and ρ or ϕ mesons, affecting the signal acceptance, scenarios in which the decays are longitudinally or transversely polarized are considered. Upper limits at the 95% confidence level on the Higgs boson branching fractions into Zρ and Zϕ are determined to be 1.04–1.31% and 0.31–0.40%, respectively, where the ranges reflect the considered polarization scenarios; these values are 740–940 and 730–950 times larger than the respective standard model expectations. These results constitute the first experimental limits on the two decay channels.


2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Maria Mehmood ◽  
Mansoor Ur Rehman ◽  
Qaisar Shafi

Abstract We explore proton decay in a class of realistic supersymmetric flipped SU(5) models supplemented by a U(1)R symmetry which plays an essential role in implementing hybrid inflation. Two distinct neutrino mass models, based on inverse seesaw and type I seesaw, are identified, with the latter arising from the breaking of U(1)R by nonrenormalizable superpotential terms. Depending on the neutrino mass model an appropriate set of intermediate scale color triplets from the Higgs superfields play a key role in proton decay channels that include p → (e+, μ+) π0, p → (e+, μ+) K0, p →$$ \overline{v}{\pi}^{+} $$ v ¯ π + , and p →$$ \overline{v}{K}^{+} $$ v ¯ K + . We identify regions of the parameter space that yield proton lifetime estimates which are testable at Hyper-Kamiokande and other next generation experiments. We discuss how gauge coupling unification in the presence of intermediate scale particles is realized, and a Z4 symmetry is utilized to show how such intermediate scales can arise in flipped SU(5). Finally, we compare our predictions for proton decay with previous work based on SU(5) and flipped SU(5).


2021 ◽  
Vol 103 (9) ◽  
Author(s):  
K. Azizi ◽  
Y. Sarac ◽  
H. Sundu
Keyword(s):  

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