We propose that the Y (4260) particle recently announced by BaBar is the first orbital excitation of a diquark-antidiquark state ([cs][cs]). Using parameters recently determined to describe the X(3872) and X(3940) we show that the Y mass is compatible with the orbital excitation picture. A crucial prediction is that Y (4260) should decay predominantly in DsDs. The Y (4260) should also be seen in B non-leptonic decays in association with one kaon. We consider the full nonet of related four-quark states and their predicted properties. Finally, we comment on a possible narrow resonance in the same channel.ROMA1 In a series of exciting experiments, BELLE and BaBar have discovered several states that, although decaying in charmonium plus pions, do not seem to fit the cc picture, in particular the X(3872) and X(3940) states.In a recent paper [1] we have pointed out that the properties of the new states can be well explained if they are S-wave diquark-antidiquark bound states with the composition (q = u, d): [(cq)(cq)] S−wave . An alternative scenario is the molecular picture where the X(3872) would be a D 0 D * 0 bound state. A crucial difference between the two alternatives is that colored objects in a rising confining potential, such as diquarks, should exhibit a series of orbital angular momentum excitations. This is clearly at variance with the molecular picture. Colorless objects bound by a short range potential should have a very limited spectrum, possibly restricted to S-wave states only.In this note we would like to propose that the first orbital excitation of a diquark-antidiquark state may have indeed been found in the state Y (4260) recently announced by the BaBar collaboration [2]. We discuss the properties of the new state in this framework and spell out a few distinctive predictions. The most revealing among them is that the dominant decay mode of Y (4260) should be in D sDs pairs. We shall also briefly discuss other states implied by the scheme and their properties. We comment on the possibility of an additional narrow state.The Y (4260) is observed by BaBar in e + e − annihilation, in association with an Initial-State-Radiation pho- * Electronic address: luciano.maiani@roma1.infn.it † Electronic address: veronica.riquer@cern.ch ‡ Electronic address: fulvio.piccinini@pv.infn.it § Electronic address: antonio.polosa@cern.ch ton, which implies J P C = 1 −− . The particle has a width of about 90 MeV and it is seen to decay in J/ψ π + π − . The π + π − mass distribution peaks around 1 GeV, consistently with a decay into J/ψ f 0 (980). BaBar reports the value [2]:(1) The diquark-antidiquark assumption together with the negative parity call for at least one unit of orbital angular momentum. In addition, the decay into f 0 (980), which fits the (

Heavy-light diquarks can be the building blocks of a rich spectrum of states which can accommodate some of the newly observed charmonium-like resonances not fitting a pure cc assignment. We examine this possibility for hidden and open charm diquark-antidiquark states deducing spectra from constituent quark masses and spin-spin interactions. Taking the X(3872) as input we predict the existence of a 2 ++ state that can be associated to the X(3940) observed by Belle and re-examine the state claimed by SELEX, X(2632). The possible assignment of the previously discovered states Ds(2317) and Ds (2457) is discussed. We predict X(3872) to be made of two components with a mass difference related to mu − m d and discuss the production of X(3872) and of its charged partner X ± in the weak decays of B +,0 .

Following the recent confirmation of the Z + (4430) resonance with J P G = 1 ++ , we have re-examined the model of S and P wave tetra--quarks. We propose a 'type-II' diquark-antidiquark model which shows to be very effective at producing a simple and comprehensive picture of the J P G = 1 ++ and 1 −− sectors of the recently discovered charged tetraquarks and of the observed Y resonances. The model is still faced with the unresolved difficulty of explaining why some states seem to have incomplete isospin multiplets.

Light scalar mesons are found to fit rather well a diquark-antidiquark description. The resulting nonet obeys mass formulas which respect, to a good extent, the Okubo-Zweig-Iizuka (OZI) rule. OZI allowed strong decays are reasonably reproduced by a single amplitude describing the switch of a qq pair, which transforms the state into two colorless pseudoscalar mesons. Predicted heavy states with one or more quarks replaced by charm or beauty are briefly described; they should give rise to narrow states with exotic quantum numbers.

Pentaquark baryons are a natural expectation of an extended picture of hadrons where quarks and di-quarks are the fundamental units. The parity/mass pattern observed, when compared to that of exotic mesons, appears as the footprint of a compact five-quark structure. What has been learned from the X, Y, Zphenomenology informs about the newly found pentaquark structure and suggests further experimental tests and directions to be explored. (C) 2015 The Authors. Published by Elsevier B.V

We analyze the Minimal Supersymmetric extension of the Standard Model that we have after the discovery of the Higgs boson at the LHC, the hMSSM (habemus MSSM?), i.e. a model in which the lighter h boson has a mass of approximately 125 GeV which, together with the non-observation of superparticles at the LHC, indicates that the SUSY-breaking scale MS is rather high, MS≳1 TeV. We first demonstrate that the value Mh≈125 GeV fixes the dominant radiative corrections that enter the MSSM Higgs boson masses, leading to a Higgs sector that can be described, to a good approximation, by only two free parameters. In a second step, we consider the direct supersymmetric radiative corrections and show that, to a good approximation, the phenomenology of the lighter Higgs state can be described by its mass and three couplings: those to massive gauge bosons and to top and bottom quarks. We perform a fit of these couplings using the latest LHC data on the production and decay rates of the light h boson and combine it with the limits from the negative search of the heavier H,A and H± states, taking into account the current uncertainties.

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In the context of the Minimal Supersymmetric extension of the Standard Model (MSSM), we reanalyze the search for the heavier CP-even H and CP-odd A neutral Higgs bosons at the LHC in their production in the gluon-fusion mechanism and their decays into gauge and lighter h bosons and into top quark pairs. We show that only when considering these processes, that one can fully cover the entire parameter space of the Higgs sector of the model. Indeed, they are sensitive to the low tan β and high Higgs mass ranges, complementing the traditional searches for high mass resonances decaying into τ -lepton pairs which are instead sensitive to the large and moderate tan β regions. The complementarity of the various channels in the probing of the complete [tan β, M A ] MSSM parameter space at the previous and upcoming phases of the LHC is illustrated in a recently proposed simple and model independent approach for the Higgs sector, the hMSSM, that we also refine in this paper.