One of the most intriguing puzzles in hadron spectroscopy are the numerous
charmonium-like states observed in the last decade, including charged states
that are manifestly exotic. The $BABAR$ experiment has extensively studied
those in B meson decays, initial state radiation processes and two photon
reactions. The study of the process $B \rightarrow J/\psi \phi K$, with a
search for the resonant states X(4140) and X(4270) in their decays to $J/\psi
\phi$, will be highlighted. The recent results of the Dalitz analysis of
$\eta_c$ to 3 pseudoscalar mesons, via 2-photon interactions, will be presented
in this reportComment: 4 pages, 9 figures, Proceedings written for the conference PANIC2014,
  submitted at DESY-PROC-2014. arXiv admin note: substantial text overlap with
  arXiv:1410.565

Prencipe, Elisabetta

English

arXiv

One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. Over the years, the experiment BABAR has extensively studied those in B meson decays, initial state radiation processes and two photon reactions. We report in this paper new and additional studies on some of those states, performed using the entire data sample collected by BABAR in e+e− collisions, at center of mass energies near 10.58 GeV/c2. Among these, the study of the process B → J/ψϕK, with a search for the resonant states X(4140) and X(4270) in their decays to J/ψϕ, will be highlighted. The recent BABAR results of the Dalitz analysis of ηc to 3 pseudoscalar mesons, via 2-photon interactions, will be also presented in this report. Preliminary results on χbJ in the field of bottomonium spectroscopy will be introduced

Prencipe Elisabetta

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Search for exotics at BABAR

Elisabetta Prencipe

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Search for exotics atBABAR

One of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic. The $BABAR$ experiment has extensively studied those in B meson decays, initial state radiation processes and two photon reactions. The study of the process $B \rightarrow J/\psi \phi K$, with a search for the resonant states X(4140) and X(4270) in their decays to $J/\psi \phi$, will be highlighted. The recent results of the Dalitz analysis of $\eta_c$ to 3 pseudoscalar mesons, via 2-photon interactions, will be presented in this repor

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Search for exotics at BABARElisabetta Prencipe1 on behalf of the BABAR Collaboration1Forschungszentrum Ju¨lich, Leo Brandt Strasse, 52428 Ju¨lich, Germany(previously addressed at JGU, University of Mainz, Germany)DOI: will be assignedOne of the most intriguing puzzles in hadron spectroscopy are the numerous charmonium-like states observed in the last decade, including charged states that are manifestly exotic.The BABAR experiment has extensively studied those in B meson decays, initial stateradiation processes and two photon reactions. The study of the process B → J/ψφK,with a search for the resonant states X(4140) and X(4270) in their decays to J/ψφ, will behighlighted. The recent results of the Dalitz analysis of ηc to 3 pseudoscalar mesons, via2-photon interactions, will be presented in this report [Contribution talk: ID 201].1 IntroductionSeveral new Charmonium-like states have been observed at BABAR, revealing a spectrum toorich to be uniquely described by potential models[1]. Different hypotheses have been proposedfrom theorists to explain their nature, such as hybrid charmonium states, diquark-antidiquarkstates or D0D¯0(∗) molecules[2]. The QCD spectrum is much richer than that of the naivequark model, as the gluons, which mediate the strong force between quarks, can also act asprincipal components of entirely new types of hadrons. These gluonic hadrons fall into twogeneral categories: glueballs (excited states of pure glue) and hybrids (composed by a quark,an antiquark, and excited glue). The additional degrees of freedom carried by gluons allowglueballs and hybrids to have spin-exotic quantum numbers JPC that are forbidden for normalmesons and other fermion-antifermion systems. Exotic quantum numbers (e.g. 0−−, 0+−, 1−+,2+−) are the easiest way to distinguish gluonic hadrons from qq¯ states. Predictions for hybridscome mainly from calculations based on the bag model, flux tube model, and constituent gluonmodel and recently, with increasing precision, from Lattice QCD. New forms of matter, suchas glueballs or molecular states, are predicted by QCD to populate the low mass region of thehadron mass spectrum[3]. This motivates the study of the J/ψ radiative and hadronic decays.Two analyses will be shortly summarized in this report: the Dalitz analysis of ηc →K+K−η/pi0 via 2-photon interactions and the study of the invariant mass systems of J/ψφ,J/ψK and KKK in B decays. The first is relevant to several issues in light meson spectroscopy,and it is recently published by BABAR[5]. No Dalitz plot analysis has been performed on ηCthree-body decays until now. The second presents a new determination of the branching frac-tion (BF) of B±,0 → J/ψK+K−K±,0 and B±,0 → J/ψφK±,0, using eight times more datathan that reported by the PDG[4], and search for exotic states.PANIC14 1arXiv:1411.0571v1  [hep-ex]  3 Nov 20142 Decay of ηc → K+K−η/pi0 via 2-photon interactionsRecently, a search for exotic resonances was performed by BABAR through Dalitz plot analysesof χc1 states[6]. Scalar mesons are still a puzzle in light-meson spectroscopy, as there are toomany states and they are not consistent with the quark model. In particular, the f0(1500)resonance, discovered in p¯p annihilations, has been interpreted as a scalar glueball[7]. However,no evidence for the f0(1500) state has been found in charmonium decays. Another glueballcandidate is the f0(1710) discovered in radiative J/ψ decays. Recently, f0(1500) and f0(1710)signals have been incorporated in a Dalitz plot analysis of B → 3K decays[8]. CharmlessB → XK could enanche gluonium production[9]. Another puzzling state is the K∗0 (1430),never observed as clear peak in Kpi invariant mass. Its parameters were measured from theLASS experiment in K−p→ K−pi+n[10].We describe a study of the decays ηc → K+K−η and ηc → K+K−pi0, with η → pi+pi−pi0,η → γγ and pi0 → γγ, produced in two-photon interactions. The data sample used is 519fb−1 at BABAR. Two-photon events in which at least one of the interacting photons is notquasireal are strongly suppressed by a dedicated selection. A clear peak of ηc is seen, and wellreconstructed in the invariant mass systems of K+K−η and K+K−pi0. The Dalitz analysisis then performed for ηc → K+K−η and ηc → K+K−pi0: the projection of the invariantmass distributions and their unbinned maximum likelihood fit are shown in Fig. 1 and 2. Aclear peak at the mass of K∗0 (1430) is observed in both cases, together with other expectedstructures. Amplitude parameterization is performed in a standard way for a pseudoscalarmeson decaying to 3 pseudscalar mesons. Full interference is allowed among the amplitudes ofall resonances in the Dalitz. No evidence for interferences between signal and background isfound, so a sum of inchoerent resonances is used for fitting the sidebands. The non-resonantcontribution is included in the fit. From our fit, we learn that the model provides an adeguatedescription of data for ηc → K+K−η, while the isobar model does not describe properly thedata for ηc → K+K−pi0. Scanning the likelihood as function of the K∗0 (1430) mass and width,we obtain: m(K∗0 (1430)) = 1438 ± 8 ± 4 MeV/c2 and Γ(K∗0 (1430)) = 210 ± 20 ± 12 MeV.Figure 1: Projections from the Dalitz plot of ηc → K+K−η. The shaded (yellow) histogramsshow the estimated background. The state K∗0 (1430) is seen as clear peak in (b) and (c).In this work also the pseudoscalar meson mixing angle is evaluated: θP = (3.1+3.1−5.0)o, andit differs 2.9σ deviation from expectations. This issue involves in theoretical discussions wherethe siglet and octet mixing angle should be considered separately.2 PANIC14Figure 2: Projections from the Dalitz plot of ηc → K+K−pi0 . The shaded (yellow) histogramsshow the estimated background. The state K∗0 (1430) is seen as clear peak in (b) and (c).3 Analysis of the decay B → J/ψKKKSeveral resonant structures, whose masses are above the DD¯ threshold, are not predicted bypotential models. For example, the X(3872) have been seen in B → XK,X → J/ψ pi+pi−, orY(4260) was observed by investigating the process e+e− → γISRX, X → J/ψpi+pi−[11, 12, 13];but no indication of new states has been observed in the J/ψ K+K− invariant mass sys-tem, until the paper quoted in Ref. [14] highlighted the possibility of a couple of resonantstates, decaying to J/ψφ, with φ → K+K− and J/ψ → µ+µ−. These observations are con-troversial. Strangeness in charmonium seems a sector still to be exploited. The rare decayB → J/ψKKK, in particular B → J/ψφK, is interesting because it is a promising place tosearch for new resonances, as it proceeds, at quark level, via the weak transition b → cc¯s. Itcould be a quasi 2-body decay, B → XgK, with Xg → J/ψφ, where Xg = |gcc¯ss¯ >, withgluonic contribution (g).An unbinned maximum likelihood fit is performed to extract the yield and calculate theBFs. Detailed explanation on these calculations are presented in Ref. [15], together with therelevant discussion for the non-resonant K+K− contribution to the BF of B → J/ψKKK andsystematic uncertainty calculation. Here we report only the relevant information for the analysisof the three invariant mass distributions: J/ψφ, J/ψK, KKK, for both B+ and B0 samples. Inthis analysis we calculate also: Rφ = B(B0 → J/ψφK0S)/B(B+ → J/ψφK+) = 0.48 ± 0.09 ±0.02 , and R2K = B(B0 → J/ψK+K−K0S)/B(B+ → J/ψK+K−K+) = 0.52 ± 0.09 ± 0.03; wefind values in agreement with the expectation of the spectator quark model (e.g., ratio R∼0.5).These are first measurements. For the first time the non-resonant K+K− contribution to theBF of B → J/ψKKK is observed. No evidence of signal is found for B0 → J/ψφ, in agreementwith theoretical predictions: we evaluate UL<1.01 · 10−6 at 90% confidence level (CL). Wesearch for the resonant states reported by the CDF Collaboration in the J/ψφ mass spectrum.The masses and the widths in our fit are fixed to values according to Ref. [14]. We observedsignificant efficiency decrease at low J/ψφ mass, due to the inability to reconstruct slow kaons inthe laboratory frame, as a result of energy loss in the beampipe and SVT material. We model theresonances with an inchoerent sum of two S-wave relativistic Breit-Wigner (BW) functions withparameters fixed to the CDF values [14]. A non-resonant contribution is described according toPHSP. The decay of a pseudoscalar meson to two vector states contains high spin contributionswhich could generate non-uniform angular distributions. However, due to the limited datasample (212 yield for B+ and 50 for B0, in the signal area, respectively) we do not includesuch angular terms, and assume that the resonances decay isotropically. The fit function isweighted by the inverse of the two-dimentional efficiency computed on the Dalitz plots (see thePANIC14 3Figure 3: Dalitz plot projections for B+ → J/ψφK+ on (a) m2J/ψφ, (b) m2φK+ , and (c) m2J/ψK+ .The continuous (red) curves are the results from fit model performed including the X(4140)and X(4270) resonances. The dashed (blue) curve in (a) indicates the projection for fit modelwith no resonances included in the fit. The shaded (yellow) histograms indicate the evaluatedbackground. Within systematic effects, a significance <2σ is found for both peaks in (a).continuous red curve in Fig. 3. Using the Feldman-Cousins method[16], we obtain the ULs at90% CL: BF (B+ → X(4140)K+) × BF (X(4140) → J/ψφ)/BF (B+ → J/ψφK+) < 0.135 ,and BF (B+ → X(4270)K+) × BF (X(4270) → J/ψφ)/BF (B+ → J/ψφK+) < 0.184. TheX(4140) limit may be compared with the CDF measurement of 0.149± 0.039± 0.024 [14] andthe LHCb limit of 0.07 [17]. The X(4270) limit may be compared with the LHCb limit of 0.08.We find that the hypothesis that the events are distributed uniformly on the Dalitz plot givesa poorer description of the data.References[1] N. Brambilla et all, CERN Yellow Report, hep-ph/0412158 (2005); Eur. Phys. J. C 71, 1534 (2011);arXiv:1404.3723 [hep-ph] (2014).[2] Barnes and Godfrey, PRD 69, 054008 (2004); Eichten, Lane and Quigg, PRD 69, 094019 (2004); Swanson,PLB 588, 189 (2004); Tornqvist, PLB 590, 209 (2004); Suzuki, PRD 72, 114013 (2005); Maiani, et all,PRD 71, 014028 (2005).[3] V. Mathieu, N. Kochelev and V. Vento, Int. J. Mod. E18, 1 (2009).[4] B. Aubert et all (BABAR Coll.), Phys. Rev. Lett. 91, 071801 (2003).[5] J.P. Lees et all (BABAR Coll.), Phys. Rev. D 79, 112004 (2014).[6] G. S. Adams et all (CLEO Coll.) Phys. Rev. D 84, 112009 (2011).[7] C. Amsler and F. Close, Phys. Rev. D 53, 295 (1996).[8] J.P. Lees et all (BABAR Coll.) Phys. Rev. D 85, 112010 (2012).[9] X.-G. He and T.C. Yuan, hep-ph/0612108.[10] D. Aston et all (LASS Coll.), Nucl Phys. B296, 493 (1988).[11] B. Aubert et all (BABAR Coll.), Phys. Rev. D. 71, 071103 (2005); Phys. Rev. D 77, 111101 (2008); Phys.Rev. D. 73, 011101 (2006).[12] S.K. Choi et all (Belle Coll.), Phys. Rev. Lett. 91, 262001 (2003);[13] B. Aubert et all (BABAR Coll.), Phys. Rev. Lett. 95, 142001 (2005);[14] T. Aaltonen et all (CDF Coll.), Phys. Rev. Lett. 102, 242002 (2009); hep-ex/1101.6058 (2011).[15] J.P. Lees et all (BABAR Coll.), hep-ex/1407.7244 (2014).[16] G. J. Feldman and R. D. Cousins, Phys. Rev. D. 57, 3873 (1998).[17] R. Aaij et all (LHCb Coll.), Phys. Rev. D 85, 091103(R) (2012).4 PANIC14

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Search for exotics at $BABAR$