The mass of the eta_b(1S), measured recently by BABAR, is significantly lower than expected from QCD predictions for the Upsilon(1S) - eta_b(1S) hyperfine splitting. We suggest that the observed eta_b(1S) mass is shifted downwards due to a mixing with a CP-odd Higgs scalar A with a mass m_A in the range 9.4 - 10.5 GeV compatible with LEP, CLEO and BABAR constraints. We determine the resulting predictions for the spectrum of the eta_b(nS) - A system and the branching ratios into tau^+ tau^- as functions of m_A.
Recent data from the CDF collaboration on the production of spin-triplet bottomonium states at the Tevatron p \bar p collider are analyzed within the NRQCD factorization formalism. The color-singlet matrix elements are determined from electromagnetic decays and from potential models. The color-octet matrix elements are determined by fitting the CDF data on the cross sections for Upsilon(1S), Upsilon(2S), and Upsilon(3S) at large p_T and the fractions of Upsilon(1S) coming from chi_b(1P) and chi_b(2P). We use the resulting matrix elements to predict the cross sections at the Tevatron for the sp…
We study bottomonium spectral functions in the quark-gluon plasma in the Upsilon and eta_b channels, using lattice QCD simulations with two flavours of light quark on highly anisotropic lattices. The bottom quark is treated with nonrelativistic QCD (NRQCD). In the temperature range we consider, 0.42 < T/T_c < 2.09, we find that the ground states survive, whereas the excited states are suppressed as the temperature is increased. The position and width of the ground states are compared to analytical effective field theory (EFT) predictions. Systematic uncertainties of the maximum entropy method …
We present a calculation of the hyperfine splittings in bottomonium using lattice Nonrelativistic QCD. The calculation includes spin-dependent relativistic corrections through O(v^6), radiative corrections to the leading spin-magnetic coupling and, for the first time, non-perturbative 4-quark interactions which enter at alpha_s^2 v^3. We also include the effect of u,d,s and c quark vacuum polarisation. Our result for the 1S hyperfine splitting is M(Upsilon,1S) - M(eta_b,1S)= 60.0(6.4) MeV. We find the ratio of 2S to 1S hyperfine splittings (M(Upsilon,2S) - M(eta_b,2S))/ (M(Upsilon,1S) - M(eta_…
We compute the electric dipole moment (EDM) of the bottom quark in minimal supersymmetric model (SUSY) with explicit CP violation. We estimate its upper bound to be 10^(-20) e-cm where the dominant contribution comes from the charginos for most of the SUSY parameter space. We also find that chargino contribution is directly correlated with the branching fraction of the B\to X_s γdecay. Furthermore, we analyze the formation of 1 P_1 resonance of the (\bar{b}b) system in e^+ e^- annihilation, and show that the CP-violating transition amplitude, induced solely by the b-quark EDM, is significantly…
The decays of pseudoscalar bottomonium eta_b into a pair of vector charmonia, J/ψJ/ψ, J/ψψ', ψ' ψ' are considered in the light cone formalism. Relativistic and leading logarithmic radiative corrections to the amplitudes of these processes are resummed. It is shown that the small value for the branching ratio of the decay eta_b-> J/ψJ/ψobtained within the leading order nonrelativistic QCD is a consequence of a fine-tuning between certain parameters, which is broken when relativistic and leading logarithmic radiative corrections are taken into account. As a result, the branching ratio obtained i…
A non-standard CP-odd Higgs boson could induce a slight (but observable) lepton universality breaking in Upsilon leptonic decays. Moreover, mixing between such a pseudoscalar Higgs boson and $η_b$ states might shift their mass levels, thereby modifying the values of the $M_{Υ(nS)}-M_{η_b(nS)}$ hyperfine spplitings predicted in the standard model. Besides, $η_b$ resonances could be broader than expected with potentially negative consequences for discovery in both $e^+e^-$ and hadron colliders. A scenario with a CP violating Higgs sector is also considered. Finally, further strategies to search …
We study the decay modes of a new, light spin-0 particle, arguing that if the mass of the (pseudo)scalar is ~11-15 GeV, it can have an appreciable branching ratio into bottomonium, in particular the rare eta's. Using non-relativistic QCD (NRQCD), we calculate its decay rate to bottomonia for mass splittings greater than the typical momentum transfer within the bound state. It can exceed that of decays to other Standard Model fermions under the assumption of couplings proportional to those of the Standard Model. At smaller splittings, where our computational methods break down, we estimate the …
A non-standard light CP-odd Higgs boson could induce a slight (but observable) lepton universality breakdown in Upsilon leptonic decays. Moreover, the mixing between such a pseudoscalar Higgs and $η_b$ states might shift the mass levels of the latter, thereby changing the values of the $m_{Υ(nS)}-m_{η_b(nS)}$ splittings predicted in the standard model. Besides, also the $η_b$ width could be broader than expected, with potentially negative consequences for its discovery in both $e^+e^-$ and hadron colliders.
The $η$ production in the $(n,n')$ bottomonium transitions $Υ(n) \to Υ(n') η, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $Γ_η(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$.Resulting $Γ_η(4,1)$ is found to be large in agreement with recent data.
The possible existence of a light CP-odd Higgs state in many new-physics models could lead to observable effects in the bottomonium sector. Experimental bounds on radiative $Υ$ decays through such a pseudoscalar state and possible mixings with the $η_b^0$ states are reviewed. Combining these two effects, we set constraints on the properties of the CP-odd Higgs in the limit of small photon energy of $BR(Υ\toγ\,τ^+τ^-)$, that is on the pseudoscalar mass-range $\sim8-10$GeV.
The $η$ production in the $(n,n')$ bottomonium transitions $Υ(n) \to Υ(n') η, $ is studied in the method used before for dipion heavy quarkonia transitions. The widths $Γ_η(n,n')$ are calculated without fitting parameters for $n=2,3,4,5, n'=1$. Resulting $Γ_η(4,1)$ is found to be large in agreement with recent data. Multipole expansion method is shown to be inadequate for large size systems considered.
The color-octet isosinglet "rho" of a new strong-interaction sector is readily produced in ppbar collisions. Its odd-parity decay to an "eta" and a gluon may exceed its decay rate to dijets. At center of mass energies sufficiently greater than the colored "rho" mass, the odd-parity production of ("omega" + colored "eta") or ("rho" + colored "pion") may be comparable to ttbar production. Considering that the "omega" has a dominant odd-parity decay mode, we end up with (Z, W, or gamma) + 4 jet events with two of the jets containing b or bbar.
The production of (eta,eta')- mesons during the decay of a CP-odd phase is studied within an evolution operator approach. We derive a quantum kinetic equation starting from the Witten-DiVecchia-Veneziano Lagrangian for pseudoscalar mesons containing a U_A(1) symmetry breaking term. The non-linear vacuum mean field for the flavour singlet pseudoscalar meson is treated as a classical, self-interacting background field with fluctuations assumed to be small. The numerical solution provides the time evolution of momentum distribution function of produced eta'- mesons after a quench at the deconfine…
We study possible effects of a light CP-odd Higgs boson on radiative Upsilon decays in the Next-to-Minimal Supersymmetric Standard Model. Recent constraints from CLEO on radiative Upsilon(1S) decays are translated into constraints on the parameter space of CP-odd Higgs boson masses and couplings, and compared to constraints from B physics and the muon anomalous magnetic moment. Possible Higgs - eta_b(nS) mixing effects are discussed, notably in the light of the recent measurement of the eta_b(1S) mass by Babar: The somewhat large Upsilon(1S) - eta_b(1S) hyperfine splitting could easily be expl…
We calculate the cross section of diffractive charge-parity C=+1 neutral meson production in virtual photon proton collision at high energies. Due to the opposite C-parities of photon and meson M (M = eta_C, pi^0, a_2) this process probes the t-channel C=-1 odderon exchange which is described here as noninteracting three-gluon exchange. Estimates for the cross section of the inelastic diffractive process gamma^* p -> eta_C X_p are presented. The total cross section of diffractive η_C meson photoproduction is found to be 47 pb. The cross sections for the diffractive production of light mesons (…
We calculate the long-distance matrix elements for the decays of the Upsilon (eta_b) and chi_b (h_b) states in lattice QCD with two flavors of light dynamical quarks. We relate the lattice matrix elements to their continuum counterparts through one-loop order in perturbation theory. In the case of the leading S-wave matrix element, we compare our result with a phenomenological value that we extract from the experimental leptonic decay rate by using the theoretical expression for the decay rate, accurate through relative order alpha_s. Whereas estimates of the leading S-wave matrix element from…
In two recent papers (arXiv:1002.1971 [hep-ph] and arXiv:0911.2460 [hep-ph]) Dermisek and Gunion provide new constraints on a light CP-odd Higgs boson in the framework of the NMSSM (or similar models) based on experimental data from LEP, CLEO, BaBar and CDF experiments. In this brief comment we argue that special care is still needed inside a narrow mass window where mixing with $η_b$ resonances below $B\bar{B}$ can occur. We also stress that observables testing lepton universality and a possible distorsion of the bottomonium mass spectrum can provide an alternative analysis at (Super) B-facto…
In a previous work we have shown that a general two-Higgs-doublet model (THDM) with a very light CP-odd scalar can be compatible with electroweak precision data, such as the rho parameter, BR(b --> s gamma), R_b, A_b, BR(Upsilon --> A gamma), BR(eta --> A gamma), and (g-2) of muon. Prompted by the recent significant change in the theoretical status of the latter observable, we comment on the consequences for this model and update the allowed parameter region. It is found that the presence of a very light scalar with a mass of 0.2 GeV is still compatible with the new theoretical prediction of t…
We present a unified analysis of the decays of bottomonia Upsilon(mS) -> Upsilon(nS) pi pi (m>n, m=2,3,4,5, n=1,2,3), charmonia J/psi -> phi (pi pi, K antiK), psi(2S) -> J/psi pi pi and the isoscalar S-wave processes pi pi -> pi pi, K antiK, eta eta. In this analysis we extend our recent study of low-lying (m=2,3) radial excitations of bottomonia to modes involving higher (m=4,5) excited states. Similarly as for the data on lower radial excitations, we confirm that the data for higher radially excited states from the BaBar and Belle collaborations can be described under conditions that the fin…
The Higgs spectrum of the minimal composite Higgs model, based on the SO(5)/SO(4) coset, consists of a unique Higgs doublet whose phenomenology does not differ greatly from the Standard Model (SM). Nevertheless, extensions beyond this minimal coset structure exhibit a richer Higgs spectrum and therefore very different Higgs physics. We explore one of these extensions, the SO(6)/SO(5) model, whose Higgs spectrum contains a CP-odd singlet scalar, eta, in addition to the Higgs doublet. Due to the pseudo-Nambu-Goldstone nature of these Higgs bosons, their physical properties can be derived from sy…
Models with an extended Higgs sector, as the NMSSM, allow for scenarios where the Standard Model-like CP-even Higgs boson H decays dominantly as H -> AA -> 4 tau where A is a light CP-odd Higgs boson. Tight constraints on this scenario in the form of lower bounds on M_H have recently been published by the ALEPH group. We show that, due to A - eta_b mixing, the branching ratio H -> AA -> 4 tau is strongly reduced for M_A in the range 9 - 10.5 GeV. This is the range of M_A in which the tension between the observed eta_b(1S) mass and its prediction based on QCD can be resolved due to mixing, and …
We study the hadronic form factors of $τ$ lepton decays $τ\to K π(η) ν$. We compute one loop corrections to the form factors using the chiral Lagrangian including vector mesons. The counterterms which subtract the divergence of the one-loop amplitudes are determined by using background field method. In the vector form factor, $K^\ast$ resonance behavior is reproduced because the diagram with a vector meson propagator is included. We fit the data of the hadronic invariant mass spectrum measured by Belle by determining some of the counterterms of the Lagrangian. Besides the hadronic invariant ma…
We extend the Higgs triplet model so as to include dark matter candidates and a simple suppression mechanism for the vacuum expectation value (v_Delta) of the triplet scalar field. The smallness of neutrino masses can be naturally explained with the suppressed value of v_Delta even when the triplet fields are at the TeV scale. The Higgs sector is extended by introducing Z_2-odd scalars (an SU(2)_L doublet eta and a real singlet s_2^0) in addition to a Z_2-even complex singlet scalar s_1^0 whose vacuum expectation value violates the lepton number conservation by a unit. In our model, v_Delta is…
We have previously proposed a light pseudoscalar Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM), the A_1^0, as a candidate to explain the HyperCP observations in Sigma^+ -> p mu^+ mu^-. In this paper we calculate the rates for several other rare decay modes that can help confirm or refute this hypothesis. The first modes we evaluate are K_L -> pi pi A_1^0, which are interesting because they are under study by the KTeV Collaboration. We next turn to eta -> pi pi A_1^0, which are interesting because they are independent of the details of the flavor-changing sector of th…
The B-factories results provide an impressive confirmation of the Standard Model (SM) description of flavor and CP violation. Nevertheless, as more data were accumulated, deviations in the 2.5-3.5 sigma range have emerged pointing to the exciting possibility of new CP-odd phase(s) and flavor violating parameters in B-decays. Primarily this seems to be the case in the time dependent CP asymmetries in penguin dominated modes (e.g. B -> phi (eta') Ks). We discuss these and other deviations from the SM and, as an illustration of possible new physics scenarios, we examine the role of the Top Two Hi…
We explore a scenario in the Next-to-Minimal-Supersymmetric-Standard-Model (NMSSM) with both a light O(10) GeV neutralino and a CP-odd Higgs boson with significant coupling to down-type fermions, evading all current B physics, LEP and WMAP bounds. Motivated by a possible slight lepton universality breaking hinted in Upsilon decays, we consider the effect of the mixing of eta(b) resonances with the pseudoscalar Higgs on the spin-dependent scattering neutralino cross section off nucleons. We conclude that this mechanism could be relevant provided that non-perturbative effects enhance the effecti…
