More about orbitally excited hadrons from lattice QCD

This is a second paper describing the calculation of spectroscopy for orbitally excited states from lattice simulations of Quantum Chromodynamics. New features include higher statistics for P-wave systems and first results for the spectroscopy of D-wave mesons and baryons, for relatively heavy quark masses. We parameterize the Coulomb gauge wave functions for P-wave and D-wave systems and compare them to those of their corresponding S-wave states.Comment: 21 pages plus 14 figs, 3 include

Spacings of Quarkonium Levels with the Same Principal Quantum Number

The spacings between bound-state levels of the Schr\"odinger equation with the same principal quantum number $N$ but orbital angular momenta $\ell$ differing by unity are found to be nearly equal for a wide range of power potentials $V = \lambda r^\nu$, with $E_{N \ell} \approx F(\nu, N) - G(\nu,N) \ell$. Semiclassical approximations are in accord with this behavior. The result is applied to estimates of masses for quarkonium levels which have not yet been observed, including the 2P $c \bar c$ states and the 1D $b \bar b$ states.Comment: 20 pages, latex, 3 uuencoded figures submitted separately (process using psfig.sty

The abundance of relativistic axions in a flaton model of Peccei-Quinn symmetry

Flaton models of Peccei-Quinn symmetry have good particle physics motivation, and are likely to cause thermal inflation leading to a well-defined cosmology. They can solve the $\mu$ problem, and generate viable neutrino masses. Canonical flaton models predict an axion decay constant F_a of order 10^{10} GeV and generic flaton models give F_a of order 10^9 GeV as required by observation. The axion is a good candidate for cold dark matter in all cases, because its density is diluted by flaton decay if F_a is bigger than 10^{12} GeV. In addition to the dark matter axions, a population of relativistic axions is produced by flaton decay, which at nucleosynthesis is equivalent to some number \delta N_\nu of extra neutrino species. Focussing on the canonical model, containing three flaton particles and two flatinos, we evaluate all of the flaton-flatino-axion interactions and the corresponding axionic decay rates. They are compared with the dominant hadronic decay rates, for both DFSZ and KSVZ models. These formulas provide the basis for a precise calculation of the equivalent \delta N_\nu in terms of the parameters (masses and couplings). The KSVZ case is probably already ruled out by the existing bound \delta N_\nu\lsim 1. The DFSZ case is allowed in a significant region of parameter space, and will provide a possible explanation for any future detection of nonzero $\delta N_\nu$

Closed-flavor pi + J/psi and pi + Upsilon Cross Sections at Low Energies from Dipion Decays

The scale of low energy c-cbar and b-bbar cross sections on light hadrons is of great importance to searches for the quark gluon plasma using the heavy-quarkonium suppression signature. Unfortunately, little is known about these near-threshold cross sections at present, and recent theoretical estimates span many orders of magnitude. Here we use experimental data on the four observed closed-flavor heavy quarkonium hadronic decays psi' -> pi pi J/psi, Upsilon' -> pi pi Upsilon, Upsilon'' -> pi pi Upsilon and Upsilon'' -> pi pi Upsilon', combined with simple models of the transition amplitudes, to estimate the pion scattering cross sections of c-cbar and b-bbar mesons near threshold. Specifically we consider the closed-flavor reactions pi J/psi -> pi psi', pi Upsilon -> pi Upsilon', pi Upsilon -> pi Upsilon'' and pi Upsilon' -> pi Upsilon'' and their time-reversed analogues. Our results may be useful in constraining theoretical models of the strong interactions of heavy quarkonia, and can be systematically improved through future detailed studies of dipion decays, notably psi' -> pi pi J/psi and Upsilon'' -> pi pi Upsilon.Comment: 6 pages, 6 figure

Di-Pion Decays of Heavy Quarkonium in the Field Correlator Method

Mechanism of di-pion transitions $nS\to n'S\pi\pi(n=3,2; n'=2,1)$ in bottomonium and charmonium is studied with the use of the chiral string-breaking Lagrangian allowing for the emission of any number of $\pi(K,\eta),$ and not containing fitting parameters. The transition amplitude contains two terms, $M=a-b$, where first term (a) refers to subsequent one-pion emission: $\Upsilon(nS)\to\pi B\bar B^*\to\pi\Upsilon(n'S)\pi$ and second term (b) refers to two-pion emission: $\Upsilon(nS)\to\pi\pi B\bar B\to\pi\pi\Upsilon(n'S)$. The one-parameter formula for the di-pion mass distribution is derived, $\frac{dw}{dq}\sim$(phase space) $|\eta-x|^2$, where $x=\frac{q^2-4m^2_\pi}{q^2_{max}-4m^2_\pi},$ $q^2\equiv M^2_{\pi\pi}$. The parameter $\eta$ dependent on the process is calculated, using SHO wave functions and imposing PCAC restrictions (Adler zero) on amplitudes a,b. The resulting di-pion mass distributions are in agreement with experimental data.Comment: 62 pages,8 tables,7 figure

Quasi Goldstone Fermion As a Sterile Neutrino

The existence of sterile neutrino is hinted by simultaneous explanation of diverse neutrino anomalies. We suggest that the quasi Goldstone fermions (QGF) arising in supersymmetric theory as a result of spontaneous breaking of global symmetry like the Peccei-Quinn symmetry or the lepton number symmetry can play a role of the sterile neutrino. The smallness of mass of QGF ($m_S \sim 10^{-3}-10$ eV) can be related to the specific choice of superpotential or K\"ahler potential (e.g., no-scale kinetic terms for certain superfields). Mixing of QGF with neutrinos implies the $R$-parity violation. It can proceed via the coupling of QGF with the Higgs supermultiplets or directly with the lepton doublet. A model which accounts for the solar and atmospheric anomalies and the dark matter is presented.Comment: 16 pages plus 3 figures include

Is the ee gamma gamma+ Missing E(T) Event an Evidence of the Light Axino?

We point out that if the Peccei-Quinn symmetry breaking scale $F_a$ is in a range of the hadronic axion window ($F_a\sim 10^6$GeV), the ee$\gamma\gamma+/\!\!\!\! E_T$ event in the CDF experiment can be naturally explained by a no-scale supergravity model with a light axino. We also stress that the hadronic axion window still survives the intergalactic photon search, since a large entropy production due to the decay of Polonyi field yields a substantial dilution of the cosmic axion density.Comment: 7 pages. We added the constraint on the hadronic axion window from the life cycle of red-giant and horizontal-branch star

Many faces of low mass neutralino dark matter in the unconstrained MSSM, LHC data and new signals

If all strongly interacting sparticles (the squarks and the gluinos) in an unconstrained minimal supersymmetric standard model (MSSM) are heavier than the corresponding mass lower limits in the minimal supergravity (mSUGRA) model, obtained by the current LHC experiments, then the existing data allow a variety of electroweak (EW) sectors with light sparticles yielding dark matter (DM) relic density allowed by the WMAP data. Some of the sparticles may lie just above the existing lower bounds from LEP and lead to many novel DM producing mechanisms not common in mSUGRA. This is illustrated by revisiting the above squark-gluino mass limits obtained by the ATLAS Collaboration, with an unconstrained EW sector with masses not correlated with the strong sector. Using their selection criteria and the corresponding cross section limits, we find at the generator level using Pythia, that the changes in the mass limits, if any, are by at most 10-12% in most scenarios. In some cases, however, the relaxation of the gluino mass limits are larger ($\approx 20$). If a subset of the strongly interacting sparticles in an unconstrained MSSM are within the reach of the LHC, then signals sensitive to the EW sector may be obtained. This is illustrated by simulating the $blj$\etslash, $l= e and \mu$, and $b\tau j$\etslash signals in i) the light stop scenario and ii) the light stop-gluino scenario with various light EW sectors allowed by the WMAP data. Some of the more general models may be realized with non-universal scalar and gaugino masses.Comment: 27 pages, 1 figure, references added, minor changes in text, to appear in JHE

What if Supersymmetry Breaking Unifies beyond the GUT Scale?

We study models in which soft supersymmetry-breaking parameters of the MSSM become universal at some unification scale, $M_{in}$, above the GUT scale, \mgut. We assume that the scalar masses and gaugino masses have common values, $m_0$ and $m_{1/2}$ respectively, at $M_{in}$. We use the renormalization-group equations of the minimal supersymmetric SU(5) GUT to evaluate their evolutions down to \mgut, studying their dependences on the unknown parameters of the SU(5) superpotential. After displaying some generic examples of the evolutions of the soft supersymmetry-breaking parameters, we discuss the effects on physical sparticle masses in some specific examples. We note, for example, that near-degeneracy between the lightest neutralino and the lighter stau is progressively disfavoured as $M_{in}$ increases. This has the consequence, as we show in $(m_{1/2}, m_0)$ planes for several different values of $\tan \beta$, that the stau coannihilation region shrinks as $M_{in}$ increases, and we delineate the regions of the $(M_{in}, \tan \beta)$ plane where it is absent altogether. Moreover, as $M_{in}$ increases, the focus-point region recedes to larger values of $m_0$ for any fixed $\tan \beta$ and $m_{1/2}$. We conclude that the regions of the $(m_{1/2}, m_0)$ plane that are commonly favoured in phenomenological analyses tend to disappear at large $M_{in}$.Comment: 24 pages with 11 eps figures; references added, some figures corrected, discussion extended and figure added; version to appear in EPJ

Hadronic and Electromagnetic Interactions of Quarkonia

We examine the hadronic interactions of quarkonia, focusing on the decays psi(2s)->psi pi pi and upsilon(2s)-> upsilon pi pi. The leading gluonic operators in the multipole expansion are matched onto the chiral lagrangian with the coefficients fit to available data, both at tree-level and loop-level in the chiral expansion. A comparison is made with naive expectations loosely based on the large-$N_c$ limit of QCD in an effort to determine the reliability of this limit for other observables, such as the binding of \ps to nuclei. Crossing symmetry is used to estimate the cross-section for inelastic \pi\ps\to\pi\pss scattering, potentially relevant for heavy ion collisions. The radiative decays psi(2s)->psi pi pi gamma and upsilon(2s)-> upsilon pi pi gamma are determined at tree-level in the chiral lagrangian. Measurement of such decays will provide a test of the multipole and chiral expansions. We briefly discuss decays from the upsilon(3s) and also the contribution from pions to the electromagnetic polarizability of quarkonia.Comment: 20 pages, 11 figures, late