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

A Measurement of the ATLAS Di-Muon Trigger Efficiency in Proton-Proton Collision at s=7\sqrt{s}=7 TeV

The B physics programme of the ATLAS experiment includes measurements of production cross sections, searches for rare B-decay signatures which are sensitive to new physics at the TeV energy scale and studies of CP violation effects in B-events, such as $B_{s}^{0}\rightarrow J/\psi \phi$ and $B_{d}^{0}\rightarrow J/\psi K_{s}^{0}$. The key to the detection of these B signals in ATLAS is to achieve a high trigger efficiency for low-$p_{T}$ di-muon events, whilst keeping an acceptable trigger rate. ATLAS developed two separate approaches for triggering on di-muon events from resonances such as $J/\psi$ and Upsilon ($\Upsilon$). The first approach is to start from a di-muon trigger selected at Level-1 while the second is based on dedicated Level-2 algorithms. The performance for these triggers has been studied using collision data at $\sqrt{s}=7$ TeV collected in 2011.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011), Paris, France, November 14-18 2011, 3 pages, 6 figur

Measurement of the eta mass at KLOE

An integrated luminosity of 410 pb^(-1), corresponding to ~ 17 million of eta events, has been analyzed to measure the eta mass using the decay eta to gamma gamma. The measurement is insensitive to the calorimeter energy calibration and the systematic error on the measurement is dominated by the uniformity of the detector response. As a cross check of the method the pi0 mass from the decay phi to pi0 gamma, pi0 to gamma gamma has been measured and it is in agreement with the most accurate previous determinations. The result obtained is m(eta) = 547.873 +/- 0.007 (stat.) +/- 0.031 (syst.) MeV, that is today best measurement of the eta mass.Comment: 7 pages, 8 figures, Contributed paper to Lepton Photon 200

Built-in reduction of statistical fluctuations of partitioning objects

Our theoretical and numerical investigation of the movement of an object that partitions a microtubule filled with small particles indicates that vibrations warranted by thermal equilibrium are reached only after a time that increases exponentially with the number of particles involved. This points to a basic mechanical process capable of breaching, on accessible time scales, the ultimate ergodic constraints that force randomness on bound microscale and nanoscale systems

Enhanced di-Higgs Production through Light Colored Scalars

We demonstrate enhanced di-Higgs production at the LHC in the presence of modifications of the effective couplings of Higgs to gluons from new, light, colored scalars. While our results apply to an arbitrary set of colored scalars, we illustrate the effects with a real color octet scalar -- a simple, experimentally viable model involving a light (~125-300 GeV) colored scalar. Given the recent LHC results, we consider two distinct scenarios: First, if the Higgs is indeed near 125 GeV, we show that the di-Higgs cross section could be up to nearly one thousand times the Standard Model rate for particular octet couplings and masses. This is potentially observable in \emph{single} Higgs production modes, such as $pp \to h h \to \gamma\gamma b\bar{b}$ as well as $pp \to h h \to \tau^+\tau^- b\bar{b}$ where a small fraction of the $\gamma\gamma$ or $\tau^+\tau^-$ events near the putative Higgs invariant mass peak contain also a $b\bar{b}$ resonance consistent with the Higgs mass. Second, if the Higgs is not at 125 GeV (and what the LHC has observed is an impostor), we show that the same parameter region where singly-produced Higgs production can be suppressed below current LHC limits, for a heavier Higgs mass, also simultaneously predicts substantially enhanced di-Higgs production. We point out several characteristic signals of di-Higgs production with a heavier Higgs boson, such as $pp \to hh \to W^+W^-W^+W^-$, which could use same-sign dileptons or trileptons plus missing energy to uncover evidence.Comment: 13 pages, 8 figure

Lineability of non-differentiable Pettis primitives

Let X be an infinite-dimensional Banach space. In 1995, settling a long outstanding problem of Pettis, Dilworth and Girardi constructed an X-valued Pettis integrable function on [0; 1] whose primitive is nowhere weakly differentiable. Using their technique and some new ideas we show that ND, the set of strongly measurable Pettis integrable functions with nowhere weakly differentiable primitives, is lineable, i.e., there is an infinite dimensional vector space whose nonzero vectors belong to ND

What we do understand of Colour Confinement

A review is presented of what we understand of colour confinement in QCD. Lattice formulation provides evidence that QCD vacuum is a dual superconductor: the chromoelectric field of a $q\bar q$ pair is constrained by dual Meissner effect into a dual Abrikosov flux tube and the static potential energy is proportional to the distance.Comment: 10 pages, 5 figures, plenary talk at "Quark Matter 99", Torino, Italy, May 10-15, 199