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J. Ferretti

Publications and source records attributed to J. Ferretti.

36 records · Page 2Linked to original sources
arXiv2016

STAX. An Axion-like Particle Search with Microwave Photons

We discuss an improved detection scheme for a light-shining-through-wall (LSW) experiment for axion-like particle searches. We propose to use: gyrotrons or klystrons, which can provide extremely intense photon fluxes at frequencies around 30 GHz; transition-edge-sensors (TES) single photon detectors in this frequency domain, with efficiency $\approx1$; high quality factor Fabry-Perot cavities in the microwave domain, both on the photon-axion conversion and photon regeneration sides. We compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude for axion masses $\lesssim 0.02$ meV.

hep-ph↗
arXiv2016

Open flavor strong decays

In this contribution, we discuss the results of a QM calculation of the open-flavor strong decays of **** light nucleon resonances. These are the results of a recent calculation, where we used a modified $^3P_0$ model for the amplitudes and the U(7) algebraic model and the Hypercentral Quark Model to predict the baryon spectrum. The decay amplitudes are compared with the existing experimental data.

hep-ph↗
arXiv2016

An interacting quark-diquark model. Strange and nonstrange baryon spectroscopy and other observables

We describe the relativistic interacting quark-diquark model formalism and its application to the calculation of strange and nonstrange baryon spectra. The results are compared to the existing experimental data. We also discuss the application of the model to the calculation of other baryon observables, like baryon magnetic moments, open-flavor strong decays and baryon masses with self-energy corrections.

hep-ph↗
arXiv2016

WIMP detection and slow ion dynamics in carbon nanotube arrays

Large arrays of aligned carbon nanotubes (CNTs), open at one end, could be used as target material for the directional detection of weakly interacting dark matter particles (WIMPs). As a result of a WIMP elastic scattering on a CNT, a carbon ion might be injected in the body of the array and propagate through multiple collisions within the lattice. The ion may eventually emerge from the surface with open end CNTs, provided that its longitudinal momentum is large enough to compensate energy losses and its transverse momentum approaches the channeling conditions in a single CNT. Therefore, the angle formed between the WIMP wind apparent orientation and the direction of parallel carbon nanotube axes must be properly chosen. We focus on very low ion recoil kinetic energies, related to low mass WIMPs (~ 10 GeV) where most of the existing experiments have low sensitivity. Relying on some exact results on two-dimensional lattices of circular obstacles, we study the low energy ion motion in the transverse plane with respect to CNT directions. New constraints are obtained on how to devise the CNT arrays to maximize the detection efficiency.

physics.ins-det↗
arXiv2016

Axion-like particle searches with sub-THz photons

We propose a variation, based on very low energy and extremely intense photon sources, on the well established technique of Light-Shining-through-Wall (LSW) experiments for axion-like particle searches. With radiation sources at 30 GHz, we compute that present laboratory exclusion limits on axion-like particles might be improved by at least four orders of magnitude, for masses m_a <~ 0.01~meV. This could motivate research and development programs on dedicated single-photon sub-THz detectors.

hep-ph↗
arXiv2015

Hadron Spectroscopy in the Unquenched Quark Model

We present the last applications of the unquenched quark model (UQM) to the description of flavour asymmetry and strangeness in the proton when baryon-meson components are included. In the meson sector, the UQM is used to calculate the charmonium and bottomonium spectra with self-energy corrections due to the coupling to the meson-meson continuum.

nucl-th↗
arXiv2015

Higher charmonia and bottomonia. Nature of the X(3872)

In this contribution, we will discuss our unquenched quark model re- sults for the spectra of cc and bb states. The spectra are calculated in the unquenched quark model formalism, where the physical mass of a meson is the sum of a bare mass contribution plus a self-energy correc- tion, due to the coupling to the meson-meson continuum. We will also discuss the quark structure of the X(3872). Its open-flavor and radiative decays are calculated in the quark model formalism. In our interpreta- tion, the wave function of the X(3872) is the sum of two contributions, a cc core plus higher Fock components, due to meson-meson continuum components. Our results for the spectra, open-flavor and radiative decays are compared to the existing experimental data.

hep-ph↗
arXiv2015

Relativistic quark-diquark model of baryons. Non strange spectrum and nucleon electromagnetic form factors

We briefly describe our relativistic quark-diquark model, developed within the framework of point form dynamics, which is the relativistic extension of the interacting quark-diquark model. In order to do that we have to show the main properties and quantum numbers of the effective degree of freedom of constituent diquark. Our results for the nonstrange baryon spectrum and for the nucleon electromagnetic form factors are discussed.

hep-ph↗
arXiv2015

Analysis Tools for Next-Generation Hadron Spectroscopy Experiments

The series of workshops on New Partial-Wave Analysis Tools for Next-Generation Hadron Spectroscopy Experiments was initiated with the ATHOS 2012 meeting, which took place in Camogli, Italy, June 20-22, 2012. It was followed by ATHOS 2013 in Kloster Seeon near Munich, Germany, May 21-24, 2013. The third, ATHOS3, meeting is planned for April 13-17, 2015 at The George Washington University Virginia Science and Technology Campus, USA. The workshops focus on the development of amplitude analysis tools for meson and baryon spectroscopy, and complement other programs in hadron spectroscopy organized in the recent past including the INT-JLab Workshop on Hadron Spectroscopy in Seattle in 2009, the International Workshop on Amplitude Analysis in Hadron Spectroscopy at the ECT*-Trento in 2011, the School on Amplitude Analysis in Modern Physics in Bad Honnef in 2011, the Jefferson Lab Advanced Study Institute Summer School in 2012, and the School on Concepts of Modern Amplitude Analysis Techniques in Flecken-Zechlin near Berlin in September 2013. The aim of this document is to summarize the discussions that took place at the ATHOS 2012 and ATHOS 2013 meetings. We do not attempt a comprehensive review of the field of amplitude analysis, but offer a collection of thoughts that we hope may lay the ground for such a document.

hep-ph↗
arXiv2015

Spectroscopy of higher bottomonia

In this contribution, we discuss our recent unquenched quark model results for the spectrum of $b \bar b$ mesons with self energy corrections, due to the coupling to the meson-meson continuum. Our unquenched quark model predictions for the masses of the recently discovered $χ_b(3P)$ states are compared to those of a re-fit of Godfrey and Isgur's relativized quark model to the most recent experimental data. The possible importance of continuum effects in the $χ_b(3P)$ states is discussed. Finally, we show our quark model results for the radiative decays of the $χ_b(3P)$ system and the open-bottom decays of $b \bar b$ mesons.

hep-ph↗
arXiv2015

The unquenched quark model

In this contribution, we briefly discuss the results for charmonium and bottomonium spectra with self-energy corrections in the unquenched quark model, due to the coupling to the meson-meson continuum. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. Finally, we discuss the results of a calculation of hybrid mesons spectrum in Coulomb Gauge QCD.

hep-ph↗
arXiv2015

The unquenched QM

In this contribution, we briefly analyze the formalism of the unquenched quark model (UQM) and its application to the calculation of hadron spectra with self-energy corrections, due to the coupling to the meson-meson continuum. In the UQM, the effects of $q \bar q$ sea pairs are introduced explicitly into the quark model through a QCD-inspired $^{3}P_0$ pair-creation mechanism. The UQM formalism can be extended to include also the effects of hybrid mesons, i.e. hybrid loops. The main applications to spectroscopy and decays are analyzed.

hep-ph↗
arXiv2014

Higher mass bottomonia

We show the results of a quark model calculation of the bottomonium spectrum with self energy corrections due to the coupling to the meson-meson continuum. The bare masses used in the calculation are computed within the relativized quark model by Godfrey and Isgur. We also give results for the open-bottom strong decay amplitudes of higher bottomonia in a 3P0 model.

hep-ph↗
arXiv2014

Quark structure of the $X(3872)$ and $χ_b(3P)$ resonances

We discuss the nature of the $χ_b(3P)$ and $X(3872)$ mesons: Are the $χ_b(3P)$'s standard $b \bar b$ mesons or $b \bar b$ states with a significative continuum component? Is the $X(3872)$ a $c \bar c$ state with continuum coupling effects or a meson-meson molecule? To do that, we compare quark model and unquenched quark model results for the mass barycenter and splittings of the $χ_b(3P)$ multiplet. Future and more precise experimental results will discriminate between the two interpretations. In the case of the $X(3872)$, we interpret it a $c \bar c$ core plus higher Fock components due to the coupling to the meson-meson continuum, thus we think that it is compatible with the meson $χ_{c1}(2P)$, with $J^{PC} = 1^{++}$. The $J^{PC} = 1^{++}$ quantum numbers are in agreement with the experimental results found by the LHCb collaboration. In our view, the $X(3872)$'s mass is lower than the quark model's predictions because of self energy shifts. We also provide an estimation of the open charm/bottom strong decay modes of the $X(3872)$ and $χ_b(3P)$ mesons, such as $X(3872) \rightarrow D \bar D^*$ and $χ_{b2}(3P) \rightarrow B \bar B$, and radiative transitions.

nucl-th↗
arXiv2013

Interpretation of the X(3872) as a charmonium state plus an extra component due to the coupling to the meson-meson continuum

We present a quark model calculation of the charmonium spectrum with self energy corrections due to the coupling to the meson-meson continuum. The bare masses used in the calculation are computed within the relativized quark model by Godfrey and Isgur. The strong decay widths of 3S, 2P, 1D and 2D $c \bar c$ states are also calculated, in order to set the values of the $^3P_0$ pair-creation model's parameters we use to compute the vertex functions of the loop integrals. Finally, the nature of the X(3872) resonance is analyzed and the main possibilities ($c \bar c$ state or $D \bar D^*$ molecule) are discussed. According to our results, the X(3872) is compatible with the meson $χ_{c1}(2P)$, with $J^{PC} = 1^{++}$, and is thus interpreted as a $c \bar c$ core plus higher Fock components due to the coupling to the meson-meson continuum. These $J^{PC} = 1^{++}$ quantum numbers are in agreement with the experimental results found by the LHCb collaboration. In our view, the X(3872)'s mass is lower than the quark model's predictions because of self energy shifts.

hep-ph↗