Abstract: The measurement of charmonium states produced in proton-neon (pNe) collisions by the LHCb experiment in its fixed-target configuration is presented. The production of J/Psi and Psi(2S) mesons is studied with a beam of 2.5 TeV protons colliding on gaseous neon targets at rest, cvorresponding to a nucleon-nucleon centre-of-mass energy root(NN)-N-s = 68.5GeV. The data sample corresponds to an integrated luminosity of 21.7 +/- 1.4 nb(-1). The J/Psi and Psi(2S) hadrons are reconstructed in mu(+) mu(-) final states. The J/Psi production cross-section per target nucleon in the centre-of-mass rapidity range y* is an element of [-2.29, 0] is found to be 506 +/- 8 +/- 46 nb/nucleon. The ratio of J/Psi and D-0 cross-sections is evaluated to (1.06 +/- 0.02 +/- 0.09)%. The Psi(2S) to J/Psi relative production rate is found to be (1.67 +/- 0.27 +/- 0.10)% in good agreement with other measurements involving beam and target nuclei of similar sizes.

Abstract: We evaluate ratios of the chi(c1) decay rates to eta (eta', K-) and one of the f(0) (1370), f(0) (1710), f(2) (1270), f(2)'(1525), K-2*(1430) resonances, which in the local hidden gauge approach are dynamically generated from the vector-vector interaction. With the simple assumption that the chi(c1) is a singlet of SU(3), and the input from the study of these resonances as vector-vector molecular states, we describe the experimental ratio B(chi(c1)-> eta f(2) (1270))/B(chi(c1) -> eta'f(2)' (1525)) and make predictions for six more ratios that can be tested in future experiments.

Abstract: The next to leading order chiral corrections to the SU(2) x SU(2) Gell-Mann-Oakes- Renner (GMOR) relation are obtained using the pseudoscalar correlator to five-loop order in perturbative QCD, together with new finite energy sum rules (FESR) incorporating polynomial, Legendre type, integration kernels. The purpose of these kernels is to suppress hadronic contributions in the region where they are least known. This reduces considerably the systematic uncertainties arising from the lack of direct experimental information on the hadronic resonance spectral function. Three different methods are used to compute the FESR contour integral in the complex energy (squared) s-plane, i.e. Fixed Order Perturbation Theory, Contour Improved Perturbation Theory, and a fixed renormalization scale scheme. We obtain for the corrections to the GMOR relation, delta(pi), the value delta(pi) = (6.2 +/- 1.6)%. This result is substantially more accurate than previous determinations based on QCD sum rules; it is also more reliable as it is basically free of systematic uncertainties. It implies a light quark condensate < 0 vertical bar(u) over baru vertical bar 0 > similar or equal to < 0 vertical bar(d) over bard vertical bar 0 > < 0 vertical bar(q) over barq vertical bar 0 >vertical bar(2GeV) = (-267 +/- 5MeV)(3). As a byproduct, the chiral perturbation theory (unphysical) low energy constant H-2(r) is predicted to be H-2(r)(nu(X) = M-p) = -(5.1 +/- 1.8) x10(-3), or H-2(r) (nu(X) = M-eta) = -(5.7 +/- 2.0) x10(-3).

Abstract: The spins and parities of low-lying states in 72Br populated in the beta decay of 72Kr have been studied via conversion electron spectroscopy. The measurements were carried out at ISOLDE using a miniorange spectrometer with Si(Li) and HPGe detectors for electrons and gamma ray detection. Results of the conversion coefficients corresponding to transitions deexciting 12 levels in 72Br are reported. The multipolarities of the transitions are deduced and the spins and parities of the levels involved are discussed. From the multipolarities of the most intense transitions to the ground state, the spin and parity of the 72Br ground state have been definitely established as 1+. The spin of the 101.2-keV isomeric state is determined to be 3-. The level scheme is compared with mean-field and shell-model calculations and oblate deformation for the 72Br ground state is deduced. No E0 transitions have been found in 72Br. E0 transitions in the neighboring isobaric nuclei, 72Se and 72Ge, have also been studied.

Abstract: We report on the thermal neutron flux measurements carried out at the Laboratorio Subterraneo de Canfranc (LSC) with two commercial 2 '' x 2 '' CLYC detectors. The measurements were performed as part of an experimental campaign at LSC with He-3 detectors, for establishing the sensitivity limits and use of CLYCs in low background conditions. Acareful characterization of the intrinsic alpha and gamma-ray background in the detectors was required and done with dedicated measurements. It was found that the alpha activities in the two CLYC crystals differ by a factor of three, and the use of Monte Carlo simulations and a Bayesian unfolding method allowed us to determine the specific alpha activities from the U-238 and Th-232 decay chains. The simulations and unfolding also revealed that the gamma-ray background registered in the detectors is dominated by the intrinsic activity of the components of the detector such as the aluminum housing and photo-multiplier and that the activity within the crystal is low in comparison. The data from the neutron flux measurements with the two detectors were analyzed with different methodologies: one based on an innovative alpha/neutron pulse shape discrimination method and one based on the subtraction of the intrinsic alpha background that masks the neutron signals in the region of interest. The neutron sensitivity of the CLYCs was calculated by Monte Carlo simulations with MCNP6 and GEANT4. The resulting thermal neutron fluxes are in good agreement with complementary flux measurement performed with He-3 detectors, but close to the detection limit imposed by the intrinsic a activity.