Search results for " flavor"

Measurement of the chi(b) (3 P) mass and of the relative rate of chi(b1) (1 P) and chi(b2) (1 P) production

2014

The production of $\chi_b$ mesons in proton-proton collisions is studied using a data sample collected by the LHCb detector, at centre-of-mass energies of $\sqrt{s}=7$ and $8$ TeV and corresponding to an integrated luminosity of 3.0 fb$^{-1}$. The $\chi_b$ mesons are identified through their decays to $\Upsilon(1S)\gamma$ and $\Upsilon(2S)\gamma$ using photons that converted to $e^+e^-$ pairs in the detector. The $\chi_b(3P)$ meson mass, and the relative prompt production rate of $\chi_{b1}(1P)$ and $\chi_{b2}(1P)$ mesons as a function of the $\Upsilon(1S)$ transverse momentum in the $\chi_b$ rapidity range 2.0< $y$<4.5, are measured. Assuming a mass splitting between the $\chi_{b1}(3P)$ an…

DETERMINATION OF ALPHA(S) FOR B-QUARKS AT THE Z(0) RESONANCE

1993

The strong coupling constant for b quarks has been determined, and its flavour independence, as predicted by QCD, investigated. The analysis involved events with lepton candidates selected from approximately 356 000 hadronic decays of the Z0, collected by the DELPHI detector at LEP in 1990 and 199 1. A method based on a direct comparison of the three-jet fraction in a b enriched sample, selected by requiring leptons with large momenta and transverse momenta, to that of the entire hadronic sample, illustrated the significant effect of the b quark mass on the multi-jet cross section, and verified the flavour independence of the strong coupling constant to an accuracy of +/- 6%. A second proce…

Light hadrons from lattice QCD with light (u, d), strange and charm dynamical quarks

2010

We present results of lattice QCD simulations with mass-degenerate up and down and mass-split strange and charm (N_f = 2+1+1) dynamical quarks using Wilson twisted mass fermions at maximal twist. The tuning of the strange and charm quark masses is performed at two values of the lattice spacing a~0.078 fm and a~0.086 fm with lattice sizes ranging from L~1.9 fm to L~2.8 fm. We measure with high statistical precision the light pseudoscalar mass m_PS and decay constant f_PS in a range 270 < m_PS < 510 MeV and determine the low energy parameters f_0, l_3 and l_4 of SU(2) chiral perturbation theory. We use the two values of the lattice spacing, several lattice sizes as well as different values of…

Dynamical twisted mass fermions with light quarks

2007

We present results of dynamical simulations with 2 flavours of degenerate Wilson twisted mass quarks at maximal twist in the range of pseudo scalar masses from 300 to 550 MeV. The simulations are performed at one value of the lattice spacing a \lesssim 0.1 fm. In order to have O(a) improvement and aiming at small residual cutoff effects, the theory is tuned to maximal twist by requiring the vanishing of the untwisted quark mass. Precise results for the pseudo scalar decay constant and the pseudo scalar mass are confronted with chiral perturbation theory predictions and the low energy constants F, \bar{l}_3 and \bar{l}_4 are evaluated with small statistical errors.

Classification of the hadronic decays of the Z$^0$ into b and c quark pairs using a neural network

1992

A classifier based on a feed-forward neural network has been used for separating a sample of about 123 500 selected hadronic decays of the Z 0 , collected by DELPHI during 1991, into three classes according to the flavour of the original quark pair: u u +d d +s s (unresolved), c c and b b . The classification has been used to compute the partial widths of the Z 0 into b and c quark pairs. This gave Γ c c /Γ h = 0.151 ± 0.008 ( stat. ) ± 0.041 ( syst. ) , Γ b b /Γ h = 0.232±0.005 ( stat. )±0.017 ( syst. ) .

Neutrino Mass Ordering from Oscillations and Beyond: 2018 Status and Future Prospects

2018

The ordering of the neutrino masses is a crucial input for a deep understanding of flavor physics, and its determination may provide the key to establish the relationship among the lepton masses and mixings and their analogous properties in the quark sector. The extraction of the neutrino mass ordering is a data-driven field expected to evolve very rapidly in the next decade. In this review, we both analyze the present status and describe the physics of subsequent prospects. Firstly, the different current available tools to measure the neutrino mass ordering are described. Namely, reactor, long-baseline (accelerator and atmospheric) neutrino beams, laboratory searches for beta and neutrinol…

CHEMICAL AND SENSORY CHARACTERISTICS OF FIVE LOQUAT CULTIVARS

2015

Fruit quality can be evaluated by combining chemical-physical and sensory analyses. In this trial, both instrumental and sensory analyses were carried out on fruit of 5 loquat cultivars (‘Nespolone di Trabia’, ‘Sanfilippara’, ‘Virticchiara’, ‘MarcenA²â€™ and ‘Golden Nugget’), with the aim of assessing their commercial quality. Fruit weight, transversal and longitudinal diameter, total soluble solid content (TSS), and titratable acidity (TA) were measured. In addition, a sensory profile of each cultivar was defined by a trained panel, which generated 16 attributes. The highest fruit weight was found in ‘Golden Nugget’ and ‘Sanfilippara’; the latter exhibited also th…

Fruit quality of two apricot cultivars

2008

Fruit quality of Sicilian, commercially affirmed, and newly selected apple varieties: potential resources for genetic improvement and specialty marke…

2012

Several apple varieties are constantly selected for improved quality traits and introduced for cultivation and marketing in addition to a few traditional and affirmed varieties. Recently, specific fruit quality traits like enhanced flavor, crispness and juiciness have been particularly requested by consumers and are gradually replacing more conventional characteristics like fruit size, peel color and sweetness in the breeding programs. Furthermore, some of the newly selected varieties exhibit a relatively low level of plasticity, posing serious problems of adaptation when cultivation is proposed in a wide range of environments. In this most recent perspective, some of the old varieties or l…

Volatile profiles of Sicilian prickly pear (Opuntia ficus indica) by SPME-GC/MS analysis

2005

The aroma compounds present in the headspace of homogenized slurries of fresh prickly pears (Opuntia ficus-indica) from Sicilian cultivars were determined. Solid Phase Microextraction (SPME) followed by Gas-chromatography/Mass Spectrometry (GC/MS) analysis was used to characterize the volatile compounds. The volatile flavour profiles of the three cultivars investigated (red, white and yellow) showed significant differences. The aromatic profile of peeled prickly pears stored for one day was different from the one of the fresh samples, mainly due to the occurrence of some oxidative and hydrolytic reactions