287 research outputs found
Gluons and the eta' nucleon coupling constant
We derive the effective chiral Lagrangian for low energy eta--nucleon and
eta'--nucleon interactions and show that gluonic degrees of freedom, via the
axial anomaly, induce a contact term in the pp -> pp eta and pp -> pp eta'
reactions. We then discuss the consequences for the extraction of g_{eta'NN}
from experimental data.Comment: 10 pages, LaTe
Mental imagery in bipolar affective disorder versus unipolar depression: Investigating cognitions at times of âpositiveâ mood
AbstractBackgroundCompared to unipolar depression (UD), depressed mood in bipolar disorder (BD) has been associated with amplified negative mental imagery of the future (âflashforwardsâ). However, imagery characteristics during positive mood remain poorly explored. We hypothesise first, that unlike UD patients, the most significant positive images of BD patients will be âflashforwardsâ (rather than past memories). Second, that BD patients will experience more frequent (and more âpowerfulâ) positive imagery as compared to verbal thoughts and third, that behavioural activation scores will be predicted by imagery variables in the BD group.MethodsBD (n=26) and UD (n=26) patients completed clinical and trait imagery measures followed by an Imagery Interview and a measure of behavioural activation.ResultsCompared to UD, BD patients reported more âflashforwardsâ compared to past memories and rated their âflashforwardsâ as more vivid, exciting and pleasurable. Only the BD group found positive imagery more âpowerfulâ, (preoccupying, ârealâ and compelling) as compared to verbal thoughts. Imagery-associated pleasure predicted levels of drive and reward responsiveness in the BD group.LimitationsA limitation in the study was the retrospective design. Moreover pathological and non-pathological periods of âpositiveâ mood were not distinguished in the BD sample.ConclusionsThis study reveals BD patients experience positive âflashforwardâ imagery in positive mood, with more intense qualities than UD patients. This could contribute to the amplification of emotional states and goal directed behaviour leading into mania, and differentiate BD from UD
Daily Distribution of Macronutrient Intakes of Professional Soccer Players From the English Premier League.
The daily distribution of macronutrient intake can modulate aspects of training adaptations, performance and recovery. We therefore assessed the daily distribution of macronutrient intake (as assessed using food diaries supported by the remote food photographic method and 24 h recalls) of professional soccer players (n=6) of the English Premier League during a 7-day period consisting of two match days and five training days. On match days, average carbohydrate (CHO) content of the pre-match (0.05) though such intakes were lower than contemporary guidelines considered optimal for pre-match CHO intake and post-match recovery. On training days, we observed a skewed and hierarchical approach (Plunch (0.6 g.kg(-1))>breakfast (0.3 g.kg(-1))>evening snacks (0.1 g.kg(-1)). We conclude players may benefit from consuming greater amounts of CHO in both the pre-match and post-match meals so as to increase CHO availability and maximize rates of muscle glycogen re-synthesis, respectively. Furthermore, attention should also be given to ensuring even daily distribution of protein intake so as to potentially promote components of training adaptation
Training Load and Carbohydrate Periodization Practices of Elite Male Australian Football Players: Evidence of Fueling for the Work Required.
The authors aimed to quantify (a) the periodization of physical loading and daily carbohydrate (CHO) intake across an in-season weekly microcycle of Australian Football and (b) the quantity and source of CHO consumed during game play and training. Physical loading (via global positioning system technology) and daily CHO intake (via a combination of 24-hr recall, food diaries, and remote food photographic method) were assessed in 42 professional male players during two weekly microcycles comprising a home and away fixture. The players also reported the source and quantity of CHO consumed during all games (n = 22 games) and on the training session completed 4 days before each game (n = 22 sessions). The total distance was greater (p < .05) on game day (GD; 13 km) versus all training days. The total distance differed between training days, where GD-2 (8 km) was higher than GD-1, GD-3, and GD-4 (3.5, 0, and 7 km, respectively). The daily CHO intake was also different between training days, with reported intakes of 1.8, 1.4, 2.5, and 4.5 g/kg body mass on GD-4, GD-3, GD-2, and GD-1, respectively. The CHO intake was greater (p < .05) during games (59 ± 19 g) compared with training (1 ± 1 g), where in the former, 75% of the CHO consumed was from fluids as opposed to gels. Although the data suggest that Australian Football players practice elements of CHO periodization, the low absolute CHO intakes likely represent considerable underreporting in this population. Even when accounting for potential underreporting, the data also suggest Australian Football players underconsume CHO in relation to the physical demands of training and competition
Quantification of Seasonal Long Physical Load in Soccer Players With Different Starting Status From the English Premier League: Implications for Maintaining Squad Physical Fitness.
PURPOSE: To quantify the accumulative training and match load during an annual season in English Premier League soccer players classified as starters (n=8, started â„60% of games), fringe players (n=7, started 30-60% of games) and non-starters (n=4, started 25.2 km/h (11.2 ± 4.2, v 2.9 ± 1.2 km; ES=2.3) than non-starters. Additionally, starters also completed more sprinting (P<0.01. ES=2.0) than fringe players who accumulated 4.5 ± 1.8 km. Such differences in total high-intensity physical work done were reflective of differences in actual game time between playing groups as opposed to differences in high-intensity loading patterns during training sessions. CONCLUSIONS: Unlike total seasonal volume of training (i.e. total distance and duration), seasonal high-intensity loading patterns are dependent on players' match starting status thereby having potential implications for training programme design
The electric dipole moment of the neutron in chiral perturbation theory
We calculate the electric dipole moments of the neutron and the Lambda within
the framework of heavy baryon chiral perturbation theory. They are induced by
strong CP-violating terms of the effective Lagrangian in the presence of the
vacuum angle theta_0. The construction of such a Lagrangian is outlined and we
are able to give an estimate for theta_0.Comment: 17 pages, 2 figure
B Decays as Spectroscope for Charmed Four-quark States
The state recently observed by BaBar in the channel
may be the first of a host of four-quark states. We give a
phenomenological account of the masses and decay modes. The isosinglet
state is the only narrow one, dominated by the observed isospin
violating decay and less than 100 keV in width. All other states are
expected to decay hadronically. Notable resonances are in doubly charged
, , wrong pairing , and also ,
channels. We propose B decays as searching ground for such 4-quark states,
which recoil against meson from B decay, or , mesons from decay. Exotic
charmonia could also be produced, and may be behind the slow bump in
inclusive decay.Comment: 6 pages and 2 figure
Noncommutative QCD corrections to the gluonic decays of heavy quarkonia
We compute the Noncommutative QCD (NCQCD) contributions to the three gluon
decay modes of heavy quarkonia. For triplet quarkonia (ortho-quarkonia), the
NCQCD correction to the QCD three gluon decay mode, like the standard model
contribution, is infrared finite. In the case of singlet quarkonia
(para-quarkonia), whose QCD three gluon decay mode has infrared singularities
which are removed using one-loop corrections to the two gluon mode, we find
that NCQCD contribution is also infrared finite. The calculations are performed
in the weak binding limit and do not require the introduction of additional
effective couplings.Comment: Version accepted for publicatio
Photo-production of Nucleon Resonances and Nucleon Spin Structure Function in the Resonance Region
The photo-production of nucleon resonances is calculated based on a chiral
constituent quark model including both relativistic corrections H{rel} and
two-body exchange currents, and it is shown that these effects play an
important role. We also calculate the first moment of the nucleon spin
structure function g1 (x,Q^2) in the resonance region, and obtain a
sign-changing point around Q^2 ~ 0.27 {GeV}^2 for the proton.Comment: 23 pages, 5 figure
Pentaquark and diquark-diquark clustering: a QCD sum rule approach
In this work we study the Theta(1540) in the framework of QCD sum rules based
on (ud)^2\bar{s} diquark clustering as suggested by Jaffe and Wilczek. Within
errors, the mass of the pentaquark is compatible with the experimentally
measured value. The mass difference between the Theta and the pentaquark with
the quantum numbers of the nucleon amounts to 70 MeV, consistent with the
interpretation of the N(1440) as a pentaquark.Comment: 10 pages, 3 figures; discussions extended, references added, version
to appear in Phys. Lett.
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