Summary
Reasons for performing study: To a large extent the success of a racehorse depends on effective and health preserving training methods. An important issue is the prevention of back pain. The ...influence of different types of training saddles (normal tree: SA, treeless: SB, flexible tree: SC) on the saddle pressure patterns in racehorses have not previously been investigated. It is commonly assumed that SA limits the motion of the back especially in the lower thoracic region during gallop.
Hypothesis: SA produces higher pressures in the caudal part of the saddle at trot (rising trot), canter and gallop (both in a jockey seat) compared to SB and SC.
Methods: Saddle pressures were measured in 8 racehorses ridden on a training track at trot (3.5 m/s), canter (6.4 m/s) and gallop (12.6 m/s). Each horse performed the protocol with each saddle. To analyse the pressure distribution over the horse's back the pressure picture was divided into thirds (TDfront, TDmid, TDhind). The stride‐mean loaded areas, forces and mean and peak pressures were determined.
Results: At canter and gallop, all 3 saddles were mainly loaded in TDfront (>80% of the rider's weight), with a decreasing gradient to TDmid and TDhind (<3%), which was least pronounced in SC. At trot, the load was shifted towards TDmid and TDhind (10–15%, each). High peak pressures occurred in TDfront at canter and gallop and in TDhind at trot.
Conclusions: The type of tree had no influence on the pressure picture of the caudal third at gallop. The high peak pressures observed in TDhind at trot in all saddles may limit the activity of the horse's back, which is of particular importance since trot is an integral part of the daily work.
The NA48/2 experiment at CERN reports the first observation of the $K^± → π^0π^0μ^±$ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. The decay ...branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c4 is measured to be (0.65 ± 0.03) × 10–6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10–6, in agreement with chiral perturbation theory predictions.
The beam and detector, used for the NA48 experiment, devoted to the measurement of
Re
(
ε
′
/
ε
)
, and for the NA48/1 experiment on rare
K
S
and neutral hyperon decays, are described.
A measurement of the form factors of charged kaon semileptonic decays is presented, based on 4.4 × 106K± → π0e±νe (K e3 ± ) and 2.3 × 106K± → π0μ±νμ (K μ3 ±) decays collected in 2004 by the NA48/2 ...experiment. The results are obtained with improved precision as compared to earlier measurements. The combination of measurements in the K e3 ± and K μ3 ± modes is also presented.
A sample of more than one million K +/- ? p + p - e +/- ? (K e 4) decay candidates with less than one percent background contamination has been collected by the NA48/2 experiment at the CERN SPS in ...2003-2004, allowing a detailed study of the decay properties. The branching ratio, inclusive of K e 4 gamma decays, is measured to be BR (K e 4) = (4.257 +/- 0.016 exp +/- 0.031 ext) X 10 - 5 with a total relative error of 0.8 % . This measurement complements the study of S- and P-wave hadronic form factors by assigning absolute values to the relative hadronic form factors obtained earlier in a simultaneous analysis of the pp scattering lengths conducted on the same data sample. The overall form factor normalization f s = 5.705 +/- 0.017 exp +/- 0.031 ext is obtained with a total relative precision of 0.6 % .
Abstract The NA48/2 experiment at CERN reports the first observation of the K ± → π 0 π 0 μ ± ν decay based on a sample of 2437 candidates with 15% background contamination collected in 2003–2004. ...The decay branching ratio in the kinematic region of the squared dilepton mass above 0.03 GeV2/c 4 is measured to be (0.65 ± 0.03) × 10 −6. The extrapolation to the full kinematic space, using a specific model, is found to be (3.45 ± 0.16) × 10 −6, in agreement with chiral perturbation theory predictions.
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