deletions | additions       diff --git a/13311371647823180.tex b/13311371647823180.tex  index cf0300d..4e9d779 100644  --- a/13311371647823180.tex  +++ b/13311371647823180.tex 
...
\item In contrast to that arising from initial state radiation, the exact beam energy spectrum arising from beamstrahlung cannot be predicted with great accuracy. Observables dependent on a precise beam-energy knowledge (e.g., Z or W masses, Z width, top quark mass, etc.) therefore profit greatly of the absence of beamstrahlung at TLEP.  \item Cross-sections with a rapid variation as a function of the centre-of-mass energy (e.g., at the Z pole, or ar the WW and $\ttbar$ thresholds) are {\it (i)} larger; and {\it (ii)} better known at TLEP, hence measured with smaller statistical and systematic uncertainties.  \item The forward region of a TLEP detector is essentially free of beamstrahlung photons, which in turm tremendously eases both the design of a luminometer and the integrated luminosity measurement.  \item The beam-related backgrounds (photons, (disrupted beams, photons,  $\epem$ pairs) originating from beamstrahlung are negligible at TLEP, and so are the parisitic $\gamma\gamma$ collisions, which would otherwise lead to significant pileup in the detector, and affect the reconstruction of jets, the determination of the missing energy and the efficiency/reliability of isolation criteria. \item The frequent emission of beamstrahlung photons along the beam axis (in both directions) weakens the use of energy and momentum constraints in kinematic fits, which in turn mostly rely on the conservation of the momentum transverse to the beam. The conditions offered by TLEP allow the four energy-momentum constraints to be used in all fits.  \end{itemize}   In summary, the known advantages of $\epem$ collisions -- cleanliness, calculability, numerous kinematic constraints, and absence of pile-up collisions -- are fully realized solely in circular colliders. When it comes to precision measurements, these advantages come right after the large integrated luminosity in order of importance.