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تسجيل مستخدم جديدSearch for intrinsic charm in vector boson production accompanied by heavy flavor jets
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Up to now, the existence of intrinsic (or valence-like) heavy quark component of the proton distribution functions has not yet been confirmed or rejected. The LHC with pp-collisions at $sqrt{s}$ = 7-13 TeV can supply us with extra unique information concerning this hypothesis. On the basis of our theoretical studies, it is demonstrated that investigations of the intrinsic heavy quark contributions look very promising in processes like $pp rightarrow Z/W + c(b) + X$. A ratio of $Z+$ heavy jets over $W+$ heavy jets differential cross section as a function of the leading jet transverse momentum is proposed to maximize the sensitivity to the intrinsic charm component of the proton.
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We consider an observable very sensitive to the non-zero intrinsic charm (IC) contribution to the proton density. It is the ratio between the differential cross sections of the photon or $Z$-boson and $c$-jet production in the $pp$ collision, $gamma(
Z) + c$, and the $gamma(Z)$ and the $b$-jet production. It is shown that this ratio can be approximately flat or increasing at large $gamma(Z)$ transverse momenta $p_T$ and their pseudo-rapidities $1.5 < eta < 2.4$ if the IC contribution is taken into account. On the contrary, in the absence of the IC this ratio decreases as $p_T$ grows. We also present the ratios of the cross sections integrated over $p_T$ as a function of the IC probability $w$. It is shown that these ratios are mostly independent on the theoretical uncertainties, and such predictions could therefore be much more promising for the search for the intrinsic charm signal at the LHC compared to the predictions for $p_T$-spectra, which significantly depend on these uncertainties.
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