اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدpp scattering in t and b spaces
148
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
We propose analytical forms, in both momentum transfer and impact parameter spaces, for the amplitudes of elastic pp scattering, giving coherent and accurate description of the observables at all energies $sqrt{s}geq 20$ GeV. The real and imaginary parts are separately identified through their roles at small and large t values. The study of the differential cross sections in b-space leads to the understanding of the effective interaction ranges contributing to elastic and inelastic processes.
قيم البحث
اقرأ أيضاً
The production of $toverline{t}$, $W+boverline{b}$ and $W+coverline{c}$ is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.
98 $pm$ 0.02 $mbox{fb}^{-1}$. The $W$ bosons are reconstructed in the decays $Wrightarrowell u$, where $ell$ denotes muon or electron, while the $b$ and $c$ quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.
We present a measurement of the ratio of top quark branching fractions R = B(t -> Wb)/B(t -> Wq), where q can be a d, s or b quark, in the lepton+jets and dilepton ttbar final states. The measurement uses data from 5.4 fb-1 of ppbar collisions collec
ted with the D0 detector at the Fermilab Tevatron Collider. We measure R = 0.90 +/- 0.04, and we extract the CKM matrix element |Vtb| as |Vtb| = 0.95 +/- 0.02, assuming unitarity of the 3x3 CKM matrix.
A method of determination of the real part of the elastic scattering amplitude is examined for high energy proton-proton and proton-nuclei elastic scattering at small momentum transfer. The method allows to decrease the number of model assumptions, t
o obtain the real parts of the spin non-flip and spin-flip amplitudes in the narrow region of momentum transfer.
The production fractions of $overline{B}_s^0$ and $Lambda_b^0$ hadrons, normalized to the sum of $B^-$ and $overline{B}^0$ fractions, are measured in 13 TeV pp collisions using data collected by the LHCb experiment, corresponding to an integrated lum
inosity of 1.67/fb. These ratios, averaged over the $b$-hadron transverse momenta from 4 to 25 GeV and pseudorapidity from 2 to 5, are $0.122 pm 0.006$ for $overline{B}_s^0$, and $0.259 pm 0.018$ for $Lambda_b^0$, where the uncertainties arise from both statistical and systematic sources. The $Lambda_b^0$ ratio depends strongly on transverse momentum, while the $overline{B}_s^0$ ratio shows a mild dependence. Neither ratio shows variations with pseudorapidity. The measurements are made using semileptonic decays to minimize theoretical uncertainties. In addition, the ratio of $D^+$ to $D^0$ mesons produced in the sum of $overline{B}^0$ and $B^-$ semileptonic decays is determined as $0.359pm0.006pm 0.009$, where the uncertainties are statistical and systematic.
The $text{t}bar{text{t}}text{H}(text{b}bar{text{b}})$ process is an essential channel to reveal the Higgs properties but has an irreducible background from the $text{t}bar{text{t}}text{b}bar{text{b}}$ process, which produces a top quark pair in assoc
iation with a b quark pair. Therefore, understanding the $text{t}bar{text{t}}text{b}bar{text{b}}$ process is crucial for improving the sensitivity of a search for the $text{t}bar{text{t}}text{H}(text{b}bar{text{b}})$ process. To this end, when measuring the differential cross-section of the $text{t}bar{text{t}}text{b}bar{text{b}}$ process, we need to distinguish the b-jets originated from top quark decays, and additional b-jets originated from gluon splitting. Since there are no simple identification rules, we adopt deep learning methods to learn from data to identify the additional b-jets from the $text{t}bar{text{t}}text{b}bar{text{b}}$ events. Specifically, by exploiting the special structure of the $text{t}bar{text{t}}text{b}bar{text{b}}$ event data, we propose several loss functions that can be minimized to directly increase the matching efficiency, the accuracy of identifying additional b-jets. We discuss the difference between our method and another deep learning-based approach based on binary classification arXiv:1910.14535 using synthetic data. We then verify that additional b-jets can be identified more accurately by increasing matching efficiency directly rather than the binary classification accuracy, using simulated $text{t}bar{text{t}}text{b}bar{text{b}}$ event data in the lepton+jets channel from pp collision at $sqrt{s}$ = 13 TeV.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
