نتایج جستجو برای: who
تعداد نتایج: 792216 فیلتر نتایج به سال:
We relate leptogenesis in a class of theories to low-energy experimental observables: quark and lepton masses and mixings. With reasonable assumptions motivated by grand unification, one can show that the CP-asymmetry parameter takes a universal form. Furthermore the dilution mass is related to the light neutrino masses. Overall, these models offer a natural explanation for a lepton asymmetry i...
Pure leptonic radiative decays of heavy-light mesons are calculated using a very simple non-relativistic model. Dominant contribution originates from photon emission from light initial quark. We find BR(B ± → ℓνγ) ∼ 3.5 × 10 −6 and BR(D s → ℓνγ) ∼ 1.7 × 10 −4. The importance of these reactions to clarify the dynamics of the annihilation graph is emphasized.
In our model with a Standard Model gauge group extended with a baryon number minus lepton number charge for each family of quarks and leptons, we calculate the baryon number relative to entropy produced in early Big Bang by the FukugitaYanagida mechanism. With the parameters, i.e., the Higgs VEVs already fitted in a very successful way to quark and lepton masses and mixing angles we obtain the ...
The motion of quark is studied in a confining bag having central color field. The Dirac equation is solved for a quark in such bag and its energy spectrum is found. It is pointed out the possibility to take into account an interaction of constituent quark with the gluon condensation as the interaction with the color background.
We study a parton shower description, based on a dipole picture, of the final state in electron-positron annihilation. In such a shower, the distribution function describing the inclusive probability to find a quark with a given energy depends on the shower evolution time. Starting from the exclusive evolution equation for the shower, we derive an equation for the evolution of the inclusive qua...
We argue that there is strong experimental evidence in the data of band c-decays that the pattern of power suppressed corrections predicted by the short distance expansion, the heavy quark effective theory and the assumption of local duality is not correct for the non-leptonic inclusive widths. The data indicate instead the presence of 1/m corrections that should be absent in the above theoreti...
We review the present status of theoretical predictions for both closed (J/ψ) and open heavy quark production in high energy collisions, and their comparisons to experimental data.
This talk summarizes recent progress in top quark physics studies for high energy linear electron-positron colliders as presented at the LCWS2000 Workshop at Fermilab. New results were presented for top pair production at threshold and in the continuum, as well as for top production at γγ colliders.
The transverse polarization (or transversity) distributions ∆T q(x), introduced 20 years ago by Ralston and Soper [1] and studied in more detail in the last decade [2], are one of the three sets of leading-twist quark and antiquark distribution functions – the other two are the momentum distributions q(x) and the helicity distributions ∆q(x). (Note that ∆T q is often called h1). Formally ∆T q i...
Article history: Received 9 October 2015 Received in revised form 20 November 2015 Accepted 14 December 2015 Available online 17 December 2015
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید