نتایج جستجو برای: boson system
تعداد نتایج: 2244675 فیلتر نتایج به سال:
In the framework of the Standard Model the mass of the physical Higgs boson is an arbitrary parameter. In this note we examine whether it is possible to determine the ratio of m H /M , where M denotes any other mass in the theory, such as the W or the Z-boson mass. We show that no such relation can be stable under renormalisation.
The precise statement of the equivalence theorem, between the longitudinally polarized states of a massive gauge boson and the corresponding goldstone mode, is discussed when the amplitude in question depends on masses of other particles (e.g., the Higgs boson) in the theory.
Measurement of the W boson helicity in t ¯ t decays
We show that one-dimensional binary mixtures of bosons or of a boson and a spin-polarized fermion are Luttinger liquids with the following instabilities: (i) For different particle densities, strong attraction between the mixture components leads to collapse, while strong repulsion leads to demixing, and (ii) For a low-density mixture of two gases of impenetrable bosons (or a spin-polarized fer...
The recent discovery of a Higgs boson at the LHC is a milestone in the quest to understand electroweak symmetry breaking. It is an important particle because it is responsible for the Higgs mechanism by which all particles acquire mass. The existence of a particle with zero spin suggests the need for new physics beyond the standard model. Z bosons are known to naturally exist in well-motivate...
Sum rules originally derived for the Mössbauer Effect are applied to weak semileptonic B decays. The sum rules follow from assuming that the decay by electroweak boson emission of an unstable nucleus or heavy quark in a bound system is described by a pointlike coupling to a current which acts only on the decaying object, that the Hamiltonian of the bound state depends on the momentum of the dec...
We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45 fb(-1). In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production ...
Methods for measuring the W -boson properties at hadron colliders are discussed. It is demonstrated that the ratio between the W and Z-boson observables can be reliably calculated using perturbative QCD, even when the individual W and Z-boson observables are not. Hence, by using a measured Zboson observable and the perturbative calculation of the ratio of the W over Z-boson observable, we can a...
چکیده : نظام انتخاباتی قواعد و چار چوب های به رسمیت شناخته شده ای است که بیانگر چگونگی تبدیل آرای مردم به مناصب و پست های سیاسی است. این نظام انتخابات باید به گونه ای عمل کند که نتیجه آن فراهم شدن مکانیسم و ساز و کار مطلوب و مناسب برای برگزاری انتخابات سالم و رقابتی باشد. به نظر می رسد نظام انتخاباتی جمهوری اسلامی ایران دارای ضعف ها و نواقصی است که به سبب آن ها نمی توان انتخابات مطلوب را برگزا...
We study dynamics of a two-level system coupled simultaneously to a pair of dissimilar reservoirs, namely, a spin bath and a boson bath, which are connected via finite interbath coupling. It is found that the steady-state population transfer in the two-level system increases with its coupling to the spin bath, while optimal transfer occurs at intermediate coupling in the transient process. If t...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید