64,408 research outputs found
From the exclusive photoproduction of heavy quarkonia at HERA to the EDDE at TeVatron and LHC
Exclusive photoproduction of heavy quarkonia at HERA is analyzed in the
framework of the Regge-eikonal approach together with the nonrelativistic bound
state formalism. Total and differential cross-sections for the process
are calculated. The model predicts
cross-sections of Exclusive Double Diffractive Events (EDDE) at TeVatron and
LHC.Comment: 14 pages, 6 figures, reference is adde
Energetics of a strongly correlated Fermi gas
The energy of the two-component Fermi gas with the s-wave contact interaction
is a simple linear functional of its momentum distribution:
E_\text{internal}=\hbar^2\Omega C/4\pi am+\sum_{\vect k\sigma}(\hbar^2
k^2/2m)(n_{\vect k\sigma}-C/k^4) where the external potential energy is not
included, is the scattering length, is the volume, n_{\vect
k\sigma} is the average number of fermions with wave vector \vect k and spin
, and C\equiv\lim_{\vect k\to\infty} k^4 n_{\vect k\up} =\lim_{\vect
k\to\infty} k^4 n_{\vect k\down}. This result is a \textit{universal
identity}. Its proof is facilitated by a novel mathematical idea, which might
be of utility in dealing with ultraviolet divergences in quantum field
theories. Other properties of this Fermi system, including the short-range
structure of the one-body reduced density matrix and the pair correlation
function, and the dimer-fermion scattering length, are also studied.Comment: 28 pages, 1 figur
General removal lemma
We formulate and prove a general result in spirit of hypergraph removal lemma
for measurable functions of several variables.Comment: 5 page
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