41 research outputs found
On the difference between the pole and the MSbar masses of the top quark at the electroweak scale
We argue that for a Higgs boson mass M_H ~125 GeV, as suggested by recent
Higgs searches at the LHC, the inclusion of electroweak radiative corrections
in the relationship between the pole and MS-bar masses of the top quark reduces
the difference to about 1 GeV. This is relevant for the scheme dependence of
electroweak observables, such as the rho parameter, as well as for the
extraction of the top quark mass from experimental data. In fact, the value
currently extracted by reconstructing the invariant mass of the top quark decay
products is expected to be close to the pole mass, while the analysis of the
total cross section of top quark pair production yields a clean determination
of the MS-bar mass.Comment: 15 pages, 1 figure; discussion extended, figure improved, references
added; accepted for publication in Phys. Lett.
Self-consistence of the Standard Model via the renormalization group analysis
A short review of recent renormalization group analyses of the
self-consistence of the Standard Model is presented.Comment: 10 pages; 5 figures; To appear in the Proceedings of the 16th
International Workshop ACAT- 2014 (Advanced Computing and Analysis Techniques
in physics), Prague, Czech Republic, 01-05 September 201
Self-consistence of the Standard Model via the renormalization group analysis
A short review of recent renormalization group analyses of the self-consistence of the Standard Model is presented.Peer Reviewe
Counting master integrals: integration by parts vs. differential reduction
The techniques of integration by parts and differential reduction differ in
the counting of master integrals. This is illustrated using as an example the
two-loop sunset diagram with on-shell kinematics. A new algebraic relation
between the master integrals of the two-loop sunset diagram that does not
follow from the integration-by-parts technique is found.Comment: 6 pages, 1 figure; minor changes to the text, figure added; to appear
in Phys. Lett.
Towards all-order Laurent expansion of generalized hypergeometric functions around rational values of parameters
We prove the following theorems:
1) The Laurent expansions in epsilon of the Gauss hypergeometric functions
2F1(I_1+a*epsilon, I_2+b*epsilon; I_3+p/q + c epsilon; z),
2F1(I_1+p/q+a*epsilon, I_2+p/q+b*epsilon; I_3+ p/q+c*epsilon;z),
2F1(I_1+p/q+a*epsilon, I_2+b*epsilon; I_3+p/q+c*epsilon;z), where
I_1,I_2,I_3,p,q are arbitrary integers, a,b,c are arbitrary numbers and epsilon
is an infinitesimal parameter, are expressible in terms of multiple
polylogarithms of q-roots of unity with coefficients that are ratios of
polynomials; 2) The Laurent expansion of the Gauss hypergeometric function
2F1(I_1+p/q+a*epsilon, I_2+b*epsilon; I_3+c*epsilon;z) is expressible in terms
of multiple polylogarithms of q-roots of unity times powers of logarithm with
coefficients that are ratios of polynomials; 3) The multiple inverse rational
sums (see Eq. (2)) and the multiple rational sums (see Eq. (3)) are expressible
in terms of multiple polylogarithms; 4) The generalized hypergeometric
functions (see Eq. (4)) are expressible in terms of multiple polylogarithms
with coefficients that are ratios of polynomials.Comment: 48 pages in LaTe
Multiple (inverse) binomial sums of arbitrary weight and depth and the all-order epsilon-expansion of generalized hypergeometric functions with one half-integer value of parameter
We continue the study of the construction of analytical coefficients of the
epsilon-expansion of hypergeometric functions and their connection with Feynman
diagrams. In this paper, we show the following results:
Theorem A: The multiple (inverse) binomial sums of arbitrary weight and depth
(see Eq. (1.1)) are expressible in terms of Remiddi-Vermaseren functions.
Theorem B: The epsilon expansion of a hypergeometric function with one
half-integer value of parameter (see Eq. (1.2)) is expressible in terms of the
harmonic polylogarithms of Remiddi and Vermaseren with coefficients that are
ratios of polynomials. Some extra materials are available via the www at this
http://theor.jinr.ru/~kalmykov/hypergeom/hyper.htmlComment: 24 pages, latex with amsmath and JHEP3.cls; v2: some typos corrected
and a few references added; v3: few references added
Recommended from our members
The electronic structure and the nature of the chemical bond in CeO2.
The X-ray photoelectron spectral structure of CeO2 valence electrons in the binding energy range of 0 to ∼50 eV was analyzed. The core-electron spectral structure parameters and the results of relativistic discrete-variational calculations of CeO8 and Ce63O216 clusters were taken into account. Comparison of the valence and the core-electron spectral structures showed that the formation of the inner (IVMO) and the outer (OVMO) valence molecular orbitals contributes to the spectral structure more than the many-body processes. The Ce 4f electrons were established to participate directly in chemical bond formation in CeO2 losing partially their f character. They were found to be localized mostly within the outer valence band. The Ce 5p atomic orbitals were shown to participate in the formation of both the inner and the outer valence molecular orbitals (MOs). A large part in the IVMO formation is taken by the filled Ce 5p1/2, 5p3/2 and O 2s atomic shells, while the Ce 5s electrons participate weakly in the chemical bond formation. The composition and the sequent order of the molecular orbitals in the binding energy range of 0 to ∼50 eV were established. A quantitative scheme for the molecular orbitals of CeO2 was built. This scheme is fundamental for understanding the nature of chemical bonding and also for the interpretation of other X-ray spectra of CeO2. Evaluations revealed that the IVMO electrons weaken the chemical bond formed by the OVMO electrons by 37%.The work was supported by the RFBR grant № 17-03-00277a. M.V. Ryzhkov acknowledges financial support of FASO of Russia ISSC of the Ural Branch of RAS № AAAA-A16-116122810214-9. A.J. Popel acknowledges funding from the UK EPSRC (grant EP/I036400/1) and Radioactive Waste Management Ltd (formerly the Radioactive Waste Management Directorate of the UK Nuclear Decommissioning Authority, contract NPO004411A-EPS02), a maintenance grant from the Russian Foundation for Basic Research (projects 13-03-90916) and CSAR bursary