scholarly journals Hypergeometric presentation for one-loop contributing to H → Z γ

2020 ◽  
Vol 2020 (5) ◽  
Author(s):  
Khiem Hong Phan ◽  
Dzung Tri Tran
Keyword(s):  
Hypergeometric Functions ◽  
Decay Channel ◽  
Form Factors ◽  
Space Time ◽  
Decay Process ◽  
Time Dimension ◽  
Higgs Decay ◽  
Arbitrary Space ◽  
First Time ◽  
Loop Form

Abstract In this paper, new analytic formulas for one-loop contributing to Higgs decay channel $H \rightarrow Z\gamma$ are presented in terms of hypergeometric functions. The calculations are performed by following the technique for tensor one-loop reduction developed in [A. I. Davydychev, Phys. Lett. B 263 (1991) 107]. For the first time, one-loop form factors for the decay process are shown which are valid at arbitrary space–time dimension $d$.

Hypergeometric representation of one-loop Higgs decay to two photons

2019 ◽  
Vol 97 (10) ◽  
pp. 1096-1103 ◽  
Author(s):  
Khiem Hong Phan
Keyword(s):  
Standard Model ◽  
Hypergeometric Function ◽  
Form Factors ◽  
Space Time ◽  
Time Dimension ◽  
Function Representation ◽  
Higgs Decay ◽  
The Standard Model ◽  
Arbitrary Space ◽  
First Time

In this paper, we derive hypergeometric function representation of one-loop contributing to Higgs decay to two photons in the standard model and its extensions. The calculations are performed at general space–time dimension d. For the first time, analytic results are published for form factors that are valid in arbitrary space–time dimension. Moreover, we confirm against analytic results in previous computations that have been available in space–time dimension d = 4 – 2ϵ at ϵ0 expansions.

scholarly journals PHASE STRUCTURE OF FOUR-FERMION THEORIES AT FINITE TEMPERATURE AND CHEMICAL POTENTIAL IN ARBITRARY DIMENSIONS

1995 ◽  
Vol 10 (15) ◽  
pp. 2241-2268 ◽  
Author(s):  
T. INAGAKI ◽  
T. KOUNO ◽  
T. MUTA
Keyword(s):  
Phase Transition ◽  
Order Phase Transition ◽  
Phase Structure ◽  
Chemical Potential ◽  
Expansion Method ◽  
Space Time ◽  
Second Order ◽  
Time Dimension ◽  
Arbitrary Space ◽  
Second Order Phase Transition

The phase structure of four-fermion theories is thoroughly investigated with varying temperature and chemical potential for arbitrary space-time dimensions (2≤D<4) by using the 1/N expansion method. It is shown that the chiral symmetry is restored in the theory under consideration for sufficiently high temperature and/or chemical potential. The critical line dividing the symmetric and the broken phase is given explicitly. It is found that for space-time dimension 2≤D<3 both the first order and the second order phase transition occur depending on the value of the temperature and chemical potential while for 3≤D<4 only the second order phase transition exists.

scholarly journals CURVATURE-INDUCED PHASE TRANSITION IN A FOUR-FERMION THEORY USING THE WEAK CURVATURE EXPANSION

1996 ◽  
Vol 11 (25) ◽  
pp. 4561-4576 ◽  
Author(s):  
TOMOHIRO INAGAKI
Keyword(s):  
Phase Transition ◽  
Chiral Symmetry ◽  
Effective Potential ◽  
Positive Curvature ◽  
Expansion Method ◽  
Space Time ◽  
Fermion Mass ◽  
De Sitter ◽  
Time Dimension ◽  
Arbitrary Space

Curvature–induced phase transition is thoroughly investigated in a four-fermion theory with N components of fermions for arbitrary space–time dimensions (2≤D<4). We adopt the 1/N expansion method and calculate the effective potential for a composite operator [Formula: see text]. The resulting effective potential is expanded asymptotically in terms of the space–time curvature R by using the Riemann normal coordinate. We assume that the space–time curves slowly, and we keep only terms independent of R and terms linear in R. In evaluating the effective potential it is found that first order phase transition is caused and the broken chiral symmetry is restored for a large positive curvature. In the space–time with a negative curvature the chiral symmetry is broken down even if the coupling constant of the four-fermion interaction is sufficiently small. We present the behavior of the dynamically generated fermion mass. The critical curvature, R cr , which divides the symmetric and asymmetric phases, is obtained analytically as a function of the space–time dimension D. At the four-dimensional limit our result R cr agrees with the exact results known in de Sitter space and the Einstein universe.

scholarly journals Semileptonic decay of $$\varOmega _c^0 \rightarrow \varXi ^- l^+ \nu _l$$ from light-cone sum rules

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
Hui-Hui Duan ◽  
Yong-Lu Liu ◽  
Ming-Qiu Huang
Keyword(s):  
Decay Width ◽  
Light Cone ◽  
Sum Rules ◽  
Semileptonic Decay ◽  
Decay Channel ◽  
Branching Ratio ◽  
Form Factors ◽  
Weak Decay ◽  
Decay Process ◽  
Sum Rule

AbstractThe weak decay process of $$\varOmega _c$$ Ω c to $$\varXi $$ Ξ is calculated in the method of QCD light-cone sum rule. The decay width of $$\varOmega _c^0 \rightarrow \varXi ^- l^+ \nu _l$$ Ω c 0 → Ξ - l + ν l and its decay branching ratio are also calculated with the form factors from this work’s calculation. To the twist-6 distribution amplitudes, the form factors $$f_1=0.66\pm 0.02, f_2=-0.76\pm 0.03, g_1=0.06\pm 0.01$$ f 1 = 0.66 ± 0.02 , f 2 = - 0.76 ± 0.03 , g 1 = 0.06 ± 0.01 and $$g_2=-0.44\pm 0.01$$ g 2 = - 0.44 ± 0.01 are given at zero recoil point. The result of the semileptonic decay width of $$\varOmega _c^0 \rightarrow \varXi ^-l^+\nu _l$$ Ω c 0 → Ξ - l + ν l is $$\varGamma =(7.51\pm 0.36)\times 10^{-15}~\mathrm{{GeV}}$$ Γ = ( 7.51 ± 0.36 ) × 10 - 15 GeV , and the prediction of the decay branching ratio $$Br(\varOmega _c^0\rightarrow \varXi ^-l^+\nu _l)=(3.06\pm 0.15)\times 10^{-3}$$ B r ( Ω c 0 → Ξ - l + ν l ) = ( 3.06 ± 0.15 ) × 10 - 3 . These results fit well with other works, and the decay width and branching ratio are improved. This not too small branching ratio gives a good direction to explore this decay channel in the future experiments.

Dual currents in arbitrary space-time dimension

1976 ◽  
Vol 13 (4) ◽  
pp. 1021-1024
Author(s):  
Edward A. Johnson
Keyword(s):  
Space Time ◽  
Time Dimension ◽  
Arbitrary Space

scholarly journals One-loop Feynman integrals with Carlson hypergeometric functions

2019 ◽  
Vol 206 ◽  
pp. 02005
Author(s):  
Khiem Hong Phan
Keyword(s):  
Hypergeometric Functions ◽  
Space Time ◽  
Time Dimension ◽  
Feynman Integrals ◽  
General Space

In this paper, we present analytic results for scalar one-loop two-, three-, four-point Feynman integrals with complex internal masses. The calculations are considered in general space-time dimension D for two- and three-point functions and D=4 for four-point functions. The analytic results are expressed in terms of the Carlson hypergeometric functions (ℛ-functions) and valid for both real and complex internal masses.

scholarly journals An event excess observed in the deeply bound region of the 12C (K−, p) missing-mass spectrum

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Yudai Ichikawa ◽  
Junko Yamagata-Sekihara ◽  
Jung Keun Ahn ◽  
Yuya Akazawa ◽  
Kanae Aoki ◽  
...  
Keyword(s):  
Mass Spectrum ◽  
Binding Energy ◽  
Decay Channel ◽  
Peak Shift ◽  
Bound State ◽  
Elastic Peak ◽  
Missing Mass ◽  
Decay Modes ◽  
Kaon Momentum ◽  
First Time

Abstract We have measured, for the first time, the inclusive missing-mass spectrum of the $^{12}$C$(K^-, p)$ reaction at an incident kaon momentum of 1.8 GeV/$c$ at the J-PARC K1.8 beamline. We observed a prominent quasi-elastic peak ($K^-p \rightarrow K^-p$) in this spectrum. In the quasi-elastic peak region, the effect of secondary interaction is apparently observed as a peak shift, and the peak exhibits a tail in the bound region. We compared the spectrum with a theoretical calculation based on the Green’s function method by assuming different values of the parameters for the $\bar{K}$–nucleus optical potential. We found that the spectrum shape in the binding-energy region $-300 \, \text{MeV} &lt; B_{K} &lt; 40$ MeV is best reproduced with the potential depths $V_0 = -80$ MeV (real part) and $W_0 = -40$ MeV (imaginary part). On the other hand, we observed a significant event excess in the deeply bound region around $B_{K} \sim 100$ MeV, where the major decay channel of $K^- NN \to \pi\Sigma N$ is energetically closed, and the non-mesonic decay modes ($K^- NN \to \Lambda N$ and $\Sigma N$) should mainly contribute. The enhancement is fitted well by a Breit–Wigner function with a kaon-binding energy of 90 MeV and width 100 MeV. A possible interpretation is a deeply bound state of a $Y^{*}$-nucleus system.

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