arXiv subjects

Yusuf Dincer

Publications and source records attributed to Yusuf Dincer.

4 recordsLinked to original sources

arXiv2003

The rare radiative decay $B_s \to ν\barν γ$ in beyond Standard Model scenarios

In this paper, I study the branching ratio of the rare radiative decay $B_s \to ν\barν γ$ in the framework of the Fourth-Generation Standard Model and the Two-Higgs-Doublet Model. It is shown that this quantity is a very effective tool for establishing new physics beyond the Standard Model. It is observed that there is a region in the parameter space in both extensions of the Standard Model for which the branching ratio show considerable departure from the Standard Model.

hep-ph↗

arXiv2003

Electroweak Effects in the Double Dalitz Decay $B_s \to l^+ l^- l'^+ l'^-$

We investigate the double Dalitz decays $B_s \to l^+ l^- l'^+ l'^-$ on the basis of the effective Hamiltonian for the transition $b \bar{s} \to l^+ l^-$, and universal form factors suggested by QCD. The correlated mass spectrum of the two lepton pairs in the decay $B_s \to e^+ e^- μ^+ μ^-$ is derived in an efficient way, using a QED result for meson decays mediated by two virtual photons: $B_s \to γ^* γ^* \to e^+ e^- μ^+ μ^-$. A comment is made on the correlation between the planes of the two lepton pairs. The conversion ratios $ρ_{lll'l'}= \frac{Γ(B_s \to l^+ l^- l'^+ l'^-)}{Γ(B_s \to γγ)}$ are estimated to be $ρ_{eeee}=3 \times 10^{-4}, ρ_{eeμμ}=9 \times 10^{-5} \text{and} ρ_{μμμμ}=3 \times 10^{-5}$, and are enhanced relative to pure QED by $10-30 %$.

hep-ph↗

arXiv2000

Fourth generation effects in the $B_s \to ν\barν γ$ decay

If the fourth generation fermions exist, the new quarks could influence the branching ratio of the decay $B_s \to ν\barν γ$. We obtain two solutions of the fourth generation CKM factor $V^*_{t's} V_{t'b}$ from the decay of $B \to X_s γ$. With these two solutions we calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay $B_s \to ν\barν γ$. The branching ratio of the decay $B_s \to ν\barν γ$ in the two cases are calculated. In one case, our results are quite different from that of SM, but almost same in another case. If a fourth generation should exist in nature and nature chooses the former case, this B meson decay could provide a possible test of the fourth generation existence.

hep-ph↗

arXiv2000

Interface fluctuations in disordered systems: Universality and non-Gaussian statistics

We employ a functional renormalization group to study interfaces in the presence of a pinning potential in $d=4-ε$ dimensions. In contrast to a previous approach [D.S. Fisher, Phys. Rev. Lett. {\bf 56}, 1964 (1986)] we use a soft-cutoff scheme. With the method developed here we confirm the value of the roughness exponent $ζ\approx 0.2083 ε$ in order $ε$. Going beyond previous work, we demonstrate that this exponent is universal. In addition, we analyze the generation of higher cumulants in the disorder distribution and the role of temperature as a dangerously irrelevant variable.

cond-mat.dis-nn↗