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S. Arunagiri

Publications and source records attributed to S. Arunagiri.

14 recordsLinked to original sources
arXiv2012

Quantum entanglement in soliton fractionalisation process

Quantum state, in relativistic quantum mechanics, itself turns out to be an entangled state due to its own degrees freedom such as spin and momentum. This peculiar entanglement leaves the transformed state mixed. We consider the fractional charge state that arises in a theory of fermion interacting with scalar background in this context. The apparent entanglement occurs between fermion ans scalar through Yukawa-type interaction. However, the spontaneous symmetry breaking causes appearance of the $c$-number zero energy solution of the Dirac equation as a pure state. Quantum entanglement in such relativistic system is proposed to have a microscopic view of the spontaneous symmetry breaking which has been realised in condensed matter system like polyacetylene.

cond-mat.mes-hall↗
arXiv2011

Similarity of zitterbewegung of electron to the Adler-Bell-Jackiw anomaly in QED: its observable manifestation in graphene

The zitterbewegung being proportional to $\sin(εt)$, it is depicted as the motion of electron from the positive energy state to that of the negative energy and vice versa in the neighbourhood of Dirac point. Since such transition involves crossing the Dirac point, the same may be the possible realisation and measure of the zitterbewegung. In this respect, we draw a similirity between the zitterbewegung and the Adler-Bell-Jackiw anomaly in (1+1) QED. In a time dependent perturbation theory, the embodiment of zitterbewegung is envisaged in the context of graphene.

cond-mat.mes-hall↗
arXiv2003

T-violating triple product asymmetries in Lambda_b --> Lambda pi pi decay

We study Lambda_b --> Lambda pi pi. The branching fraction is predicted to be about 4.38 x 10^{-6}%. Within the standard model, we compute T-odd triple product asymmetries to be about 1.4, 4.3, 6.5 and 7.2% respectively due to s_{Lambda_b}(s_Lambda) . (p_Lambda x p_pi) and p_Lambda (p_pi) . (s_Lambda x s_{Lambda_b}).

hep-ph↗
arXiv2003

Triple product correlations in B --> anti-Lambda p pi

Triple product correlations (TPC's) involving strange quark spin are elucidated in b --> u u(bar) s process within the standard model. They arise when light quark masses are nonzero. As the momenta and spins of constituent quarks are related to that of the parent hadron, the quark masses are, however small, important and relevant in TPC studies. At this level the TPC's of interest are of the form s_s.[p_u X p_u(bar)] and s_s.[p_s X p_u]. As an application, we look at T-violating effects in B --> anti-Lambda p pi through the TPC s_Λ.[p_ΛX p_p] for which triple product asymmetry is found to be 5.7%-7.6% in the vanishing limit of the strong phase.

hep-ph↗
arXiv2002

Remarks on CP Asymmetries in $D^0/\bar {D^0} \ra K_S π^+ π^-$

We consider the interference of resonant amplitudes leading to the final state $K_S π^+ π^-$ in $D^0/\bar {D^0}$ decays. Each of these amplitudes consists of both Cabibbo allowed and doubly Cabibbo suppressed transitions. The role of strong phase arising out of Breit-Wigner resonant propagators is emphasised. Invoking the $ΔS = ΔQ$ rule, $K_S$ in the final state is identified as the mass eigenstate of superposed weak eigenstates $K^0$ and $\bar K^0$. A nonzero CP asymmetry appears to be possible in three body decays.

hep-ph↗
arXiv2000

On the short distance nonperturbative corrections in heavy quark expansion

We study the corrections due to renormalons to the heavy hadron decay width.The renormalons contribution estimated in terms of finite gluon mass based on the assumption that the gluon mass represents the short distance nonperturbative effects in the standard OPE (and hence in the heavy quark expansion). We found that the corrections are about 10% of the leading decay rate. We point out the implications for the assumption of quark-hadron duality in heavy quark expansion.

hep-lat↗
arXiv2000

Spectator effects and quark-hadron duality in inclusive beauty decays

The two important issues concerning the theory of inclusive decays are studied: (1) evaluation of expectation values of four-quark operators in order to systematically include the spectator effects and (2) estimation of duality breaking corrections in heavy quark expansion. Our study leads to the theoretical prediction of the ratio of lifetimes of $Λ_b$ and $B$ close to the experimental one and the duality breaking corrections of about 10% of the leading decay rate.

hep-ph↗
arXiv2000

Pattern of Lifetimes of Beauty Hadrons and Quark-Hadron Duality in Heavy Quark Expansion

We discuss (i) the evaluation of the expectation values of four-quark operators assuming that the heavy quark expansion for $b$ sector converges at the third order in $1/m_Q$, and (ii) the estimation of the duality breaking short distance nonperturbative corrections to the parton decay rate. We finally point out the implications of the result obtained for the assumption of quark-hadron duality in heavy quark expansion.

hep-ph↗
arXiv2000

On the short distance nonperturbative corrections in heavy quark expansion

We estimate the renormalon corrections to the inclusive decay rate of heavy hadrons. We assume the gluon mass term $λ^2 \gg `^2$ to imitate the short distance nonperturbative effects. It is found that the the inclusive decay rates are corrected by an amount of about 0.2 $Γ_0$ for $B$ meson and 0.21 $Γ_0$ for baryon. This is significant in view of the discrepancy of lifetimes of $B$ and $\lbb$.

hep-ph↗
arXiv2000

A note on spectator effects and quark-hadron duality in inclusive beauty decays

In this paper, we evaluate the expectation values of four-quark operators for the inclusive beauty decays from the differences in the inclusive total decay rates, assuming that the heavy quark expansion converges at $O(1/m^3)$. The obtained expectation values yeilds the ratio $τ(Λ_b)/τ(B)$ close to the experimental onee. We further point out that the quark-hadron duality violation would be rather small allowing predictions of inclusive quantities.

hep-ph↗
arXiv2000

Spectators effect in inclusive beauty decays

I review the role of the spectator quarks effect in the inclusive beauty decays. The evaluation of the expectation values of four-quark operators between hadronic states and its consequences are discussed.

hep-ph↗
arXiv1999

Colour-straight four-quark operators and liftemes of beautiful hadrons

Using the relation between the harmonic oscillator wave function and the light quark scattering form factor, the expectation values of colour-straight four-quark operators are evaluated and found to be directly proportional to the cubic power of the oscillator strength. It is predicted that the ratio τ(Λ_b)/τ(B) \approx 0.79(0.84) due to the factorizable (nonfactorisable) piece, against the experimental 0.79 \pm 0.06. Notwithstanding the numerical prediction, the present study shows that the four-quark operators play a role as far the lifetimes of b-flavoured hadrons are concerned.

hep-ph↗