We present a new and sensitive method to observe direct CP violation in $D$ mesons using Bose symmetry and Dalitz plot. We apply the method to processes such as $B to D^0bar{D}^0 P$, where $P$ is either a $K$ or a $pi$. By choosing to reconstruct $D$
mesons only through their decays into CP eigenstates, we show that any asymmetry in the Dalitz plot can arise only through direct CP violation. We further show how CP violation parameters can be determined. Since the approach involves only Bose symmetry, the method is applicable to any multi-body process that involves $D^0bar{D}^0$ in the final state. We briefly discuss how $Bto D^* bar{D}^* P$ can also be used in a similar way.
We study $mu - e$ conversion with sequential four generations. A large mass for the fourth generation neutrino can enhance the conversion rate by orders of magnitude. We compare constraints obtained from $mu - e$ conversion using experimental bounds
on various nuclei with those from $mu to e gamma$ and $mu to ebar e e$. We find that the current bound from $mu - e$ conversion with Au puts the most stringent constraint in this model. The relevant flavor changing parameter $lambda_{mu e} = V^*_{mu 4}V_{e4}^{}$ is constrained to be less than $1.6times 10^{-5}$ for the fourth generation neutrino mass larger than 100 GeV. Implications for future $mu -e$ conversion, $mu to egamma$ and $mu to ebar e e$ experiments are discussed.
We consider extension of the standard model $SU(2)_l times SU(2)_h times U(1)$ where the first two families of quarks and leptons transform according to the $SU(2)_l$ group and the third family according to the $SU(2)_h$ group. In this approach, the
largeness of top-quark mass is associated with the large vacuum expectation value of the corresponding Higgs field. The model predicts almost degenerate heavy $W$ and $Z$ bosons with non-universal couplings, and extra Higgs bosons. We present in detail the symmetry breaking mechanism, and carry out the subsequent phenomenology of the gauge sector. We compare the model with electroweak precision data, and conclude that the extra gauge bosons and the Higgs bosons whose masses lie in the TeV range, can be discovered at the LHC.
We consider scale invariant theories of continuous mass fields, and show how interactions of these fields with the standard model can reproduce unparticle interactions. There is no fixed point or dimensional transmutation involved in this approach. W
e generalize interactions of the standard model to multiple unparticles in this formalism and explicitly work out some examples, in particular we show that the product of two scalar unparticles behaves as a normalized scalar unparticle with dimension equal to the sum of the two composite unparticle dimensions. Extending the formalism to scale invariant interactions of continuous mass fields, we calculate three point function of unparticles.
We study the M{o}ller and Bhabha scattering in the noncommutative extension of the standard model(SM) using the Seiberg-Witten maps of this to first order of the noncommutative parameter $theta_{mu u}$. We look at the angular distribution $dsigma/dO
mega$ to explore the noncommutativity of space-time at around $Lambda_{NC} sim$ TeV and find that the distribution deviates significantly from the one obtained from the commutative version of the standard model.
Couplings between standard model particles and unparticles from a nontrivial scale invariant sector can lead to long range forces. If the forces couple to quantities such as baryon or lepton (electron) number, stringent limits result from tests of th
e gravitational inverse square law. These limits are much stronger than from collider phenomenology and astrophysics.
We propose a model that introduces a supersymmetric unparticle operator in the minimal supersymmetric Standard Model. We analyze the lowest dimension operator involving an unparticle. This operator behaves as a Standard Model gauge singlet and it int
roduces a new parameter into the Higgs potential which can provide an alternative way to relax the upper limit on the lightest Higgs boson mass. This operator also introduces several unparticle interactions which can induce a neutral Higgsino to decay into a spinor unparticle. It also induces violation of scale invariance around the electroweak scale. It is necessary for the scale of this violation to be larger than the lightest supersymmetric particle mass to maintain the latter as the usual weakly interacting massive particle dark matter candidate. An alternative is to have unparticle state as dark matter candidate. We also comment on some collider implications.
