Narrow Results

As the progress of quantum computers, it is desired to propose many more efficient cryptographic constructions with post-quantum security. In the literatures, almost all cryptographic schemes and protocols can be explained and constructed modularly from certain cryptographic primitives, among which an Identity-Based Hash Proof System (IB-HPS) is one of the most basic and important primitives. Therefore, we can utilize IB-HPSs with post-quantum security to present several types of post-quantum secure schemes and protocols. Up until now, all known IB-HPSs with post-quantum security are instantiated based on latticed-based assumptions. However, all these lattice-based IB-HPSs are either in the random oracle model or not efficient enough in the standard model. Hence, it should be of great significance to construct more efficient IB-HPSs from lattices in the standard model.

In this paper, we propose a new smooth IB-HPS with anonymity based on the Learning with Errors (LWE) assumption in the standard model. This new construction is mainly inspired by a classical identity-based encryption scheme based on LWE due to Agreawal et al. in Eurocrypt 2010. And our innovation is to employ the algorithm SampleGaussian introduced by Gentry et al. and the property of random lattice to simulate the identity secret key with respect to the challenge identity. Compared with other existing IB-HPSs in the standard model, our master public key is quite compact. As a result, our construction has much lower overheads on computation and storage.

We discuss theoretical issues in rare and radiative kaon decays. The interest is twofold: to extract useful short-distance information and understand the underlying dynamics. We emphasize channels where either we can understand nonperturbative aspects of QCD or there is a chance to test the Standard Model.

A superstring action is quantised with Neveu–Schwarz (NS) and Ramond (R) boundary conditions. The zero mass states of the NS sector are classified as the vector gluons, W-mesons, B_μ-mesons and scalars containing Higgs. 15 zero mass fermions are obtained from the Ramond sector. A spacetime supersymmetric Hamiltonian of the Standard Model is presented without any conventional SUSY particles.

We give a brief account of the description of the standard model in noncommutative geometry as well as the thermal time hypothesis, questioning their relevance for quantum gravity.

This paper reviews and updates the Standard Model prediction of the τ lepton g-2. Updated QED and electroweak contributions are presented, together with new values of the leading-order hadronic term, based on the recent low energy e⁺ e^- data from BaBar, CMD-2, KLOE and SND, and hadronic light-by-light contribution. The total prediction is confronted to the available experimental bounds on the τ lepton anomaly, and prospects for its future measurements are briefly discussed.

The dilepton decays of the top quark are a powerful laboratory for probing the Standard Model and searching for hints of a more fundamental theory. We present a detailed analysis of the production cross section and the kinematic qualities of top quark pair candidate events in collisions at = 1.96 TeV collected by the CDF detector which include two leptons in the final state, suggesting the decay . We describe the selection of candidate events to suppress major backgrounds and present the number of observed events over background. As a test of the top quark hypothesis, the kinematics of the events are analyzed via a measurement of M_top with unprecedented precision.

We discuss how various mechanisms, including type-2 Randall-Sundrum and Dvali-Shifman, may be combined to create possibly realistic domain-wall-brane models with one extra infinite dimension.

We incorporate the parameters of the gauge group G into the gauge theory of interactions through a nonlinear partial-trace σ-model Lagrangian on G/H. The minimal coupling of the new (Goldstone-like) scalar bosons provides mass terms to those intermediate vector bosons associated with the quotient G/H, without spoiling gauge invariance, while the H-vector potentials remain massless. The main virtue of a partial trace on G/H, rather than on the entire G, is that we can find an infinite-dimensional symmetry, with nontrivial Noether invariants, which ensures quantum integrability in a non-canonical quantization scheme. The present formalism is explicitly applied to the case G = SU(2)× U(1), as a Higgsless alternative to the Standard Model of electroweak interactions, although it can also be used in low-energy phenomenological models for strong interactions.

We consider a locally scale invariant extension of the Standard Model of particle physics and argue that it fits both the particle and cosmological observations. The model is scale invariant both classically and quantum mechanically. The scale invariance is broken (or hidden) by a mechanism which we refer to as cosmological symmetry breaking. This produces all the dimensionful parameters in the theory. The cosmological constant or dark energy is a prediction of the theory and can be calculated systematically order by order in perturbation theory. It is expected to be finite at all orders. The model does not suffer from the hierarchy problem due to the absence of scalar particles, including the Higgs, from the physical spectrum.

We consider the standard model with local scale invariance. The theory shows exact scale invariance of dimensionally regulated action. We show that massless gauge fields, which may be Abelian or non-Abelian, lead to vanishing contribution to the cosmological constant in this theory. This result follows in the quantum theory, to all orders in the gauge couplings. However, we have not considered contributions higher orders in the gravitational coupling. Similarly we also find that massless fermion fields yield null contribution to the cosmological constant. The effective cosmological constant in this theory is nonzero due to the phenomenon of cosmological symmetry breaking, which also gives masses to all the massive fields, besides generating the Planck mass. We find a simple relationship between the curvature scalar and the vacuum value of the Higgs field in the limit when we ignore all other contributions to the energy density besides the vacuum energy.

We review the recent programme undertaken to construct, systematically and algorithmically, large classes of heterotic vacua, as well as the search for the MSSM therein. Specifically, we outline the monad construction of vector bundles over complete intersection Calabi–Yau threefolds, their classification, stability, equivariant cohomology and subsequent relevance to string phenomenology. It is hoped that this top–down algorithmic approach will isolate special corners in the heterotic landscape.

We suggest the model with the gauge group ⋯ ⊗ SU(6)⊗ SU(5) ⊗ SU(4)⊗ SU(3)⊗ SU(2)⊗ U(1). This group is the infinite continuation of the gauge group SU(4)⊗ SU(3)⊗ SU(2) ⊗ U(1) of Farhi–Susskind model. The constructed model contains fermions from the fundamental representations of any SU(N) subgroups of the gauge group. In the construction of the model we use essentially the requirement that it possesses an additional discrete symmetry that is the continuation of the Z₆ symmetry of the Standard Model. It has been found that there exists such a choice of the hypercharges of the fermions that the chiral anomaly is absent while the symmetry is preserved.

We discuss an alternative implementation of the Higgs boson within the Standard Model which is possible if the renormalizability condition is relaxed. Namely, at energy scale Λ the Higgs boson interacts at tree-level only with matter fermions, while the full gauge invariance is still maintained. The interactions with the electroweak gauge bosons are induced at low energies through the radiative corrections. In this scenario the Higgs boson can be arbitrarily heavy, interacting with the Standard Model fields arbitrarily weakly. No violation of unitarity in the scattering of longitudinal electroweak bosons occurs, since they become unphysical degrees of freedom at energies Λ ~ TeV.

The Large Hadron Collider (LHC) began 7 TeV C.M. energy operation in April, 2010. The CMS experiment immediately analyzed the earliest data taken in order to "rediscover" the Standard Model (SM) of high energy physics. By the late summer, all SM particles were observed and CMS began to search for physics beyond the SM and beyond the present limits set at the Fermilab Tevatron. The first LHC run ended in Dec., 2010 with a total integrated luminosity of about 45 pb^-1 delivered to the experiments.

In this paper, on a talk given at Lawrence Berkeley Laboratory, we discuss higher-order non-perturbative corrections in inclusive semileptonic decays of B mesons. First the generic calculation is reviewed and then we identify the relevant hadronic matrix-elements up to . For a quantitative analysis of these effects, the value of these new matrix-elements is estimated within an approximation scheme. We investigate the role of so-called "intrinsic-charm" operators in this decay, appearing first at order in the heavy-quark expansion. These operators induce an expansion infrared sensitive to the charm quark . Parametrically the power corrections complement the estimate of the potential impact of contributions, which we will explore. In this context, we draw semiquantitative conclusions for the expected scale of valence weak annihilation contribution in semileptonic B decays. Furthermore the effects on the integrated rate and on kinematic moments are then estimated up to .

This review gives some recollections on the recent history of the concepts of vacuum and mass and the search for higgs. According to the widely spread terminology, the Higgs field permeates vacuum and serves as the origin of masses of all fundamental particles including the Higgs boson — the higgs.

We review the current status of |V_cb|, |V_ub| and |V_tb|, the absolute values of the matrix elements in the CKM third column.

In 1964, a new particle was proposed by several groups to answer the question of where the masses of elementary particles come from; this particle is usually referred to as the Higgs particle or the Higgs boson. In July 2012, this Higgs particle was finally found experimentally, a feat accomplished by the ATLAS Collaboration and the CMS Collaboration using the Large Hadron Collider at CERN. It is the purpose of this review to give my personal perspective on a brief history of the experimental search for this particle since the '80s and finally its discovery in 2012. Besides the early searches, those at the LEP collider at CERN, the Tevatron Collider at Fermilab, and the Large Hadron Collider at CERN are described in some detail. This experimental discovery of the Higgs boson is often considered to be the most important advance in particle physics in the last half a century, and some of the possible implications are briefly discussed. This review is partially based on a talk presented by the author at the conference "Higgs Quo Vadis," Aspen Center for Physics, Aspen, CO, USA, March 10–15, 2013.

This is a continuation of recent studies of ϒ(nS) production at the LHC in pp collisions. Our previous studies were for rapidity y = -1 to 1 for the CMS detector, while the present study is for y = 2.5 to 4.0 at the LHC.

The current status of lattice calculations is reviewed, with a particular emphasis on the question whether lattice simulations have matured to a stage where there is full interaction with experiment. Particular examples include the hadron spectrum, mesonic form factors and decay constants, the axial charge of the nucleon, and the hadronic vacuum polarization contribution to the muon (g-2).