Properties and Decays of the Bc+B_c^+ meson

Recent studies of properties and decays of the $B_c^+$ meson by the LHC experiments are presented. Mass and lifetime measurements are discussed and some of the many new observed decays are reported.Comment: Presented at the 2014 Flavor Physics and CP Violation (FPCP-2014), Marseille, France, May 26-30 2014, 10 pages, 6 figure

Costly Coasian Contracts

We identify and investigate the basic 'hold-up problem' which arises whenever each party to a contract has to pay some ex-ante cost for the contract to become feasible. We then proceed to show that, under plausible circumstances, a 'contractual solution' to this hold-up problem is not available. This is because a contractual solution to the hold-up problem typically entails writing a 'contract over a contract' which generates a fresh set of ex-ante costs, and hence is associated with a new hold-up problem.Ex-ante contractual costs, hold-up problem, Coase theorem, contracts over contracts, incomplete contracts.

Cooperation and non-halting strategies

This note is a response to an unpublished paper by Evans and Thomas (1998) of which we have recently become aware. Evans and Thomas (1998) take issue with a paper that we published some years back on 'Cooperation and Effective Computability' in repeated games (Anderlini and Sabourian 1995). In that paper we showed that it is only the cooperative equilibria of an infinitely repeated two-player common-interest game with no discounting that survive both the restriction that players' strategies must be computable, and appropriately computable trembles. Evans and Thomas (1998) assert that our results are seemingly not robust to changes in the set of computable strategies at the disposal of each player. In particular, they claim that our equilibrium selection result does not extend to the case in which players are allowed to choose strategies that halt on certain histories but do not halt on others. The purpose of this note is to show that the claim in Evans and Thomas (1998) is misleading. We present a modification of the set-up of our earlier paper in which the cooperative equilibria are selected when strategies that halt on certain histories and do not halt on others are allowed. Although extensive modifications are required, the proof of this extension of our earlier result runs along the same general line of argument as the original proof

Communication in Dynastic Repeated Games: `Whitewashes' and `Coverups

We ask whether communication can directly substitute for memory in dynastic repeated games in which short lived individuals care about the utility of their offspring who replace them in an infinitely repeated game. Each individual is unable to observe what happens before his entry in the game. Past information is therefore conveyed from one cohort to the next by means of communication. When communication is costless and messages are sent simultaneously, communication mechanisms or protocols exist that sustain the same set of equilibrium payoffs as in the standard repeated game. When communication is costless but sequential, the incentives to `whitewash' the unobservable past history of play become pervasive. These incentives to whitewash can only be countered if some player serves as a `neutral historian' who verifies the truthfulness of others' reports while remaining indifferent in the process. By contrast, when communication is sequential and (lexicographically) costly, all protocols admit only equilibria that sustain stage Nash equilibrium payoffs. We also analyze a centralized communication protocol in which history leaves a `footprint' that can only hidden by the current cohort by a unanimous `coverup'. We show that in this case only weakly renegotiation proof payoffs are sustainable in equilibrium.Dynastic Repeated Games, Communication, Whitewashing, Coverups

Transaction Costs and the Robustness of the Coase Theorem

This paper explores the extent to which the presence of ex-ante transaction costs may lead to failures of the Coase Theorem. In particular we identify and investigate the basic `hold-up problem' which arises whenever the parties to a Coasian negotiation have to pay some ex-ante costs for the negotiation to take place. We then show that a `Coasian solution' to this hold-up problem is not available. This is because a Coasian solution to the hold-up problem typically entails a negotiation about the payment of the costs associated with the future negotiation which in turn is associated with a fresh set of ex-ante costs, and hence with a new hold-up problemTransaction Costs, Hold-Up Problem, Coase Theorem, Coasian Negotiation.