Quarkonium Mass Splitting Revisited: Effects of Closed Mesonic Channels

Modifications of the mass spectrum the quarkonium induced by its virtual dissociation into a pair of heavy mesons is considered. Coupling between quark and mesonic channels results in noticeable corrections to spin-dependent mass splitting. In particular, the observable hierarchy of mass splittings in the $\chi_c, \chi_b$ and $\chi'_b$ multiplets is reproduced.Comment: 9 pages, plain LaTe

Elusive exotic states

Existence of flavor exotic QQ\bar{q}\bar{q} molecular-type states is investigated. Attractive force between two {\it pseudoscalar} H = (Q\bar{q}) heavy meson is generated by the (correlated) two-pion exchange. Emergence of a (loosely) bound state depends crucially on the value of the coupling constant g in the H^*H\pi vertex. For g value calculated from the experimental upper limit on the width of D^* meson considered mechanism alone is strong enough to generate a bound state in the BB system and the DD system is very close to become bound. Such states, if exist, are stable with respect to strong interactions. They may be observed as scalar particles with the mass M\approx 2\,m_H and the flavor quantum number \pm 2

Heavy-flavored strange pentaquark seems not to exist

Possible existence of a molecular-type heavy-flavored strange pentaquark is considered. No narrow state of such a type is shown to exist.Comment: 10 pages in RevTex, 1 figure include

Hadronic molecules: meson-baryon hybrids

The existence of hadronic molecular-type hybrids consisting of a baryon and a meson is argued. Long-range interactions due to one-pion exchange is shown to be strong enough to produce a loosely bound state. Specific features of a molecular hybrid are discussed.Comment: 7 pages in RevTeX plus 1 figure (available upon request

Text Embeddings Reveal (Almost) As Much As Text

How much private information do text embeddings reveal about the original text? We investigate the problem of embedding \textit{inversion}, reconstructing the full text represented in dense text embeddings. We frame the problem as controlled generation: generating text that, when reembedded, is close to a fixed point in latent space. We find that although a na\"ive model conditioned on the embedding performs poorly, a multi-step method that iteratively corrects and re-embeds text is able to recover $92\%$ of $32\text{-token}$ text inputs exactly. We train our model to decode text embeddings from two state-of-the-art embedding models, and also show that our model can recover important personal information (full names) from a dataset of clinical notes. Our code is available on Github: \href{https://github.com/jxmorris12/vec2text}{github.com/jxmorris12/vec2text}.Comment: Accepted at EMNLP 202

Trust in Crowds: probabilistic behaviour in anonymity protocols

The existing analysis of the Crowds anonymity protocol assumes that a participating member is either ‘honest’ or ‘corrupted’. This paper generalises this analysis so that each member is assumed to maliciously disclose the identity of other nodes with a probability determined by her vulnerability to corruption. Within this model, the trust in a principal is defined to be the probability that she behaves honestly. We investigate the effect of such a probabilistic behaviour on the anonymity of the principals participating in the protocol, and formulate the necessary conditions to achieve ‘probable innocence’. Using these conditions, we propose a generalised Crowds-Trust protocol which uses trust information to achieves ‘probable innocence’ for principals exhibiting probabilistic behaviour

Factorization Contributions and the Breaking of the ΔI=1/2\Delta I=1/2 Rule in Weak ΛNρ\Lambda N\rho and ΣNρ\Sigma N\rho Couplings

We compute the modified factorization contributions to the $\Lambda\rightarrow N\rho$ and $\Sigma\rightarrow N\rho$ couplings and demonstrate that these contributions naturally include $\Delta I=3/2$ terms which are comparable ($\simeq 0.4$ to $-0.8$ times) in magnitude to the corresponding $\Delta I=1/2$ terms. As a consequence, we conclude that models which treat vector meson exchange contributions to the weak conversion process $\Lambda N\rightarrow NN$ assuming such weak couplings to satisfy the $\Delta I=1/2$ rule are unlikely to be reliable.Comment: 13 pages, uses REVTEX Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html . Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-5.T172.ps To appear in Physical Review