Fast Vacuum Decay into Quark Pairs in Strong Color Electric and Magnetic Fields

We study quark-pair creations in strong color electromagnetic fields. We point out that, for massless quarks, the vacuum persistency probability per unit space-time volume is zero, i.e., the quark-pair creation rate w is infinite, in general homogeneous color electromagnetic fields, while it is finite when the color magnetic field is absent. We find that the contribution from the lowest Landau level (LLL) dominates this phenomenon. With an effective theory of the LLL projection, we also discuss dynamics of the vacuum decay, taking into account the back reaction of pair creations.Comment: 4 pages, 1 figure, contribution to the proceedings of International conference on the structure of baryons (BARYONS'10), RCNP, Osaka, Japan, Dec. 7-11, 2010; fig.2 delete

The role of dissociation and eating disorder symptoms in facing loss, abandonment and sexual abuse trauma sequelae in the case of Ana

The link between eating disorder symptoms and both dissociation and childhood sexual abuse has received significant empirical support. This paper surveyed current literature regarding that relationship and examined the role of dissociation in both eating disorder symptoms and in overcoming complex trauma symptoms. The question of whether dissociation serves as a protective defense or a pathological process, particularly in individuals who have suffered chronic sexual abuse, has often been posed. To that end, case material from a three-year individual psychotherapy treatment of a young woman with an eating disorder and history of sexual abuse was used to gain understanding of the use of both conscious and unconscious dissociation, and eating disorder symptoms to defend against psychological pain related to trauma and feelings of loss and abandonment. ^ The study considered two central questions. First, did the patient utilize eating disordered symptoms to bring about the by-products of dissociation (i.e. soothing, numbing and self-protection from psychological pain), once she began to re-live formerly dissociated experiences in treatment? Second, in helping patients to face past traumas and to enhance their understanding of the impact of those traumas on current functioning, is it therapeutic to dismantle dissociation in treatment? Findings from case material, current research and consultation with experts were used to support conclusions regarding these questions.^ Both literature and case material reviewed in this project suggest that a strong link exists between dissociation and sexual abuse trauma, and eating disorder symptoms and dissociation. Optimal treatment for patients presenting with both eating disorder symptoms and complex trauma histories would involve a relational approach, which helps patients to uncover the underlying attachment and trauma dynamics that drive and maintain symptoms. Additionally, helping patients to understand the possible dissociative aspects and symbolism of binge/purge cycles in the context of past and recurring trauma is crucial. Symptoms are dissociative in that they allow for the disavowal of painful affects and assist albeit maladaptively, in affect regulation. In many cases, tackling dissociative aspects of eating disorder symptoms in the aforementioned manner helps patients lead healthier lives psychologically and achieve their personal goals.

D1 (2420) and its interactions with a kaon: Open charm states with strangeness

In this work we present an attempt to describe the X1(2900) found by the LHCb collaboration, in the experimental data on the invariant mass spectrum of D-K+, as a three-meson molecular state of the KρD¯ system. We discuss that the interactions in all the subsystems are attractive in nature, with the ρD¯ interaction generating D¯1(2420) and the Kρ resonating as K1(1270). We find that the system can form a three-body state but with a mass higher than that of X1(2900). We investigate the KρD system too, finding that the three-body dynamics generates an isoscalar state, which can be related to Ds1∗(2860), and an exotic isovector state. This latter state has a mass similar to that of the X0(2900) and X1(2900) states found by LHCb, but a very small width (∼7.4±0.9 MeV) and necessarily requires more than two quarks to describe its properties. We hope that our findings will encourage experimental investigations of the isovector KρD state. Finally, in the pursuit of finding a description for X1(2900), we study the πK̄∗D∗ system where K̄∗D∗ forms 0+, 1+, and 2+ states. We do not find a state that can be associated with X1(2900)

The

We have studied the exotic doubly charmed D*D system providing a natural explanation for the peak recently observed by LHCb, in terms of D*+D0 and D*0D+ with isospin I = 0. The width has been evaluated accurately based on the decay widths of the D* states. The D0D0π+ decay mode of the bound state formed is studied in detail, showing a narrow peak below the D*+D0 threshold and some strength above it, as observed in the experiment. The remarkable agreement of this approach and the latter experimental analysis supports strongly the molecular nature of this state, the first example of a meson with two open charmed quarks. This study can be naturally extended to the bottom sector giving interesting features for the B(*)(s)B(*)(s) counterparts found there. In addition, our previous study on the D*D* molecular state has been revisited taking into account the insights extracted from the Tcc state and the new results are included in the present manuscript