Non-commutative SU(N) gauge theories and asymptotic freedom

In this paper we analyze the one-loop renormalization of the $\theta$-expanded $\rm SU(N)$ Yang-Mills theory. We show that the {\it freedom parameter} $a$, key to renormalization, originates from higher order non-commutative gauge interaction, represented by a higher derivative term $b h \theta^{\mu\nu}\hat F_{\mu\nu}\star\hat F_{\rho\sigma}\star\hat F^{\rho\sigma}$. The renormalization condition fixes the allowed values of the parameter $a$ to one of the two solutions: $a=1$ or $a=3$, i.e. to $b=0$ or to $b=1/2$, respectively. When the higher order interaction is switched on, ($a=3$), pure non-commutative SU(N) gauge theory at first order in $\theta$-expansion becomes one-loop renormalizable for various representations of the gauge group. We also show that, in the case $a=3$ and the adjoint representation of the gauge fields, the non-commutative deformation parameter $h$ has to be renormalized and it is asymptotically free.Comment: 16 pages, no figure

The one-loop renormalization of the gauge sector in the noncommutative standard model

In this paper we construct a version of the standard model gauge sector on noncommutative space-time which is one-loop renormalizable to first order in the expansion in the noncommutativity parameter $\theta$. The one-loop renormalizability is obtained by the Seiberg-Witten redefinition of the noncommutative gauge potential for the model containing the usual six representations of matter fields of the first generation.Comment: 16 pages, 2 figure

TeV Scale Implications of Non Commutative Space time in Laboratory Frame with Polarized Beams

We analyze $e^{+}e^{-}\rightarrow \gamma\gamma$, $e^{-}\gamma \rightarrow e^{-}\gamma$ and $\gamma\gamma \rightarrow e^{+}e^{-}$ processes within the Seiberg-Witten expanded noncommutative scenario using polarized beams. With unpolarized beams the leading order effects of non commutativity starts from second order in non commutative(NC) parameter i.e. $O(\Theta^2)$, while with polarized beams these corrections appear at first order ($O(\Theta)$) in cross section. The corrections in Compton case can probe the magnetic component($\vec{\Theta}_B$) while in Pair production and Pair annihilation probe the electric component($\vec{\Theta}_E$) of NC parameter. We include the effects of earth rotation in our analysis. This study is done by investigating the effects of non commutativity on different time averaged cross section observables. The results which also depends on the position of the collider, can provide clear and distinct signatures of the model testable at the International Linear Collider(ILC).Comment: 22 pages, 19 figures, new comments and references added, few typos corrected, Published in JHE

Psychometric Properties of the Serbian Smartphone Application-Based Addiction Scale (SABAS) and Validation of the English Version Among Non-native English Speakers

The present study evaluated the psychometric properties of the Serbian Smartphone Application-Based Addiction Scale (SABAS) and the original English version of the same scale administered to a Serbian-speaking sample. In Study 1, 599 participants completed Serbian SABAS, with 189 having both test and retest data. Results suggested good internal consistency ( α = .81) and test–retest reliability ( ICC = .795, p < .001, 95% CI [.731, .844], r test-retest = .803) of the scale. Convergent validity of the SABAS was evaluated through correlations with the Smartphone Addiction Scale–Short Version (SAS-SV), as well as with anxiety, depression, worry, duration, and purpose of smartphone use. Divergent validity of the SABAS was evaluated through comparing the correlations with entertainment and productive smartphone use. The modified CFA model showed an acceptable fit ( χ 2 (8) = 25.53, p = .001, CFI = .961, TLI = .926, RMSEA = .096, SRMR = .042), confirming the unidimensionality of the SABAS. In the second study, the English SABAS, completed by 335 non-native speakers from Serbia, also showed a good fit of the single-factor model ( χ 2 (9) = 12.56, p = .184, CFI = .990, TLI = .984, RMSEA = .036, SRMR = 0.026), and good psychometric features. Based on the study’s findings, the Serbian version of SABAS is a reliable and valid measure for screening the risk of smartphone addiction. Moreover, the English version can be used among non-native Serbian English speakers

On UV/IR mixing in noncommutative gauge field theories

In formulating gauge field theories on noncommutative (NC) spaces it is suggested that particles carrying gauge invariant quantities should not be viewed as pointlike, but rather as extended objects whose sizes grow linearly with their momenta. This and other generic properties deriving from the nonlocal character of interactions (showing thus unambiguously their quantum-gravity origin) lead to a specific form of UV/IR mixing as well as to a pathological behavior at the quantum level when the noncommutativity parameter theta is set to be arbitrarily small. In spite of previous suggestions that in a NC gauge theory based on the theta-expanded Seiberg-Witten (SW) maps UV/IR mixing effects may be under control, a fairly recent study of photon self-energy within a SW theta-exact approach has shown that UV/IR mixing is still present. We study the self-energy contribution for neutral fermions in the theta-exact approach of NC QED, and show by explicit calculation that all but one divergence can be eliminated for a generic choice of the noncommutativity parameter theta. The remaining divergence is linked to the pointlike limit of an extended object.Comment: 10 pages, a figure added, version to appear in JHE

The Balkan region preferences for the treatment of anxiety disorders

The most countries from West Balkan region do not have the official guidelines for the treatment of patients with anxiety disorders (AD).We have done the survey on preferences of treatment of patients with AD. We have collected data from sample of 221 psychiatrists from Croatia (41 psychiatrists), Macedonia (81 psychiatrists) and Serbia (99 psychiatrists). They give as information about their preferences for treating patients with AD.The results indicate that the vast majority of psychiatrists report that almost all patients with AD receive benzodiazepines prior to first psychiatric visit. The majority of psychiatrist would opt for SSRI/SNRI antidepressants (91–97%) as the monotherapy or in combination with benzodiazepines (53–59%) or in combination with cognitive-behavior (25–35%) or psychodynamic psychotherapy (12–16%).The most indicative difference between psychiatrists from different countries is result about the use of pregabalin – almost half of Serbian subsample would opt for pregabalin, but only a quarter of Croatian subsample and no psychiatrist from Macedonian subsample would choose pregabalin. Also, much more Macedonian and Serbian psychiatrist would opt for CBT treatment, but, in contrast, much more Croatian psychiatrist would opt for psychodynamic psychotherapy versus CBT. There is the dissimilarity between preferences for patients’ treatment and preferences for psychiatrists himself/herself treatment:– more than half of the sample would opt for benzodiazepines in their patients but only the third of the sample would prefer benzodiazepines for himself/herself treatment;– more psychiatrists would prefer to receive psychotherapy treatment than they would prefer to give it to their patients.Disclosure of interestThe authors have not supplied their declaration of competing interest.</jats:sec