17 research outputs found
New physics contributions to moments of inclusive b → c semileptonic decays
No full textInclusive semileptonic B → decays, where ℓ = μ, e, are by now standard candles in the determination of the CKM element |V|. These determinations rely on the heavy-quark expansion and use moments of decay spectra to extract the non-perturbative parameters directly from data under the standard model assumption.At the same time, new physics could influence the moments of the inclusive decay. In this paper, we compute power-corrections and next-to-leading order corrections in the strong coupling constant using the full basis of dimension-six new physics operators for the inclusive B → decay. We provide predictions for lepton energy, hadronic and leptonic invariant mass moments, and perform a phenomenological study to show the possible impact of new physics. Our results could be used to perform a global fit including new physics contributions.Inclusive semileptonic decays, where , are by now standard candles in the determination of the CKM element . These determinations rely on the heavy-quark expansion and use moments of decay spectra to extract the non-perturbative parameters directly from data under the standard model assumption. At the same time, new physics could influence the moments of the inclusive decay. In this paper, we compute power-corrections and next-to-leading order corrections in the strong coupling constant using the full basis of dimension-six new physics operators for the inclusive decay. We provide predictions for lepton energy, hadronic and leptonic invariant mass moments, and perform a phenomenological study to show the possible impact of new physics. Our results could be used to perform a global fit including new physics contributions
UTILIZATION OF THE KRUENG ACEH RIVER BEDROOM POST SETUP ACCORDING TO AD-DAULAH MILK PERSPECTIVE: Case Study In Krueng Barona Jaya District
No full textThe Krueng Aceh Watershed (DAS) is one of the state assets managed by the Sumatra-I River Basin, so it is widely used by the surrounding community to meet the needs of life on the banks of the Krueng Aceh river. Management of land along the river is the main goal to anticipate in reducing the potential for flooding. Therefore, the author wants to examine in detail the process of riverbank land use carried out by the Krueng Barona Jaya community, forms of riverbank land use and their use according to the perspective of milk al-daulah. The method used in this study is a qualitative method through primary data obtained by direct field research using interview, observation, and documentation techniques. The results of this study indicate that the process of using land along the Krueng Aceh river by the Krueng Baroena Jaya community after the Krueng Aceh river arrangement refers to the past law, namely customary law, so there is no administrative data recorded as evidence that they have permission to use the riverbanks. The forms of land use along the Krueng Aceh river that are carried out by the Krueng Barona Jaya community on riverbank land are by constructing buildings, opening culinary stalls, plantation land and livestock land. In terms of utilization carried out by the people of Krueng Barona Jaya in terms of buildings, the licensing process, and the forms of utilization, it is a violation that is contrary to the Regulation of the Minister of PUPR of the Republic of Indonesia Number 28/PRT/M/2015 Article 22 concerning Determination of River Border Lines and the concept of milk al-daula. Therefore, the government must immediately bring back the land along the Krueng Aceh banks so that its utilization is in accordance with the applicable provisions
Auf der Suche nach neuer Physik in Bottom-Quark-Zerfällen
No full textIn recent years, small deviations between experimental measurements and predictions from the Standard Model (SM) have been observed in bottom-quark decays, which indicate that Lepton Flavour Universality (LFU) may be violated. These small deviations, the so-called b-anomalies, have been observed in the two decay channels b → cℓ ̄ν and b → sℓℓ. To ensure that the b-anomalies are not an underestimation of the systematic uncertainties, we aim in this thesis to improve the precision of flavour physics prediction while also providing insight on the tension between theory prediction and experimental measurement by incorporating New Physics (NP) effects and their impact on observables in the bottom-quark decay.
This dissertation is written in the form of a cumulative work based on our six articles, four of which have been published in international peer-reviewed journals and the remaining two are being prepared for publication. First, we investigate the background signals of the inclusive decay B → Xcℓ ̄ν that is relevant for the extraction of |Vcb|. In order to increase precision, we argue that removing the background signals from Monte-Carlo simulation data should be avoided because it introduces uncertainties. Instead, we can precisely compute the background signals using Heavy Quark Expansion (HQE).
In addition, we investigate the LFU symmetry of the SM in the semileptonic B → Xcℓ ̄ν decays. Ratios of branching fractions between decays are used to probe the LFU hypothesis, where our calculation of the LFU ratios for the SM takes into account the mass effects in the total decay rate. We provide updated results for the branching ratio of B → Xcτ ̄ν. If there is a difference between SM predictions and experimental data, this could indicate the presence of NP impacts.
We also investigate the possibility of NP effect in the inclusive semileptonic B → Xcℓ ̄ν decay. The calculations rely on the HQE and use non-perturbative parameters extracted from decay spectra. The extraction of HQE parameters is done assuming the SM, but we explore the idea that NP effects might be hidden in the HQE parameters. The primary goal is to lay the groundwork for a global fit analysis that includes the full basis of NP operators, allowing for the extraction of HQE parameters and consequently an updated result for |Vcb| with NP effects.
In the baryonic decay channel we investigate the possibility of the Lepton Flavour Violation (LFV) for the exclusive decay Λb → Λℓ−ℓ+ using a full basis of NP operators for the first time. We investigate the branching ratio and forward-backward symmetry of the decay quantitatively using both a model-independent and model-dependent approach. We emphasize that the baryonic decay constrains the NP Wilson coefficients differently from the mesonic decay, which has the potential to further constrain the allowed parameter space for NP models. We can also improve the constraint of the NP models by reducing the hadronic uncertainties caused by the ten independent local form factors of Λb → Λ. To improve the control of the uncertainties, we introduce a new parametrization for the local form factors in which the form factor parameters are bounded due to orthonormal polynomials that diagonalize the form factor contribution within their respective dispersive bounds. We show, using a Bayesian analysis of available lattice QCD data, that our model provides excellent control over systematic uncertainty when extrapolating to the region of large hadronic recoil.
As part of this thesis’s final project, we investigate the light-cone distribution amplitude (LCDA) of the B meson. We are particularly interested in three-particle LCDAs, which can be found in higher dimensional vacuum-to-meson matrix elements. These matrix elements can be parametrized in terms of two parameters. To estimate the parameters, we propose alternative diagonal QCD sum rules. The sum rules of our new approach have the advantage of being positive definite, which means that we expect the quark-hadron duality to be more accurate than the previous studied sum rules.In den letzten Jahren wurden kleine Abweichungen zwischen experimentellen Messungen und Vorhersagen des Standardmodells (SM) bei Bottom-Quark-Zerfällen beobachtet, was auf eine Verletzung der Lepton Flavour Universalität (LFU) hindeuten könnte. Diese Abweichungen, die sogenannten b-Anomalien, wurden in den beiden Zerfallskanälen b → cℓ ̄ν und b → sℓℓ beobachtet. Um sicherzustellen, dass die b-Anomalien nicht eine Unterschätzung der systematischen Unsicherheiten sind, zielen wir in dieser Arbeit darauf ab, die Genauigkeit der Vorhersagen der Flavour-Physik zu verbessern und gleichzeitig einen Einblick in die Spannung zwischen der theoretischen Vorhersage und der experimentellen Messung zu geben, indem wir die Effekte der Neuen Physik (NP) und ihre Auswirkungen auf die Observablen im Bottom-Quark-Zerfall ber ̈ucksichtigen.
Diese Dissertation ist in Form einer kumulativen Arbeit geschrieben, die auf unseren sechs Artikeln basiert, von denen vier in internationalen, von Experten begutachteten Zeitschriften veröffentlicht wurden und die restlichen zwei sind in Vorbereitung zur Veröffentlichung. Zunächst untersuchen wir die Hintergrundsignale des inklusiven Zerfalls B → Xcℓ ̄ν, der für die Extraktion von |Vcb| relevant ist. Um die Genauigkeit zu erhöhen, argumentieren wir, dass die Subtraktion der Hintergrundsignale aus den Monte-Carlo-Simulationsdaten vermieden werden sollte, da dies Unsicherheiten mit sich bringt. Stattdessen können wir die Hintergrundsignale mithilfe der Heavy Quark Expansion (HQE) präzise berechnen.
Darüber hinaus untersuchen wir die LFU-Symmetrie des SM in den semileptonischen B → Xcℓ ̄ν Zerfällen. Unsere Berechnung der LFU-Verhältnisse für das SM berücksichtigt die Masseneffekte in der Gesamtzerfallsrate. Wir liefern aktualisierte Ergebnisse für das Verzweigungsverhältnis von B → Xcτ ̄ν. Die Verzweigungsverhältnisse zwischen den Zerfällen werden verwendet, um die LFU-Hypothese zu überprüfen. Wenn es einen Unterschied zwischen den SM-Vorhersagen und den experimentellen Daten gibt, könnte dies auf das Vorhandensein von Auswirkungen der Neuen Physik hinweisen.
Wir untersuchen auch die Möglichkeit eines NP-Effekts im inklusiven semileptonischen B → Xcℓ ̄ν Zerfall. Die Berechnungen beruhen auf der HQE und verwenden nicht-perturbative Parameter, die aus Zerfallsspektren extrahiert werden. Die Extraktion der HQE-Parameter erfolgt unter der Annahme des SM, aber wir untersuchen die Idee, dass NP-Effekte in den HQE-Parametern versteckt sein könnten. Das primäre Ziel ist es, den Grundstein für eine globale Fit-Analyse zu legen, die die gesamte Basis der NP-Operatoren einschließt und die Extraktion von HQE-Parametern und folglich ein aktualisiertes Ergebnis für |Vcb| mit NP-Effekten ermöglicht.
Im baryonischen Zerfallskanal untersuchen wir erstmals die Möglichkeit der Lepton Flavour Violation (LFV) für den exklusiven Zerfall Λb → Λℓ−ℓ+ unter Verwendung einer vollständigen Basis von NP-Operatoren. Wir untersuchen das Verzweigungsverhältnis und die Vorwärts-Rückwärts-Symmetrie des Zerfalls quantitativ sowohl mit einem modellunabhängigen als auch mit einem modellabhängigen Ansatz. Wir betonen, dass der baryonische Zerfall die NP-Wilson-Koeffizienten anders einschränkt als der mesonische Zerfall, was das Potenzial hat, den zulässigen Parameterraum für NP-Modelle weiter einzuschränken. Wir können auch die Einschränkung der NP-Modelle verbessern, indem wir die hadronischen Unsicherheiten reduzieren, die durch die zehn unabhängigen lokalen Formfaktoren von Λb → Λ verursacht werden. Um die Kontrolle der Unsicherheiten zu verbessern, führen wir eine neue Parametrisierung für die lokalen Formfaktoren ein, bei der die Formfaktorparameter aufgrund der Verwendung von orthonormalen Polynomen begrenzt sind, die den Formfaktorbeitrag innerhalb ihrer jeweiligen dispersiven Grenzen diagonalisieren. Anhand einer Bayes’schen Analyse verfügbarer Gitter-QCD-Daten zeigen wir, dass unser Modell eine ausgezeichnete Kontrolle über die systematische Unsicherheit bei der Extrapolation in den Bereich des großen hadronischen Rückstoßes bietet.
Im Rahmen des Abschlussprojekts dieser Arbeit untersuchen wir die Lichtkegelverteilungsamplitude (LCDA) des B-Mesons. Wir interessieren uns besonders für die LCDAs von drei Teilchen, die in höherdimensionalen Vakuum-Meson-Matrixelementen gefunden werden können. Diese Matrixelemente können mit zwei Parametern parametrisiert werden. Um die Parameter abzuschätzen, schlagen wir alternative diagonale QCD-Summenregeln vor. Die Summenregeln unseres neuen Ansatzes haben den Vorteil, dass sie positiv definit sind, was bedeutet, dass wir erwarten, dass die Quark-Hadron-Dualität genauer ist als die bisher untersuchten Summenregeln
Thoracoscopic division of vascular rings in infants and children
No full textAuthors: Al-Bassama Abdulrahman, Saquib Mallick, Al-Qahtani, Aayed, & Al-Tokhais, Tariq, , From the Division of Pediatric Surgery, Department of Surgery,
Author: Al-Boukai, Ahmed From the Department of Radiology,
Author: Thalag Ahmed, From Department of Anaesthesia,
Author: Aksaadu Muslem, From Department of Surgery, King Khalid University Hospital and College of Medicine, King Saud University, PO Box 86572,
Riyadh 11632, Saudi ArabiaObjective: Traditionally vascular rings in infants and children are treated through an open thoracotomy.
Recently, thoracoscopic surgery has been used for these complex procedures. This study reports our
early experience with thoracoscopic division of vascular rings and evaluates the efficacy and safety of
this approach.
Material and Methods: Patients who underwent thoracoscopic division of vascular rings at King Khalid
University Hospital, Riyadh, Saudi Arabia, from December 2004 to January 2006 are included. Their
data were carefully analyzed looking at demographics, clinical presentation, diagnostic modality, type of
the anomaly, operative details, complications, and outcome.
Results: A total of 9 patients underwent thoracoscopic division of vascular rings. Age at surgery ranged
between 2 and 108 months (mean, 24 months). Weight varied between 5.3 and 32 kg (mean, 10.3 kg).
All patients were symptomatic. Computed tomographic scan was diagnostic and accurately defined the
type of anomaly in all the patients. Four patients had a right aortic arch with an aberrant left subclavian
artery and left ductus/ligamentum arteriosum, 2 had double aortic arches, and 3 had a right aberrant
subclavian artery. One patient developed right-sided pneumothorax on the contralateral site, and another
one developed apnea 12 hours after surgery, requiring mechanical ventilation. There was no mortality.
Operative time ranged between 50 and 145 minutes, the mean being 107 minutes. The average hospital
stay was 4 days. Five patients had their preoperative symptoms completely resolved, and the rest are
showing steady improvement. The average follow-up period is 6 months
Impact of background effects on the inclusive V cb determination
No full textAbstract The determination of the CKM element V cb from inclusive semileptonic b → cℓ ν ¯ decays has reached a high precision thanks to a combination of theoretical and experimental efforts. Aiming towards even higher precision, we discuss two processes that contaminate the inclusive V cb determination; the b → u background and the contribution of the tauonic mode: b → c(τ → μν ν ¯ ) ν ¯ . Both of these contributions are dealt with at the experimental side, using Monte-Carlo methods and momentum cuts. However, these contributions can be calculated with high precision within the Heavy-Quark Expansion. In this note, we calculate the theoretical predictions for these two processes. We compare our b → u results qualitatively with generator-level Monte-Carlo data used at Belle and Belle II. Finally, we suggest to change the strategy for the extraction of V cb by comparing the data on B → Xℓ directly with the theoretical expressions, to which our paper facilitates
Lepton flavour violation in rare
No full textLepton flavour violation (LFV) naturally occurs in many new physics models, specifically in those explaining the B anomalies. While LFV has already been studied for mesonic decays, it is important to consider also baryonic decays mediated by the same quark transition. In this paper, we study LFV in the baryonic using for the first time a full basis of New Physics operators. We present expected bounds on the branching ratio in a model-independent framework and using two specific new physics models. Finally, we point out the interplay and orthogonality between the baryonic and mesonic LFV searches
Standard Model predictions for Lepton Flavour Universality ratios of inclusive semileptonic decays
No full textWe present Standard Model predictions for lepton flavour universality ratios
of inclusive . For the , these
ratios are very close to unity as expected. For the mode, we update the
SM prediction for the branching ratio including power-corrections in the
heavy-quark expansion up to . These inclusive ratios serve as an
important cross-check of the exclusive modes, in
which tensions exists between the predictions and measurements in those modes.Comment: 13 pages, 1 figur
Dispersive bounds for local form factors in transitions
No full textWe investigate the ten independent local form-factors relevant to the
-baryon decay , combining information of
lattice QCD and dispersive bounds. We propose a novel parametrization of the
form factors in terms of orthonormal polynomials that diagonalizes the form
factor contributions to the dispersive bounds. This is a generalization of the
unitarity bounds developed for meson-to-meson form-factors. In contrast to
ad-hoc parametrizations of these form factors, our parametrization provides a
degree of control of the form-factor uncertainties at large hadronic recoil.
This is of phenomenological interest for theoretical predictions of, e.g.,
and decay
processes.Comment: 20 pages, 4 figure
“Hudud al-‘Alam” about the Bulgarians and Authenticity of its Data
No full textВ хазарский период различные групы болгар Восточной и Юго-Восточной Европы были описаны в сочинениях мусульманских географов. Однако вхождение болгар в состав различных государственных образований раннего средневековья, а также их рассеяность на территории Европы породили довольно противоречивую и запутанную информацю о них в письменных источниках. Именно это и заставляет с особой осторожностью относиться к подобным сведениям и даже ставить под сомнение их достоверность. В особенной степени сказанное можно отнести к тексту «Худуд ал-‘Алам», ставящему перед исследователями массу вопросов.Usually, researchers see in “Hudud al-‘Alam” a difficult compiling written source of the ending of 10-th century AD, that does not deserve the special trust herein. However the evidences of anonymous treatise about the Bulgarians is of a special interest. So, “Hudud al-‘Alam” contains the information about the “Inner Bulgarians”. The analysis of text of this book allowed to come to the conclusion, that the anonymous author named the “Inner” those Bulgarians who lived in the steppes of Don basin and Azov Sea coast. Word-combination “Inner Bulgarians” could relate to the left (western) wing of the primary union of the nomadic Pro-Bulgarians. Besides, the anonymous author named the Volga Bulgarians as the “B.rtas”. He called also the Danube Bulgarians as “V.n.n.d.r’. Thus, the anonymous author of “Hudud al-‘Alam” used the different muslem written sources and as a result he met many difficulties. Therefore he created his the Map of the World. Besides, author of “Hudud al-‘Alam” reflected the new realities of the end of 10-th centuries AD. Therefore we must very carefully behave to the information of this medieval written source
