Light-Quark Decays in Heavy Hadrons

We consider weak decays of heavy hadrons (bottom and charmed) where the heavy quark acts as a spectator. Theses decays are heavily phase-space suppressed but may become experimentally accessible in the near future. These decays are interesting as a QCD laboratory to study the behaviour of the light quarks in the colour-background field of the heavy spectator.Comment: 11 pages, 6 table

Precision Physics with B^0_s -> J/psi phi at the LHC: The Quest for New Physics

CP-violating effects in the time-dependent angular distribution of the B^0_s -> J/psi[-> ell^+ ell^-] phi[-> K^+K^-] decay products play a key role for the search of new physics. The hadronic Standard-Model uncertainties are related to doubly Cabibbo-suppressed penguin contributions and are usually assumed to be negligibly small. In view of recent results from the Tevatron and the quickly approaching start of the data taking at the LHC, we have a critical look at the impact of these terms, which could be enhanced through long-distance QCD phenomena, and explore the associated uncertainty for the measurement of the CP-violating B^0_s-\bar B^0_s mixing phase. We point out that these effects can actually be controlled by means of an analysis of the time-dependent angular distribution of the B^0_s -> J/psi[-> ell^+ ell^-] \bar K^{*0}[-> pi^+ K^-] decay products, and illustrate this through numerical studies. Moreover, we discuss SU(3)-breaking effects, which limit the theoretical accuracy of our method, and suggest internal consistency checks of SU(3).Comment: 28 pages, 10 figure

Effective Field Theory of Gravity: Leading Quantum Gravitational Corrections to Newtons and Coulombs Law

In this paper we consider general relativity and its combination with scalar quantum electrodynamics (QED) as an effective quantum field theory at energies well below the Planck scale. This enables us to compute the one-loop quantum corrections to the Newton and Coulomb potential induced by the combination of graviton and photon fluctuations. We derive the relevant Feynman rules and compute the nonanalytical contributions to the one-loop scattering matrix for charged scalars in the nonrelativistic limit. In particular, we derive the post-Newtonian corrections of order $Gm/\text c^2 r$ from general relativity and the genuine quantum corrections of order $G\hbar/\text c^3 r^2$.Comment: 14 pages, 12 figure

The Golden Modes B^0 -> J/psi K_{S,L} in the Era of Precision Flavour Physics

The B^0 -> J/\psi K_{S,L} channels are outstanding probes of CP violation. We have a detailed look at the associated Standard-Model uncertainties, which are related to doubly Cabibbo-suppressed penguin contributions, and point out that these usually neglected effects can actually be taken into account unambiguously through the CP asymmetries and the branching ratio of the B^0 -> J/\psi pi^0 decay. Using the most recent B-factory measurements, we find a negative shift of the extracted value of beta, which softens the tension in the fits of the unitarity triangle. In addition, this strategy can be used to constrain a possible new-physics phase in B^0-\bar B^0 mixing. The proposed strategy is crucial to fully exploit the tremendous accuracies for the search for this kind of new physics that can be achieved at the LHC and future super-flavour factories.Comment: 4+1 pages, 4 figure

Limits on New Physics from exclusive B→D(∗)ℓνˉB \to D^{(*)}\ell \bar\nu Decays

We consider the exclusive decays $B \to D^{(*)}\,\ell \bar\nu$ and study the effect of non $V-A$ structures on the observables. We extend the standard model hadronic current by additional right-handed vector as well as left- and right-handed scalar and tensor contributions and calculate the decay rates including the perturbative corrections up to order $\alpha_s$. Using the data of the exclusive semileptonic $b \to c$ decays and recent calculations of the form factors at the non-recoil point we discuss the constraints to the wrong helicity admixtures in the hadronic current.Comment: 7 page

Minimal flavor violation and anomalous top decays

Top quark physics at the LHC may open a window to physics beyond the standard model and even lead us to an understanding of the phenomenon "flavour". However, current flavour data is a strong hint that no "new physics" with a generic flavour structure can be expected in the TeV scale. In turn, if there is "new physics" at the TeV scale, it must be "minimally flavour violating". This has become a widely accepted assumption for "new physics" models. In this paper we propose a model-independent scheme to test minimal flavour violation for the anomalous charged $Wtq$, $q\in{d,s,b}$, and flavour-changing $Vtq$, $q\in{u,c}$ and $V\in{Z,\gamma,g}$ couplings within an effective field theory framework, i.e., in a model-independent way. We perform a spurion analysis of our effective field theory approach and calculate the decay rates for the anomalous top-quark decays in terms of the effective couplings for different helicities by using a two-Higgs doublet model of type II, under the assumption that the top-quark is produced at a high-energy collision and decays as a quasi-free particle.Comment: 12 pages, 6 figure

Efficacy of standard and low dose hydrochlorothiazide in the recurrence prevention of calcium nephrolithiasis (NOSTONE trial): protocol for a randomized double-blind placebo-controlled trial

Background: Nephrolithiasis is a global healthcare problem with a current lifetime risk of 18.8% in men and 9.4% in women. Given the high cost of medical treatments and surgical interventions as well as the morbidity related to symptomatic stone disease, medical prophylaxis for stone recurrence is an attractive approach. Thiazide diuretics have been the cornerstone of pharmacologic metaphylaxis for more than 40 years. However, evidence for benefits and harms of thiazides in the prevention of calcium containing kidney stones in general remains unclear. In addition, the efficacy of the currently employed low dose thiazide regimens to prevent stone recurrence is not known. Methods: The NOSTONE trial is an investigator-initiated 3-year prospective, multicenter, double-blind, placebo-controlled trial to assess the efficacy of standard and low dose hydrochlorothiazide treatment in the recurrence prevention of calcium containing kidney stones. We plan to include 416 adult (≥ 18 years) patients with recurrent (≥ 2 stone episodes in the last 10 years) calcium containing kidney stones (containing ≥50% of calcium oxalate, calcium phosphate or a mixture of both). Patients will be randomly allocated to 50 mg or 25 mg or 12.5 mg hydrochlorothiazide or placebo. The primary outcome will be incidence of stone recurrence (a composite of symptomatic or radiologic recurrence). Secondary outcomes will be individual components of the composite primary outcome, safety and tolerability of hydrochlorothiazide treatment, changes in urinary biochemistry elicited by hydrochlorothiazide treatment and impact of baseline disease severity, biochemical abnormalities and stone composition on treatment response. Discussion: The NOSTONE study will provide long-sought information on the efficacy of hydrochlorothiazide in the recurrence prevention of calcium containing kidney stones. Strengths of the study include the randomized, double-blind and placebo-controlled design, the large amount of patients studied, the employment of high sensitivity and high specificity imaging and the exclusive public funding support. Trial registration: ClinicalTrials.gov, NCT03057431. Registered on February 20 2017

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