278 research outputs found
Lessons from Recent Measurements of D-\bar D Mixing
An impressive progress in measurements of the D-\bar D mixing parameters has
been made in recent years. We explore the implications of these measurements to
models of new physics, especially in view of recent upper bounds on the amount
of CP violation. We update the constraints on non-renormalizable four-quark
operators. We show that the experiments are close to probing minimally flavor
violating models with large tan beta. The data challenge models with a scale of
order TeV where the flavor violation in the down sector is suppressed by
alignment and, in particular, certain classes of supersymmetric models and of
warped extra dimension models.Comment: 20 pages, 1 figure. Added references, minor corrections and
clarifications. Matches published versio
Kualitas Pengalaman Kuliner Bali Dan Pengaruhnya Terhadap Niat Berperilaku Wisatawan
Banyak wisatawan yang saat ini mengunjungi Bali untuk mengalami pengalaman budaya yang kuat dan juga mencoba masakan khas Bali. Penelitian ini bertujuan untuk mengukur persepsi wisatawan terhadap kualitas makanan tradisional Bali dan pengaruhnya terhadap kepuasan kuliner wisatawan serta kepuasan wisatawan terhadap Bali sebagai destinasi wisata. Survei terhadap 207 responden dilakukan dan data primer yang terkumpul dianalisis dengan menggunakan metode SEM-PLS. Temuan menunjukkan kualitas makanan dapat memicu pemilihan destinasi dan berkontribusi terhadap kepuasan yang dirasakan. Hasil penelitianjuga menggambarkan bahwa kepuasan destinasi dan kuliner dapat memicu niat berperilaku wisatawan seperti mengkonsumsi kembali makanan tradisional Bali, mengunjungi Bali sebagai tempat liburan, atau merekomendasikan orang lain untuk mengkonsumsi makanan Bali atau mengunjungi Bali. Secara keseluruhan, hasil penelitian ini menunjukkan bahwa kualitas pengalaman kuliner yang dialami wisatawan mampu mempengaruhi niat berperilaku dengan melalui kepuasan terhadap pengalaman kuliner dan kepuasan terhadap destinasi secara tidak langsung. Many visitors nowadays are visiting Bali to experience a strong cultural experience and trying Balinese unique cuisines. This research aimed to analyze the effects of quality of Balinese traditional food, tourist culinary experience satisfaction and also destination experience satisfaction towards tourist's behavioral intentions. A questionnaire that involved 207 respondents was completed and being analyzed using SEM-PLS method. The findings indicates quality of food may trigger destination choice and contribute to perceived satisfaction. Second, the findings illustrate that the destination and culinary satisfaction may triggering tourist behavior intention such as reconsume Balinese traditional food, revisit Bali as leisure destination, or recommend other people to try Balinese food or visit Bali. In essence, the results imply that quality of culinary experience affects the tourist behavioural intentions indirectly through the tourist's culinary experience satisfaction and destination experience satisfaction
Modulatory effect of fluoride and irradiation on rat molar rate of wear
The hypothesis was tested that fluoride (F-) modulates molar wear rate in the irradiated rat and that enamel solubility and dentin hardness are involved in this process. Seventy five 21 day-old rats were divided into 5 groups. Groups received either F-(25 ppm) in the drinking water or irradiation to the head (15 Gy in a single dose), or a combination of the two. The rate of occlusal wear was assessed by computerized planimetry.The amount of wear was significantly higher in the F- and irradiation monotreated rats, while under combined treatment it did nor differ significantly from the control values. Fluoridation or irradiation suppressed enamel solubility, as measured by calcium release in the etchant. Dentin microhardness, expressed in Vickers hardness number, was enhanced after either treatment, but remained unaffected when F- administration preceded irradiation. Enamel solubility and dentin microhardness did not correlate significantly with the rate of occlusal wear.L’hypothèse vérifiée dans cette recherche a été la modulation par le fluoré (F-) de l’usure des molaires du rat irradié et de l’éventuelle contribution de la solubilité de l’émail et de la dureté dentinaire dans ce processus. Soixante-dix rats âgés de 21 jours ont été divisés en 5 groupes. Les groupes ont reçu soit 25ppm F- dans l’eau de boisson, soit une dose unique d’irradiation (15 Gy) dans la sphère cranio-faciale, soit les deux traitements combinés. Le niveau d’usure occlusale des molaires a été déterminée par planimétrie computerisée.La quantité d’usure a été plus prononcée chez les animaux recevant uniquement du F- ou une irradiation tandis que les deux traitements combinés ont été suivis par des valeurs d’usure semblables a celles mesurées chez les témoins. La solubilité de l’émail, établie selon la quantité de calcium présente dans la solution corrosive et exprimée en mg/l Ca+ +, a été réduite par chacun des deux traitements. La dureté de la dentine, exprimée en unités Vickers, a été amplifiée par chaque traitement, restant toutefois inchangée uniquement chez les animaux recevant du F- avant l’irradiation. Les resultats de l’étude corrélative entre l’usure occlusale et la solubilité de l’émail ou la dureté dentinaire n’ont pas atteint des valeurs significatives
Covariant Description of Flavor Conversion in the LHC Era
A simple covariant formalism to describe flavor and CP violation in the
left-handed quark sector in a model independent way is provided. The
introduction of a covariant basis, which makes the standard model approximate
symmetry structure manifest, leads to a physical and transparent picture of
flavor conversion processes. Our method is particularly useful to derive robust
bounds on models with arbitrary mechanisms of alignment. Known constraints on
flavor violation in the K and D systems are reproduced in a straightforward
manner. Assumptions-free limits, based on top flavor violation at the LHC, are
then obtained. In the absence of signal, with 100 fb^{-1} of data, the LHC will
exclude weakly coupled (strongly coupled) new physics up to a scale of 0.6 TeV
(7.6 TeV), while at present no general constraint can be set related to Delta
t=1 processes. LHC data will constrain Delta F=2 contributions via same-sign
tops signal, with a model independent exclusion region of 0.08 TeV (1.0 TeV).
However, in this case, stronger bounds are found from the study of CP violation
in D-bar D mixing with a scale of 0.57 TeV (7.2 TeV). In addition, we apply our
analysis to models of supersymmetry and warped extra dimension. The minimal
flavor violation framework is also discussed, where the formalism allows to
distinguish between the linear and generic non-linear limits within this class
of models.Comment: 24 pages, 6 figures. Some corrections and clarifications; references
added. Matches published versio
Charming CP Violation and Dipole Operators from RS Flavor Anarchy
Recently the LHCb collaboration reported evidence for direct CP violation in
charm decays. The value is sufficiently large that either substantially
enhanced Standard Model contributions or non-Standard Model physics is required
to explain it. In the latter case only a limited number of possibilities would
be consistent with other existing flavor-changing constraints. We show that
warped extra dimensional models that explain the quark spectrum through flavor
anarchy can naturally give rise to contributions of the size required to
explain the the LHCb result. The D meson asymmetry arises through a sizable
CP-violating contribution to a chromomagnetic dipole operator. This happens
naturally without introducing inconsistencies with existing constraints in the
up quark sector. We discuss some subtleties in the loop calculation that are
similar to those in Higgs to \gamma\gamma. Loop-induced dipole operators in
warped scenarios and their composite analogs exhibit non-trivial dependence on
the Higgs profile, with the contributions monotonically decreasing when the
Higgs is pushed away from the IR brane. We show that the size of the dipole
operator quickly saturates as the Higgs profile approaches the IR brane,
implying small dependence on the precise details of the Higgs profile when it
is quasi IR localized. We also explain why the calculation of the coefficient
of the lowest dimension 5D operator is guaranteed to be finite. This is true
not only in the charm sector but also with other radiative processes such as
electric dipole moments, b to s\gamma, \epsilon'/\epsilon_K and \mu\ to
e\gamma. We furthermore discuss the interpretation of this contribution within
the framework of partial compositeness in four dimensions and highlight some
qualitative differences between the generic result of composite models and that
obtained for dynamics that reproduces the warped scenario.Comment: 14 page
Muscular dysfunction elicited by creep of lumbar viscoelastic tissues.
Abstract The biomechanics, histology and electromyography of the lumbar viscoelastic tissues and multifidus muscles of the in vivo feline were investigated during 20 min of static as well as cyclic flexion under load control and during 7 h of rest following the flexion. It was shown that the creep developed in the viscoelastic tissues during the 20 min of static or cyclic flexion did not fully recover over the 7 h of following rest. It was further seen that a neuromuscular disorder with five distinct components developed during and after the static and cyclic flexion. The neuromuscular disorder consisted of a decreasing magnitude of reflexive EMG from the multifidus upon flexion as well as of superimposed spasms. The recovery period was characterized by an initial muscle hyperexcitability, a slowly increasing reflexive EMG and a delayed hyperexcitability. Histological data from the supraspinous ligament demonstrate significant increase (× 10) in neutrophil density in the ligament 2 h into the recovery and even larger increase (×100) 6 h into the recovery from the 20 min flexion, indicating an acute soft tissue inflammation. It was concluded that sustained static or cyclic loading of lumbar viscoelastic tissues may cause micro-damage in the collagen structure, which in turn reflexively elicit spasms in the multifidus as well as hyperexcitability early in the recovery when the majority of the creep recovers. The micro-damage, however, results in the time dependent development of inflammation. In all cases, the spasms, initial and delayed hyperexcitabilities represent increased muscular forces applied across the intervertebral joints in an attempt to limit the range of motion and unload the viscoelastic tissues in order to prevent further damage and to promote healing. It is suggested that a significant insight is gained as to the development and implications of a common idiopathic low back disorder as well as to the development of cumulative trauma disorders
Predictions from Heavy New Physics Interpretation of the Top Forward-Backward Asymmetry
We derive generic predictions at hadron colliders from the large
forward-backward asymmetry observed at the Tevatron, assuming the latter arises
from heavy new physics beyond the Standard Model. We use an effective field
theory approach to characterize the associated unknown dynamics. By fitting the
Tevatron t \bar t data we derive constraints on the form of the new physics.
Furthermore, we show that heavy new physics explaining the Tevatron data
generically enhances at high invariant masses both the top pair production
cross section and the charge asymmetry at the LHC. This enhancement can be
within the sensitivity of the 8 TeV run, such that the 2012 LHC data should be
able to exclude a large class of models of heavy new physics or provide hints
for its presence. The same new physics implies a contribution to the
forward-backward asymmetry in bottom pair production at low invariant masses of
order a permil at most.Comment: 11 pages, 6 figures. v2: added remarks on EFT validity range, dijet
bounds and UV completions; matches published versio
Rare B decays and Tevatron top-pair asymmetry
The recent Tevatron result on the top quark forward-backward asymmetry, which
deviates from its standard model prediction by 3.4, has prompted many
authors to build new models to account for this anomaly. Among the various
proposals, we find that those mechanisms which produce via - or
-channel can have a strong correlation to the rare B decays. We demonstrate
this link by studying a model with a new charged gauge boson, . In terms of
the current measurements on decays, we conclude that the branching
ratio for is affected most by the new effects.
Furthermore, using the world average branching ratio for the exclusive B decays
at level, we discuss the allowed values for the new parameters.
Finally, we point out that the influence of the new physics effects on the
direct CP asymmetry in B decays is insignificant.Comment: 15 page, 6 figures, typos corrected and references added, final
version to appear journa
The flavor puzzle in multi-Higgs models
We reconsider the flavor problem in the models with two Higgs doublets. By
studying two generation toy models, we look for flavor basis independent
constraints on Yukawa couplings that will give us the mass hierarchy while
keeping all Yukawa couplings of the same order. We then generalize our findings
to the full three generation Standard Model. We find that we need two
constraints on the Yukawa couplings to generate the observed mass hierarchy,
and a slight tuning of Yukawa couplings of order 10%, much less than the
Standard Model. We briefly study how these constraints can be realized, and
show how flavor changing currents are under control for mixing in
the near-decoupling limit.Comment: 26 pages, typos are corrected, references are added, the final
versio
Flavour physics from an approximate U(2)^3 symmetry
The quark sector of the Standard Model exhibits an approximate U(2)^3 flavour
symmetry. This symmetry, broken in specific directions dictated by minimality,
can explain the success of the Cabibbo-Kobayashi-Maskawa picture of flavour
mixing and CP violation, confirmed by the data so far, while allowing for
observable deviations from it, as expected in most models of ElectroWeak
Symmetry Breaking. Building on previous work in the specific context of
supersymmetry, we analyze the expected effects and we quantify the current
bounds in a general Effective Field Theory framework. As a further relevant
example we then show how the U(2)^3 symmetry and its breaking can be
implemented in a generic composite Higgs model and we make a first analysis of
its peculiar consequences. We also discuss how some partial extension of U(2)^3
to the lepton sector can arise, both in general and in composite Higgs models.
An optimistic though conceivable interpretation of the considerations developed
in this paper gives reasons to think that new physics searches in the flavour
sector may be about to explore an interesting realm of phenomena.Comment: 29 pages, 5 figure
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