New physics searches at kaon and hyperon factories.

Rare meson decays are among the most sensitive probes of both heavy and light new physics. Among them, new physics searches using kaons benefit from their small total decay widths and the availability of very large datasets. On the other hand, useful complementary information is provided by hyperon decay measurements. We summarize the relevant phenomenological models and the status of the searches in a comprehensive list of kaon and hyperon decay channels. We identify new search strategies for under-explored signatures, and demonstrate that the improved sensitivities from current and next-generation experiments could lead to a qualitative leap in the exploration of light dark sectors.

The muon Smasher's guide.

We lay out a comprehensive physics case for a future high-energy muon collider, exploring a range of collision energies (from 1 to 100 TeV) and luminosities. We highlight the advantages of such a collider over proposed alternatives. We show how one can leverage both the point-like nature of the muons themselves as well as the cloud of electroweak radiation that surrounds the beam to blur the dichotomy between energy and precision in the search for new physics. The physics case is buttressed by a range of studies with applications to electroweak symmetry breaking, dark matter, and the naturalness of the weak scale. Furthermore, we make sharp connections with complementary experiments that are probing new physics effects using electric dipole moments, flavor violation, and gravitational waves. An extensive appendix provides cross section predictions as a function of the center-of-mass energy for many canonical simplified models.

Light Scalars and the Koto Anomaly.

We show that the recent excess presented by KOTO in their search for K_{L}→π^{0}νν[over ¯] may be due to weakly coupled scalars produced from Kaon decays. We study two concrete realizations, the minimal Higgs portal and a hadrophilic scalar model, and demonstrate that they can explain the observed events while satisfying existing limits. The simplicity of these models, and their possible relations to interesting UV constructions, provides strong theoretical motivation for a new physics interpretation of the KOTO data.

Long-lived particles at the energy frontier: the MATHUSLA physics case.

We examine the theoretical motivations for long-lived particle (LLP) signals at the LHC in a comprehensive survey of standard model (SM) extensions. LLPs are a common prediction of a wide range of theories that address unsolved fundamental mysteries such as naturalness, dark matter, baryogenesis and neutrino masses, and represent a natural and generic possibility for physics beyond the SM (BSM). In most cases the LLP lifetime can be treated as a free parameter from the [Formula: see text]m scale up to the Big Bang Nucleosynthesis limit of [Formula: see text] m. Neutral LLPs with lifetimes above [Formula: see text]100 m are particularly difficult to probe, as the sensitivity of the LHC main detectors is limited by challenging backgrounds, triggers, and small acceptances. MATHUSLA is a proposal for a minimally instrumented, large-volume surface detector near ATLAS or CMS. It would search for neutral LLPs produced in HL-LHC collisions by reconstructing displaced vertices (DVs) in a low-background environment, extending the sensitivity of the main detectors by orders of magnitude in the long-lifetime regime. We study the LLP physics opportunities afforded by a MATHUSLA-like detector at the HL-LHC, assuming backgrounds can be rejected as expected. We develop a model-independent approach to describe the sensitivity of MATHUSLA to BSM LLP signals, and compare it to DV and missing energy searches at ATLAS or CMS. We then explore the BSM motivations for LLPs in considerable detail, presenting a large number of new sensitivity studies. While our discussion is especially oriented towards the long-lifetime regime at MATHUSLA, this survey underlines the importance of a varied LLP search program at the LHC in general. By synthesizing these results into a general discussion of the top-down and bottom-up motivations for LLP searches, it is our aim to demonstrate the exceptional strength and breadth of the physics case for the construction of the MATHUSLA detector.

Unrestored Electroweak Symmetry.

The commonly assumed cosmological history of our Universe is that at early times and high temperatures the Universe went through an electroweak phase transition (EWPT). Assuming an EWPT, and depending on its strength, there are many implications for baryogenesis, gravitational waves, and the evolution of the Universe in general. However, it is not true that all spontaneously broken symmetries at zero temperature are restored at high temperature. In particular the idea of "inverse symmetry breaking" has long been established in scalar theories with evidence from both perturbative and lattice calculations. In this Letter we demonstrate that with a simple extension of the standard model it is possible that the EW symmetry was always broken or only temporarily passed through a symmetry-restored phase. These novel phase histories have many cosmological and collider implications that we discuss. The model presented here serves as a useful benchmark comparison for future attempts to discern the phase of our Universe at T≳a few GeV.

Aligned and Spontaneous Flavor Violation.

We present a systematic spurion setup called aligned flavor violation (AFV) that allows for new physics couplings to quarks that are aligned with standard model (SM) Yukawa couplings, but do not necessarily share their hierarchies nor are family universal. Additionally, we show that there is an important subset of AFV called spontaneous flavor violation (SFV), which naturally arises from UV completions where the quark family number and CP groups are spontaneously broken. Flavor-changing neutral currents are strongly suppressed in SFV extensions of the SM. We study SFV from an effective field theory perspective and demonstrate that SFV new physics with significant and preferential couplings to first or second generation quarks may be close to the TeV scale.

Females Are More Likely Than Males to Fill an Opioid Prescription in the Year After Anterior Cruciate Ligament Reconstruction.

Purpose: To report rates of preoperative and postoperative opioid use between male and female patients and to identify risk factors for extended opioid use following anterior cruciate ligament reconstruction (ACLR). Methods: Patients undergoing ACLR between 2011 and 2018 were identified from the PearlDiver database. The opioid refill rates for males vs females were compared at monthly intervals for 1 year after ACLR. Patients who filled an opioid prescription <3 months before surgery were classified as opioid users, while those who had never filled one were classified as nonopioid users. Results: Of 106,995 ACLR patients, 37,890 (35.4%) were opioid users <3 months before surgery, and 37,554 (35.1%) had never filled an opioid prescription. Of the preoperative opioid users, 20,413 (53.9%) were female and 17,477 (46.1%) were male (P < .001). Postoperatively, females were at higher risk of filling an opioid prescription at each monthly interval, except for the first month after surgery. The refill rate for opioid users was also higher than that for nonopioid users at each monthly interval after ACLR. In addition to patient sex, a preoperative diagnosis of anxiety/depression, low back pain, myalgia, a history of drug dependence, alcohol abuse, and tobacco use increased a patient's risk of filling an opioid prescription postoperatively. Conclusions: This study demonstrated that females are significantly more likely to be opioid users than males prior to ACLR and are more likely to continue to refill an opioid prescription in the year following surgery. Multiple risk factors were associated with prolonged postoperative opioid utilization, including female sex, anxiety/depression, low back pain, myalgia, a history of drug dependence, alcohol abuse, and tobacco use. Level of Evidence: Level III, retrospective cohort study.

Doximity Orthopaedic Surgery Program Rankings Are Associated with Academic Productivity.

Doximity residency rankings are used to compare training programs. Reputation is a component of Doximity rankings and is based on physician surveys. Outcomes-based measures allow for objective program comparison and may be more appropriate when assessing programs. This study evaluated how Doximity rankings of orthopaedic surgery residency programs compare with an outcomes-based ranking of programs based on academic productivity. This study also evaluated whether program size and type were associated with academic productivity. Methods: Orthopaedic program rankings, size, type, and research productivity were recorded from Doximity. An academic productivity score was calculated by averaging the mean percentage of alumni clinical trials and alumni publications. Analysis of variance and post hoc analyses were performed to determine whether academic productivity was associated with program reputation, size, and type. Results: One hundred seventy-five orthopaedic residency programs were included. Program rankings, size, and type had a statistically significant association with academic productivity (p < 0.0001). The 44 orthopaedic programs in the top quartile had an academic productivity score of 79.1 ± 13 in comparison with programs in the bottom quartile, who had a score of 38.3 ± 12.1 (p < 0.0001). Of the programs in the top quartile of reputation rankings, 32 (73%) were also in the top quartile for academic productivity. Programs with more residents demonstrated greater academic productivity than smaller programs. Twenty-three programs (13%) had more than 30 residents and a mean academic productivity of 76.2 ± 14.8. In comparison, 13 programs (7.5%) had 10 or fewer residents with an academic productivity score of 40.6 ± 16.3 (p < 0.0001). An academic productivity score differed significantly based on program type: university (63.9 ± 14.8), military (54.7 ± 16.9), university/community (46.3 ± 15.6), and community (38.7 ± 15) (p < 0.0001). Conclusions: Academic productivity among orthopaedic residency programs is associated with Doximity ranking, program size, and type. This information can be used by medical students, residents, and physicians to understand the Doximity rankings and how they correlate with this objective measure. Level of Evidence: III.

Odd tracks at hadron colliders.

New physics that exhibits irregular tracks such as kinks, intermittent hits, or decay in flight may easily be missed at hadron colliders. We demonstrate this by studying viable models of light, O(10 GeV), colored particles that decay predominantly inside the tracker. Such particles can be produced at staggering rates, and yet, may not be identified or triggered on at the LHC, unless specifically searched for. In addition, the models we study provide an explanation for the original measurement of the anomalous charged track distribution by CDF. The presence of irregular tracks in these models reconcile that measurement with the subsequent reanalysis and the null results of ATLAS and CMS. Our study clearly illustrates the need for a comprehensive study of irregular tracks at the LHC.

Development and Outcomes of a Streamlined Outpatient Newborn Circumcision Clinic.

INTRODUCTION: Abnormal penile anatomy is suspected in approximately 20% of newborns whose families desire circumcision, yet there is no clear method to refer such cases for anatomical assessment and circumcision under local anesthesia when safe. The aim of this study was to describe development, implementation and outcomes of a newborn circumcision clinic for boys where concern about anatomical circumcision suitability exists. METHODS: The workflow of a pediatric urology outpatient clinic was modified and a circumcision clinic implemented. Staff educational materials and electronic medical record referral templates were created. Circumcision suitability was assessed via checklist, and suitable patients circumcised on the same day. Clinical data were reviewed to evaluate initial implementation and patient outcomes. RESULTS: Of 833 boys evaluated from January 2014 to April 2018, 657 (79%) were suitable to circumcise, all of whom underwent a circumcision. Of those suitable 244 (37%) had normal anatomy. The remaining 413 (63%) had minor anatomical abnormalities, most commonly penoscrotal web (297/657, 45%) and penile raphe deviation (60/657, 9%). No short-term complications were noted. Most (595/657, 91%) returned for followup within 6 weeks after circumcision. Success was achieved in 593/595 boys (99.7%), and 2 boys (0.3%) required acquired buried penis repair. Of the 176 boys with anatomy unsuitable for clamp circumcision (buried penis, chordee or hypospadias), 144/176 (82%) elected for surgical reconstruction. CONCLUSIONS: Implementing a newborn circumcision clinic for boys with possible anatomical abnormalities is feasible. Most boys are circumcised safely and successfully without general anesthesia. Operative circumcision under general anesthesia is reserved for boys requiring surgical reconstruction for significant anatomical abnormalities.

Utilization of and barriers to enhanced recovery pathway implementation in pediatric urology.

INTRODUCTION: Enhanced Recovery Pathways (ERPs), also known as ERAS® pathways, are standardized pathways composed of 21-24 perioperative elements designed to improve post-surgical recovery. ERP has been shown to be safe and effective in children undergoing bladder reconstruction but has not been widely utilized. OBJECTIVE: The aim of this study was to assess utilization of ERPs in pediatric urology and identify barriers to establishing these standardized pathways. STUDY DESIGN: Pediatric urologists who were members of the Societies for Pediatric Urology (SPU) were surveyed regarding their familiarity with standardized ERPs, current use of ERP elements, and encountered or perceived barriers to standardized ERP implementation. Willingness to implement ERP elements in a child undergoing bladder reconstruction was assessed with a 5-point Likert scale. Descriptive analysis was performed; Fisher's exact test was performed to assess associations between respondent demographics and ERP familiarity. RESULTS: Of 714 distributed surveys, 113 (16%) valid responses were collected. 69% of respondents were male, 58% practiced at academic institutions, and 57% performed 1-5 bladder reconstructions a year. 61% were somewhat familiar or not familiar with standardized ERP. While 54% currently utilize individual ERP elements, only 20% have standardized pathways. Out of 24 possible ERP elements, a median of 15 elements (range 0-24) were implemented by the respondents whether they reported they were implementing ERP elements or had standardized pathways in place. 15 of 24 ERP elements were found to be nearly universally acceptable, with greater than 90% of respondents being somewhat or very willing to implement them in the presented case scenario (Summary Figure). 62% and 56% of those who currently implement ERP elements and experienced barriers noted lack of administrative/leadership support and inability to achieve consensus among pediatric colleagues, respectively, as common barriers in standardization. For those who have not attempted standardization, the most common perceived barrier was pathway unfamiliarity (48%). DISCUSSION: Over half of respondents were not familiar with enhanced recovery pathways but were willing to implement a majority of the pathway elements, suggesting potential for ERP standardization in pediatric urology. Buy-in from colleagues and leadership would be necessary to overcome perceived barriers of standardized pathway development. CONCLUSION: Administrative support and more widespread knowledge of ERP amongst pediatric urologists are necessary to facilitate further implementation in children undergoing bladder reconstruction.

Urinary Tract Infection After Robot-assisted Laparoscopic Pyeloplasty: Are Urine Cultures and Antibiotics Helpful?

OBJECTIVE: To evaluate how variations in peri-operative urine culture (UCx) and antibiotic prophylaxis utilization following robot assisted laparoscopic pyeloplasty (RALP) affect post-RALP urinary tract infection (UTI) rates in children, then use data to generate a standardized care pathway. METHODS: Patients undergoing RALP at a single institution from January 2014 to October 2018 were retrospectively reviewed. Patients with vesicoureteral reflux, neurogenic bladder, intermittent catheterization, <=2 months follow-up after stent removal, or age >=18 years were excluded. UCx use, UCx results, and pre- and post-RALP antibiotic use were recorded. The primary outcome was symptomatic UTI, tracked until 60 days after stent removal. UTI was defined as presence of fever or urinary symptoms, a positive UCx with >=10,000 colony forming units of one uropathogen, and a positive urinalysis. RESULTS: A total of 152 patients were included (72% male [73% circumcised], 61% white, and 23% Hispanic). One underwent a re-operative pyeloplasty, yielding 153 encounters. Eight patients (5.2%; 95% CI 1.7-8.7%) developed post-RALP UTI. Uncircumcised status and use of pre-operative prophylactic antibiotics were associated with post-RALP UTI (P = .03 and P < .01, respectively). Use of post-RALP antibiotics, whether prophylactic or therapeutic, was not associated with lower UTI rates (P = .92). Positive pre-RALP UCx and positive intra-operative stent removal UCx were associated with higher UTI rates (P = .03 and P < .01, respectively). CONCLUSION: UTI occurred in 5.2% of our cohort of >150 patients. As post-RALP antibiotic use was not associated with lower UTI rates, prophylactic antibiotics may be reserved for patients with risk factors. A standardized care pathway could safely reduce unnecessary utilization of UA/UCx and antibiotics.

Assessment of operative competency for thyroidectomy: Comparison of resident self-assessment vs attending surgeon assessment.

BACKGROUND: Self-awareness of skill, essential for progression as a surgeon, has direct bearing on postresidency practice; however, studies have supported that residents achieve self-perceived competence later than believed by program directors. This study compares residents' self-perception of operative competency to attending surgeon's evaluation using Computer Enhanced Visual Learning, a validated online hemithyroidectomy-specific assessment tool. METHODS: Eleven otolaryngology-Head and Neck Surgery (HNS) residents completed a preoperative module and postoperative survey, later reviewed by an attending surgeon. Eighty-three performances were assessed for inter-rater reliabilities of key surgical steps. RESULTS: Almost perfect agreement (Kappa = 0.81-1.00) was shown in 11 of 18 parameters. Substantial agreement (Kappa = 0.61-0.80) was demonstrated in the remaining seven parameters. CONCLUSIONS: Otolaryngology-HNS trainees have high self-awareness of their performance at each step in a hemithyroidectomy. Standardized assessment tools can allow for documentation of procedural performance and serve as guides for improvement. This is the only study to examine otolaryngology-HNS trainees' self-perceived skill compared to an attending surgeon's assessment for hemithyroidectomy.