Charged lepton flavor violation (cLFV) processes, potentially important for various beyond the Standard Model physics scenarios are analyzed in the Standard Model effective field theory framework. We consider the most relevant two-quark-two-lepton (2q2e) operators for the leptonic and semileptonic LFV B -decay (LFVBD) processes Bs -> mu+e-; B+ -> K+mu+e-; B0 -> K+0 mu+e-, and Bs -> mu-e+. We analyze the interplay among the Wilson coefficients responsible for these LFVBDs and other cLFV processes, like CR(mu -> e), ei -> ej gamma, ei -> ejekem, and Z -> eiej, to find the maximal possible LFV effects in B -meson decays. We probe the scale of new physics in relation to the constraints imposed by both classes of the LFV decays while considering both the present bounds and future expectations. In view of proposed experiments at LHCb-II and Belle II to study charged LFV processes, we have also provided the upper limits on the indirect constraints on such LFVBDs. For the processes where the B meson is decaying to mu+ and e -/+, we show that new physics can be constrained by an enhancement of 2-4 orders of magnitude on the current sensitivities of the branching ratios of B+ -> K+mu+e-; B0 -> K+0 mu+e-, and Bs -> phi mu+e -/+.

During the initial stages of the COVID-19 pandemic, New York State shifted voting rules for school elections from in-person voting to an all-mail regimen with ballots mailed to every voter. We examine the effects of this voting rule shift and find that although the likelihood of budget passage remains largely unchanged, this shift brought about a significant increase in voter participation. Our findings provide empirical evidence for discussions on ways to increase voter turnout for school budget elections, where voter participation is often low.

This study extends the earlier literature on changes in school enrollment in the wake of the COVID-19 pandemic by using data for the second COVID-19 school year (2021-2022) from the state of New York. Contrary to expectations that the resumption of fully-live instruction would reverse the first COVID-19 year's declines in public school enrollment, we find that enrollment continued to drop sharply in the second COVID-19 school year, when schools were entirely back to in-person learning. These declines in enrollment vary substantially by grade, race and poverty and are robust to controlling for other COVID-19 related factors. In addition, we find mixed results for the number of private school students but significant increases in home-schooled students in the two COVID-19 years. The findings have important educational and fiscal implications.

In this work we assess the potential of discovering new physics by searching for lepton-flavour-violating (LFV) decays of the Z boson, Z→ℓ _i ℓ _j , at the proposed circular e^+e^- colliders CEPC and FCC-ee. Both projects plan to run at the Z -pole as a “Tera Z factory”, i.e., collecting 𝒪( 10^12) Z decays. In order to discuss the discovery potential in a model-independent way, we revisit the LFV Z decays in the context of the Standard Model effective field theory and study the indirect constraints from LFV μ and τ decays on the operators that can induce Z→ℓ _i ℓ _j . We find that, while the Z→μ e rates are beyond the expected sensitivities, a Tera Z factory is promising for Z→τℓ decays, probing New Physics at the same level of future low-energy LFV observables.

The null results of the LHC searches have put strong bounds on new physics scenarios such as supersymmetry (SUSY). With the latest values for the top quark mass and strong coupling, we study the upper bounds on the sfermion masses in split SUSY from the observed Higgs boson mass and electroweak (EW) vacuum stability. To be consistent with the observed Higgs mass, we find that the largest values of supersymmetry breaking scales $M_{S}$ for $\tan\beta=2$, $\tan\beta=4$, and $\tan\beta=50$ are $10^{6.2}$, $10^{4.5}$, and $10^{4.3}\, {\rm GeV}$, respectively. In particular, split SUSY with $\tan\beta \gtrsim 4$ can be probed in future 100 TeV proton–proton colliders such as FCC-hh and SppC. In addition, the Higgs quartic coupling becomes negative at about $10^{8.2}$, $10^{8.7}$, and $10^{9.6}\, {\rm GeV}$ respectively for $m_h =$ 123, 125, and 127 GeV from EW vacuum stability. These bounds are about one order smaller than the Standard Model due to the extra Higgs–Higgsino–gaugino couplings. We briefly comment on the lifetime of gluinos in our study and compare it with the current LHC observations. Additionally, we comment on the prospects of the discovery of prompt gluinos at the FCC-hh and SppC.

Anomalies in recent LHCb, Belle and Babar measurements of $R_{D^{(*)}}$, and $R_{K^{(*)}}$ in $B$ decays may indicate the new physics beyond the Standard Model (SM). The leptoquarks ($LQ$) that couple to the $3^{\mathrm{rd}}$ generation quarks and leptons have been proposed as a viable new physics (NP) explanation. Such left-handed $LQ$s can couple to both bottom and top quarks. Since top particles decay before the hadronization, it is possible to reconstruct chirality of boosted top quarks and consequently the chirality of top coupling to the $LQ$s. We perform analysis on the top quark's chirality in the pair-production channel of the $LQ$, which can be purely left-handed in comparison to unpolarized $t\bar{t}$ SM background. We study the prospects of distinguishing the chirality of a potential $LQ$ signal for the high luminosity run of the LHC and other future colliders.

Renormalization Group Equations (RGEs) are indispensable tool to know the behavior of physical parameters at different energy scales. They are also extremely crucial if we want to extend our known Standard Model gauge group by some extra gauge groups and the $\beta$-functions are the soul of these RGEs. In literature although it is quite common to find long, final expressions of the RGEs, unfortunately it is difficult to find any pedagogical review to calculate these $\beta$-function coefficients explicitly from the known formulae. Therefore in this note we shall try to explain the detail calculations of RGEs by giving some explicit examples taken from the literature. The goal and hope is to provide a hand on experience on calculating these RGEs for the young readers.

In more than half of U.S. states over the past two decades, the implementation of merit aid programs has dramatically reduced net tuition expenses for college-bound students who attend in-state colleges. Although the intention of these programs was to improve access to enrollment for high-achieving students, it is possible that they had unanticipated effects. We analyze whether state funding for higher education and K-12 education changed as a result of program implementation, and whether local school districts attempt to counter any such changes. We employ two methodologies to study whether this has been the case: a difference-in-differences model and a synthetic control estimation strategy. We find robust evidence that implementation of state merit aid programs led to an economically (and statistically) significant decline in state funding for K-12 education, which was mostly offset through increases in local revenues by school districts. These results have important implications for understanding how merit aid policies could have unintended consequences for the students they aim to support.

Many extensions of the standard model contain an extra U(1)' gauge group with a heavy Z' gauge boson. Perhaps the most clear signal for such a Z' would be a resonance in the invariant mass spectrum of the lepton pairs to which it decays. In the absence of such a signal, experiments can set limits on the couplings of such a Z', using a standard formula from theory. We repeat its derivation and find that, unfortunately, the standard formula in the literature is a factor of 8 too small. We briefly explore the implication for existing experimental searches and encourage the high-energy physics community to reexamine analyses that have used this formula.

Combining anomaly with $Z^\prime$ mediation allows us to solve the tachyonic problem of the former and avoid fine tuning in the latter. This model includes an extra $U(1)^\prime$ gauge symmetry and extra singlet scalar $S$ which provides a solution to the `$\mu$ problem' of the Minimal Supersymmetric Standard Model (MSSM). The low-energy particle spectrum is calculated from the UV inputs using the Renormalization Group Equations. The benchmark points considered in the original model, suggested before the Higgs discovery, predicted a Higgs mass heavier than the generic MSSM value. In 2012, the Higgs particle was discovered and found to have a mass of 125 GeV. Therefore, we can use that value and other current LHC data to scan the parameter space and update the predictions of the model, in particular the mass of the $Z^\prime$ gauge boson.

Many extension of the standard model contain an extra U(1)u0027 gauge group with a heavy Zu0027 gauge boson. Perhaps the most clear signal for such a Zu0027 would be a resonance in the invariant mass spectrum of the lepton pairs it decays to. In absence of such a signal, experiments can set limits on the couplings of such a Zu0027, using a standard formula from theory. We repeat its derivation and find that unfortunately the standard formula in the literature is a factor of 8 too small. We briefly explore the implication for existing experimental searches and encourage the high energy physics community to re-examine analyses that have used this formula.

Effect of constraints on Tiebout competition: evidence from a school finance reform. Regional Studies. Michigan's school finance reform significantly increased state aid to low-spending districts and placed restraints on the growth of spending in high-spending districts. It is noteworthy that there is no literature yet on the impact of such reforms on resource allocation by school districts. This study begins to fill this gap. It finds that the reform led the high-spending districts to allocate a lower share of their total expenditure to support services and a higher share to instruction (relative to the low-spending districts). To the extent that instructional expenditures are more productive and contribute to student achievement more than support services expenditures, these results suggest that the reform led to a relative increase in productivity in the high-spending districts.

Charter schools have been one of the most important dimensions of recent school reform measures in the United States. Though there have been numerous studies on the effects of charter schools, these have mostly been confined to analyzing their effects on student achievement, student demographic composition, parental satisfaction, and the competitive effects on traditional public schools. This study departs from the existing literature by investigating the effect of charter schools on enrollment in private schools. To investigate this issue empirically, we focus on the state of Michigan where there was a significant spread of charter schools in the nineties. Using data on private school enrollment from biennial NCES private school surveys, and using a fixed effects as well as an instrumental variables strategy that exploits exogenous variation from Michigan charter law, we investigate the effect of charter school penetration on private school enrollment. We do not find any causal evidence that charter schools led to a decline in enrollment in the private schools. Further, we do not find evidence that enrollments in Catholic or other religious schools were affected differently from those in non-religious private schools. Our results are robust to a variety of sensitivity checks.

The proton is a fundamental constituent of matter. It is an extended object with finite size that can be inferred with some degree of accuracy from several measurements. Using constraints from the analytic behavior of the form factors we present here a model-independent study that extracts the proton magnetic radius from scattering data. From electronproton scattering data we find r M = 0.91 +0.03 −0.06±0.02 fm. When we include electron-neutron scattering data and ππ data, we find r M = 0.87 +0.04 −0.05±0.01 fm and r M = 0.87 +0.02 −0.02 fm respectively. The neutron magnetic radius is extracted as r M = 0.89 +0.03 −0.03 fm combining all three data sets.

Local financing of public schools in the United States leads to a bundling of two distinct choices – residential choice and school choice – and has been argued to increase the degree of socioeconomic segregation across school districts. A school finance reform, aimed at equalization of school finances, can in principle weaken this link between housing choice and choice of schools. In this paper, we study the impacts of the Michigan school finance reform of 1994 (Proposal A) on spatial segregation. The reform was a state initiative intended to equalize per-pupil expenditures between Michigan school districts and reduce the role of local financing. We find that Proposal A was responsible for increases in the value of housing stock in the lowest-spending school districts, and for improvements in several socioeconomic indicators in these districts, implying a decline in neighborhood sorting. We also find that the reform affected dispersion of incomes and educational attainment within school districts, increasing within-district heterogeneity in the lowest-spending school districts, while decreasing the same in the highest-spending districts. However, there is continued high demand for residence in the highest-spending communities, suggesting the importance of neighborhood peer effects (local social capital) and implying that even a comprehensive government aid program can fail to make a large impact on residential segregation.

We combine constraints from analyticity with experimental electron-proton scattering data to determine the proton magnetic radius without model-dependent assumptions on the shape of the form factor. We also study the impact of including electron-neutron scattering data, and pi pi -> N (N) over bar data. Using representative data sets we find for a cut of Q(2) <= 0.5 GeV2, r(M)(p) = 0.91(-0.06)(+0.03) +/- 0.02 fm using just proton scattering data; r(M)(p) = 0.87(-0.05)(+0.04) +/- 0.01 fm adding neutron data; and r(M)(p) = 0.87(-0.02)(+0.02) fm adding pp data. We also extract the neutron magnetic radius from these data sets obtaining r(M)(n) = 0.89(-0.03)(+0.03) fm from the combined proton, neutron, and pi pi data.

In this paper, we investigate the role of college selectivity in mobility decisions (both in-state and out-of-state) of freshmen students following Georgia’s HOPE scholarship program. How did HOPE affect the selectivity of colleges attended by Georgia’s freshmen students? Did it induce Georgia’s freshmen students who would have otherwise attended more selective out-of-state colleges to instead attend less selective in-state ones? Or was there movement to more selective ones, both in-state and out-of-state? Using student residency and enrollment data from IPEDS and selectivity data from Barron’s and Peterson’s, we find that in the aftermath of HOPE, Georgia freshmen attended relatively more selective colleges overall. Disaggregating further, we find that Georgia freshmen attending in-state colleges attended more selective ones. Georgia freshmen attending out-of-state colleges were also more likely to attend more selective colleges, most likely due to an increase in the reservation price to go to out-of-state colleges following HOPE. Our results are robust to a variety of sensitivity checks and have important policy implications. In particular, Peltzman had observed in his classic 1973 paper that in-kind subsidies can induce individuals to invest in less quality-adjusted human capital than they might otherwise. The fact that Georgia freshmen attended relatively more selective colleges in the post-HOPE period allays, to some extent, the concern that state merit aid programs can adversely affect long-term outcomes and human capital formation.

The Great Recession led to marked declines in state revenue. In this paper we investigate whether (and how) local school districts modified their funding and taxing decisions in response to state aid declines in the post-recession period. Our results reveal school districts responded to state aid cuts in the post-recession period by countering these cuts. Relative to the pre-recession period, a unit decrease in state aid was associated with a relative increase in local funding. To further probe the school district role, we explore whether the property tax rate, which reflects decisions of districts facing budgetary needs, responded to state aid cuts. We find, relative to the pre-recession period, the post-recession period was characterized by a strong negative relationship between property tax rate and state aid per pupil. We also find important heterogeneities in these responses by region, property wealth, and importance of School Tax Relief Program revenue in district budgets.