scholarly journals A new angle on an old problem: helicity approach to neutron beta decay in the Standard Model

2019 ◽  
Vol 79 (11) ◽  
Author(s):  
Stefan Groote ◽  
Jürgen G. Körner ◽  
Blaženka Melić
Keyword(s):  
Axial Vector ◽  
Form Factors ◽  
Semileptonic Decays ◽  
The Other ◽  
Vector Form ◽  
Neutron Beta Decay ◽  
Heavy Baryons ◽  
The Standard Model ◽  
The One ◽  
Three Body

AbstractWe elaborate on the dichotomy between the description of the semileptonic decays of heavy hadrons on the one hand and the semileptonic decays of light hadrons such as neutron $$\beta $$β decays on the other hand. For example, almost without exception the semileptonic decays of heavy baryons are described in cascade fashion as a sequence of two two-body decays $$B_1 \rightarrow B_2 + W_\mathrm{off-shell}$$B1→B2+Woff-shell and $$W_{\mathrm{off-shell}} \rightarrow \ell + \nu _\ell $$Woff-shell→ℓ+νℓ whereas neutron $$\beta $$β decays are analyzed as true three-body decays $$n \rightarrow p + e^- +{\bar{\nu }}_e$$n→p+e-+ν¯e. Within the cascade approach it is possible to define a set of seven angular observables for polarized neutron $$\beta $$β decays as well as the longitudinal, transverse and normal polarization of the decay electron. We determine the dependence of the observables on the usual vector and axial vector form factors. In order to be able to assess the importance of recoil corrections we expand the rate and the $$q^2$$q2 averages of the observables up to NLO and NNLO in the recoil parameter $$\delta =(M_n-M_p)/(M_n+M_p)= 0.689\cdot 10^{-3}$$δ=(Mn-Mp)/(Mn+Mp)=0.689·10-3. Remarkably, we find that the rate and three of the four parity conserving polarization observables that we analyze are protected from NLO recoil corrections when the second class current contributions are set to zero.

scholarly journals Weak scale from Planck scale: Mass scale generation in a classically conformal two-scalar system

2020 ◽  
Vol 2020 (3) ◽  
Author(s):  
Junichi Haruna ◽  
Hikaru Kawai
Keyword(s):  
Scalar Field ◽  
Standard Model ◽  
Planck Scale ◽  
Vacuum Expectation ◽  
Vacuum Expectation Value ◽  
The Other ◽  
Expectation Value ◽  
Weak Scale ◽  
The Standard Model ◽  
The One

Abstract In the standard model, the weak scale is the only parameter with mass dimensions. This means that the standard model itself cannot explain the origin of the weak scale. On the other hand, from the results of recent accelerator experiments, except for some small corrections, the standard model has increased the possibility of being an effective theory up to the Planck scale. From these facts, it is naturally inferred that the weak scale is determined by some dynamics from the Planck scale. In order to answer this question, we rely on the multiple point criticality principle as a clue and consider the classically conformal $\mathbb{Z}_2\times \mathbb{Z}_2$ invariant two-scalar model as a minimal model in which the weak scale is generated dynamically from the Planck scale. This model contains only two real scalar fields and does not contain any fermions or gauge fields. In this model, due to a Coleman–Weinberg-like mechanism, the one-scalar field spontaneously breaks the $ \mathbb{Z}_2$ symmetry with a vacuum expectation value connected with the cutoff momentum. We investigate this using the one-loop effective potential, renormalization group and large-$N$ limit. We also investigate whether it is possible to reproduce the mass term and vacuum expectation value of the Higgs field by coupling this model with the standard model in the Higgs portal framework. In this case, the one-scalar field that does not break $\mathbb{Z}_2$ can be a candidate for dark matter and have a mass of about several TeV in appropriate parameters. On the other hand, the other scalar field breaks $\mathbb{Z}_2$ and has a mass of several tens of GeV. These results will be verifiable in near-future experiments.

The axial vector form factors and electroproduction sum rules

1966 ◽  
Vol 44 (2) ◽  
pp. 427-439 ◽  
Author(s):  
G. Furlan ◽  
R. Jengo ◽  
E. Remiddi
Keyword(s):  
Sum Rules ◽  
Axial Vector ◽  
Form Factors ◽  
Vector Form

scholarly journals Axial Vector Form Factors from Lattice QCD that Satisfy the PCAC Relation

2020 ◽  
Vol 124 (7) ◽  
Author(s):  
Yong-Chull Jang ◽  
Rajan Gupta ◽  
Boram Yoon ◽  
Tanmoy Bhattacharya
Keyword(s):  
Lattice Qcd ◽  
Axial Vector ◽  
Form Factors ◽  
Vector Form

Effects of Chromium Picolinate on Beginning Weight Training Students

1992 ◽  
Vol 2 (4) ◽  
pp. 343-350 ◽  
Author(s):  
Deborah L. Hasten ◽  
E. Paul Rome ◽  
B. Don Franks ◽  
Maren Hegsted
Keyword(s):  
Bench Press ◽  
Weight Lifting ◽  
The Other ◽  
Chromium Picolinate ◽  
Double Blind ◽  
Significant Treatment ◽  
College Age ◽  
The One ◽  
Body Circumferences ◽  
Three Body

Changes in body weight (BW), a sum of three body circumferences (ΣC), a sum of three skinfolds (ΣSF), and the one-repetition maximum (IRM) for the squat (SQ) and bench press (BP) were examined in 59 college-age students (37 males [MI, 22 females [F]) over a 12-week weight lifting program. Using a double-blind protocol, half of the students were given 200 μg/day chromium (Cr) in the form of chromium picolinate (CrPic) while the other half received a placebo (P). Therefore four groups were randomly formed: F-CrPic (n=12), F-P (n=10), M-CrPic (n=18), and M-P (n=19). All groups had significant increases in ΣC and significant decreases in ΣSF. No treatment effects were seen for the strength measurements, although the males experienced greater absolute increases. The only significant treatment effect found was due to the F-CrPic group gaining more BW (p=0.0048) than the other three groups. It was concluded that CrPic supplementation had a greater effect on the females than on the males.

scholarly journals THE TOROID DIPOLE MOMENT OF THE NEUTRINO

1998 ◽  
Vol 13 (30) ◽  
pp. 5257-5277 ◽  
Author(s):  
VLADIMIR M. DUBOVIK ◽  
VALENTIN E. KUZNETSOV
Keyword(s):  
Dipole Moment ◽  
Mass Shell ◽  
Dipole Moments ◽  
Form Factors ◽  
Dispersion Method ◽  
Anapole Moment ◽  
Electromagnetic Interactions ◽  
Loop Approximation ◽  
The Standard Model ◽  
The One

We discuss the third electromagnetic characteristic of the neutrino, i.e. the toroid dipole moment (TDM), in the framework of the Standard Model. The TDM's distinctions from and similarities to an anapole moment are mentioned. The calculations of toroid dipole moments of νe,μ,τ neutrinos have been done by the dispersion method in the one-loop approximation of the SM for the Majorana case and generalized to the Dirac one. We found them to be different from zero in the case of massive as well as massless neutrinos. The behavior of the νe,μ,τ toroid form factors is also presented in the [Formula: see text] range. All external particles are on the mass shell and there are no problems with the physical interpretation of the final result. Some manifestations of the electromagnetic interactions of neutrinos, induced by their toroid moments, are also remarked on.

scholarly journals PHOTON-PAIR CONVERSION INTO NEUTRINOS IN A STRONG MAGNETIC FIELD

2001 ◽  
Vol 16 (25) ◽  
pp. 1659-1665 ◽  
Author(s):  
A. V. KUZNETSOV ◽  
N. V. MIKHEEV
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Strong Magnetic Field ◽  
Asymptotic Form ◽  
Axial Vector ◽  
Electroweak Interaction ◽  
The Other ◽  
The Standard Model ◽  
Loop Amplitude ◽  
The Magnetic Field

A general analysis of the three-vertex loop amplitude in a strong magnetic field, based on the asymptotic form of the electron propagator in the field, is performed. In order to investigate the photon–neutrino process [Formula: see text], the vertex combinations of the scalar–vector–vector (SVV), pseudoscalar–vector–vector (PVV), three-vector (VVV), and axial-vector–vector–vector (AVV) types are considered. It is shown that only the SVV amplitude grows linearly with the magnetic field strength, while in the other amplitudes, PVV, VVV and AVV, the linearly growing terms are canceled. The process [Formula: see text] is investigated in the left–right-symmetric extension of the standard model of electroweak interaction, where the effective scalar νν e e coupling could exist. Possible astrophysical manifestations of the considered process are discussed.

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