SSP2012 - 5th International Symposium on Symmetries in Subatomic Physics

W. Heil(1), F. Allendinger(3), C. Gemmel(1), S. Karpuk(1), Yu.Sobolev(1) , K.Tullney(1), M.Burghoff(2), W. Kilian(2), S.Knappe-Grüneberg(2), W.Müller(2), A.Schnabel(2), F.Seifert(2), L.Trahms(2), and U.Schmidt(3) 1Institut für Physik, 55099 Mainz, Germany 2Physikalisch-Technische Bundesanstalt, 10587 Berlin, Germany 3University of Heidelberg, Germany We discuss the design and performance...

Lorentz and CPT invariance are among the symmetries that can be investigated with ultrahigh precision in subatomic physics. Being spacetime symmetries, Lorentz and CPT invariance can be violated by minuscule amounts in many theoretical approaches to underlying physics that involve novel spacetime concepts, such as quantized versions of gravity. Regardless of the underlying mechanism, the...

The SUSY prediction for the muon magnetic moment is reviewed, and the complementarity between low-energy and LHC measurements for analyzing SUSY is discussed.

In recent years the use of atom and ion traps as well as advances in the applicability of the Geant Monte Carlo code for beta particle energies have resulted in a number of new precise determinations of the beta-neutrino correlation and beta-asymmetry parameter in nuclear beta decays. Such measurements are mainly sensitive to time-reversal invariant scalar and tensor weak currents and parity...

Measurements in nuclear and neutron decays offer a window to determine specific fundamental couplings, like the Vud matrix element of the CKM matrix, and to perform sensitive tests of discrete symmetries. This talk will focus on two topics of precision measurements in beta decay. The first concerns recent results from pure Fermi transitions as well as recent developments from nuclear mirror...

One of the most fundamental principles on which our current understanding of nature is based is the invariance of physical laws under Lorentz transformations. Theories trying to unify the Standard Model with Quantum Gravity may break this invariance, and and dedicated high-precision experiments at low energy could be used to reveal such suppressed signals from the Planck scale. In the...

We discuss the possibility of observing CPT violation from top anti-top production in hadronic colliders. We present a general approach by studying constraints on the mass difference between the top and anti-top quarks. We present current bounds from Tevatron data, and analyze the prospects of improving these bounds at the LHC.

Currently, the high-precision Penning trap mass spectrometer PENTATRAP is being built up at the Max-Planck-Institut für Kernphysik, Heidelberg, Germany. It aims at mass-ratio measurements of medium- to high-Z elements with uncertainties of a few parts in 10^12. Mass-ratios will be determined by the measurement of cyclotron frequency-ratios in the strong magnetic field of the trap. This will be...

One of the goals of precision measurements in nuclear beta-decay is searching for deviations from the Standard Model that could point to new physics. The primary aim of WITCH experiment [1] at the ISOLDE/CERN facility is the search for a scalar interaction in beta-decay by a precise (0.5%) determination of the beta-neutrino angular correlation coefficient, a, which would constrain a possible...

Nuclear few-body systems become attractive avenues for study of low-energy parity violation because experiments start to meet the precision requirements and theoretical calculations can be performed reliably. In this talk, an attempt of parametrizing low-energy parity-violating observables by the Danilov parameters will be introduced. Analyses of two-nucleon observables, based on the modern...

Hot and dense matter out of quarks and gluons forms various status with external parameters such as the temperature, the chemical potential, the magnetic field, etc turned on and changed. The phase trasitions are characterized by realization of symmetries but the phase structure highly depends on the dynamical properties of matter. In this talk I will focus particularly on recent...

Observations of new charmonium(-like) and bottomonium(-like) states (sometimes refered to as "XYZ" states) at e+e- colliders have changed our picture of quarkonia systems as QCD bound states. Potential models with a linear confinement ansatz, which were able to predict many conventional states with an accuracy of ~1 MeV, absolutely fail in describing many of the new states. Symmetries play an...

The key for understanding the low energy QCD is chiral symmetry. This approximate symmetry allows for construction of a successful systematic approach to low energy QCD. The main application of this theory are processes involving light pseudoscalar mesons. For example isospin breaking decay of eta mesoninto three pions provide precise constraints for ratios of the light quark masses and...

Electric dipole moments (EDMs) break parity and time-reversal (T) symmetry and, by the CPT-theorem, CP-symmetry. If measured they are unambigious signs of new physics, since CP-violation in the quark mixing matrix predict EDMs orders of magnitude away from current experimental limits. The SM also contains the QCD vacuum angle (the theta term) whose value is unknown but strongly limited by...

I review the impressive recent progress towards the present state of the art in the understanding and application of perturbative QCD to Standard Model processes.

A brief review of the impact of searches for electric dipole moments of nucleons, atoms and molecules on fundamental sources of CP (or T) violation in nature. The focus will be on the use of effective field theory to disentangle the constraints on different fundamental CP-odd sources, and the implications of direct LHC exclusion limits on possible new physics at or near the electroweak scale.

The LHCb experiment carries out precision measurements of CP asymmetries in the heavy quark sector in order to look for signs of physics beyond the Standard Model. If present, new physics amplitudes can interfere with SM processes and affect CP asymmetry observables such that they might deviate from predicted CKM values. The LHCb program includes a wide search for CP observables in different...

Although CP violation in the B-meson system has been well established by the B factories, there has been no direct observation of time-reversal violation in this system. Using 468 million B-Bbar pairs collected by the BABAR detector at SLAC, we measure T-violating parameters in the time evolution of neutral-B mesons by comparing the probabilities of B0 or anti-B0 transforming into definite CP...

The decays B -> tau nu, B -> D tau nu, and B -> D* tau nu are sensitive to physics beyond the standard model, in particular to contributions from charged Higgs bosons. The multiple-neutrino final states make studies of these decays particularly challenging and require reconstruction of the full event, which can be performed only at an electron-positron collider. We use the full BABAR data set...

With an integrated luminosity goal larger than 75 ab-1, the SuperB factory is expected to be built on the Tor Vergata campus near Rome Italy by 2016. Its goal is to unravel the detailed structure of the new physics likely to be discovered at the LHC, and to explore BSM physics beyond the direct reach of the LHC. These goals will be achieved through the study of a wide variety of rare B, charm...

Hadronic parity violation is studied in the photo-disintegration of the deuteron at low energies. We calculate the parity-violating spin asymmetries $P_{x'}$ and $P_{z'}$ with the polarized outgoing neutrons. Non-vanishing asymmetry arises from the interference of opposite parity states in the initial and final state wave functions. Parity admixtures are accounted by using a pionless effective...

Many extensions of the standard model contain an additional $U(1)^\prime$ gauge group with an associated $Z^\prime$ gauge boson. In some of those constructions the $U(1)^\prime$ charges are generation dependent and therefore introduce tree-level flavor changing neutral currents mediated by the $Z^\prime$. We discuss the phenomenology of these FCNC couplings for meson decays and possible LHC...

Time reversal invariance violating (TRIV) effects in low energy physics could be very important for a search for new physics, being complementary to neutron and atomic electric dipole moment (EDM) measurements. In this relation, we discuss a sensitivity of some TRIV observables in neutron scattering and nuclear EDMs to different models of time-reversal (CP) violation and their dependencies on...

The phase diagram of QCD at non-zero chemical potential is difficult to calculate from first principles because the coupling strength is large, preventing ordinary perturbation theory, and the action is complex, leading to the "sign problem" and preventing conventional lattice simulations. To understand better how to deal with complex actions and to obtain a qualitative picture of the phase...

Warped extra dimensions (WED) are among the most popular alternatives to supersymmetry for addressing the gauge hierarchy problem. In addition, they simultaneously allow for an elegant explanation of the observed fermion mass hierarchy and hierarchical quark mixing by virtue of wave function overlaps along the extra (spatial) dimension. Strong constraints on models with WED come from...

When it comes to illustrating principles of symmetries in physics, the work of the Dutch artist M.C. Escher ranks very high. Escher had an intuitive approach; with the added level of interpretation by physicists and mathematicians his work becomes even more fascinating. One of M.C. Escher's most intriguing works depicts a man standing in a gallery who looks at a print of a city that...

A number of observables accessible with neutrons are sensitive to violation of time-reversal invariance and, due to the the requirement of symmetry under the combination of charge-conjugation (C), parity (P), and time-reversal (T), of CP symmetry. These include the neutron EDM and T-violating correlations in neutron decay. I will discuss this with particular emphasis on the recently...

The NPDGamma experiment aims to measure the parity-odd correlation between the neutron spin and the direction of the emitted photon in neutron-proton capture. A parity violating asymmetry (to be measured to 10$^{-8}$) from this process can be directly related to the strength of the hadronic weak interaction between nucleons, specifically the $\Delta I=1$ contribution. The experiment has been...

We consider neutron radiative beta-decay and compute the T-odd triple momentum correlation in the decay rate arising from electromagnetic final-state interactions in the Standard Model. Our expression for the corresponding T-odd asymmetry is exact in O(alpha) up to terms of recoil order, and we evaluate it numerically under various kinematic conditions. Noting the universality of the V-A...

The Qweak collaboration recently completed a two year long program of measurements, with the aim of making a precision measurement of the parity violating analyzing power from elastic scattering of 1.16 GeV, longitudinally polarized, electrons on protons at very low $Q^2$. At low momentum transfer, the measured asymmetry is directly related to the weak charge of the proton $Q_W^p = 1 -...

Atomic parity non-conservation (PNC) experiments provide unique precision tests of the electroweak sector of the standard model at very low energies. Precision measurements of spin-dependent atomic PNC can determine nuclear anapole moments and probe the weak interaction within the nucleus. Among current efforts on PNC are ongoing experiments in a chain of Ytterbium and Dysprosium isotopes at...

After a series of parity violation electron scattering experiments in order to explore the strangeness content of the nucleon, we plan on a new, improved parity violation experiment where we will measure the weak charge of the proton with a relative accuracy of 1.7%. This accuracy results in a measurement of the effective electroweak mixing angle sin^2 theta_W of 1.5 per mille, in...

The comparison of different types of clocks and frequency standards over periods of a few years has allowed to place stringent limits on variations of fundamental constants in terrestrial laboratories in the present epoch. Presently, all experiments are consistent with the constancy of constants, for example the relative change of the fine structure constant is constrained in the range of the...

There are new results for the variation of the fine structure constant alpha based on the quasar absorption spectra data. These results indicate the variation of alpha in space [1]. The spatial variation can explain fine tuning of the fundamental constants which allows humans (and any life) to appear. We appeared in the area of the Universe where the values of the fundamental constants are...

I review theoretical status of some models that were invoked in connection with "change of couplings in time" and "Lorentz invariance violation", and give my personal perspective on this subject. I then argue that the scope of the present experimental program can be expanded, in particular in the direction embracing the search for the short-time transient effects using precise clocks and magnetometers.

Optical transitions can occur in some highly charged ions (HCIs) when the ion stage and nuclear charge are tuned such that orbitals with different principal quantum number and angular momentum are nearly degenerate. In these cases the transition energy may be within laser range even though the ionisation energy is large (of order several hundred eV). We have identified several such systems and...

The constraint on a possible time-variation of physical constants set by an experiment depends both on the accuracy of the measurement and on the sensitivity of the system the measurement is performed on. Here, we present a laboratory experiment using a system with a highly enhanced sensitivity to a possible time-variation of the proton-to-electron-mass ratio, μ. Due to an incidental...

A single trapped ion opens a promising path for a measurement of atomic parity violation (APV). Since the sensitivity of the APV grows stronger than the third power of the atomic number Z, a single Ra ion is an excellent candidate for APV experiments, enabling a precise measurement of the electroweak mixing angle in the Standard Model of particle physics. Online laser spectroscopy of ...

The Standard Model of Particle Physics predicts that the effect of weak interactions in the nuclei of molecules results in parity violating observables. Parity violation has already been seen in atomic systems but not in molecules. We are currently building a setup that can detect parity violation in heavy diatomic molecules. Using a traveling-wave Stark decelerator we will decelerate and trap...

on behalf of the UCN Project Team August 2011 marked the official startup of regular beam operation of the ultracold neutron (UCN) source at the Paul Scherrer Institute. Switzerland. The design goal is to exceed the currently available UCN densities by a factor 50 to 100 and to use these neutrons for fundamental physics experiments, most prominently the search for a neutron electric...

The progress in producing and trapping antihydrogen [1-3] in the last decade has opened up the way to perform stringent tests of the validity of the CPT theorem (charge conjugation, parity and time reversal symmetry) using a purely anti-atomic system. The comparison of the 1S-2S transition in antihydrogen with that of hydrogen, of which the latter is measured with a relative accuracy of about...

Antiprotonic helium is a metastable three-body neutral atom consisting of an antiproton, a helium nucleus and an electron, which we serendipitously discovered some 20 years ago. The antiproton, which normally annihilates within a few picoseconds when injected into matter, can be "stored" in this system for up to several microseconds, and laser spectroscopy is possible within this time window....

Low-energy antiprotons are an ideal tool to study fundamental symmetries, especially CPT symmetry, by the precision spectroscopy of exotic atoms containing an antiproton. The investigation of the hyperfine structure of such atoms allows first of all the determination of the antiproton magnetic moment, the most precise value of which was obtained recently by the ASACUSA collaboration at the...

We observed spin-flips with a single proton for the first time and measured the particle’s magnetic moment with a relative precision of 8.9e-6. The developed techniques can be directly transferred to measure the magnetic moment of the antiproton, which can be improved by more than a factor of 100. By application of the so-called double Penning trap technique, we finally aim at a measurement...

I will overview several hints which cosmology provides for physics beyond the Standard Model and discuss possible solutions of cosmological problems of the Standard Model.

Precise determination of the least well known mixing angle of PMNS matrix, 13, is essential for future measurements of CP-violation in the lepton sector. The Daya Bay reactor neutrino experiment is designed to determine 13 with a sensitivity of 0.01 or better in sin2213.The experiment is located in southern China, near the Daya Bay nuclear power plant. The designed sensitivity is based on...

The T2K (Tokai to Kamioka) long-baseline neutrino experiment searches for the appearance of electron neutrinos in a 0.7 GeV muon neutrino beam as it travels 295km between Tokai, Japan and the Super-Kamiokande detector. The rate of this process is sensitive to the neutrino mixing angle theta-13 and the CP-violating phase delta of the PMNS mixing matrix. A sophisticated suite of beam monitors...

Neutrino oscillation experiments give clear evidences that neutrinos mix and have non-zero masses. The value of the neutrino mass scale is very important for cosmology and the evolution of the universe as well as for nuclear and particle physics. The determination of the neutrino masses is being addressed by the analysis of cosmological data, by the search for neutrinoless double beta decay...

The MAJORANA collaboration is actively pursuing research and development aimed at a tonne-scale 76Ge neutrinoless double-beta decay (bb(0n)-decay) experiment. The current, primary focus is the construction of the MAJORANA DEMONSTRATOR experiment, an R&D effort that will field approximately 40kg of germanium detectors with mixed enrichment levels. This article provides a status update on...

NOvA is a long-baseline neutrino experiment designed to study nu_mu --> nu_e and anti-nu_mu --> anti-nu_e oscillations. It will measure the neutrino mixing angle theta_13 with a high precision, probe the neutrino mass hierarchy, and search for CP violation in neutrino oscillations. The experiment consists of two detectors. The Near Detector will be located at Fermilab close to the source of...

We try to envision that there might be a dark-matter world and neutrinos, especially the right-handed ones, might be coupled directly with particles in the dark-matter world. This means that the minimal Standard Model [1], which describes the ordinary-matter world to begin with, should be extended in some way. Our candidate theory would be the extended Standard Model based on $SU_c(3)...

We discuss the interplay between lepton asymmetry L and neutrino oscillations in the early Universe. Neutrino oscillations may suppress or enhance previously existing L. On the other hand L is capable to suppress or enhance neutrino oscillations. The mechanism of L enhancement in resonant neutrino oscillations in the early Universe is numerically analyzed. Lepton asymmetry cosmological...

We argue that the present classical formalism of neutrino oscillations is just approximate (cf. PDG 2006), thus still requiring various second-order corrections : internal momentum dispersion from internal mass dispersion ; apparent violation of Lorentz invariance, in transitions of the kind m1 => m2 , between different mass eigenstates, salient in phase factors through the energy shifts ...

The muon as a laboratory for studying charged lepton-flavour violation (cLFV) has proven to be one of the most sensitive areas in the probe to search for “New Physics”, due to the muon’s copious production rate and relatively long lifetime. The search at the intensity frontier with precision-type experiments is complementary to the search for new particles at the high-energy frontier of TeV...

The Mu2e Experiment will search for coherent, neutrino-less conversion of muons into electrons in the field of a nucleus, with a sensitivity improvement of a factor of 10,000 over existing limits. Such a charged lepton flavor-violating reaction probes new physics complementary to the LHC and can reach a scale unavailable by direct searches at either present or planned high energy colliders....

We would like to describe an experiment, called COMET, to search for muon to electron conversion in a muonic atom at J-PARC. This process is charged lepton flavor violating. Recently we have taken a staging approach, and COMET Phase-I will be mentioned in more details. This has received supportive endorsement from the J-PARC PAC and J-PARC review committees. We are hoping that COMET Phase-I...

Permanent Electric Dipole Moments (EDMs) of fundamental particles violate both time invariance and parity. Assuming the CPT theorem, this implies CP violation. The CP violation of the Standard Model is orders of magnitude too small to be observed experimentally in EDMs in the foreseeable future. It is also way too small to explain the asymmetry in abundance of matter and...

The standard model of particle physics predicts that the permanent electric dipole moment (EDM) of the electron is very nearly zero. A non-zero value would violate time reversal symmetry. Many extensions to the standard model predict an electron EDM just below current experimental limits, thus there is great interest in new experiments and in improving current experimental precision. I...

Theoretical studies are presented how the Electric Dipole Moment (EDM) of the electron in H-like ions in electric storage rings can be sensitively determined. The investigation follows the recent proposals to measure the muon EDM [1], the nuclear EDM [2] and the electron EDM in H-like Highly Charged Ions (HCI) [3] in magnetic storage rings, as well as the proposals to measure muon, proton and...

At the Cooler Synchrotron COSY a novel (P-even, T-odd) null test of time-reversal invariance to an accuracy of 10-6 is planned as an internal target transmission experiment. The parity conserving time-reversal violating observable is the total cross-section asymmetry Ay,xz. This quantity is measured using a polarized proton beam with an energy of 135 MeV and an internal tensor polarized...

The quest for the neutron electric dipole moment (nEDM) started more than fifty years ago and is still one of the most important tasks faced by experimental physicists. The reason is that a non zero value of this observable would break both parity (P) and time reversal (T) symmetries. Such symmetry violation is predicted by the Standard Model (SM) as well as by the various Standard Model...

The electric dipole moment (EDM) of an electron that implies the violation of the time-reversal symmetry has been searched from a half century ago. Francium (Fr) is one of the most promising candidates that could lead to observe a significant EDM because the electron EDM would be enhanced by being bounded in a heavier atom. Therefore, a factory of laser-cooled Fr atoms is being constructed...

We study the implications of the global $U(1)_R$ symmetry present in minimal lepton flavor violating extensions of the seesaw. In the context of minimal seesaw setups with a slightly broken $U(1)_R$, it is shown that depending on the $R$-charge assignments two classes of generic models can be identified. Models where the right-handed neutrino masses and the lepton number breaking scale are...

We analyze leptogenesis in the context of seesaw models with almost conserved lepton number, focusing on the L-conserving contribution to the CP asymmetry. We find that, contrary to previous claims, leptogenesis is feasible with heavy neutrino masses ~ 10^6 GeV, well below the gravitino bound for supersymmetric scenarios.

Narrow optical transitions in highly charged ions (HCIs) are of particular interest for metrology and fundamental physics. Atomic clocks could exploit the low susceptibility of HCIs to external electric fields. The highest sensitivity for a changing fine structure constant ever predicted for a stable atomic system is found in Ir$^{17+}$. However, spectroscopy of HCIs is hindered by the large...

The physics goals of the WASA-at-COSY collaboration are based on meson production and decays. One has to analyse different rare decay channels of the mesons to fulfill the physics motivation of finding the symmetry breaking patterns. The combination of high intensity COSY (COoler SYnchrotron) beams and the WASA 4pi detector setup allows us to measure the rare decay channels of light mesons....

Main assumptions of simulation of antiproton and light antinucleus interactions with nuclei are presented. Cross sections of scatterings of the antiparticles by protons and nuclei in the energy range from 100 MeV/c to 1000 GeV/c per anti-nucleon are calculated in the Glauber approximation which provides an excellent description of all known antiproton-nucleus cross sections. The...

We present successful baryogenesis models in the framework of the scalar condensate baryogenesis scenario compatible with inflation. We have numerically followed the evolution of the baryon charge carrying field and the baryon charge of the Universe from the inflationary stage till the baryon asymmetry formation. It is known that particle creation processes play an essential role...

The results of a very large study of around 300 quasar absorption systems using data from both the Keck telescope and the Very Large Telescope provide hints that there is a spatial gradient in the variation of the fine structure constant, alpha. In one direction on the sky alpha appears to have been smaller in the past, while in the other direction it appears to have been larger. A remarkable...